Coagulation Disorders USMLE Step 1 Practice Question
A 31 year old woman presents with unilateral leg swelling 2 weeks after starting an estrogen containing oral contraceptive. Her mother had multiple deep venous thromboses. Coagulation studies are normal. Genetic testing reveals a mutation that makes factor V resistant to inactivation. Which of the following proteins normally inactivates factor V?
Answer choices
- AFactor VII
- BAntithrombin
- CPlasmin
- DVon Willebrand factor
- EActivated protein CCorrect answer
- FProtein S
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