Laboratory Diagnosis of Congenital Factor V Deficiency, Routine, Specific Coagulation Tests with Molecular Methods

Congenital Factor V (FV) deficiency is a rare bleeding disorder that inherit in autosomal recessive manner. Diagnosis of FV deficiency (FVD) is made by routine coagulation tests, FV activity and molecular analysis. In patients with FVD, routine coagulation tests including activated partial thromboplastin time (APTT), prothrombin time (PT), and even bleeding time (BT) are prolonged while thrombin time (TT) is normal. FV activity assay can use for confirmation of diagnosis as well as for differential diagnosis with acquired forms of disease. Mixing study can be used for screening of inhibitor against FV. In this situation, addition of normal plasma cannot correct prolonged PT and PTT while in congenital FVD prolongation is corrected. Molecular diagnosis of FVD is straight forward but due to large size of FV gene and genetic variability molecular diagnosis is restricted to research laboratory.