Methylenetetrahydrofolate Reductase (MTHFR) Genotyping

General Use: 

The MTHFR (Methylenetetrahydrofolate Reductase) enzyme catalyzes the formation of 5-methyltetrahydrofolate, the major circulating form of active folate. Absence of active folate leads to accumulation of plasma homocysteine. The 677 C>T polymorphism of MTHFR leads to decreased MTHFR enzymatic activity and elevated homocysteine. The 1298 A>C polymorphism is associated with significant increases in plasma homocysteine levels only when in combination with the 677 C>T polymorphism. Elevated plasma homocysteine has been shown to be a risk factor for atherosclerotic heart disease, myocardial infarction, cerebrovascular disease, and venous thrombosis. Additionally, associations between the 677 C>T polymorphism and increased risk for methotrexate toxicity, increased chemosensitivity of colon and breast cancers to 5-fluorouracil, and increased risk of fetal neural tube defects in pregnant women have also been reported, although these associations remain controversial.

Limitations: 

Other genetic variants of the MTHFR gene that are not detected in the assay may influence MTHFR enzymatic activity. Other genetic and non-genetic factors may also influence plasma folate and homocysteine levels, and the balance of proper coagulation.

Methodology: 

Real-time polymerase chain reaction with fluorescence detection.