5-methyltetrahydrofolate and Epilepsy

Epilepsia dependiente de piridoxina por deficiencia en el gen PNPO.

Topics: Adolescent; Brain Diseases, Metabolic; Chromosomes, Human, Pair 17; Epilepsy; Female; Humans; Hypoxia-Ischemia, Brain; Mutation, Missense; Polymorphism, Single Nucleotide; Pyridoxaminephosphate Oxidase; Pyridoxine; Seizures; Tetrahydrofolates; Uniparental Disomy

Folate metabolism in the brain is critically important and serves a number of vital roles in nucleotide synthesis, single carbon metabolism/methylation, amino acid metabolism, and mitochondrial translation. Genetic defects in almost every enzyme of folate metabolism have been reported to date, and most have neurological sequelae. We report 2 patients presenting with a neurometabolic disorder associated with biallelic variants in the MTHFS gene, encoding 5,10-methenyltetrahydrofolate synthetase. Both patients presented with microcephaly, short stature, severe global developmental delay, progressive spasticity, epilepsy, and cerebral hypomyelination. Baseline CSF 5-methyltetrahydrolate (5-MTHF) levels were in the low-normal range. The first patient was treated with folinic acid, which resulted in worsening cerebral folate deficiency. Treatment in this patient with a combination of oral L-5-methyltetrahydrofolate and intramuscular methylcobalamin was able to increase CSF 5-MTHF levels, was well tolerated over a 4 month period, and resulted in subjective mild improvements in functioning. Measurement of MTHFS enzyme activity in fibroblasts confirmed reduced activity. The direct substrate of the MTHFS reaction, 5-formyl-THF, was elevated 30-fold in patient fibroblasts compared to control, supporting the hypothesis that the pathophysiology of this disorder is a manifestation of toxicity from this metabolite.

Topics: Amino Acid Transport Systems, Acidic; Antiporters; Brain; Carbon-Nitrogen Ligases; Epilepsy; Female; Folate Receptor 1; Hereditary Central Nervous System Demyelinating Diseases; Humans; Male; Metabolic Diseases; Microcephaly; Mitochondrial Diseases; Nervous System Malformations; Neuroaxonal Dystrophies; Psychomotor Disorders; Tetrahydrofolates

We describe neurotransmitter abnormalities in two patients with drug-resistant epilepsy resulting from deleterious de novo mutations in sodium channel genes. Whole exome sequencing identified a de novo SCN2A splice-site mutation (c.2379+1G>A, p.Glu717Gly.fs*30) resulting in deletion of exon 14, in a 10-year old male with early onset global developmental delay, intermittent ataxia, autism, hypotonia, epileptic encephalopathy and cerebral/cerebellar atrophy. In the cerebrospinal fluid both homovanillic acid and 5-hydroxyindoleacetic acid were significantly decreased; extensive biochemical and genetic investigations ruled out primary neurotransmitter deficiencies and other known inborn errors of metabolism. In an 8-year old female with an early onset intractable epileptic encephalopathy, developmental regression, and progressive cerebellar atrophy, a previously unreported de novo missense mutation was identified in SCN8A (c.5615G>A; p.Arg1872Gln), affecting a highly conserved residue located in the C-terminal of the Nav1.6 protein. Aside from decreased homovanillic acid and 5-hydroxyindoleacetic acid, 5-methyltetrahydrofolate was also found to be low. We hypothesize that these channelopathies cause abnormal synaptic mono-amine metabolite secretion/uptake via impaired vesicular release and imbalance in electrochemical ion gradients, which in turn aggravate the seizures. Treatment with oral 5-hydroxytryptophan, l-Dopa/Carbidopa, and a dopa agonist resulted in mild improvement of seizure control in the male case, most likely via dopamine and serotonin receptor activated signal transduction and modulation of glutamatergic, GABA-ergic and glycinergic neurotransmission. Neurotransmitter analysis in other sodium channelopathy patients will help validate our findings, potentially yielding novel treatment opportunities.

Topics: Autistic Disorder; Channelopathies; Child; Drug Resistant Epilepsy; Epilepsy; Exome; Female; Homovanillic Acid; Humans; Hydroxyindoleacetic Acid; Male; Muscle Hypotonia; Mutation, Missense; NAV1.2 Voltage-Gated Sodium Channel; NAV1.6 Voltage-Gated Sodium Channel; Neurotransmitter Agents; Receptors, Dopamine; Seizures; Sequence Analysis, DNA; Sodium Channels; Tetrahydrofolates

Analysis of pyridoxal 5'-phosphate (PLP) concentration in 256 cerebrospinal fluid (CSF) samples from patients with neurological symptoms showed that the variance is greater than indicated by previous studies. The age-related lower reference limit has been revised to detect inborn errors of metabolism that lead to PLP depletion without a high false positive rate: < 30 days, 26 nmol/L; 30 days to 12 months, 14 nmol/L; 1-2 years, 11 nmol/L; > 3 years, 10 nmol/L. Inborn errors leading to PLP concentrations below these values include pyridoxine-dependent epilepsy due to antiquitin deficiency, and molybdenum cofactor deficiency that leads to the accumulation of sulfite, a nucleophile capable of reacting with PLP. Low PLP levels were also seen in a group of children with transiently elevated urinary excretion of sulfite and/or sulfocysteine, suggesting that there may be other situations in which sulfite accumulates and inactivates PLP. There was no evidence that seizures or the anticonvulsant drugs prescribed for patients in this study led to significant lowering of CSF PLP. A small proportion of patients receiving L-dopa therapy were found to have a CSF PLP concentration below the appropriate reference range. This may have implications for monitoring and treatment. A positive correlation was seen between the CSF PLP and 5-methyl-tetrahydrofolate (5-MTHF) and tetrahydrobiopterin (BH(4)) concentrations. All are susceptible to attack by nucleophiles and oxygen-derived free-radicals, and CSF has relatively low concentrations of other molecules that can react with these compounds. Further studies of CSF PLP levels in a wide range of neurological diseases might lead to improved understanding of pathogenesis and possibilities for treatment.

Topics: Adolescent; Adult; Biopterins; Child; Child, Preschool; Cysteine; Epilepsy; False Positive Reactions; Female; Free Radicals; Humans; Infant; Infant, Newborn; Levodopa; Male; Metabolism, Inborn Errors; Middle Aged; Nervous System Diseases; Oxygen; Pyridoxal Phosphate; Reference Values; Reproducibility of Results; Sulfites; Tetrahydrofolates

Cerebral folate deficiency (CFD) is increasingly recognized in various neurological conditions, raising the question of whether it might represent a clear-cut clinical syndrome.. Retrospective analysis of patients with low cerebral spinal fluid (CSF) 5-methyltetrahydrofolate (5MTHF) values was performed.. 58 pediatric patients with low (-2nd to -3rd standard deviation) and 45 patients with very low 5MTHF values (<3rd standard deviation) were identified, including 22 patients with defined underlying neurological conditions. The leading symptoms were mental retardation (n=84), motor retardation (n=75), epilepsy (n=53), ataxia (n=44) and pyramidal tract signs (n=37). There was no relationship between 5MTHF levels and the severity of clinical disease, the duration of clinical disease, distinct neurological symptoms and antiepileptic drug treatment, respectively. Genetical analysis for mutations in the folate receptor 1 gene proved normal in all 16 children studied.. For the majority of patients CFD is not a clear-cut neurometabolic syndrome but the common result of different genetic, metabolic or unknown processes. Nevertheless, CFD may represent a treatable disease-modifying factor which should therefore be addressed in prospective studies.

Topics: Abnormalities, Multiple; Adolescent; Ataxia; Child; Child, Preschool; Epilepsy; Female; Folic Acid Deficiency; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Pyramidal Tracts; Retrospective Studies; Syndrome; Tetrahydrofolates; Young Adult

We studied seven children with CNS folate deficiency (CFD). All cases exhibited psychomotor retardation, regression, cognitive delay, and dyskinesia; six had seizures; four demonstrated neurological abnormalities in the neonatal period. Two subjects had profound neurological abnormalities that precluded formal behavioral testing. Five subjects received ADOS and ADI-R testing and met diagnostic criteria for autism or autism spectrum disorders. They exhibited difficulties with transitions, insistence on sameness, unusual sensory interests, and repetitive behaviors. Those with the best language skills largely used repetitive phrases. No mutations were found in folate transporter or folate enzyme genes. These findings demonstrate that autistic features are salient in CFD and suggest that a subset of children with developmental regression, mental retardation, seizures, dyskinesia, and autism may have CNS folate abnormalities.

Topics: Adolescent; Autistic Disorder; Brain; Child; Child, Preschool; Developmental Disabilities; Dyskinesias; Epilepsy; Female; Folic Acid; Folic Acid Deficiency; Humans; Infant; Infant, Newborn; Intellectual Disability; Male; Pregnancy; Psychomotor Disorders; Reference Values; Regression, Psychology; Tetrahydrofolates

Cerebral folate deficiency (CFD) has been described as a neurological syndrome associated with low 5-methyltetrahydrofolate (5-MTHF) values in cerebrospinal fluid (CSF) with normal folate concentrations in plasma. Our aim was to analyse CSF 5-MTHF concentrations in a paediatric control population and in patients with various neurological disorders.. We studied plasma and CSF samples from 63 paediatric controls (age range: 2 days to 18 years, average: 3.8 years) and from 165 patients (age range: 1 day to 22 years, average: 5.0 years) with severe epileptic encephalopathies of unknown origin, movement disorders, Rett syndrome and mitochondrial diseases. CSF 5-methyltetrahydrofolate was analysed by reverse phase HPLC with fluorescence detection (excitation: 295 nm and emission: 355 nm).. A negative correlation between 5-MTHF values and age of controls was observed (r=-0.468; p<0.0001) and reference values were therefore stratified into 3 age groups. Regarding patients, 122 out of 165 showed normal CSF 5-MTHF values while 43 showed decreased values ranging from profound to mild deficiencies. Increased CSF total protein values were associated with the presence of low 5-MTHF concentrations (chi(2)=7.796; p=0.005).. The application of this method has been useful for the establishment of reference values and for diagnosis of CFD in paediatric patients. Furthermore, increased CSF total protein concentrations should be considered as a marker of a possible CFD.

Topics: Adolescent; Child; Child, Preschool; Chromatography, High Pressure Liquid; Epilepsy; Fluorescence; Humans; Mitochondrial Diseases; Movement Disorders; Nervous System Diseases; Reference Values; Rett Syndrome; Tetrahydrofolates

Topics: Electroencephalography; Epilepsy; Humans; Tetrahydrofolates

Topics: Animals; Blood-Brain Barrier; Brain; Cats; Epilepsy; Folic Acid; Tetrahydrofolates