Snapshot A 30-year-old Caucasian man presents with sudden shortness of breath. He denies any recent long train or plane rides, but endorses a history of multiple DVTs. A Doppler ultrasound shows a small DVT in his left calf. His complete blood count is normal. His PT and PTT are also normal. He is started on LMWH with the intention of bridging to warfarin. A few days later, his activated protein C resistance assay comes back positive for a factor V Leiden mutation. Overview Introduction Hypercoagulable state/thrombophilia from mutated factor V Epidemiology Most common cause of inherited hypercoagulable states Most common in Caucasians etiology Pathogenesis login to view 6 more bullets Genetics login to view 4 more bullets Presentation Symptoms/physical exam login to view 8 more bullets STUDIES Normal PT/PTT Differential Diagnosis Protein C/S deficiency Malignancy HIT Antiphospholipid syndrome Antithrombin deficiency login to view 2 more bullets Diagnosis Activated protein C resistance assay (factor V Leiden specific functional assay) if positive, confirm with DNA testing Treatment Prevention login to view 3 more bullets If thrombosis login to view 1 more bullet If pregnant, give thromboprophylaxis login to view 2 more bullets Long-term antithrombotic therapy not recommended Complications Miscarriage Thrombosis Prognosis Mortality not affected