No association between methylenetetrahydrofolate reductase C677T polymorphism and breast cancer.

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme (EC 1.5.1.20), that reduces 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a carbon donor for the homocysteine to methionine conversion. MTHFR is a keyenzyme that regulates folate metabolism which has an important role in DNA synthesis, DNA repair and methylation