FACTOR V LEIDEN MUTATION IS A POINT MUTATION THAT CAUSES RESISTANCE OF FACTOR V DEGRADATION BY ACTIVATED PROTEIN C. THIS MUTATION IS ASSOCIATED WITH INCREASED RISK OF VENOUS THROMBOSIS. THIS ASSAY IS USED IN PATIENTS WITH CLINICALLY SUSPECTED THROMBOPHILIA AND FAMILY HISTORY OF FACTOR V LEIDEN MUTATION.

THE PROTHROMBIN G20210A MUTATION IS THE SECOND MOST COMMON INHERITED PREDISPOSITION TO HYPERCOAGULABILITY. HETEROZYGOUS PROTHROMBIN G20210A MUTATION IS ASSOCIATED WITH A 2 TO 6 FOLD INCREASED LIFETIME RELATIVE RISK OF VTE. THIS RISK IS FURTHER INCREASED IN COMBINATION WITH PREGNANCY AND OCP USE.

HOMOZYGOUS MUTATION FOR MTHFR (METHYLENETETRAHYDROFOLATE REDUCTASE) IS ASSOCIATED WITH HYPERHOMOCYSTEINEMIA WHICH IS AN INDEPENDENT RISK FACTOR FOR STROKE, MI, PERIPHERAL ARTERIAL DISEASE AND VENOUS THROMBOSIS. INDIAN STUDIES SUGGEST THAT HETEROZYGOSITY FOR MTHFR C677T IS ALSO ASSOCIATED WITH ELEVATED HOMOCYSTEINE LEVELS. THIS ASSAY DETECTS BOTH C677T AND A1298C MUTATION.