Coagulation Disorders USMLE Step 1 Practice Question
A 30-year-old woman with three recurrent first-trimester miscarriages presents with left leg swelling and pain. Vital signs show BP 118/76, HR 92, RR 16, Temp 37°C, SpO2 98%. Duplex ultrasound confirms left femoral deep venous thrombosis. Laboratory studies reveal prolonged activated partial thromboplastin time (aPTT 48 seconds) that does not correct with normal plasma mixing. Platelet count is normal at 250,000/μL. She denies prior thrombotic events or anticoagulant use. Which diagnosis best explains these findings?
Answer choices
- AAntiphospholipid antibody syndromeCorrect answer
- BVitamin K deficiency
- CVon Willebrand disease
- DDisseminated intravascular coagulation
- EHemophilia A
- FFactor V Leiden mutation
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