Methylenetetrahydrofolate reductase polymorphism (C677T), hyperhomocysteinemia, and risk of ischemic cardiovascular disease and venous thromboembolism: … (original) (raw)

MTHFR3 is a critical enzyme regulating the metabolism of folate and methionine , both of which are important factors in DNA methylation and synthesis. MTHFR irreversibly converts 5,10-meth ylenetetrahydrofolate to 5.methyltetrahydrofolate, the primary methyl donor for the remethylation of homocysteine to methionine. A com mon 677Câ€"*T (Alaâ€"*Val) mutation of the gene was found to enhance the thermolability of the enzyme , and the variant homozygous genotype is associated with elevation in plasma homocysteine levels (7), decrease in plasma 5-methyltetrahydrofolate levels (8), as well as risk of spina bifida (9).