Factor V Leiden mutation: the most commonly inherited risk factor for venous thromboembolism

Factor V Leiden mutation is a common genetic risk factor for venous thrombosis. It has been documented in up to 65% of patients with unexplained venous thromboembolism. This genetic mutation is now known to be the most common inherited cause of activated protein C (APC) resistance. Recently, FV Leiden mutation has been associated with adverse pregnancy outcomes (including recurrent fetal loss, severe preeclampsia, placental abruption, intrauterine growth restriction and stillbirth), in addition to venous thromboembolic disorders. In this article, we discuss the genetic basis, diagnosis and clinical significance of FV Leiden mutation. Awareness of the clinical manifestations associated with FV Leiden mutation should ensure screening of appropriate populations and prophylaxis against thromboembolic disease when indicated.