What is it?

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme that breaks down the amino acid homocysteine. When this enzyme’s gene is mutated, its function is interfered with and there is too much of it. There can be two variants of the mutations and a person can be either homozygous or heterozygous to the mutation, depending on whether he got the mutated gene from both of his parents or only from one of them. High levels of homocysteine may result in congenital anomalies, mental health conditions, and certain types of cancer.