Coagulation Disorders USMLE Step 1 Practice Question
A 19-year-old previously healthy man presents with acute bilateral leg pain, cyanosis of his feet, and gangrene developing within hours. Laboratory studies show a platelet count of 150,000/μL, PT 13 seconds, aPTT 38 seconds, and fibrinogen 280 mg/dL. He has no personal or family history of thrombosis. Which of the following is the most likely diagnosis?
Answer choices
- AAntiphospholipid syndrome
- BFactor V Leiden heterozygosity
- CProthrombin G20210A mutation
- DDisseminated intravascular coagulation
- EProtein C deficiency (acute phase)Correct answer
- FProtein S deficiency (acquired)
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