Test Details: This test is used to determine genetic contribution to hyperhomocysteinemia for individuals with elevated plasma homocysteine. The common MTHFR gene variant c.677C>T may reduce MTHFR enzyme activity and contribute to a mild to moderate increase in plasma homocysteine concentrations. MTHFR testing may be considered to determine a genetic contribution to hyperhomocysteinemia, although treatment for this condition depends on plasma/urine homocysteine and the patient’s symptoms rather than the presence or absence of these MTHFR variants.