Diagnosis and management of factor V Leiden.

INTRODUCTION: The discovery of the factor V Leiden (FVL) missense mutation (Arg506Gln) causing factor V resistance to the anticoagulant action of activated protein C was a landmark that allowed a better understanding of the basis of inherited thrombotic risk. FVL mutation is currently the most common known hereditary defect predisposing to venous thrombosis. Areas covered: Novel data-driven FVL diagnosis and therapeutic approaches in the management of FVL carriers in various clinical settings. Brief conclusions on topics of direct clinical relevance including currently available indications for primary and secondary prophylaxis, the management of female, pediatric carriers and asymptomatic relatives. Latest evidence on the association between FVL and cancer, as well as the possible use of direct oral anticoagulant therapy. Expert commentary: Although FVL diagnosis nowadays is highly accurate, many doubts remain regarding the best management and therapeutic protocols. The main role of clinicians is to tailor therapeutic strategies to carriers and their relatives. High familial penetrance, distinctive aspects of the first thrombotic event (provoked/unprovoked, age, etc.) and laboratory biomarkers can guide the optimal management of secondary antithrombotic prophylaxis, primary prophylaxis in asymptomatic individuals, and whether to screen relatives.