The MTHFR gene provides instructions for making an enzyme called methylenetetrahydrofolate reductase - a key enzyme in the folate metabolism pathway which regulates DNA methylation, synthesis, and repair. Polymorphisms in the MTHFR gene have been studied as possible risk factors for a variety of common conditions. These include heart disease, stroke, hypertension, high blood pressure during pregnancy, glaucoma, psychiatric disorders, and certain types of cancer.
Low plasma folate and its derivatives have been linked with depressive disorders in studies dating back over 30 years. A recent study showed that the T variant of MTHFR C677T was significantly more common in people with a history of depressive disorder, even with normal levels of folate, homocysteine and vitamin B12. 2
folate, homocysteine, vitamin B12, C677T