angiotensinogen and Cardiomyopathy--Hypertrophic

Some studies have reported that angiotensin converting enzyme (ACE) and angiotensinogen (AGT) genes have been associated with hypertrophic cardiomyopathy (HCM). However, there have been inconsonant results among different studies. To clarify the influence of ACE and AGT on HCM, a systemic review and meta-analysis of case-control studies were performed. The following databases were searched to indentify related studies: PubMed database, the Embase database, the Cochrane Central Register of Controlled Trials database, China National Knowledge Information database, and Chinese Scientific and Technological Journal database. Search terms included "hypertrophic cardiomyopathy", "angiotensin converting enzyme" (ACE) or "ACE" and "polymorphism or mutation". For the association of AGT M235T polymorphism and HCM, "angiotensin converting enzyme" or "ACE" was replaced with "angiotensinogen". A total of seventeen studies were included in our review. For the association of ACE I/D polymorphism and HCM, eleven literatures were included in the meta-analysis on association of penetrance and genotype. Similarly, six case-control studies were included in the meta-analysis for AGT M235T. For ACE I/D polymorphism, the comparison of DI/II genotype vs DD genotype was performed in the present meta-analysis. The OR was 0.73 (95% CI: 0.527, 0.998, P = 0.049, power = 94%, alpha = 0.05) after the study which deviated from Hardy-Weinberg Equilibrium was excluded, indicating that the ACE I/D gene polymorphism might be associated with HCM. The AGT M235T polymorphism did not significantly affect the risk of HCM. In addition, ACE I/D gene polymorphism did not significantly influence the interventricular septal thickness in HCM patients. In conclusion, the ACE I/D polymorphism might be associated with the risk of HCM.

Topics: Angiotensinogen; Cardiomyopathy, Hypertrophic; Case-Control Studies; Gene Frequency; Genotype; Humans; Odds Ratio; Peptidyl-Dipeptidase A; Polymorphism, Genetic; Risk Factors

The renin-angiotensin (RAS) pathway has an important role in the etiology of heart failure and given the importance of RAS as a therapeutic target in various cardiomyopathies, genetic polymorphisms in the RAS genes may modulate the risk and severity of disease in cardiomyopathy patients. In the present study, we examined the association of RAS pathway gene polymorphisms, angiotensin converting enzyme (ACE), angiotensinogen (AGT), and angiotensin receptor type 1 (AGTR1) with risk and disease severity in Asian Indian idiopathic cardiomyopathy patients. The case-control study was conducted in 400 cardiomyopathy patients diagnosed with HCM, DCM, or restrictive cardiomyopathy (RCM) and 235 healthy controls. Genotyping of patients and controls was done by PCR-RFLP assays. Left ventricular wall thickness and left ventricular ejection fraction were measured by means of M-mode echocardiography. We observed significantly higher prevalence of ACE DD and AGTR1 1166CC genotypes in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) patients. Also, 235TT genotype of AGT (M235T) was significantly associated with enhanced risk of the disease phenotype in HCM, DCM, and RCM.

Topics: Adult; Angiotensinogen; Cardiomyopathy, Dilated; Cardiomyopathy, Hypertrophic; Female; Humans; Male; Middle Aged; Peptidyl-Dipeptidase A; Polymorphism, Restriction Fragment Length; Receptor, Angiotensin, Type 1; Renin-Angiotensin System

Variations of angiotensinogen (AGT) gene have been associated with cardiac hypertrophy. We hypothesized that AGT gene polymorphism may play a modifier role in the diversity of left ventricular outflow obstruction.. The polymorphisms of the AGT gene were genotyped in 225 patients with hypertrophic cardiomyopathy (HCM) and 243 age-and sex-matched healthy controls. The effect of the A and G alleles on the expression of the reporter gene were evaluated in vitro using dual-luciferase reporter assays.. Our results showed that the frequency of the A allele was higher in patients than in controls (50.2 % vs. 35.8 %, p < 0.05). Patients carrying the AA and AG genotypes had a higher proportion of left ventricular outflow obstruction (30.1 % vs. 17.0 %, p < 0.05) and heart failure (NYHA functional class III ~ IV, 35.4 % vs. 18.8 %, p < 0.05) than those carrying the GG genotype had. After adjusted for age, sex, the thickness of the interventricular septum, family history of HCM, and sudden death, the A allele conferred a 2.4-fold risk for left ventricular outflow obstruction than the GG genotype did (adjusted OR = 2.4, 95 %CI 1.2-4.8). The G allele suppressed the expression of the reporter gene significantly compared with the A allele (p < 0.05).. AGT gene variations may be genetic modifiers for the development of HCM.

Topics: Adult; Angiotensinogen; Cardiomyopathy, Hypertrophic; China; Comorbidity; Female; Genetic Markers; Genetic Predisposition to Disease; Genetic Variation; Humans; Male; Polymorphism, Single Nucleotide; Prevalence; Risk Factors; Ventricular Outflow Obstruction

Hypertrophic cardiomyopathy (HCM) is a complex disorder and genetically transmitted cardiac disease with a diverse clinical course. The objective of the present study was to examine the association of the T704C polymorphism of exon 2 of the angiotensinogen (AGT) gene with HCM in a South Indian population from Andhra Pradesh. Subjects and methods. One-hundred and fifty HCM (90 sporadic hypertrophic cardiomyopathy [SHCM] and 60 familial hypertrophic cardiomyopathy [FHCM]) patients and 165 age- and sex-matched normal healthy controls without known hypertension and left ventricular hypertrophy were included in the study. DNA was isolated from peripheral leukocytes and the region of interest in the AGT gene bearing a missense mutation methionine to threonine substitution at codon 235 (M235T) of exon 2, was amplified by polymerase chain reaction (PCR). The PCR products were subjected to restriction digestion with the enzyme SfaNI.. Significant differences were detected in genotypic distribution (p = 0.04) as well as the allelic frequency (p = 0.003) between the SHCM patients and controls. The polymorphism did not show any association with FHCM.. Our results suggest that the T allele of the AGT gene is significantly associated with SHCM in a South Indian population from Andhra Pradesh. However, we did not find significant association of this polymorphism with FHCM.

Topics: Amino Acid Substitution; Angiotensinogen; Cardiomyopathy, Hypertrophic; Case-Control Studies; Female; Gene Frequency; Genetic Predisposition to Disease; Genotyping Techniques; Humans; India; Male; Middle Aged; Polymorphism, Single Nucleotide

To evaluate the influence of the angiotensinogen(AGT) gene M235T variant on the prevalence and severity of hypertrophic cardiomyopathy(HCM).. The authors conducted a case-control study on 152 subjects, including 72 HCM patients and 80 normal controls. Polymerase chain reaction(PCR) combined with restriction fragment length polymorphism(RFLP) was used to detect the M235T variant of AGT gene. Interventricular septum thickness, left ventricular posterior wall thickness and apical wall thickness were measured by means of M-mode echocardiography under two-dimensional guidance in the parasternal long-axis plane and apical two- and four-chamber views.. (1) The genotype distributions of AGT gene in both groups were in agreement with Hardy-Weinberg equilibrium. (2) The genotype distributions of the M235T variant differed significantly in HCM patients and controls(chi-square=6.090 P<0.05). The frequencies of TT genotype and T235 allele in HCM patients were higher than did the patients in controls(TT genotype 0.63 vs 0.45 OR=2.037 95%CI 1.064-7.899 P<0.05 T235 allele 0.78 vs 0.64 OR=1.990 95%CI 1.197-3.308 P<0.01). (3)The patients with the TT genotype had significantly greater mean left ventricular maximal wall thickness than did the patients with the MM and MT genotypes [(19.1+/-4.8) mm vs(15.3+/-2.6)mm and(16.2+/-5.1)mm F=4.261 P<0.05].. The variant M235T of the AGT gene is significantly associated with HCM in this population. The genotype TT or allele T might be a genetic risk factor for the development and extent of hypertrophy in HCM patients.

Topics: Adult; Aged; Angiotensinogen; Cardiomyopathy, Hypertrophic; Female; Genotype; Humans; Male; Middle Aged; Polymorphism, Genetic

Hypertrophic cardiomyopathy (HCM) has a great variability in its morphofunctional expression. This study analyzes whether angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) gene polymorphisms modulate the phenotypic expression in Spanish patients with HCM.. Forty Spanish HCM patients were studied. Twenty-six out of these 40 patients belonged to 7 families with familial HCM, and the remaining 14 patients had either a sporadic HCM or a HCM with unknown family incidence. A group of 269 healthy subjects was included as control for the genotype study. Maximal wall thickness, ventricular mass and several diastolic function indexes were measured in each patient by Doppler-echocardiography. The insertion/deletion (I/D) polymorphism of ACE gene and the M235T polymorphism of AGT gene were studied in both patients and healthy subjects.. A higher frequency in patients than in controls was found for D allele (0.79 vs 0.64; p = 0.02) and for DD genotype (62.5 vs 41.2%; p = 0.02). Conversely, no difference was observed in M235T polymorphism between both groups. Neither DD genotype of ACE, nor TT genotype of AGT determined a greater degree of ventricular hypertrophy or a worse diastolic function in patients with HCM.. D allele and DD genotype are predisposing factors to express HCM. In this series of Spanish patients, I/D polymorphism of ACE and M235T polymorphism of AGT do not modify phenotypic expression of HCM.

Topics: Adolescent; Adult; Aged; Angiotensinogen; Base Sequence; Cardiomyopathy, Hypertrophic; DNA Probes; Echocardiography, Doppler; Female; Gene Expression Regulation, Enzymologic; Genotype; Humans; Male; Middle Aged; Molecular Sequence Data; Peptidyl-Dipeptidase A; Phenotype; Polymerase Chain Reaction; Polymorphism, Genetic; Spain

To examine the contribution of the renin-angiotensin system to hypertrophic cardiomyopathy (HCM), we studied 96 patients with HCM (mean age 50 years, 55% male), 105 of their unaffected siblings and offspring, and 160 healthy subjects without known hypertension and left ventricular hypertrophy (LVH) who were frequency matched to cases by age and sex. Patients were divided into familial or sporadic HCM (FHCM or SHCM) groups with or without affected members of their family. The region of interest in the angiotensinogen (AGT) gene, the missense mutation with methione-to-threonine amino acid substitution at codon 235 in angiotensinogen (M235T), was amplified by polymerase chain reaction with the use of allele-specific oligonucleotide primers flanking the polymorphic region of the AGT gene to amplify template deoxyribonucleic acid prepared from peripheral leukocytes. The T allele frequency was higher in the SHCM group than in unaffected siblings and offspring (88% vs 78%, X2 = 4.6, p < 0.05). The M allele frequency was higher in unaffected siblings and offspring than in patients with SHCM (23% vs 12%, X2 = 4.6, p < 0.05). The T allele frequency among unaffected siblings and offspring was similar to that observed in healthy subjects (78% vs 78%). We conclude that HCM, especially in sporadic cases, is partially determined by genetic disposition. The molecular variant of angiotensinogen T235 seems to be a predisposing factor for cardiac hypertrophy in HCM and carries an approximately twofold increased risk.

Topics: Adult; Alleles; Angiotensinogen; Base Sequence; Cardiomyopathy, Hypertrophic; DNA Primers; Female; Gene Frequency; Genotype; Humans; Japan; Male; Middle Aged; Molecular Sequence Data; Mutation; Phenotype; Polymerase Chain Reaction; Polymorphism, Genetic

The phenotypic expression of left ventricular hypertrophy (LVH) in patients with hypertrophic cardiomyopathy (HCM) is variable. This phenotypic variability is not completely explained by the responsible mutations or other known factors. Recent data denote a role for the modifier genes and environmental factors. We studied the role of 3 potential modifier genes, i.e., angiotensinogen (AGT), angiotensin II receptor 1a (AT1a), and endothelin-1 (END1) on the phenotypic expression of LVH in patients with hypertrophic cardiomyopathy (HCM).. The study population was comprised of 108 genetically independent patients with HCM. Left ventricular mass index (LVMI) and LVH score were determined per published protocols. The genotypes of AGT (M235T, T174M, and G-6A), AT1a, and END1 were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or mutation-specific PCR (MS-PCR).. Male patients had higher mean LVMI and LVH score than female patients (146.0 +/- 33.5 vs 129.4 +/- 33.6, p = 0.01 and 6.0 vs 5.0, p = 0.010, respectively). Gender accounted for 4.8% and 5.4% of the variability of LVMI and LVH score, respectively. The END1 genotypes also had a significant influence on LVH scores accounting for 2.9% of their variability (p = 0.042). The median LVH score was greater in patients with the AA and AG genotypes, as compared to patients with the GG genotype (7.0 vs 5.0, p = 0.034). Neither the AGT nor the AT1 genotypes had a significant influence on the expression of LVH. In multivariate regression analysis, END1 and gender accounted for 7.3% of the variability of the LVH score (p = 0.007).. Our results show that gender and the END1 gene modify the phenotypic expression of hypertrophy in patients with HCM.

Topics: Adult; Angiotensinogen; Cardiomyopathy, Hypertrophic; DNA Primers; Endothelin-1; Female; Gene Expression; Genotype; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Phenotype; Polymerase Chain Reaction; Polymorphism, Genetic; Receptors, Angiotensin; Sex Characteristics

We demonstrated that phosphatidylinositide-specific phospholipase C (PLC) activity was greater in cardiomyopathic hamster hearts (BIO 14.6 and BIO 53.58) then in hamster controls (F1b). Inositol trisphosphate (IP3) production was markedly greater in both of the cardiomyopathic hamsters, BIO 14.6 and BIO 53.58. We have also determined the sarcoplasmic reticulum (SR) function of heart. Calcium uptake into SR markedly increased in BIO 14.6. On the other hand, it significantly decreased in BIO 53.58 compared with F1b. It is well known that IP3 stimulates calcium release from SR. In BIO 14.6, calcium release from SR stimulated by IP3 increased, but its effect decreased in BIO 53.58 compared with F1b. These results suggest that PI response may produce high intracellular calcium levels in both BIO 14.6 and BIO 53.58 myocytes. In addition, in the BIO 53.58 hamster the sarcoplasmic reticulum deteriorate in function. It was concluded from these results that a prolonged high intracellular calcium level may lead to the death of BIO 53.58 myocytes. The expression of angiotensinogen mRNA was observed in the hamster heart. There was no differences in its expression level between F1b, BIO 14.6 and BIO 53.58. There was no effect of ages on its expression in these hamster hearts. We have also determined the distribution of angiotensinogen in these hamsters. At 4 weeks of age, the immunohistochemical study revealed that angiotensinogen was widely distributed in subendocardium in these hamsters. There was no difference in its distribution between F1b, BIO 14.6 and BIO 53.58. But at 20 weeks old of age its immunoreactivity decreased in BIO 53.58.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Angiotensinogen; Animals; Calcium; Cardiomyopathy, Hypertrophic; Cricetinae; Immunohistochemistry; Male; Mesocricetus; Myocardium; Phosphatidylinositols; Renin-Angiotensin System; RNA, Messenger; Sarcoplasmic Reticulum; Second Messenger Systems; Type C Phospholipases