phytosterols and Intestinal-Diseases

The aim of this study was to assess the potential value of the measurement of plasma xenosterols (or phytosterols) concentrations in clinical practice.. Recent genetic studies suggest that individuals with elevated plasma phytosterol concentrations due to monogenic and polygenic variants are at an increased risk of coronary artery disease. This supports early observations that elevated plasma phytosterol concentrations are per se atherogenic.. Measurement of plasma phytosterols can identify individuals with xenosterolemia (or phytosterolemia). This may be clinically useful in four ways: Establishing a diagnosis and informing management of patients with homozygous phytosterolemia; Providing a comprehensive differential diagnosis for familial hypercholesterolemia; Providing an index of cholesterol absorption that may inform personalized pharmacotherapy; and Informing more precise assessment of risk of cardiovascular disease.

Topics: Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

The purpose of this review was to summarize important and updated information on sitosterolemia. Sitosterolemia is an inherited lipid disorder consisting of high levels of plasma plant sterols. This sterol storage condition is caused by biallelic loss-of-function genetic variants in either ABCG5 or ABCG8, leading to increased intestinal absorption and decreased hepatic excretion of plant sterols. Clinically, patients with sitosterolemia usually exhibit xanthomatosis, high levels of plasma cholesterol, and premature atherosclerotic disease, but presentation can be highly heterogeneous. Therefore, recognition of this condition requires a high level of suspicion, with confirmation upon genetic diagnosis or through measurement of plasma phytosterols. Treatment of sitosterolemia with both a plant sterol-restricted diet and the intestinal cholesterol absorption inhibitor ezetimibe can reduce efficiently the levels of plasma plant sterols, consisting in the first-line therapy for this disease.. Since hypercholesterolemia is often present in individuals with sitosterolemia, it is important to search for genetic variants in ABCG5 and ABCG8 in patients with clinical criteria for familial hypercholesterolemia (FH), but no variants in FH implicated genes. Indeed, recent studies have suggested that genetic variants in ABCG5/ABCG8 can mimic FH, and even when in heterozygosis, they may potentially exacerbate the phenotype of patients with severe dyslipidemia. Sitosterolemia is a genetic lipid disorder characterized by increased circulating levels of plant sterols and clinically manifested by xanthomatosis, hematologic disorders, and early atherosclerosis. Awareness about this condition, a rare, but commonly underdiagnosed and yet treatable cause of premature atherosclerotic disease, is imperative.

Topics: Atherosclerosis; Cholesterol; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Xanthomatosis

Lipid injectable emulsions have been in clinical use for over 60 years. The first product launched was Intralipid, which consisted of an emulsion of soybean oil in water for intravenous administration. It was a key source of essential fatty acids and an alternative source of energy for patients with gastrointestinal dysfunction requiring long-term parenteral nutrition. With clinical experience, a condition known as parenteral nutrition-associated liver disease (PNALD), or intestinal failure-associated liver disease (IFALD), was observed, with a focus on carbohydrate and fat energy. Modifying the daily doses and infusion rates had some salutary effects, but PNALD persisted. Subsequently, on closer inspection of the fatty acids profile and phytosterol concentrations, degradation products arising from chemical and physical stability issues of the available lipid injectable emulsions were implicated. Recently, the US Food and Drug Administration convened an online workshop entitled "The Role of Phytosterols in PNALD/IFALD," with an emphasis on (1) the multifactorial pathophysiology of PNALD/IFALD, (2) risk associated with phytosterols, and (3) regulatory history. The scope of this review includes the multifactorial pathophysiology of PNALD/IFALD as it relates to the pharmaceutical aspects of the various lipid injectable emulsions on the market, with respect to potential proinflammatory components, as well as physical and chemical stability issues that may also affect products' safe intravenous administration to patients.

Topics: Emulsions; Fat Emulsions, Intravenous; Fish Oils; Humans; Intestinal Diseases; Liver Diseases; Liver Failure; Parenteral Nutrition; Phytosterols; Soybean Oil

A 17-year-old boy with acute coronary syndrome was admitted to our hospital. He had xanthomas over his elbow and Achilles tendon and a high level of low-density lipoprotein cholesterol; therefore, his initial diagnosis was familial hypercholesterolemia. However, a genetic analysis revealed a compound heterozygous mutation in the ABCG5 gene with a high serum level of sitosterol, leading to the diagnosis of sitosterolemia. After lipid-lowering treatment, percutaneous coronary intervention was performed. Furthermore, a persistently high C-reactive protein level and images of large arteries led to a diagnosis of Takayasu arteritis. To our knowledge, this is the first case of sitosterolemia complicated by Takayasu arteritis.

Topics: Acute Coronary Syndrome; Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 5; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols; Takayasu Arteritis

Sitosterolemia is a lipid disorder characterized by the accumulation of phytosterols in plasma and organs, caused by mutations in the ABCG5 and/or ABCG8 genes. The disease is frequently misdiagnosed and mistreated as familial hypercholesterolemia (FH). To gain a better understanding of the disease, the current status of diagnosis and treatment of Chinese patients with sitosterolemia was reviewed and summarized.. Literature search was performed. The clinical features and molecular characteristics of Chinese patients with sitosterolemia were analysed. Four children with sitosterolemia and the treatment experience were described.. Fifty-five patients with sitosterolemia have been reported in China. These patients were aged from 3 months to 67 years at diagnosis, and the median was 8 years of age. Several complications, such as xanthomas in 47 patients (85%), thrombocytopenia in 17 patients (31%), anemia in 14 patients (25%), and cardiovascular damage in 12 patients (22%), were observed. Thirty-nine patients (71%) exhibited mutations in the ABCG5 gene, 15 patients (27%) showed mutations in ABCG8, and variations in both genes occurred in one patient (2%). A patient with two clinically rare diseases, namely, sitosterolemia and glycogen storage disease type VI (GSD VI)), is reported here for the first time. The four reported patients were treated with low cholesterol and phytosterol-limited diet alone or combined with cholestyramine. Even though decreases were observed for total plasma cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C), and these levels were as low as normal in some patients, the levels of plant sterols remained above the normal range. However, TC, LDL-C and plant sterol levels remained at high levels in patients treated with a control diet control only.. The analysis reveals that different from Caucasians carrying mainly variations in ABCG8, most Chinese patients have mutations in the ABCG5 gene, and Arg446Ter, Gln251Ter, anArg389His might be hot-spot mutations in Chinese patients. The current survey provides clinical data to enable the development of a standardized protocol for the diagnosis and treatment of sitosterolemia in China.

Topics: Adolescent; Adult; Aged; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Child; Child, Preschool; China; Female; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Mutation; Phytosterols; Young Adult

Inherited hypercholesterolemias include monogenic and polygenic disorders, which can be very rare (eg, cerebrotendinous xanthomatosis (CTX)) or relatively common (eg, familial combined hyperlipidemia [FCH]). In this review, we discuss familial hypercholesterolemia (FH), FH-mimics (eg, polygenic hypercholesterolemia [PH], FCH, sitosterolemia), and other inherited forms of hypercholesterolemia (eg, hyper-lipoprotein(a) levels [hyper-Lp(a)]). The prevalence, genetics, and management of inherited hypercholesterolemias are described and selected guidelines summarized.

Topics: Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

In this review, we summarize the genetics and mechanisms of sitosterolemia and sterol trafficking, and provide an update on the understanding of the prevalence of ABCG5 and ABCG8 variants and their role in human disease.. Defects in ABCG5/G8 result in the accumulation of xenosterols. It had been previously thought that near total LoF of one of the proteins was required to cause pathology. However, recently there was the first report of a patient with Sitosterolemia who was heterozygous for mutations in both genes. Moreover, large population studies have demonstrated the even simple heterozygous carriers are associated with altered lipid profiles and cardiovascular risk. Broader screening has added to the rapidly growing list of gene variants indicating that the prevalence of ABCG5/G8 variants is higher than previous thought, especially in patients with hypercholesterolemia.. These findings support a strategy of measuring xenosterol levels in patients with hypercholesterolemia to screen for ABCG5/G8 variants, and then tailoring treatment with a sterol absorption inhibitor, like ezetimibe, where indicated. Xenosterol trafficking affects remnant clearance and maybe pathogenically linked to the increased risk of atherosclerosis.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols; Sterols

Sitosterolemia is a lipid disorder characterized by the accumulation of dietary xenosterols in plasma and tissues caused by mutations in either

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cholesterol; Enterocytes; Hepatocytes; History, 21st Century; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Mutation; Phytosterols

Sitosterolemia is an inherited metabolic disorder characterized by increased levels of plant sterols, such as sitosterol. This disease is caused by loss-of-function genetic mutations in ATP-binding cassette (ABC) subfamily G member 5 or member 8 (ABCG5 or ABCG8, respectively), both of which play important roles in selective excretion of plant sterols from the liver and intestine, leading to failure to prevent absorption of food plant sterols. This disorder has been considered to be extremely rare. However, accumulated clinical data as well as genetics suggest the possibility of a much higher prevalence. Its clinical manifestations resemble those observed in patients with familial hypercholesterolemia (FH), including tendon xanthomas, hyper LDL-cholesterolemia, and premature coronary atherosclerosis. We provide an overview of this recessive genetic disease, diagnostic as well as therapeutic tips, and the latest diagnostic criteria in Japan.

Topics: Disease Management; Humans; Hypercholesterolemia; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Phytosterols

The ABCG5/G8 heterodimer is the primary neutral sterol transporter in hepatobiliary and transintestinal cholesterol excretion. Inactivating mutations on either the ABCG5 or ABCG8 subunit cause Sitosterolemia, a rare genetic disorder. In 2016, a crystal structure of human ABCG5/G8 in an apo state showed the first structural information on ATP-binding cassette (ABC) sterol transporters and revealed several structural features that were observed for the first time. Over the past decade, several missense variants of ABCG5/G8 have been associated with non-Sitosterolemia lipid phenotypes. In this review, we summarize recent pathophysiological and structural findings of ABCG5/G8, interpret the structure-function relationship in disease-causing variants and describe the available evidence that allows us to build a mechanistic view of ABCG5/G8-mediated sterol transport.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Biliary Tract; Catalysis; Cholesterol; Homeostasis; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Liver; Phytosterols

Sitosterolemia is a recessive inherited metabolic disorder of unknown prevalence, characterized by increased levels of plasma plant sterols. It is caused by 28 and 31 variants in ABCG5 and ABCG8 genes, respectively, and is characterized by a predisposition to hyperabsorption and accumulation of toxic levels of plant sterols in plasma. Its clinical picture is extremely heterogeneous. The main clinical features are tendinous and cutaneous xanthomas, arthritis or arthralgia, premature cardiovascular disease and atherosclerosis. These characteristics are shared with familial hypercholesterolemia (FH), making it possible for sitosterolemia to be misdiagnosed as homozygous FH, especially in pediatric patients. In such cases, a specific chromatography-based laboratory method is essential to differentiate sitosterol and cholesterol. Hematological abnormalities (hemolytic anemia and macrothrombocytopenia) may be present in 25-35% of patients, in whom it is usually associated with the main clinical features, as occurs in the 70% of the cases. In this context, the peripheral blood smear is essential and reveals giant platelets and stomatocytes. Only 21 causative variants in ABCG5/ABCG8 are associated with macrothrombocytopenia. Most physicians still do not recognize these hematological abnormalities or relate them to sitosterolemia. Patients may suffer long-term misdiagnosis of immune thrombocytopenia and be at high risk of receiving harmful therapies or of not benefitting from a low-cholesterol diet and/or from the gold standard treatment with ezetimibe. This drug reduces the levels of plasma plant sterols, provokes regression of xanthomas, and can alleviate hematological abnormalities. Finally, to identify genetic defects, recent advances in high-throughput sequencing, especially in the use of targeted sequencing of pre-specified genes, have begun to be incorporated in the first-line approach in the field of genetic disorders.

Topics: Animals; Cardiovascular Diseases; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

Non-cholesterol sterols are validated biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis. However, their use in metabolic disturbances has not been systematically explored. Therefore, we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders. Potentially relevant studies were retrieved by a systematic search of three databases in July 2018 and ninety-four human studies were included. Cholesterol-standardized levels of campesterol, sitosterol and cholestanol were collected to reflect cholesterol absorption and those of lathosterol and desmosterol to reflect cholesterol synthesis. Their use as biomarkers was examined in the following metabolic disorders: overweight/obesity (

Topics: Biomarkers; Cardiovascular Diseases; Cholesterol; Desmosterol; Diabetes Mellitus; Humans; Intestinal Absorption; Intestinal Diseases; Kidney Diseases; Liver Diseases; Metabolic Diseases; Obesity; Overweight; Phytosterols; Sitosterols; Sterols

Sitosterolemia is a rare autosomal recessive disorder of dyslipidemia due to mutations of genes ABCG5 and ABCG8, leading to highly elevated plasma levels of plant sterols and expanded body pools of cholesterol.. We present a 9-year-old and a 7-year-old Chinese boy with hypercholesterolemia and xanthomas of sitosterolemia due to ABCG5 gene mutations. We also make a literature review of another 30 sitosterolemic children cases that have been reported with virulence ABCG5 gene mutations.. We took peripheral blood samples from 2 patients and their parents to conduct genetic analysis by next-generation sequencing (NGS) technologies.. The 2 patients received dietary modifications without pharmaceuticals treatment.. A c.1166G>A (Arg389His) homozygosis mutation in exon 9 was observed in case 1, whereas a c.751C>T (Gln251*) homozygosis mutation in exon 6 was found in case 2. Literature review found another 30 pediatric cases with sitosterolemia due to ABCG5 gene mutation. The lipid profile was normalized and xanthomas got smaller with combined therapy of a combined low-cholesterol and low-phytosterols diet.. These suggested that in patients (especially Asian patients) with multiple xanthomas, severe hypercholesterolemia, or elevated low-density lipoprotein-cholesterol, sitosterolemia should be considered in the differential diagnosis. Early diagnosis is important, and restriction of both cholesterol and phytosterols diet should suggested for these patients.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; Child; Diagnosis, Differential; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Phenotype; Phytosterols

Sitosterolemia or phytosterolemia is a rare autosomal recessive hereditary lipid storage disorder. It is caused by homozygous or compound heterozygous mutations in one of the two ABCG5 and ABCG8 genes encoding the intestinal and hepatic heterodimer ABCG5 (sterolin 1)/ABCG8 (sterolin 2) efflux transporters. These mutations lead to intestinal hyperabsorption and reduced hepatic secretion of cholesterol and plant sterols with subsequent accumulation of phytosterols and cholesterol in plasma and deposition in tissue (xanthoma). Phytosterols are found mainly in vegetable oils, margarine, nuts, grains, soybeans and avocados. Patients with sitosterolemia show extreme phenotypic heterogeneity from almost asymptomatic individuals to those with combined severe hypercholesterolemia at a young age, leading to increased atherosclerosis and premature cardiac death. Early abnormalities include hemolytic anemia with stomatocytosis, macrothrombocytopenia and splenomegaly. In addition to strict avoidance of phytosterol-containing foods, the use of the sterol absorption inhibitor ezetimibe, possibly in combination with the bile acid-binding resin cholestyramine, is the most effective treatment option.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Mutation; Phytosterols

Familial hypercholesterolemia has long been considered a monogenic disorder. However, recent advances in genetic analyses have revealed various forms of this disorder, including polygenic and oligogenic familial hypercholesterolemia. We review the current understanding of the genetic background of this disease.. Mutations in multiple alleles responsible for low-density lipoprotein regulation could contribute to the development of familial hypercholesterolemia, especially among patients with mutation-negative familial hypercholesterolemia. In oligogenic familial hypercholesterolemia, multiple rare genetic variations contributed to more severe familial hypercholesterolemia.. Familial hypercholesterolemia is a relatively common 'genetic' disorder associated with an extremely high risk of developing coronary artery disease. In addition to monogenic familial hypercholesterolemia, different types of familial hypercholesterolemia, including polygenic and oligogenic familial hypercholesterolemia, exist and have varying degrees of severity. Clinical and genetic assessments for familial hypercholesterolemia and clinical risk stratifications should be performed for accurate diagnosis, as should cascade screening and risk stratification for the offspring of affected patients.

Topics: Animals; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Risk Assessment

Sitosterolemia is a rare inherited disease characterized by increased levels of plant sterols, such as sitosterol. The cause of this disease is ATP-binding cassette (ABC) subfamily G member 5 or member 8 (ABCG5 or ABCG8, respectively) gene mutations. Recent advances in genetics have revealed that the prevalence of subjects with deleterious mutations in ABCG5 and/or ABCG8 genes could be more than 1 in ~200,000 individuals among the general population. Furthermore, accumulated evidence, including infantile cases exhibiting progression/regression of systemic xanthomas associated with LDL cholesterol levels, have shown that the elevation of LDL cholesterol seems to be the major cause of development of atherosclerosis and not the elevation of sitosterol. Regarding therapies, LDL apheresis, as well as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, could be useful for sitosterolemia, in addition to ezetimibe and/or colestimide. In this study, we provide the current understanding and future perspectives of sitosterolemia, which is currently considered an extremely rare disorder but is expected to be much more prevalent in clinical settings.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Coronary Artery Disease; Heterozygote; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Mutation; Phenotype; Phytosterols; Polymorphism, Genetic; Proprotein Convertase 9; Sitosterols

Current evidence indicates that foods with added plant sterols or stanols can lower serum levels of low-density lipoprotein cholesterol. This review summarizes the recent findings and deliberations of 31 experts in the field who participated in a scientific meeting in Winnipeg, Canada, on the health effects of plant sterols and stanols. Participants discussed issues including, but not limited to, the health benefits of plant sterols and stanols beyond cholesterol lowering, the role of plant sterols and stanols as adjuncts to diet and drugs, and the challenges involved in measuring plant sterols and stanols in biological samples. Variations in interindividual responses to plant sterols and stanols, as well as the personalization of lipid-lowering therapies, were addressed. Finally, the clinical aspects and treatment of sitosterolemia were reviewed. Although plant sterols and stanols continue to offer an efficacious and convenient dietary approach to cholesterol management, long-term clinical trials investigating the endpoints of cardiovascular disease are still lacking.

Topics: Anticholesteremic Agents; Canada; Cardiovascular Diseases; Cholesterol; Cholesterol, LDL; Congresses as Topic; Diet; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

Essentials Diagnosis of sitosterolemia, a rare recessive or syndromic disorder, is usually delayed. Peripheral blood smear is extremely useful for establishing the suspicion of sitosterolemia. High-throughput sequencing technology enables the molecular diagnosis of inherited thrombocytopenias. Accurate characterization of sitosterolemia helps us determine appropriate management.. Background Sitosterolemia (STSL) is a recessive inherited disorder caused by pathogenic variants in the ABCG5 and ABCG8 genes. Increased levels of plasma plant sterols (PSs) usually result in xanthomas and premature coronary atherosclerosis, although hematologic abnormalities may occasionally be present. This clinical picture is unfamiliar to many physicians, and patients may be at high risk of misdiagnosis. Objectives To report two novel ABCG5 variants causing STSL in a Spanish patient, and review the clinical and mutational landscape of STSL. Patient/Methods A 46-year-old female was referred to us with lifelong macrothrombocytopenia. She showed familial hypercholesterolemia-related xanthomas. Molecular analysis was performed with high-throughput sequencing. Plasma PS levels were evaluated with gas-liquid chromatography. The STSL landscape was reviewed with respect to specific online databases and all reports published since 1974. Results A blood smear revealed giant platelets and stomatocytes. Novel compound heterozygous variants were detected in exons 7 (c.914C>G) and 13 (c.1890delT) of ABCG5. The patient showed an increased plasma level of sitosterol. These findings support the diagnosis of STSL. In our review, we identified only 25 unrelated STLS patients who presented with hematologic abnormalities including macrothrombocytopenia. It remains unknown why only some patients develop hematologic abnormalities. Conclusions This is the first Spanish STSL patient to be reported and molecularly characterized. The early diagnosis of STLS is strongly supported by the presence of stomatocytes in blood smears. The definitive diagnosis of STSL by measurement of serum PS levels and molecular analyses prompted the use of ezetimibe therapy.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; DNA Mutational Analysis; Ezetimibe; Female; Genetic Predisposition to Disease; High-Throughput Nucleotide Sequencing; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Middle Aged; Mutation; Phenotype; Phytosterols; Sitosterols; Spain; Thrombocytopenia; Xanthomatosis

Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol and premature cardiovascular disease, with a prevalence of approximately 1 in 200-500 for heterozygotes in North America and Europe. Monogenic FH is largely attributed to mutations in the LDLR, APOB, and PCSK9 genes. Differential diagnosis is critical to distinguish FH from conditions with phenotypically similar presentations to ensure appropriate therapeutic management and genetic counseling. Accurate diagnosis requires careful phenotyping based on clinical and biochemical presentation, validated by genetic testing. Recent investigations to discover additional genetic loci associated with extreme hypercholesterolemia using known FH families and population studies have met with limited success. Here, we provide a brief overview of the genetic determinants, differential diagnosis, genetic testing, and counseling of FH genetics.

Topics: Apolipoprotein B-100; Cholesterol Ester Storage Disease; Diagnosis, Differential; Genetic Counseling; Genetic Predisposition to Disease; Genetic Testing; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Proprotein Convertase 9; Proprotein Convertases; Receptors, LDL; Serine Endopeptidases; Xanthomatosis, Cerebrotendinous

Sitosterolemia is an autosomal recessive disorder characterized by increased intestinal absorption of plant sterols. It is caused by mutations in genes encoding ATP-binding cassette, subfamily G5 (ABCG5) or G8 (ABCG8), and clinical features include elevated plant sterol levels, xanthomas, and accelerated atherosclerosis. Although it was originally reported in patients with normolipemic xanthomas, patients with sitosterolemia also hyperabsorb cholesterol, and serum cholesterol levels tend to be elevated.. We report an infant with sitosterolemia who presented with severe hypercholesterolemia and intertriginous xanthomas.. A 15-month-old Korean girl presented with yellow dermal plaques over flexural areas including the wrist, neck, and gluteal folds, which were consistent with intertriginous xanthomas. The lesions were first noticed at 3 months of age when she was being exclusively breastfed. Her total cholesterol and low-density lipoprotein-cholesterol levels were 675 and 540 mg/dL, respectively. A low-fat/low-cholesterol diet and cholestyramine therapy were introduced. Unexpectedly, her serum cholesterol level decreased dramatically and normalized in 2 months. Cholestyramine was tapered off. The xanthomas also regressed and disappeared by 3 years of age. Gas chromatography-mass spectrometric analysis was performed with serum drawn at 3 years of age when her low-density lipoprotein-cholesterol was 118 mg/dL, which revealed striking elevation of her sitosterol level at 19.36 mg/dL. Direct sequencing for ABCG5 revealed compound heterozygous null mutations c.904+1G>A (p.Met302Asnfs*82) and c.1336C>T(p.Arg446*).. Our case suggests that sitosterolemia can present with severe hypercholesterolemia and intertriginous xanthomas. Sitosterolemia should be suspected when a patient with hypercholesterolemia shows unexpectedly good response to dietary modification or bile acid sequestrant therapy.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Diet, Fat-Restricted; Female; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols; Treatment Outcome; Xanthogranuloma, Juvenile

To provide an update on recent advances made in our mechanistic and pathophysiological understanding of the rare human disease Sitosterolemia, the role of ABCG5/ABCG8 in sterol trafficking and how newer data implicate a more wider role in the body.. Sitosterolemia is caused by a genetic defect of sterolins (ABCG5/ABCG8) mapped to the STSL locus. Polymorphic variations in STSL have been linked to lipid levels and gallstone disease in whites. Newer studies now link this locus to a more diverse ethnic group for gallstone disease, susceptibility to biliary cancer, and show variants that alter sterolin function. Intriguingly, carriers of a mutant allele seem to show protection against carotid wall disease. Although the 'promoter' region of the STSL is minimal, regulatory regions responsive to liver X receptor have remained elusive, but no longer; two intronic regions in ABCG8 have now been identified. Xenosterol accumulation leads to loss of abdominal fat, infertility, and premature death. Xenosterol accumulation in mouse platelet membranes leads to platelet hyperactivation, increased microparticle formation, and reduced αIIbβ3 surface expression. In humans, phytosterols may promote liver injury in parenteral nutrition-associated liver disease.. Progress in understanding sterolin function is beginning to show that xenosterols can be toxic and are involved on pathogenesis, and the role of ABCG5/ABCG8 may extend into other metabolic processes by altering intracellular sterol metabolism.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Biological Transport, Active; Blood Platelets; Cell Membrane; Genetic Loci; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Liver X Receptors; Mice; Mutation; Orphan Nuclear Receptors; Phytosterols; Polymorphism, Genetic; Promoter Regions, Genetic; Sterols

Sitosterolemia is a rare autosomal recessively inherited disease caused by mutations affecting ABCG5 or ABCG8, which are located on human chromosome band 2p21. Around 100 cases have been reported in the literature. Sitosterolemic patients typically exhibit a 30-fold to 100-fold increase in plasma concentrations of plant sterols. The clinical manifestations include xanthomas, premature atherosclerosis, hemolytic anemia, and macrothrombocytopenia. It is noteworthy that abnormal hematological parameters may be the only clinical feature of sitosterolemic patients, suggesting that sitosterolemia may be more frequent than previously thought. Severe accumulation of plant sterols in mouse models of sitosterolemia induced complex cardiac lesions, anemia, and macrothrombocytopenia, disrupted adrenal and liver cholesterol homeostasis, and caused infertility and hypertriglyceridemia. It remains unclear whether all disease traits are present in sitosterolemic patients. The drug ezetimibe appears to be effective in reducing plasma plant sterol levels, promotes xanthoma regression, and improves the cardiovascular and hematological signs in sitosterolemic patients.

Topics: Anemia, Hemolytic; Animals; Anticholesteremic Agents; Atherosclerosis; Azetidines; Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Mice; Phytosterols; Thrombocytopenia; Xanthomatosis

Parenteral nutrition is a life-saving therapy for infants with intestinal failure. However, long-term parenteral nutrition carries the risk of progressive liver disease. Substantial data has implicated components of parenteral soybean oil in the pathogenesis of parenteral nutrition-associated liver disease (PNALD). Elevated serum concentrations of phytosterols, an abundance of omega-6 polyunsaturated fatty acids, and a relative paucity of α-tocopherol have been associated with the risk of cholestasis and hepatic injury observed in PNALD. Currently available treatment strategies include the reduction of the dose of administered parenteral soybean oil and/or the replacement of parenteral soybean oil with alternative parenteral lipid emulsions. The purpose of this review is to provide an overview of the pathogenetic mechanisms associated with the development of PNALD and the data evaluating currently available treatment strategies.

Topics: alpha-Tocopherol; Cholestasis; Dietary Fats; Fat Emulsions, Intravenous; Fatty Acids, Omega-6; Humans; Intestinal Diseases; Liver; Liver Diseases; Parenteral Nutrition; Phytosterols; Soybean Oil

Sitosterolemia (STSL) is a rare autosomal recessive disease, manifested by extremely elevated plant sterols (PS) in plasma and tissue, leading to xanthoma and premature atherosclerotic disease. Therapeutic approaches include limiting PS intake, interrupting enterohepatic circulation of bile acid using bile acid binding resins such as cholestyramine, and/or ileal bypass, and inhibiting intestinal sterol absorption by ezetimibe (EZE). The objective of this review is to evaluate sterol metabolism in STSL and the impact of the currently available treatments on sterol trafficking in this disease. The role of PS in initiation of xanthomas and premature atherosclerosis is also discussed. Blocking sterols absorption with EZE has revolutionized STSL patient treatment as it reduces circulating levels of non-cholesterol sterols in STSL. However, none of the available treatments including EZE have normalized plasma PS concentrations. Future studies are needed to: (i) explore where cholesterol and non-cholesterol sterols accumulate, (ii) assess to what extent these sterols in tissues can be mobilized after blocking their absorption, and (iii) define the factors governing sterol flux.

Topics: Absorption; Atherosclerosis; ATP Binding Cassette Transporter, Subfamily G; ATP-Binding Cassette Transporters; Azetidines; Cholesterol; Disease Progression; Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Kinetics; Lipid Metabolism, Inborn Errors; Membrane Proteins; Membrane Transport Proteins; Phytosterols; Sitosterols; Sterol O-Acyltransferase; Sterol O-Acyltransferase 2; Sterols; Xanthomatosis

Recommendations about the use of plant stanol/sterol esters have not been updated since 2001. There have been many developments in medicines for lipid-lowering since 2001. In this review, the use of margarines containing stanol or sterol esters, to lower LDL cholesterol is considered in the 2011 setting. Firstly, there is a brief overview of the effects of the stanols/sterols on LDL cholesterol, which shows that these agents have a modest ability to lower LDL cholesterol, and are not effective in all conditions. Secondly, the relevance of the stanols/sterols in 2010/1 is questioned, given they have not been shown to reduce clinical endpoints, and have no effects on HDL cholesterol or triglyceride levels. Finally, there is a section comparing the stanols/sterols with the present day prescription lipid lowering medicines. Prescription drugs (statins, ezetimibe, and niacin) have a much greater ability to lower LDL cholesterol than the stanol/sterol esters, and also increase levels of HDL cholesterol and decrease levels of triglycerides. The statins and niacin have been shown to reduce cardiovascular clinical endpoints. Except in borderline normo/hypercholesterolemia, prescription drugs should be preferred to stanol/sterol esters for lowering LDL cholesterol in 2011.

Topics: Anticholesteremic Agents; Azetidines; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus; Ezetimibe; Fibric Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Margarine; Micronutrients; Niacin; Phytosterols; Sitosterols; Triglycerides

Topics: Anemia, Hemolytic; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Thrombocytopenia

Atherosclerosis, driven by inflamed lipid-laden lesions, can occlude the coronary arteries and lead to myocardial infarction. This chronic disease is a major and expensive health burden. However, the body is able to mobilize and excrete cholesterol and other lipids, thus preventing atherosclerosis by a process termed reverse cholesterol transport (RCT). Insight into the mechanism of RCT has been gained by the study of two rare syndromes caused by the mutation of ABC transporter loci. In Tangier disease, loss of ABCA1 prevents cells from exporting cholesterol and phospholipid, thus resulting in the build-up of cholesterol in the peripheral tissues and a loss of circulating HDL. Consistent with HDL being an athero-protective particle, Tangier patients are more prone to develop atherosclerosis. Likewise, sitosterolemia is another inherited syndrome associated with premature atherosclerosis. Here mutations in either the ABCG5 or G8 loci, prevents hepatocytes and enterocytes from excreting cholesterol and plant sterols, including sitosterol, into the bile and intestinal lumen. Thus, ABCG5 and G8, which from a heterodimer, constitute a transporter that excretes cholesterol and dietary sterols back into the gut, while ABCA1 functions to export excess cell cholesterol and phospholipid during the biogenesis of HDL. Interestingly, a third protein, ABCG1, that has been shown to have anti-atherosclerotic activity in mice, may also act to transfer cholesterol to mature HDL particles. Here we review the relationship between the lipid transport activities of these proteins and their anti-atherosclerotic effect, particularly how they may reduce inflammatory signaling pathways. Of particular interest are recent reports that indicate both ABCA1 and ABCG1 modulate cell surface cholesterol levels and inhibit its partitioning into lipid rafts. Given lipid rafts may provide platforms for innate immune receptors to respond to inflammatory signals, it follows that loss of ABCA1 and ABCG1 by increasing raft content will increase signaling through these receptors, as has been experimentally demonstrated. Moreover, additional reports indicate ABCA1, and possibly SR-BI, another HDL receptor, may directly act as anti-inflammatory receptors independent of their lipid transport activities. Finally, we give an update on the progress and pitfalls of therapeutic approaches that seek to stimulate the flux of lipids through the RCT pathway.

Topics: Animals; Atherosclerosis; ATP Binding Cassette Transporter 1; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Cholesterol; Coronary Vessels; Hepatocytes; Humans; Hypercholesterolemia; Inflammation; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Models, Biological; Myocardial Infarction; Phenotype; Phytosterols; Tangier Disease

Fish oil (FO)-based lipid emulsions (LEs) have been reported to prevent hepatic dysfunction in patients treated with parenteral nutrition (PN). We studied patients with alterations of γ-glutamyl transferase (GGT) associated with the administration of PN containing olive/soybean (O/S)-based LE. The aim of this study was to determine whether the strategy of reducing the lipid dose by 50%, by changing to an FO-based LE, reduced plasma levels of phytosterols (PS) and GGT more effectively and safely, than the strategy of reducing lipid contribution by 50% while maintaining the same LE composition.. A randomized double-blind clinical trial was carried out in patients with normal initial GGT, who after a minimum of 1 wk of daily PN (0.8 g/kg of O/S-based LE) presented with GGT values twice the upper normal value. At the time of randomization 1:1, lipids were reduced to 0.4 g/kg daily. Group A maintained O/S LE and group B changed to FO LE. The primary endpoints were reduction of plasmatic PS and GGT on day 7 after randomization, performed in the study population per protocol by Student's t test and simple linear regression. Secondary outcomes included alkaline phosphatase (AP), alanine transaminase (ALT), and total bilirubin (BIL), and safety variables.. Nineteen patients were included. On day 7 after randomization, GGT and AP values were higher in the O/S group (n = 10; GGT: median [Med], 4.99; interquartile range [IQR], 4.09; AP: Med, 2.59 μkat/L; IQR 1.74) than in the FO group (n = 9; GGT: Med, 2.26 μkat/L; IQR, 1.07; AP: Med, 1.2 μkat/L; IQR 1.44). Although there were no differences in ALT and BIL values, the ALT decrease was larger and more statistically significant in the FO group than in the O/S group (P = 0.009). Total PS (Med, 21.10 μg/mL; IQR, 5.50) in the O/S group was higher than in the FO group (Med, 13.4 μg/mL; IQR, 10.65; P = 0.002). Significant decreases in PS and their fractions were observed, with the exception of campesterol and stigmasterol.. Plasma accumulation of PS and high values of GGT, AP, and ALT can be prevented with the exclusive administration of FO-based LE.

Topics: Aged; Alanine Transaminase; Alkaline Phosphatase; Bilirubin; Double-Blind Method; Fat Emulsions, Intravenous; Female; Fish Oils; gamma-Glutamyltransferase; Humans; Hypercholesterolemia; Intestinal Diseases; Linear Models; Lipid Metabolism, Inborn Errors; Liver; Liver Function Tests; Male; Middle Aged; Parenteral Nutrition; Phytosterols; Plant Oils; Prospective Studies; Treatment Outcome

To assess the association between biomarkers of thyroid status and 5α-stanols in patients with sitosterolemia treated with ezetimibe (EZE).. Eight patients with sitosterolemia (16-56 years of age) were studied during 14 weeks off EZE therapy and 14 weeks on EZE (10 mg/day). Serum thyroid biomarkers (free triiodothyronine [FT3], free thyroxine [FT4], FT3/FT4 ratio, thyroid-stimulating hormone), 5α-stanols (sitostanol and cholestanol), and cholestanol precursors (total cholesterol and its synthesis marker lathosterol, and 7α-hydroxy-4-cholesten-3-one cholestenol) were measured at baseline and during the 14 weeks off EZE and on EZE.. EZE increased FT3/FT4 (10% ± 4%; P = .02). EZE reduced plasma and red blood cells sitostanol (-38% ± 6% and -20% ± 4%; all P < .05) and cholestanol (-18% ± 6% and -13% ± 3%; all P < .05). The change in plasma cholestanol level on EZE inversely correlated with the change in FT3/FT4 (r = -0.86; P = .01). EZE lowered total cholesterol (P < .0001) and did not affect 7α-hydroxy-4-cholesten-3-one cholestanol. EZE increased (P < .0001) lathosterol initially, but the level was not sustained, resulting in similar levels at week 14 off EZE and on EZE.. In patients with STSL, 5α-stanols levels might be associated with thyroid function. EZE reduces circulating 5α-stanols while increasing FT3/FT4, implying increased conversion of T4 to T3, thus possibly improving thyroid hormone status.. ClinicalTrials.govNCT01584206.

Topics: Adolescent; Adult; Anticholesteremic Agents; Cholestanol; Cholestenones; Cholesterol; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Sitosterols; Thyrotropin; Thyroxine; Triiodothyronine; Young Adult

To assess if ezetimibe (EZE), a sterol-absorption inhibitor, improves platelet (PLT) count and size relative to its effect on plasma plant sterol (PS) in patients with sitosterolemia (STSL).. Patients with STSL (5 males, 3 females, 16-56 years of age) receiving EZE intervention as part of their routine care participated in this study. EZE was discontinued for 14 weeks (off) and then resumed for another 14 weeks (on). Hematology variables along with plasma and red blood cells (RBC) PS and total cholesterol (TC) levels were measured at the end of each phase.. EZE increased PLT count (23% ± 9%) and decreased mean PLT volume (MPV; 10% ± 3%, all P < .05). In patients off EZE, PLT counts inversely correlated (r = -0.96 and r = -0.91, all P < .01) with plasma and RBC PS to TC ratio (PS/TC), and MPV positively correlated (r = 0.91, P = .03 and r = 0.93, P = .02) with plasma and RBC PS/TC. EZE reduced plasma and RBC sitosterol (-35% ± 4% and -28% ± 3%), total PS (-37% ± 4% and -28% ± 3%, all P < .0001) levels, and PS/TC (-27% ± 4% and -28% ± 4%, P < .01).. EZE reduces plasma and RBC PS levels, while increasing PLT count and decreasing MPV, and thereby may reduce the risk for bleeding in STSL. Plasma PS levels and ABCG5/ABCG8 genes should be analyzed in patients with unexplained hematologic abnormalities.

Topics: Adolescent; Adult; Anticholesteremic Agents; Azetidines; Canada; Cholesterol; Erythrocyte Count; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Pilot Projects; Platelet Count; Treatment Outcome; United States; Young Adult

Plant sterol (PS) supplementation is increasingly accepted as a dietary strategy to lower plasma cholesterol concentrations. However, information is scarce about the effect of increased PS intake in potentially vulnerable groups, such as phytosterolemia heterozygotes (HET).. This study assessed the responsiveness of circulating PS and lipid concentrations and cholesterol kinetics (absorption and synthesis) to daily PS supplementation in HET (ABCG8 S107X mutation) compared with a healthy control cohort.. A double-blind, randomized, crossover, placebo-controlled study was conducted in 10 HET and 15 control subjects. The participants had a mean (±SEM) age of 34 ± 2 y and a BMI (in kg/m²) of 29.9 ± 1.1 and consumed ∼1.6 g PS or placebo capsules daily with supper for 4 wk. Cholesterol absorption and synthesis were assessed by using [¹³C]cholesterol and deuterium oxide, respectively.. Plasma LDL-cholesterol concentrations decreased (P = 0.006) in both groups after PS supplementation (HET: 2.73 ± 0.19 mmol/L; control: 3.11 ± 0.19 mmol/L) compared with placebo (HET: 3.12 ± 0.20 mmol/L; control: 3.50 ± 0.21 mmol/L), whereas PS concentrations (campesterol+β-sitosterol) increased (P = 0.03) in both groups after PS supplementation (HET: 39.72 ± 6.05 μmol/L; control: 24.03 ± 1.65 μmol/L) compared with placebo (HET: 27.32 ± 3.80 μmol/L; control: 21.12 ± 2.05 μmol/L). Cholesterol absorption efficiency decreased (P = 0.010) by ∼22% and ∼17% and synthesis rates increased (P = 0.040) by ∼20% and ∼24% in the HET and control groups, respectively, in response to PS consumption compared with placebo.. These data suggest that heterozygosity for the ABCG8 S107X mutation does not influence the action of dietary PS on circulating cholesterol concentrations but may affect sterol absorption.

Topics: Adolescent; Adult; Aged; Amino Acid Substitution; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Cholesterol; Cohort Studies; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Female; Heterozygote; Humans; Hypercholesterolemia; Intestinal Absorption; Intestinal Diseases; Kinetics; Lipid Metabolism, Inborn Errors; Lipids; Male; Middle Aged; Mutant Proteins; Phytosterols; Young Adult

As sitosterolemic patients have an increased cardiovascular risk, there is concern that reducing serum LDL-cholesterol concentrations by plant sterols enriched functional foods might adversely affect vascular function. Whether increased concentrations of plant sterols truly affect vascular function and whether these effects are exclusive to the larger vessels remains unknown. We compared the effects of long-term plant sterol and -stanol consumption on changes in retinal vessels diameter which reflex alterations in the microcirculation. Three randomized groups were studied at baseline and after 85-weeks. Group one (N=11) consumed plant sterol enriched margarine (2.5g/day), the second (N=8) plant stanol enriched margarine (2.5g/day), and the control group (N=11) non-enriched margarine (2.5g/day). Serum cholesterol-standardized campesterol and sitosterol concentrations increased by 354.84±168.22·102μmol/mmol and 84.36±48.26·102μmol/mmol (p<0.001), respectively in the sterol group, while decreasing non-significantly in the plant stanol group. Serum LDL-cholesterol concentrations decreased significantly in both the plant sterol (-0.33±0.33mmol/L, p=0.016) and -stanol groups (-0.38±0.34mmol/L, p=0.018) compared to the increase in the controls (0.29±0.34mmol/L). The mean change in venular diameters for the plant sterol group (2.3±3.1μm), plant stanol groups (-0.8±3.4μm) and control group (-0.8±5.1μm) did not reach significance but the change in cholesterol-standardized campesterol concentrations correlated positively with the change in venular diameter independent of changes in serum LDL-cholesterol concentrations (r=0.39, N=30, p=0.033). Increased serum campesterol concentration correlated positively with increased retinal venular diameter, independent from changes in serum LDL-cholesterol concentrations. This may constitute an explanation for the suggested effects of plant sterols on vascular function. However, this novel finding needs confirmation and further study.

Topics: Adolescent; Adult; Aged; Arterioles; Cholesterol; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Plant Extracts; Retinal Vessels; Sitosterols; Sterols; Venules

It has been demonstrated that statins can increase intestinal sterol absorption. Augments in phytosterolemia seems related to cardiovascular disease.. We examined the role of soluble fiber intake in endogenous cholesterol synthesis and in sterol absorption among subjects under highly effective lipid-lowering therapy.. In an open label, randomized, parallel-design study with blinded endpoints, subjects with primary hypercholesterolemia (n = 116) were assigned to receive during 12 weeks, a daily dose of 25 g of fiber (corresponding to 6 g of soluble fibers) plus rosuvastatin 40 mg (n = 28), rosuvastatin 40 mg alone (n = 30), sinvastatin 40 mg plus ezetimibe 10 mg plus 25 g of fiber (n = 28), or sinvastatin 40 mg plus ezetimibe 10 mg (n = 30) alone.. The four assigned therapies produced similar changes in total cholesterol, LDL-cholesterol, and triglycerides (p < 0.001 vs. baseline) and did not change HDL-cholesterol. Fiber intake decreased plasma campesterol (p < 0.001 vs. baseline), particularly among those patients receiving ezetimibe (p < 0.05 vs. other groups), and β-sitosterol (p = 0.03 vs. baseline), with a trend for lower levels in the group receiving fiber plus ezetimibe (p = 0.07). Treatment with rosuvastatin alone or combined with soluble fiber was associated with decreased levels of desmosterol (p = 0.003 vs. other groups). Compared to non-fiber supplemented individuals, those treated with fibers had weight loss (p = 0.04), reduced body mass index (p = 0.002) and blood glucose (p = 0.047).. Among subjects treated with highly effective lipid-lowering therapy, the intake of 25 g of fibers added favorable effects, mainly by reducing phytosterolemia. Additional benefits include improvement in blood glucose and anthropometric parameters.

Topics: Azetidines; Blood Glucose; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fiber; Ezetimibe; Female; Fluorobenzenes; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Pyrimidines; Rosuvastatin Calcium; Sitosterols; Sulfonamides; Triglycerides

Topics: Cardiovascular Diseases; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Whistleblowing

Sitosterolemia, also known as phytosterolemia, results from increased intestinal absorption of plant sterols and decreased intestinal and biliary excretion of sterols, resulting in increased levels of plant sterols in the plasma. The most common symptoms include xanthomas, premature atherosclerosis, hemolytic anemia and macrothrombocytopenia, however delayed diagnosis or misdiagnosis also occur.. Clinical exome sequencing was performed on a 10-year-old boy whom we followed up with signs of pancytopenia accompanied by macrothrombocytopenia and stomatocytosis. In addition, the blood sterol levels of the patient and his family were studied.. A novel homozygous c.904 + 5G > C intronic variant was detected in ABCG5 gene in index case. The mother and father were identified as carriers. The blood plant sterol levels of the patient and his family were studied, and the levels in the patient confirmed Sitosterolemia. Sitosterol levels decreased dramatically with restricted diet and ezetimibe treatment.. In children, signs of Sitosterolemia may be subtle and the only symptom may be hematological. Therefore, Sitosterolemia should be kept in mind in children with stomatocytosis and macrothrombocytopenia.

Topics: Adolescent; Child; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Pancytopenia; Phytosterols; Sitosterols

Clinical manifestations and genetic backgrounds of Japanese patients with sitosterolemia have been unclear.. We searched PubMed for studies using the keywords "sitosterolemia" or "phytosterolemia" and "Japan". Moreover, we added information from the members of the Committee on Primary Dyslipidemia under the Research Program on Rare and Intractable Disease of the Ministry of Health, Labour and Welfare (MHLW) of Japan.. We identified 36 patients with sitosterolemia caused by biallelic pathogenic mutations in the ATP-binding cassette subfamily G member 5 (ABCG5) or ATP-binding cassette subfamily G member 8 (ABCG8) from 31 families in Japan. The diagnosed age ranged from 0 to 64 years (median 13 years). The median sitosterol and LDL cholesterol levels were 100 μg/ml (IQR: 50-183), and 193 mg/dl (IQR: 108-295), respectively. All the patients exhibited cutaneous and/or tendon xanthomas, up to 9 (25%) patients exhibited premature coronary artery disease, 5 (16%) patients exhibited arthritis, and 8 (22%) patients exhibited blood abnormalities. Ezetimibe was administered to all the patients, including infantile cases, while statins, colestimide, evolocumab, probucol, and LDL apheresis were also used.. We are providing a demographic overview of the clinical and genetic backgrounds of Japanese patients with sitosterolemia.

Topics: Adenosine Triphosphate; Adolescent; Adult; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Child; Child, Preschool; Humans; Hypercholesterolemia; Infant; Infant, Newborn; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Middle Aged; Phytosterols; Young Adult

Sitosterolemia is a rare autosomal recessive disorder caused by homozygous or compound heterozygous variants in. From 443 familial hypercholesterolemia index cases, 260 were negative for familial hypercholesterolemia genes and were sequenced for the. Testing genes associated with sitosterolemia in the molecular routine workflow of a familial hypercholesterolemia cascade screening program allowed the precise diagnosis of sitosterolemia in a substantial number of patients with varying LDL-C levels and high incidence of early atherosclerotic cardiovascular disease and hematologic abnormalities.

Topics: Adolescent; Adult; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cardiovascular Diseases; Cholesterol; Cholesterol, LDL; Female; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Young Adult

Topics: Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Pregnancy

Plant sterol intake is widely recommended for patients with cardiovascular risk factors based on the inhibitory effect on intestinal cholesterol absorption. Although plant sterols, once absorbed, can promote atherosclerosis, their intake is believed to be safe because of poor absorption, except in rare hyperabsorbers with homozygous ABCG5/8 mutations. We report a case of new-onset type 1 diabetes accompanied by hypercholesterolemia. At the initial presentation with diabetic ketoacidosis, the patient showed marked hypercholesterolemia. Whole-exome sequencing revealed a heterozygous pathogenic variant in ABCG5 (p.R419H). The initial serum plant sterol levels were markedly high (sitosterol 32.5 μg/mL, campesterol 66.0 μg/mL), close to the range observed in patients with homozygous ABCG5/8 mutations, which were largely reduced by insulin treatment without ezetimibe. The addition of ezetimibe normalized plant sterol levels. These findings provide the first evidence that uncontrolled diabetes plays a causal role in the pathogenesis of phytosterolemia.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; Diabetes Mellitus; Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols

We report a noteworthy case of a 10-year-old girl who presented with papular and nodular lesions on the skin that were clinically and histologically mistaken for progressive nodular histiocytosis. During the clinical management of the patient, the high lipid levels raised the suspicion of lipid metabolism disease and helped us to make the correct diagnosis of sitosterolemia. In sitosterolemia, proper management such as restriction of plant sterol intake and administration of cholesterol absorption inhibitor can improve prognosis.

Topics: Child; Cholesterol; Female; Histiocytosis; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Sitosterols; Skin Diseases; Xanthomatosis

Sitosterolemia is an inherited metabolic disorder characterized by increased levels of plant sterols, such as sitosterol. This disease is caused by loss-of-function genetic mutations in the ATP-binding cassette (ABC) subfamily G member 5 or member 8 (ABCG5 or ABCG8, respectively), both of which play important roles in the selective excretion of plant sterols from the liver and intestine, leading to a failure to excrete plant sterols. Sitosterolemia, which is currently considered a rare genetic disorder, has been described as a phenocopy of homozygous familial hypercholesterolemia (FH). Typical phenotypes of sitosterolemia, including elevated low-density lipoprotein (LDL) cholesterol, tendon xanthomas, and premature coronary artery disease, overlap those of homozygous FH; however, there are substantial differences between these two diseases in terms of treatments and prognoses. Moreover, it is of note that sitosterolemia appears to be quite underdiagnosed, although accurate diagnosis and appropriate interventions will likely to lead to better prognoses compared with homozygous FH. Unlike cases of homozygous FH, dietary counseling is quite effective in reducing the LDL cholesterol as well as sitosterol of patients with sitosterolemia. In this chapter, we summarize the current understandings of this disease and provide useful tips for the diagnosis as well as better treatment of patients with sitosterolemia.

Topics: Adenosine Triphosphate; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cholesterol; Cholesterol, LDL; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols; Sitosterols

Sitosterolemia (STSL) is an extremely rare genetic disease. Xanthomas as the first symptom are frequently misinterpreted as familial hypercholesterolemia (FH) in children. Inappropriate treatment may deteriorate the condition of STSL.. To present the clinical and laboratory characteristics of xanthomatous children diagnosed with sitosterolemia in comparison with childhood FH with xanthomas.. We summarized and compared the clinical characteristics of STSL and FH patients with xanthomas as the first manifestations and investigated the different indicators between the STSL and FH groups, as well as their diagnostic values for STSL.. Two tertiary pediatric endocrinology departments contributed ten STSL cases. Five of the STSL patients (50%) experienced mild anemia, whereas two (20%) had vascular complications. The xanthomas of the STSL group displayed morphologies comparable to those of the FH group. There were ten cases of homozygous FH (HoFH) with xanthomas as the predominant symptom of the control group who had no anemia. The serum cholesterol (Chol) levels of the STSL and FH groups were 12.57 (9.55 ~ 14.62) mmol/L and 17.45 (16.04 ~ 21.47) mmol/L, respectively (p value 0.002). The serum low-density lipoprotein cholesterol (LDL-c) levels of the STSL and FH groups were 9.26 ± 2.71 mmol/L and 14.58 ± 4.08 mmol/L, respectively (p value 0.003). Meanwhile, the mean platelet volume (MPV) levels of the STSL and FH groups were 11.00 (9.79 ~ 12.53) fl. and 8.95 (8.88 ~ 12.28) fl., respectively (p value 0.009). The anemia proportions of the STSL and FH groups were 50% and 0%, respectively (p value 0.033). The AUC values of Chol, LDL-c, MPV, hemoglobin (Hb) for the diagnosis of STSL were 0.910, 0.886, 0.869, 0.879, respectively. Chol ≤ 15.41 mmol/L, LDL-c ≤ 13.22 mmol/L, MPV ≥ 9.05 fl., or Hb≤120 g/L were the best thresholds for diagnosing STSL with childhood xanthomas.. The xanthoma morphology of STSL patients resembles that of FH patients. Xanthomas as the initial symptom of a child with Chol ≤ 15.41 mmol/L, LDL-c≤13.22 mmol/L, MPV ≥ 9.05 fl., or Hb≤120 g/L, he was most likely to have STSL.

Topics: Child; Cholesterol; Cholesterol, LDL; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols; Xanthomatosis

Sitosterolemia is a rare inherited condition in which plant sterols are stored and deposited in the tissues. Described in 1974 by Battacharyya and Connor, it is characterized by tendon and tuberous xanthomas and a propensity to premature coronary atherosclerosis. We present the first reported case of the disease being manifest in the periorbital region. A 44-year-old man presented with a six-month history of swelling below the left eyebrow overlying the orbital rim, but without displacement of the globe. Magnetic resonance imaging identified a soft tissue mass within the orbit, with subsequent biopsy confirming a xanthogranulomatous process consistent with the diagnosis of sitosterolemia. Management of sitosterolemia aims to reduce plasma plant sterol concentrations which subsequently lowers serum cholesterol reducing the xanthomas and atherosclerotic cardiovascular diseases. This report highlights a rare, under-recognised condition (and indeed the first reporting periocular disease), and the potential dangers if misdiagnosed as hypercholesterolemia.

Topics: Adult; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols

Heart failure (HF) and cardiac arrhythmias share overlapping pathological mechanisms that act cooperatively to accelerate disease pathogenesis. Cardiac fibrosis is associated with both pathological conditions. Our previous work identified a link between phytosterol accumulation and cardiac injury in a mouse model of phytosterolemia, a rare disorder characterized by elevated circulating phytosterols and increased cardiovascular disease risk. Here, we uncover a previously unknown pathological link between phytosterols and cardiac arrhythmias in the same animal model. Phytosterolemia resulted in inflammatory pathway induction, premature ventricular contractions (PVC) and ventricular tachycardia (VT). Blockade of phytosterol absorption either by therapeutic inhibition or by genetic inactivation of NPC1L1 prevented the induction of inflammation and arrhythmogenesis. Inhibition of phytosterol absorption reduced inflammation and cardiac fibrosis, improved cardiac function, reduced the incidence of arrhythmias and increased survival in a mouse model of phytosterolemia. Collectively, this work identified a pathological mechanism whereby elevated phytosterols result in inflammation and cardiac fibrosis leading to impaired cardiac function, arrhythmias and sudden death. These comorbidities provide insight into the underlying pathophysiological mechanism for phytosterolemia-associated risk of sudden cardiac death.

Topics: Animals; Arrhythmias, Cardiac; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cytokines; Death, Sudden, Cardiac; Fibrosis; Heart Failure; Hypercholesterolemia; Inflammation; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Membrane Transport Proteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Phytosterols

谷固醇血症是一种罕见的常染色体隐性遗传脂质代谢异常疾病，其特征为血浆和组织中谷固醇的含量增高、蓄积。现报道1例以血小板减少和肝功能异常就诊，通过相关检查发现ABCG5基因突变确诊为谷固醇血症患儿，同时分析患儿的临床特征。.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; Child; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Liver; Mutation; Phytosterols; Thrombocytopenia

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Blood Platelet Disorders; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mice; Phytosterols

Topics: Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

Topics: Blood Platelets; Child; Erythrocytes, Abnormal; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols; Thrombocytopenia

报道1例以鼻衄、脾大起病，后因肝功能异常而最终诊断为谷固醇血症的病案。文中患者的诊治过程曲折，期间经历了两次肝脏穿刺组织学检查、脾脏切除手术，但病因一直未能明确。最终，通过基因检测等检查确诊并予以治疗，此后患者肝功能改善、未再出现鼻衄。该例病案提醒临床医生，遇到反复肝功能异常的患者，若经常规实验室、影像学及组织学检查后仍未明确病因，则应重视遗传代谢性肝病相关基因的筛查，利于及时诊断、尽早治疗。.

Topics: Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Liver; Phytosterols

The present study was conducted to establish a practical method for measuring non-cholesterol sterols and reference intervals of serum levels.. Healthy subjects (109 men and 151 women), four patients with sitosterolemia, and 10 heterozygous mutation carriers of ABCG5/ABCG8 genes were investigated. Then, three non-cholesterol sterols (sitosterol, campesterol, and lathosterol) of fasting serum samples were measured via a practical and highly sensitive gas chromatography (GC) method with 0.2 µg/mL as the lower limit of quantification. The coefficient of variation (CV) values for within-run reproducibility were 3.06%, 1.89%, and 1.77% for lathosterol, campesterol, and sitosterol, respectively. The CV values for between-run reproducibility were 2.81%, 2.06%, and 2.10% for lathosterol, campesterol, and sitosterol, respectively.. The serum levels of sitosterol and campesterol were significantly higher in women than in men, whereas the serum levels of lathosterol were significantly higher in men than in women. Because of these gender difference, the determination of reference intervals of the three sterol values was performed by considering gender. The reference intervals of sitosterol, campesterol, and lathosterol were 0.99-3.88, 2.14-7.43, and 0.77-3.60 µg/mL in men and 1.03-4.45, 2.19-8.34, and 0.64-2.78 µg/mL in women, respectively. The serum levels of sitosterol and campesterol were higher in patients with sitosterolemia (94.3±47.3 and 66.3±36.6 µg/mL, respectively) than in healthy subjects.. These results demonstrate a practical and highly sensitive GC method to measure non-cholesterol sterol levels and gender-segregated reference intervals of sitosterol, campesterol, and lathosterol in Japanese healthy subjects.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cholesterol; Cholesterol, Dietary; Chromatography, Gas; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Reference Values; Reproducibility of Results; Sex Factors; Sitosterols

HepG2 cells were incubated with a 16.5:1.7:1 ratio of cholesterol:sitosterol:campesterol (CSC), a ratio of the major sterols observed in the plasma of phytosterolemia patients, or with cholesterol alone in combination with [

Topics: Carbon Radioisotopes; Cholesterol; Cholesterol Esters; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation; Hep G2 Cells; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Models, Biological; Phytosterols; Receptors, LDL; Sitosterols

Vegetable lipid emulsions (LE) contain non-declared phytosterols (PS). We aimed to determine PS content depending on the brand and LE batch, and in adult hospitalised patients treated with parenteral nutrition (PN), to establish the association between plasma and administered PS. Part I was the LE study: totals and fractions of PS in three to four non-consecutive batches from six LE were analysed. Part II was the patient study: patients with at least 7 previous days of PN with 0·8 g/kg per d of an olive/soyabean (O/S) LE were randomised (day 0) 1:1 to O/S or 100 % fish oil (FO) at a dose of 0·4 g/kg per d for 7 d (day 7). Plasma PS, its fractions, total cholesterol on days 0 and 7, their clearance and their association with PS administered by LE were studied. In part I, LE study: differences were found in the total PS, their fractions and cholesterol among different LE brands and batches. Exclusive soyabean LE had the highest content of PS (422·36 (sd 130·46) μg/ml). In part II, patient study: nineteen patients were included. In the O/S group, PS levels were maintained (1·11 (sd 6·98) μg/ml) from day 0 to 7, while in the FO group, significant decreases were seen in total PS (-6·21 (sd 4·73) μg/ml) and their fractions, except for campesterol and stigmasterol. Plasma PS on day 7 were significantly associated with PS administered (R2 0·443). PS content in different LE brands had great variability. PS administered during PN resulted in accumulation and could be prevented with the exclusive administration of FO LE.

Topics: Adult; Cholesterol; Fat Emulsions, Intravenous; Female; Fish Oils; Humans; Hypercholesterolemia; Inpatients; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Parenteral Nutrition; Parenteral Nutrition Solutions; Phytosterols; Plant Oils; Prospective Studies; Stigmasterol; Vegetables

Sitosterolemia is a rare lipid metabolism disease with heterogeneous manifestations. Atherosclerosis can occur in children, and therefore, early detection, diagnosis, and treatment of this disease are important. We studied 18 pediatric patients with sitosterolemia who showed a significant increase in plasma lipid levels and analyzed their clinical, biochemical, and genetic characteristics. We recorded the initial serum lipid results and clinical manifestations of the patients. Lipid and plant sterol levels were measured after homozygous or compound heterozygous mutations of ABCG5 or ABCG8 were identified by genetic testing. Plasma plant sterol levels were analyzed by gas chromatography. Fourteen cases of sitosterolemia were examined by ultrasound and echocardiography. The initial total cholesterol and low-density lipoprotein levels of the children were significantly increased, but then markedly decreased after diet control or drug treatment, and even reached normal levels. Carotid atherosclerosis and aortic valve regurgitation were present in three of 14 patients. Serum lipid levels of children with sitosterolemia and xanthomas were notably higher than those without xanthomas. There were no significant differences in clinical manifestations between patients with different genotypes. In conclusion, sitosterolemia should be considered in children with hyperlipidemia who do not present with xanthomas, especially with a significant increase in total cholesterol and low-density lipoprotein levels. There does not appear to be a correlation between clinical phenotype and genotype.

Topics: Child; Child, Preschool; Female; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols

Sitosterolemia (STSL), also known as phytosterolemia, is a rare autosomal recessive hereditary disease caused by mutations in the ABCG5 or ABCG8 genes. The disease is a result of disorders in lipoprotein metabolism, and is characterized by tendinous and tuberous xanthomas, elevated plasma cholesterol and phytosterol levels, and thrombocytopenia and hemolytic anemia in several patients. The manifestations of STSL are diverse and can easily be misdiagnosed. In recent years, cases of this disease in children have been reported in succession. There is therefore a need for clinicians to improve identification of STSL and perform early intervention.. We evaluated four children with STSL caused by genetic mutations in ABCG5 or ABCG8, as well as their family members, by analyzing their clinical characteristics and performing Trio-whole exome sequencing. The biological consequences of the mutations were analyzed using various bioinformatics software. We also analyzed the consequences of a mutation commonly observed in STSL patients on the structure of the protein involved.. We identified five previously unreported pathogenic mutations of different phenotypes of STSL: ABCG5 NM_022436:c.1337G>A; ABCG8 NM_022437:c.965-1G>A, c.323-1G>C, c.1418C>G and c.1534G>A. We also report the structural changes brought about by a mutation common in STSL patients, as well as the possible consequences of these changes.. Our findings further broaden the genotypic and phenotypic profiles of the onset of STSL in the pediatric population and provide information for the diagnosis and treatment of this disease.

Topics: Asian People; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Child; Child, Preschool; Exome Sequencing; Female; Genetic Predisposition to Disease; Genetic Testing; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mutation; Phenotype; Phytosterols

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cardiometabolic Risk Factors; Cholesterol, Dietary; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Intestinal Absorption; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Patient Care Management; Phytosterols

Sitosterolemia is caused by homozygous or compound heterozygous gene mutations in either ATP-binding cassette subfamily G member 5 (ABCG5) or 8 (ABCG8). Since ABCG5 and ABCG8 play pivotal roles in the excretion of neutral sterols into feces and bile, patients with sitosterolemia present elevated levels of serum plant sterols and in some cases also hypercholesterolemia. A 48-year-old woman was referred to our hospital for hypercholesterolemia. She had been misdiagnosed with familial hypercholesterolemia at the age of 20 and her serum low-density lipoprotein cholesterol (LDL-C) levels had remained about 200-300 mg/dL at the former clinic. Although the treatment of hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors was ineffective, her serum LDL-C levels were normalized by ezetimibe, a cholesterol transporter inhibitor. We noticed that her serum sitosterol and campesterol levels were relatively high. Targeted analysis sequencing identified a novel heterozygous ABCG5 variant (c.203A>T; p.Ile68Asn) in the patient, whereas no mutations were found in low-density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type 9 (PCSK9), or Niemann-Pick C1-like intracellular cholesterol transporter 1 (NPC1L1). While sitosterolemia is a rare disease, a recent study has reported that the incidence of loss-of-function mutation in the ABCG5 or ABCG8 gene is higher than we thought at 1 in 220 individuals. The present case suggests that serum plant sterol levels should be examined and ezetimibe treatment should be considered in patients with hypercholesterolemia who are resistant to HMG-CoA reductase inhibitors.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; Cholesterol; Cholesterol, LDL; Diagnostic Errors; Ezetimibe; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Loss of Function Mutation; Middle Aged; Phytosterols; Sitosterols; Treatment Failure

We herein report a rare case presenting with severe hypercholesterolemia, massive Achilles tendon xanthomas, and multi-vessel coronary artery disease. Initially, the patient was misdiagnosed with familial hypercholesterolemia. However, a genetic analysis using our custom sequencing panel covering genes associated with Mendelian lipid disorders revealed him to have a genetic basis of sitosterolemia with compound heterozygous mutations in the adenosine triphosphate binding cassette subfamily G5 (ABCG5) gene. A comprehensive genetic analysis can be particularly useful for diagnosing cases with severe phenotypes, leading to appropriate and medical therapies. Our patient was refractory to statins, whereas ezetimibe and PCSK9 inhibitor with a low-plant-sterol diet successfully reduced his serum levels of low-density lipoprotein cholesterol.

Topics: Achilles Tendon; Antibodies, Monoclonal, Humanized; Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; Cholesterol, LDL; Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Mutation; Phytosterols; Treatment Outcome; Xanthomatosis

Sitosterolemia is an inherited lipid disorder which presents with elevated serum sitosterol and can result in an increased risk of premature cardiovascular disease. However, sitosterol cannot be accurately measured by routine diagnostic assays, meaning that sitosterolemia diagnosis can often be difficult, especially with many clinical features overlapping with familial hypercholesterolemia. With such complications resulting in increasing reports of misdiagnosis, the prevalence of sitosterolemia is predicted to be much higher than previously reported.. Gas chromatography-mass spectrometry was utilized to measure sitosterol levels of normocholesterolemic and hypercholesterolemic children. Subsequently, an epidemiologically determined cutoff level of sitosterol was calculated and applied to estimate the prevalence of children with increased sitosterol and identify potential sitosterolemia patients. Massively parallel sequencing was used to confirm the diagnosis in suspected patients.. Samples from 109 normocholesterolemic and 220 hypercholesterolemic were tested for phytosterols. Sitosterol and campesterol levels were significantly increased in hypercholesterolemic children (mean 22.0±45.9 μmol/L for sitosterol and 26.0±32.8 μmol/L for campesterol) compared to normocholesterolemic children (mean 12.1±4.9 μmol/L for sistosterol and 14.8±6.7 μmol/L for campesterol). Via application of a cutoff of 35.9 μmol/L, the prevalence rates for increased and overtly increased sitosterol in hypercholesterolemic children were 6.4% and 1.4% respectively. Furthermore, 3 suspected sitosterolemia patients were identified, with 2 patients receiving molecular confirmation for sitosterolemia diagnosis.. Our findings reaffirm that the prevalence of sitosterolemia is probably much higher than previously reported, which also indicates the significant risk of misdiagnosis of sitosterolemia with familial hypercholesterolemia. Special lipid testing including sitosterol, especially in children with uncontrolled hypercholesterolemia, is recommended in children in order to identify potential sitosterolemia patients that would otherwise be neglected.

Topics: Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Child; Child, Preschool; Cholesterol; Female; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Pedigree; Phytosterols; Prevalence; Sitosterols

The heterodimeric ATP-binding cassette (ABC) sterol transporter, ABCG5/G8, is responsible for the biliary and transintestinal secretion of cholesterol and dietary plant sterols. Missense mutations of ABCG5/G8 can cause sitosterolemia, a loss-of-function disorder characterized by plant sterol accumulation and premature atherosclerosis. A new molecular framework was recently established by a crystal structure of human ABCG5/G8 and reveals a network of polar and charged amino acids in the core of the transmembrane domains, namely, a polar relay. In this study, we utilize genetic variants to dissect the mechanistic role of this transmembrane polar relay in controlling ABCG5/G8 function. We demonstrated a sterol-coupled ATPase activity of ABCG5/G8 by cholesteryl hemisuccinate (CHS), a relatively water-soluble cholesterol memetic, and characterized CHS-coupled ATPase activity of three loss-of-function missense variants, R543S, E146Q, and A540F, which are respectively within, in contact with, and distant from the polar relay. The results established an in vitro phenotype of the loss-of-function and missense mutations of ABCG5/G8, showing significantly impaired ATPase activity and loss of energy sufficient to weaken the signal transmission from the transmembrane domains. Our data provide a biochemical evidence underlying the importance of the polar relay and its network in regulating the catalytic activity of ABCG5/G8 sterol transporter.

Topics: Adenosine Triphosphatases; Adenosine Triphosphate; Allosteric Regulation; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Binding Sites; Biological Transport; Cholesterol; Cholesterol Esters; Cholic Acid; Gene Expression; Humans; Hypercholesterolemia; Intestinal Diseases; Kinetics; Lipid Metabolism, Inborn Errors; Lipoproteins; Models, Molecular; Mutation; Phytosterols; Pichia; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; Recombinant Proteins; Thermodynamics

Non-cholesterol sterols are validated markers for fractional intestinal cholesterol absorption (cholestanol) and endogenous cholesterol synthesis (lathosterol). This study's objective was to evaluate markers for cholesterol synthesis and absorption in children exposed to two different intravenous lipid emulsions that rapidly change serum plant sterol concentrations as part of their parenteral nutrition (PN).. Serum samples from two different studies were used: (1) nine PN-dependent children with intestinal failure associated liver disease (IFALD) whose soy-based, plant sterol-rich lipid (SO) was replaced with a fish-based, plant sterol-poor (FO) lipid; and (2) five neonates prescribed SO after birth. In the first study, samples were collected at baseline (prior to FO initiation) and after 3 and 6 months of FO. In study 2, samples were collected at 1 and 3 weeks of age.. In study 1, a 7-fold reduction in campesterol, a 12-fold reduction in sitosterol, and a 15-fold reduction in stigmasterol was observed 6 months after switching to FO. Serum cholesterol concentrations did not change, but cholesterol-standardized lathosterol increased (3-fold) and cholesterol-standardized cholestanol decreased (2-fold). In study 2, after 3 weeks of SO, sitosterol and campesterol concentrations increased 4-5 fold. At the same time, cholesterol-standardized lathosterol increased 69% and cholesterol-standardized cholestanol decreased by 29%.. Based on these finding we conclude that changes in serum plant sterol concentrations might have direct effects on endogenous cholesterol synthesis, although this needs to be confirmed in future studies. Moreover, we speculate that this changed synthesis subsequently affects intestinal cholesterol absorption.

Topics: Animals; Biomarkers; Child; Child, Preschool; Cholesterol; Fat Emulsions, Intravenous; Female; Fish Oils; Humans; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Intestinal Absorption; Intestinal Diseases; Liver; Liver Diseases; Male; Parenteral Nutrition; Parenteral Nutrition Solutions; Phytosterols; Soybean Oil

Cardiovascular disease is expected to remain the leading cause of death worldwide despite the introduction of proprotein convertase subtilisin/kexin type 9 inhibitors that effectively control cholesterol. Identifying residual risk factors for cardiovascular disease remains an important step for preventing and clinically managing the disease. Here we report cardiac injury and increased mortality occurring despite a 50% reduction in plasma cholesterol in a mouse model of phytosterolemia, a disease characterized by elevated levels of dietary plant sterols in the blood. Our studies show accumulation of stigmasterol, one of phytosterol species, leads to left ventricle dysfunction, cardiac interstitial fibrosis and macrophage infiltration without atherosclerosis, and increased mortality. A pharmacological inhibitor of sterol absorption prevents cardiac fibrogenesis. We propose that the pathological mechanism linking clinical sitosterolemia to the cardiovascular outcomes primarily involves phytosterols-induced cardiac fibrosis rather than cholesterol-driven atherosclerosis. Our studies suggest stigmasterol is a potent and independent risk factor for cardiovascular disease.

Topics: Animals; Atherosclerosis; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cell Survival; Dietary Supplements; Fibrosis; Human Umbilical Vein Endothelial Cells; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocardium; Phytosterols; Stigmasterol; Ventricular Dysfunction, Left

Topics: Adolescent; Anemia, Hemolytic, Congenital; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Blood Platelets; Child; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mutation, Missense; Phytosterols; Thrombocytopenia

Topics: Cholestanol; Cholesterol; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Intestinal Diseases; Limit of Detection; Lipid Metabolism, Inborn Errors; Phytosterols; Reference Standards; Sitosterols; Xanthomatosis, Cerebrotendinous

Topics: Adult; ATP Binding Cassette Transporter, Subfamily G, Member 5; Genetic Diseases, Inborn; Heterozygote; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mutation; Phytosterols

Phytosterolemia is a rare genetic disease caused by mutation of the ABCG5/8 gene. Our aim was to elucidate the natural history and homeostasis of phytosterolemia.. We analyzed a Hutterite kindred consisting of 21 homozygotes with phytosterolemia assembled over a period of two decades, all of whom carried the ABCG8 S107X mutation and were treated with ezetimibe.. Most of these subjects were asymptomatic and devoid of clinical stigmata, and this, since they were ascertained primarily by a process of cascade testing, suggests that, relative to its true prevalence, phytosterolemia is a condition of low morbidity. All subjects have responded well to treatment with ezetimibe. Initial (pre-treatment) and post-ezetimibe levels of cholesterol and sitosterol were measured and percentage changes on ezetimibe were calculated. We found initial levels to be inversely related to subjects' ages as were percentage responses to ezetimibe therapy. There was also a direct correlation between initial levels and percentage responses to ezetimibe. Hence on-treatment levels were very uniform.. This evidence of a link with age leads us to propose that an age-related change in cholesterol and sterol homeostasis occurs at puberty in phytosterolemia and that the change is due to high sterol and/or stanol levels causing feedback inhibition of sterol regulatory element-binding protein (SREBP-2) processing. This would explain the well-documented phenomenon of depressed cholesterol synthesis in phytosterolemia. It is also well-known that LDL-receptor activity is increased, and this feasibly explains reduced LDL levels and consequent reduction of plasma cholesterol and sitosterol levels. Downregulated SREBP-2 processing would be expected to also lower proprotein convertase subtilisin/kexin type 9 (PCSK9) levels and this would explain high LDL-receptor activity. The above state could be termed disrupted homeostasis and the alternative, seen mostly in children and characterized by hypercholesterolemia and hypersterolemia, simple homeostasis.

Topics: Adolescent; Adult; Age Factors; Anticholesteremic Agents; Asymptomatic Diseases; ATP Binding Cassette Transporter, Subfamily G, Member 8; Biomarkers; Canada; Child; Child, Preschool; Cholesterol; Ezetimibe; Female; Genetic Predisposition to Disease; Homeostasis; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Mutation; Phenotype; Phytosterols; Prevalence; Puberty; Rare Diseases; Risk Factors; Sitosterols; Time Factors; Treatment Outcome; United States; Young Adult

Sitosterolemia is an extremely rare, autosomal recessive disease characterized by high plasma cholesterols and plant sterols because of increased absorption of dietary cholesterols and sterols from the intestine, and decreased excretion from biliary tract. Previous study indicated that sitosterolemic patients might be vulnerable to post-prandial hyperlipidemia, including high remnant-like lipoprotein particles (RLP) level. Here we evaluate whether a loading dietary fat increases a post-prandial RLP cholesterol level in sitosterolemic patients compared to heterozygous familial hypercholesterolemic patients (FH).. We recruit total of 20 patients: 5 patients with homozygous sitosterolemia, 5 patients with heterozygous sitosterolemia, and 10 patients with heterozygous FH as controls from May 2015 to March 2018 at Kanazawa University Hospital, Japan. All patients receive Oral Fat Tolerance Test (OFTT) cream (50 g/body surface area square meter, orally only once, and the cream includes 34% of fat, 74 mg of cholesterol, and rich in palmitic and oleic acids. The primary endpoint is the change of a RLP cholesterol level after OFTT cream loading between sitosterolemia and FH. We measure them at baseline, and 2, 4, and 6 hours after the oral fat loading.. This is the first study to evaluate whether sitosterolemia patients have a higher post-prandial RLP cholesterol level compared to heterozygous FH patients.. The result may become an additional evidence to restrict dietary cholesterols for sitosterolemia. This study is registered at University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN ID: UMIN000020330).

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Cholesterol; Dietary Fats; Female; Follow-Up Studies; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Postprandial Period; Prognosis; Triglycerides; Young Adult

We aimed to clarify post-prandial accumulation of remnant-like particles (RLP) in patients with sitosterolemia.. After oral fat load, there was no significant difference of the iAUC of LDL-C between sitosterolemia and heterozygous FH, whereas the iAUC of apoB48 was significantly larger in the sitosterolemic subjects compared with that of heterozygous FH (2.9 µg/mL×h vs. 1.3 µg/mL×h, p＜0.05). Under these conditions, the iAUCs of RLP-C and RLP-TG levels were significantly larger in the sitosterolemic subject compared with those of heterozygous FH (9.5 mg/dL×h vs. 5.7 mg/dL×h, p＜0.05; 149 mg/dL×h vs. 40 mg/dL×h, p＜0.05, respectively), whereas those of heterozygous carriers were comparable with those with heterozygous FH.. Post-prandial lipoprotein metabolism in sitosterolemia appeared to be impaired, leading to their elevation in serum sterol levels. (UMIN Clinical Trials Registry number, UMIN000020330).

Topics: Adolescent; Adult; Biomarkers; Cholesterol; Female; Follow-Up Studies; Heterozygote; Humans; Hypercholesterolemia; Incidence; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Phytosterols; Postprandial Period; Prognosis; Triglycerides

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 8; Child, Preschool; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Mutation; Phytosterols; Xanthomatosis

Topics: Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Sterols

Topics: Atherosclerosis; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols

Topics: Biomarkers; Cholesterol; Humans; Hypercholesterolemia; Hyperlipidemias; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols; Postprandial Period; Prognosis; Risk Factors; Triglycerides

Sitosterolemia displays high plasma total sterols [high plant sterols (PS) + normal to high total cholesterol (TC)] with normal to moderately elevated low-density lipoprotein (LDL) levels. High LDL, intermediate-density lipoprotein (IDL) and very low-density lipoprotein (VLDL) particles, low high-density lipoprotein (HDL), and increased non-HDL and the ratios of TC and triglycerides (TG) to HDL can increase the risk for atherosclerosis. Ezetimibe (EZE) can reduce plasma PS and TC levels in sitosterolemia, but its effect on lipoprotein subclasses has not been previously reported.. Sitosterolemia patients (n = 8) were taken off EZE for 14 weeks (OFF EZE) and placed on EZE (10 mg/d) for 14 weeks (ON EZE). Serum lipids were measured enzymatically and lipoprotein subclasses were assessed by polyacrylamide gel electrophoresis.. EZE reduced (p < 0.05) total sterols (-12.5 ± 4.1%) and LDL-sterol (-22.7 ± 5.7%) and its sterol mass of large VLDL (-24.4 ± 4.5%), VLDL remnants (-21.1 ± 7.9%) and large IDL (-22.4 ± 7.2%) compared to OFF EZE. EZE did not affect large LDL subclasses or mean LDL particle size (273.8 ± 0.6 vs. 274.6 ± 0.3 Å). EZE increased HDL-sterol (25.5 ± 8.0%, p = 0.008) including intermediate (34 ± 14%, p = 0.02) and large (33 ± 16%, p = 0.06) HDL. EZE reduced non-HDL-sterol (-21.8± 5.0%), total sterols/HDL (-28.2 ± 5.5%) and TG/HDL (-27.4 ± 6.5%, all p < 0.01).. EZE improves VLDL and HDL subfraction distribution, thereby reducing the atherogenic lipid profile, thus providing potential clinical benefit in sitosterolemia beyond TC and PS reduction.

Topics: Adolescent; Adult; Anticholesteremic Agents; Cholesterol, HDL; Electrophoresis, Polyacrylamide Gel; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins, HDL; Lipoproteins, IDL; Lipoproteins, VLDL; Male; Middle Aged; Phytosterols; Treatment Outcome; Young Adult

Topics: Ezetimibe; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins, HDL; Phytosterols

Severe hypercholesterolemia associated or not with xanthomas in a child may suggest the diagnosis of homozygous autosomal dominant hypercholesterolemia (ADH), autosomal recessive hypercholesterolemia (ARH) or sitosterolemia, depending on the transmission of hypercholesterolemia in the patient's family. Sitosterolemia is a recessive disorder characterized by high plasma levels of cholesterol and plant sterols due to mutations in the ABCG5 or the ABCG8 gene, leading to a loss of function of the ATP-binding cassette (ABC) heterodimer transporter G5-G8.. We aimed to perform the molecular characterization of two children with severe primary hypercholesterolemia.. Case #1 was a 2 year-old girl with high LDL-cholesterol (690 mg/dl) and tuberous and intertriginous xanthomas. Case #2 was a 7 year-old boy with elevated LDL-C (432 mg/dl) but no xanthomas. In both cases, at least one parent had elevated LDL-cholesterol levels. For the molecular diagnosis, we applied targeted next generation sequencing (NGS), which unexpectedly revealed that both patients were compound heterozygous for nonsense mutations: Case #1 in ABCG5 gene [p.(Gln251*)/p.(Arg446*)] and Case #2 in ABCG8 gene [p.(Ser107*)/p.(Trp361*)]. Both children had extremely high serum sitosterol and campesterol levels, thus confirming the diagnosis of sisterolemia. A low-fat/low-sterol diet was promptly adopted with and without the addition of ezetimibe for Case #1 and Case #2, respectively. In both patients, serum total and LDL-cholesterol decreased dramatically in two months and progressively normalized.. Targeted NGS allows the rapid diagnosis of sitosterolemia in children with severe hypercholesterolemia, even though their family history does not unequivocally suggest a recessive transmission of hypercholesterolemia. A timely diagnosis is crucial to avoid delays in treatment.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Biomarkers; Child; Child, Preschool; Cholesterol, LDL; Codon, Nonsense; Diet, Fat-Restricted; DNA Mutational Analysis; Ezetimibe; Female; Genetic Predisposition to Disease; Heterozygote; High-Throughput Nucleotide Sequencing; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Phenotype; Phytosterols; Predictive Value of Tests; Severity of Illness Index; Treatment Outcome; Up-Regulation

Sitosterol is the most abundant plant sterol found in our diet. Sitosterolemia (OMIM 210250), also known as phytosterolaemia, is a rare autosomal recessive disease caused by the inability to efficiently excrete plant sterol, and is characterized by cutaneous xanthomas and accelerated atherosclerosis. Sitosterolaemia is caused by homozygous or compound heterozygous mutations in either ABCG5 or ABCG8 (both on chromosome 2p21), which encode the sterol efflux transporter ABCG5 (sterolin-1) and ABCG8 (sterolin-2), respectively. To investigate a Tunisian family with several members who manifested with generalized cutaneous xanthomas, whereas others had only isolated xanthelasmas. Genetic analysis was performed based on exome sequencing of DNA obtained from five affected individuals and one unaffected individual from a Tunisian family.. A novel mutation in the ABCG8 gene, designated c.965-1G>C, was identified by exome sequencing in the members of this family. The homozygous form was associated with generalized cutaneous xanthomatosis while the heterozygous form was linked to isolated xanthelasmas. Our results indicate a gene dosage effect of ABCG8 and suggest that individuals at risk should be followed closely.

Topics: Adult; ATP Binding Cassette Transporter, Subfamily G, Member 8; Female; Heterozygote; Homozygote; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Mutation; Pedigree; Phytosterols; Skin Diseases; Tunisia; Xanthomatosis

Sitosterolemia is a rare lipid metabolism disorder that involves storage of plant sterols. This disease is associated with atherosclerosis, but detailed vascular endothelial assessment is difficult.. We report a 5-year-old girl with sitosterolemia who presented with xanthomas at 23 months of age. Her total cholesterol was 868 mg/dL, and her plasma sitosterol level was 9.48 mg/dL. Direct sequencing detected a homozygous mutation in gene ABCG5 (p.Arg389His). Echocardiographic examination revealed that the carotid artery intima media thickness (cIMT) was 0.4 mm with heterogenous hyperechogenicity inside the arterial wall. She was treated using dietary therapy and ezetimibe, which effectively lowered her sitosterol levels. After 3 years of treatment, her cIMT was stable in diameter and arterial wall echogenicity had improved.. Sitosterolemia is a unique disorder in which it is difficult to avoid premature atherosclerosis because of high sitosterol levels. cIMT measurement with arterial wall assessment may improve management.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; Carotid Arteries; Carotid Intima-Media Thickness; Child, Preschool; Cholesterol, LDL; Echocardiography; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Mutation; Phytosterols

Topics: Adolescent; Blood Component Removal; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Phytosterols; Treatment Outcome

Topics: Adolescent; Adult; Child; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols; Young Adult

Parenteral plant sterols (PSs) are considered hepatotoxic; however, liver PSs and their associations with liver injury in patients with intestinal failure (IF) have not been reported.. We analyzed liver and serum PS (avenasterol, campesterol, sitosterol, and stigmasterol) concentrations and ratios to cholesterol and their associations with biochemical and histologic liver damage in children with IF during (n = 7) parenteral nutrition (PN) and after weaning off it (n = 9), including vegetable oil-based lipid emulsions.. Liver avenasterol, sitosterol, and total PS concentrations and cholesterol ratios were 2.4-fold to 5.6-fold higher in PN-dependent patients ( P < .05). Parenteral PS delivery reflected liver avenasterol and sitosterol ratios to cholesterol ( r = 0.83-0.89, P = .02-.04), while serum and liver total PS levels were positively interrelated ( r = 0.98, P < .01). Any liver histopathology was equally common while portal inflammation more frequent (57 vs 0%, P = .02) in PN-dependent patients. All liver PS fractions correlated positively with histologic portal inflammation ( r = 0.53-0.66, P < .05), and their total concentration was significantly ( P = .01) higher among patients with versus without portal inflammation. In PN-dependent patients, liver fibrosis and any histopathology correlated with liver campesterol and stigmasterol levels ( r = 0.79-0.87, P ≤ .03).. Among children with IF, parenteral PSs accumulate in the liver, reflect their increased serum levels, and relate with biochemical liver injury, portal inflammation, and liver fibrosis, thus supporting their role in promoting liver damage.

Topics: Alanine Transaminase; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Child; Child, Preschool; Cholesterol; Female; gamma-Glutamyltransferase; Humans; Infant; Inflammation; Intestinal Diseases; Liver; Male; Parenteral Nutrition; Phytosterols; Plant Oils; Portal Vein; Sitosterols; Stigmasterol; Triglycerides

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Genetic Testing; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Mutation; Phytosterols

Whole-exome sequencing allows for an unbiased and comprehensive mutation screening. Although successfully used to facilitate the diagnosis of single-gene disorders, the genetic cause(s) of a substantial proportion of presumed monogenic diseases remain to be identified. We used whole-exome sequencing to examine offspring from a consanguineous marriage featuring a novel combination of congenital hypothyroidism, hypomagnesemia and hypercholesterolemia. Rather than identifying one causative variant, we report the first instance in which three independent autosomal-recessive single-gene disorders were identified in one patient. Together, the causal variants give rise to a blended and seemingly novel phenotype: we experimentally characterized a novel splice variant in the thyroglobulin gene (c.638+5G>A), resulting in skipping of exon 5, and detected a pathogenic splice variant in the magnesium transporter gene TRPM6 (c.2667+1G>A), causing familial hypomagnesemia. Based on the third variant, a stop variant in ABCG5 (p.(Arg446*)), we established a diagnosis of sitosterolemia, confirmed by elevated blood plant sterol levels and successfully initiated targeted lipid-lowering treatment. We propose that blended phenotypes resulting from several concomitant single-gene disorders in the same patient likely account for a proportion of presumed monogenic disorders of currently unknown cause and contribute to variable genotype-phenotype correlations.

Topics: Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 5; Consanguinity; Female; Humans; Hypercholesterolemia; Hypothyroidism; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Magnesium Deficiency; Male; Mutation; Pedigree; Phenotype; Phytosterols; RNA Splicing; Thyroglobulin; TRPM Cation Channels; Young Adult

Topics: Biomarkers; Blood Platelets; Child; Erythrocytes, Abnormal; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipids; Male; Phytosterols

ATP binding cassette (ABC) transporters play critical roles in maintaining sterol balance in higher eukaryotes. The ABCG5/ABCG8 heterodimer (G5G8) mediates excretion of neutral sterols in liver and intestines. Mutations disrupting G5G8 cause sitosterolaemia, a disorder characterized by sterol accumulation and premature atherosclerosis. Here we use crystallization in lipid bilayers to determine the X-ray structure of human G5G8 in a nucleotide-free state at 3.9 Å resolution, generating the first atomic model of an ABC sterol transporter. The structure reveals a new transmembrane fold that is present in a large and functionally diverse superfamily of ABC transporters. The transmembrane domains are coupled to the nucleotide-binding sites by networks of interactions that differ between the active and inactive ATPases, reflecting the catalytic asymmetry of the transporter. The G5G8 structure provides a mechanistic framework for understanding sterol transport and the disruptive effects of mutations causing sitosterolaemia.

Topics: Adenosine Triphosphatases; Amino Acid Sequence; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Binding Sites; Biocatalysis; Crystallography, X-Ray; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Bilayers; Lipid Metabolism, Inborn Errors; Lipoproteins; Models, Molecular; Molecular Sequence Data; Nucleotides; Phytosterols; Protein Folding; Protein Multimerization; Protein Structure, Tertiary; Sterols

Whole exome sequencing (WES) technologies have accelerated genetic studies of Mendelian disorders, yielding approximately 30% diagnostic success. We encountered a 13-year-old Japanese female initially diagnosed with familial hypercholesterolemia on the basis of clinical manifestations of severe hypercholesterolemia (initial LDL cholesterol=609 mg/dl at the age of one) and systemic intertriginous xanthomas with histories of recurrent self-limiting episodes of fever and arthritis. Both her phenotypes seemed to co-segregate in a recessive manner. We performed WES on this patient, who was considered a proband. Among 206,430 variants found in this individual, we found 18,220 nonsense, missense, or splice site variants, of which 3,087 were rare (minor allele frequency ≤ 0.01 or not reported) in 1000 Genome (Asian population). Filtering by assuming a recessive pattern of inheritance with the use of an in silico annotation prediction tool, we successfully narrowed down the candidates to the compound heterozygous mutations in the ABCG5 gene (c.1256G＞A or p.Arg419His/c.1763-1G＞A [splice acceptor site]) and to the double-compound heterozygous mutations in the MEFV gene (c.329T＞C/C or p.Leu110Pro/c.442G＞C/C or p.Glu148Val). The patient was genetically diagnosed with sitosterolemia and familial Mediterranean fever using WES for the first time. Such a comprehensive approach is useful for identifying causative mutations for multiple unrelated inheritable diseases.

Topics: Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 5; Cholesterol, LDL; Computational Biology; Exome; Familial Mediterranean Fever; Female; Genome, Human; High-Throughput Nucleotide Sequencing; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Phytosterols; Polymerase Chain Reaction; Polymorphism, Single Nucleotide

A young girl, age 8.5 years, presented with profound hypercholesterolemia and early xanthomatosis, suggesting homozygous familial (or type II) hypercholesterolemia. The patient's low density lipoprotein (LDL) receptor function and parental lipoprotein profiles were determined to be normal, prompting revision of the initial diagnosis to pseudohomozygous familial hypercholesterolemia. When she subsequently presented with giant platelets, the case was presented to colleagues on an electronic mailing list. It was recommended that plasma and sterol analysis be performed, which led to a diagnosis of sitosterolemia. The presentation of profound hypercholesterolomia in childhood that ultimately is not attributed as due to homozygous or compound heterozygous defects in the LDL receptor gene has been termed pseudohomozygous familial (or type II) hypercholesterolemia (PHT2HC). Patients diagnosed with PHT2HC subsequently confirmed to have sitosterolemia have been previously reported only rarely. The challenge of achieving accurate specific diagnosis and appropriate workup for these conditions in children is discussed in the context of this rare case and review of the historical literature concerning these conditions.

Topics: Blood Platelets; Child; Diagnosis, Differential; Female; Homozygote; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Receptors, LDL; Sterols; Treatment Outcome; Xanthomatosis

Sitosterolemia is a very rare autosomal recessive lipoprotein metabolic disorder caused by homozygous or compound heterozygous mutations in one of the two adenosine triphosphate-binding cassette transporter genes, ABCG5 and ABCG8. Sitosterolemia is clinically characterized by xanthomas and atherosclerosis, arthritis, fever, hemolysis and macrothrombocytopenia even in early childhood. We described a 16-month-old girl, who had numerous yellowish-brown intertriginous xanthomas along the skin creases on the extremities with severe hypercholesterolemia and elevated plant sterol levels. Histopathologically, xanthoma showed aggregation of foam cells in the dermis with a zone of mucin deposits in the dermal papilla. Electron microscopy showed numerous membrane-bound lipid droplets and multivesicular lipid bodies in the foam cells, a round cell containing lipid droplets in the basal cell layer and abundant mucin deposits just beneath the basal lamina. Diagnosis of sitosterolemia was confirmed by DNA sequencing showing compound heterozygosity for previously reported missense mutations in exon 9 of ABCG5. Infants presenting with multiple xanthomas should be investigated for sitosterolemia, if there is no family history of dyslipidemia.

Topics: Female; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Skin; Xanthomatosis

Topics: Abdominal Pain; Amish; Anticholesteremic Agents; Azetidines; Biopsy; Diagnosis, Differential; Ezetimibe; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Predictive Value of Tests; Retroperitoneal Fibrosis; Retroperitoneal Space; Tomography, X-Ray Computed; Treatment Outcome; Xanthomatosis; Young Adult

Topics: Child, Preschool; Female; Hematologic Diseases; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Xanthomatosis

The consumption of plant sterols is associated with a decrease in LDL cholesterol. However, it is also associated with an increase in plasma plant-sterol (sitosterol, campesterol) levels that may be detrimental. Indeed, the genetic disease sitosterolaemia, which is characterized by elevated plasma levels of plant sterol, is associated with premature atherosclerosis. Yet, although plasma plant-sterol levels are recognized markers of cholesterol absorption, the relationship between such levels and atherosclerosis is not clear. Several studies have analysed the association between plasma plant-sterol levels and cardiovascular disease (CVD), but have found conflicting results. Although the largest prospective trials and genome-wide association studies suggest that high plasma levels of plant sterols are associated with increased CV risk, other studies have reported no such association and even an inverse relationship. Thus, the available data cannot confirm an increased CV risk with plant sterols, but cannot rule it out either. Only a prospective interventional trial to analyse the effects of plant-sterol-enriched food on the occurrence of CV events can exclude a potential CV risk linked with their consumption.

Topics: Animals; Cardiovascular Diseases; Epidemiologic Studies; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Mice; Phytosterols; Plaque, Atherosclerotic; Risk Factors

Topics: Adult; Blood Cell Count; Erythrocytes, Abnormal; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Leukocytes, Mononuclear; Lipid Metabolism, Inborn Errors; Phytosterols

Sitosterolemia (phytosterolemia) is a rare inherited sterol storage disorder, characterized by significantly elevated plasma levels of plant sterols. The clinical features of sitosterolemia are xanthomas, premature atherosclerosis, arthritis, and, occasionally, liver function impair and hematologic abnormalities. This disorder is caused by mutations of ABCG5/ABCG8 genes. We report here the clinical, laboratory, and molecular genetic features of 13 patients with sitosterolemia from eight unrelated families who had specific hematologic problems of macrothrombocytopenia, hemolytic anemia, and splenomegaly besides the major clinical manifestations. The peripheral blood films showed some unique features: large platelets surrounded by a circle of vacuoles, and various abnormal erythrocyte shapes, especially stomatocyte. According to these distinct changes of blood cell morphology, we identified two sitosterolemia patients who lacked the classical clinical phenomena. All the patients had been misdiagnosed with immune thrombocytopenia (ITP), Evans syndrome, or secondary ITP with delay being 28.8 years between symptom onset and correct diagnosis. These results indicate that sitosterolemia is certainly not as rare as originally thought. The phenomena of macrothrombocytopenia/hemolysis might represent a new platelet disorder. Plasma plant sterols and ABCG5/ABCG8 genes should be analyzed when such hematologic abnormalities are unexplained.

Topics: Adult; Anemia, Hemolytic, Congenital; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Blood Platelets; Cell Shape; Cholesterol; Delayed Diagnosis; Diagnostic Errors; DNA Mutational Analysis; Erythrocytes, Abnormal; Exons; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Osmotic Fragility; Pedigree; Phenotype; Phytosterols; Prevalence; Purpura, Thrombocytopenic, Idiopathic; Splenectomy; Splenomegaly; Thrombocytopenia; Vacuoles; Xanthomatosis

Phytosterolemia is a rare autosomal recessive sterol storage disease caused by mutations in ABCG5 and ABCG8 genes. A 9-year-old Turkish boy who was presented with exclusively hematologic abnormalities had elevated plant sterol levels. Sequencing of ABCG5 and ABCG8 genes revealed a novel homozygous IVS10-1 G>T mutation in ABCG5 gene. Four of the 13 family members had xanthoma but they had neither hematologic abnormalities nor IVS10-1 G>T mutation. Ezetimibe therapy reduced plant sterol levels in association with marked clinical improvement. Plant sterol levels and ABCG5/ABCG8 genes should be analysed in patients with unexplained hemolytic anemia and macrothrombocytopenia.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Azetidines; Child; Ezetimibe; Hematologic Diseases; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Phytosterols; Point Mutation

Phytosterolemia is a rare autosomal recessive disorder characterized by dramatically elevated circulating levels of plant sterols (PS). Phytosterolemia is believed to be responsible for severe premature atherosclerosis. The clinical, biological and molecular genetic features of 5 patients with phytosterolemia and transient severe hypercholesterolemia challenge this hypothesis.. Our patients were referred for suspected homozygous familial hypercholesterolemia. Despite the phenotype, this diagnosis was invalidated and phytosterolemia was confirmed by the identification of mutations in the ABCG5/ABCG8 transporter complex. Plasma PS were analyzed with a mass spectrometric-gas chromatographic procedure. Vascular status was assessed with carotid ultrasonography and completed (for 4 of the 5 patients) with femoral ultrasonography; additional examinations of cardiovascular status included a stress test, determination of coronary calcium score, echocardiography, non-invasive assessment of endothelium-dependent dilatation and coronarography.. The 5 patients displayed markedly elevated levels of both β-sitosterol and campesterol (15-30 fold higher than normal values). However, none displayed significant signs of infraclinical premature atherosclerosis (respectively at the ages of 32, 27, 29, 11 and 11 years). All patients were characterized by very high levels of total (>450 mg/dl) and LDL-cholesterol (>350 mg/dl) at diagnosis which decreased markedly on dietary intervention alone. Treatment with cholestyramine or Ezetimibe ± atorvastatin normalized cholesterol levels, although plasma PS concentrations remained elevated.. The clinical and biological characteristics of our patients, considered together with reports of cases which equally lack CVD, support the contention that the premature atherosclerosis associated with phytosterolemia in some patients may be due at least in part to mechanisms independent of elevated circulating phytosterol levels.

Topics: Adolescent; Adult; Age Factors; Atherosclerosis; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Retrospective Studies; Severity of Illness Index; Young Adult

Sitosterolaemia is caused by mutations in either ABCG5 or ABCG8. Chinese and Japanese individuals usually have mutations in ABCG5. We herein report a known and a novel mutation in ABCG8 and their potential interaction with NPC1L1 polymorphisms in a Chinese family with sitosterolaemia. We sequenced ABCG5 and ABCG8 and measured the levels of plasma plant sterols in a 15-year-old Chinese girl with clinical sitosterolaemia (xanthomas with elevated low-density lipoprotein cholesterol (LDL-C) and plant sterols) and her apparently healthy family members. NPC1L1 was sequenced in the genetically affected sibling and other family members. A known mutation, c.490C＞T (p. Arg164(＊)), in exon 4 and a novel mutation, c.1949T＞G (p.Leu650Arg), in exon 13 of ABCG8 were detected in the proband and her sister, who had elevated sterols but low LDL-C levels and no xanthomas. The genetically affected sister, but not the proband, carried two additional heterozygous changes in NPC1L1 (rs2072183 C＞G, rs2301935 A＞C), which were inherited from the mother, who also had a low LDL-C level. In this study, we detected a known and a novel mutation in ABCG8 in a Chinese patient with sitosterolaemia. The same mutations were found in her clinically normal sister, suggesting that the contrasting features with the proband may be related to different variants in NPC1L1 and/or some other undetermined lipid-related genetic factors.

Topics: Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; China; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Membrane Proteins; Membrane Transport Proteins; Mutation; Pedigree; Phytosterols; Polymerase Chain Reaction; Polymorphism, Genetic; Prognosis; Sitosterols

Increased serum concentrations of plant sterols, including stigmasterol, during parenteral nutrition (PN) have been linked with serum biochemical signs of intestinal failure-associated liver disease (IFALD), whereas clinical data on their correlation to histologic liver injury have been limited.. We studied interrelations between serum noncholesterol sterols and histologic liver injury in pediatric-onset intestinal failure (IF).. Serum plant sterols (stigmasterol, avenasterol, sitosterol, and campesterol), cholestanol, and cholesterol precursors (cholestenol, lathosterol, and desmosterol) were measured in 50 IF patients at a median age 7.3 y and in 86 matched controls. Forty patients underwent liver biopsies. Sixteen patients had been receiving PN for 45 mo, and 34 patients had received PN for 9.1 mo but had not received PN for 5.4 y.. Serum plant sterols were higher in patients who were currently receiving PN than in controls and were related to conjugated bilirubin (r = 0.799-0.541, P < 0.05). During PN, the ratio of serum stigmasterol to cholesterol was 3.3-fold higher in patients with portal inflammation, and the ratio of avenasterol to cholesterol was 3.9-fold higher in patients with cholestasis (P < 0.05 for both). Ratios of stigmasterol and avenasterol to cholesterol were correlated with portal inflammation (r = 0.549-0.510, P < 0.05), cholestasis (r = 0.501-0.491, P = 0.048-0.053), and serum bile acids (r = 0.591-0.608, P < 0.05). The median (IQR) ratio of serum cholestanol to cholesterol was higher during (269 100× μg/mg cholesterol; 203-402 100× μg/mg cholesterol) than after (175 100× μg/mg cholesterol; 156-206 100× μg/mg cholesterol; P < 0.001) weaning off PN and was correlated with cholestasis (r = 0.428), portal inflammation (r = 0.511), and fibrosis (r = 0.323, P < 0.05 for all). After weaning off PN, ratios of cholestenol and lathosterol to cholesterol were >2-fold higher in patients with persistent liver steatosis than in those without steatosis or controls (P < 0.01 for all), whereas lathosterol was correlated with the steatosis grade (r = 0.320, P < 0.050).. Increased serum stigmasterol and avenasterol concentrations parallel the portal inflammation and cholestasis during PN, thereby reinforcing their contribution to IFALD. A bile acid malabsorption-driven increase in cholesterol synthesis underpins persistent liver steatosis after weaning off PN. Serum cholestanol reflects liver injury in IF patients.

Topics: Adolescent; Bile Acids and Salts; Body Mass Index; Body Weight; Child; Child, Preschool; Cholestanol; Cholesterol; Cross-Sectional Studies; Female; Humans; Intestinal Diseases; Intestines; Liver Diseases; Male; Parenteral Nutrition; Phytosterols; Prospective Studies; Stigmasterol

Sitosterolemia is a rare, autosomal recessive disease caused by mutations in the adenosine triphosphate-binding cassette transporter genes ABCG5 or ABCG8 that result in accumulation of xenosterols in the body. Clinical manifestations include tendon xanthomas, premature coronary artery disease, hemolytic anemia, macrothrombocytopenia, and bleeding. Although the effect of sterol accumulation on the predisposition for atherosclerosis is evident, how xenosterol accumulation leads to defects in platelet physiology is unknown. Sitosterolemia induced in Abcg5- and Abcg8-deficient mice fed a high plant sterol diet resulted in accumulation of free sterols in platelet plasma membranes, leading to hyperactivatable platelets characterized by constitutive binding of fibrinogen to its αIIbβ3 integrin receptor, internalization of the αIIbβ3 complex, generation of platelet-derived microparticles, and changes in the quantity and subcellular localization of filamin. The latter was associated with macrothrombocytopenia, shedding of GPIbα, impaired platelet adhesion to von Willebrand factor, and inability to form stable thrombi. Plasma levels of soluble GPIbα were strongly correlated with plasma sitosterol levels in samples from human sitosterolemic patients, implicating a similar mechanism of sterol-induced platelet passivation in the human disease. Intercalation of plant sterols into the plasma membrane therefore results in dysregulation of multiple platelet activation pathways, leading to macrothrombocytopenia and bleeding.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Blood Platelets; Disease Models, Animal; Fibrinogen; Filamins; Hemorrhage; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Phenotype; Phytosterols; Platelet Activation; Platelet Glycoprotein GPIIb-IIIa Complex

Topics: Animals; Blood Platelets; Hemorrhage; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Phytosterols; Platelet Activation

The present paper focuses on clinical issues concerning the psychopharmacological treatment of severe forms of post-traumatic stress disorder (PTSD).Using a case study, we discuss problems in this field against the background of psychodynamic and psychotraumatological theories. We also present strategies for the appropriate use of psychotropic drugs in the psychotherapy of PTSD.

Topics: Adoption; Adult; Child; Child Abuse; Child Abuse, Sexual; Child, Abandoned; Combined Modality Therapy; Countertransference; Drug Substitution; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Phytosterols; Projection; Psychoanalytic Theory; Psychotherapy, Psychodynamic; Psychotropic Drugs; Somatoform Disorders; Stress Disorders, Post-Traumatic

To determine whether long-term exposure to moderate elevations in plasma plant sterol levels increases risk for atherosclerosis.. In Old Order Amish participants aged 18 to 85 years, with (n=110) and without (n=181) 1 copy of the ABCG8 G574R variant, we compared mean plasma levels of plant sterols and cholesterol precursors and carotid intima-media wall thickness. Carriers of a single 574R allele had increased plant sterol levels (eg, 35%-37% higher plasma levels of sitosterol, campesterol, and stigmasterol) and increased plant sterol/cholesterol ratios (P<0.001 for all). 574R carriers had significantly decreased levels of lathosterol and lanosterol, precursors in a pathway for endogenous cholesterol synthesis, suggesting that plant sterols may alter regulation of genes involved in cholesterol synthesis. The G574R variant was not associated with high-density lipoprotein cholesterol or low-density lipoprotein cholesterol levels. Compared with noncarriers, 574R carriers had decreased carotid intima-media wall thickness (0.62 versus 0.66 mm; age- and sex-adjusted P=0.03). Adjustment for body weight, blood pressure, and standard lipid measures (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides) did not alter this association.. Although the G574R variant is associated with moderately elevated plant sterol levels, carriers of the 574R allele had modestly lower levels of carotid wall thickness compared with noncarriers.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amish; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Biomarkers; Carotid Artery Diseases; Carotid Intima-Media Thickness; Case-Control Studies; Female; Gene Frequency; Genetic Predisposition to Disease; Genetic Variation; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Pennsylvania; Phenotype; Phytosterols; Risk Assessment; Risk Factors; Up-Regulation; Young Adult

We prospectively evaluated incidence of prolonged (>28 days) parenteral nutrition (PN), associated complications, and significance of parenteral plant sterols (PS) in neonatal intestinal failure-associated liver disease (IFALD) compared with children.. We recruited 28 neonates (mean age 50 days, range 28-126) and 11 children (6.9 y, 2.1-16.6) in all of Finland. Patients underwent repeated measurements of serum cholesterol, noncholesterol sterols, including PS, cholestanol and cholesterol precursors, and liver biochemistry during and 1 month after discontinuation of PN. Healthy matched neonates (n=10) and children (n=22) served as controls.. IFALD occurred more frequently among neonates (63%) than children (27%; P<0.05). Ratios of serum PS, including stigmasterol, sitosterol, avenasterol, and campesterol, and total PS were increased among neonates compared with healthy controls and children on PN by 2- to 22- and 2- to 5-fold (P<0.005), respectively. Neonates with IFALD had significantly higher ratios of serum PS and cholestanol compared with neonates without IFALD (P<0.05). Total duration of PN associated with serum cholestanol, stigmasterol, avenasterol, alanine aminotransferase, and aspartate aminotransferase (r=0.472-0.636, P<0.05). Cholestanol and individual serum PS, excluding campesterol, reflected direct bilirubin (r=0.529-0.688, P<0.05). IFALD persisted after discontinuation of PN in 25% of neonates with 4.2- and 2.2-times higher ratios of serum stigmasterol and cholestanol compared with neonates without IFALD (P<0.05).. Frequent occurrence of IFALD among neonates on PN displays an association to duration of PN and markedly increased serum PS, especially stigmasterol, in comparison to healthy neonates and children on PN. Striking accumulation of parenteral PS may contribute to IFALD among neonates.

Topics: Adolescent; Age Factors; Alanine Transaminase; Aspartate Aminotransferases; Bilirubin; Child; Child, Preschool; Cholestanol; Cholesterol; Dietary Fats; Fat Emulsions, Intravenous; Female; Finland; Humans; Infant; Infant, Newborn; Intestinal Diseases; Liver Diseases; Male; Olive Oil; Parenteral Nutrition; Phytosterols; Plant Oils; Prevalence; Prospective Studies; Soybean Oil; Stigmasterol

Phytosterolemia is a rare autosomal recessive disease of plant sterol metabolism, the pathophysiological features of which are high plasma levels of plant sterols and xanthomatosis caused by mutations of ABCG5 and ABCG8 genes, and the combination of hemolysis and macrothrombocytopenia is an unusual clinical manifestation. All the patients of the 3 unrelated phytosterolemia first presented with prominent macrothrombocytopenia and stomatocytosis. They were either homozygous or compound heterozygous for ABCG5/ABCG8 gene mutations and had significantly elevated serum plant sterols levels quantified using high-performance liquid chromatography. The in vitro study demonstrated that sitosterol can cause changes in shape and osmotic fragility of red blood cells. These findings suggest that macrothrombocytopenia and stomatocytosis could be initial and main features in some patients with phytosterolemia and that serum phytosterols and relevant genes should be analyzed in patients whose macrothrombocytopenia and/or stomatocytosis are unexplained, especially whose parents are of consanguineous marriage.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Erythrocytes, Abnormal; Female; Heterozygote; Homozygote; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mutation; Osmotic Fragility; Pedigree; Phytosterols; Sitosterols; Xanthomatosis

Topics: Acid-Base Imbalance; Anemia, Hemolytic, Congenital; Erythrocytes, Abnormal; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Metabolism, Inborn Errors; Middle Aged; Phytosterols; Thrombocytopenia

Phytosterolemia is an inherited disorder characterized by hypercholesterolemia and premature atherosclerosis, together with increased inflammatory states in some cases. The underlying mechanisms of atherogenesis in phytosterolemia, however, have not been completely elucidated. In this study, we investigated whether phytosterols would affect inflammatory reactions in macrophages and macrophage cell lines.. We incubated RAW264.7 cells (RAW) and mouse peritoneal macrophages (MPMs) with sitosterol (Sito), campesterol (Camp) or cholesterol (Chol) at low (8 µM, 16 µM) or high (160 µM) concentrations, and investigated their effects on LPS-induced secretion of IL-6 and TNF-α. We also analyzed their effects on endoplasmic reticulum (ER) stress in both cells, and on the cell proliferation of RAW.. At low sterol concentrations, only Chol resulted in a tendency toward the increased secretion of TNF-α from MPMs. At high concentrations, Chol induced a significant increase in TNF-α secretions from both cells; however, Sito resulted in a non-significant increase in TNF-α secretion. The effects on IL-6 secretions of Sito were also significantly less than those of Chol. Camp increased the secretions of both cytokines from MPMs; however, the extent of these increases was less pronounced than that of Chol. Augmentation of ER stress was greatest with Chol among the sterols, and the proliferation of RAW cells was inhibited only with Chol.. The lesser degree of inflammatory reactions and toxicity in macrophages with phytosterols than with cholesterol suggests that plant sterols themselves might not be primarily responsible for atherogenesis in phytosterolemia.

Topics: Alternative Splicing; Animals; Cell Proliferation; Cells, Cultured; Cholesterol; DNA-Binding Proteins; Endoplasmic Reticulum; Hypercholesterolemia; Interleukin-6; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipopolysaccharides; Macrophage Activation; Macrophages; Mice; Phytosterols; Regulatory Factor X Transcription Factors; Transcription Factors; Tumor Necrosis Factor-alpha

Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition.

Topics: Affect; Animals; Anxiety Disorders; Atherosclerosis; ATP-Binding Cassette Transporters; Behavior, Animal; Brain; Cholesterol; Desmosterol; Diet; Hippocampus; Homeostasis; Hydroxycholesterols; Hypercholesterolemia; Intestinal Diseases; Lanosterol; Lipid Metabolism, Inborn Errors; Male; Maze Learning; Memory; Mice; Mice, Mutant Strains; Phytosterols; Sitosterols; Stigmasterol

Phytosterolemia is a rare autosomal recessive lipid storage disease. It is caused by mutations of ABCG5 and ABCG8 genes and characterized by the increased plasma levels of plant sterols. The common clinical manifestations include tendon and tuberous xanthomas and premature coronary heart disease; it has occasionally been associated with hematologic abnormalities.. We report a phytosterolemia patient presenting exclusively with macrothrombocytopenia and stomatocytic hemolysis and discuss its clinical significance.. The patient, aged 31 years, was born of a consanguineous marriage. He had epistaxis from childhood and underwent splenectomy because of thrombocytopenia, anemia and splenomegaly at the age of 9 years. His blood film showed prominent stomatocytes and macroplatelets. High performance liquid chromatography showed a grossly elevated level of phytosterols in the blood. The patient was confirmed to be a homozygote of missense mutation R419H in ABCG5.. We describe a phytosterolemia patient whose clinical manifestations were macrothrombocytopenia, stomatocytic hemolysis and splenomegaly, without the common features of this disorder. Our results suggest that blood cells could be a target for the toxic effect of plasma plant sterols, which should be measured in patients with unexplained stomatocytosis and/or macrothrombocytopenia in order to determine if they have phytosterolemia.

Topics: Adult; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Blood Platelets; Cell Size; Consanguinity; Erythrocytes, Abnormal; Hemolysis; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Mutation, Missense; Phytosterols; Splenomegaly; Thrombocytopenia

To study the clinical features and ABCG5/ABCG8 gene mutations of three pedigrees of phytosterolemia presented with macrothrombocytopenia and hemolysis.. Erythrocyte and platelet morphology were examined under light microscope. Plasma sterol levels were measured by high pressure/performance liquid chromatography method. All of ABCG5 and ABCG8 exons and intron-exon boundaries were directly sequenced to identify mutations, the corresponding gene mutation sites of three families members and healthy individuals were detected.. All the patients presented macrothrombocytopenia, hemolysis, splenomegaly and xanthomas. The blood smears showed large platelets, some as large as erythrocytes, and abnormal erythrocyte shapes, such as stomatocytes. Plasma concentrations of phytosterols, especially sitosterol were markedly elevated (30 fold) in the affected patients. Four mutations were identified in these three pedigrees, ABCG5 C20896T (R446X) and A20883G, ABCG8 del43683-43724 and del1938C-1939G/ins1938T. The latter three were novel mutations reported for the first time.. Phytosterolemia associated with macrothrombocytopenia and hemolysis is a new subtype of this disease. Plasma phytosterols and related gene analysis should be performed when ever an unexplained macrothrombocytopenia, especially combined with haemolysis or/and stomatocytosis.

Topics: Adult; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Blood Platelets; DNA Mutational Analysis; Erythrocytes, Abnormal; Female; Hemolysis; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Mutation; Pedigree; Phytosterols; Platelet Count; Thrombocytopenia

Mutations in ABCG5 or ABCG8 transporters are responsible for sitosterolemia, an autosomal recessive disease characterized by the accumulation of plant sterols. The aim of this study was to investigate the effects of ABCG5 and ABCG8 deficiency on TG metabolism in mice. Experiments were carried out in wild-type (G5/G8+/+) mice, mice heterozygous for ABCG5 and ABCG8 deficiency (G5/G8+/-) and ABCG5/G8-deficient (G5/G8-/-) mice fed a chow diet. Plasma TG were 2.6 and 4.3-fold higher in fasted G5/G8+/- and G5/G8-/- mice, respectively, than in G5/G8+/+ mice. Postprandial TG were 5-fold higher in G5/G8-/- mice. TG metabolism studies indicate that: first, the fractional catabolic rate was significantly lower in G5/G8+/- (1.3-fold) and G5/G8-/- mice (1.5-fold) compared to G5/G8+/+ and postheparin plasma lipoprotein lipase activities were significantly lower in G5/G8+/- (1.8-fold) and G5/G8-/- mice (5.4-fold) than in G5/G8+/+. Second, liver TG secretion was 1.3-fold higher in G5/G8+/- and G5/G8-/- than in G5/G8+/+ mice and this was associated with an increase in liver LXR, FAS, ACAC and CD36 gene expression. Third, TG intestinal secretion, determined after an oral fat gavage of glycerol tri[9,10(n)-(3)H] oleate, was 5.8-fold higher in G5/G8-/- than in G5/G8+/+ mice. Also, the HOMA index was 2.6-fold higher in G5/G8-/- than in G5/G8+/+ mice, reflecting a degree of insulin resistance. In conclusion, ABCG5/G8 deficiency in mice fed a chow diet markedly raises TG levels by impairing TG catabolism and by increasing liver and intestinal TG secretion.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Biological Transport; CD36 Antigens; fas Receptor; Fasting; Gene Expression; Heterozygote; Homozygote; Hypercholesterolemia; Hypertriglyceridemia; Intestinal Diseases; Intestinal Mucosa; Intestines; Lipid Metabolism, Inborn Errors; Lipoproteins; Liver; Liver X Receptors; Metabolic Networks and Pathways; Mice; Mice, Knockout; Orphan Nuclear Receptors; Phytosterols; Postprandial Period; Triglycerides