USMLE-Rx Step 1 Qmax Challenge #1372

Check out today’s Step 1 Qmax Question Challenge.

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A 10-year-old boy is brought to the emergency department after falling from his bicycle. He presents with a large, painfully swollen knee; aspiration shows gross hemarthrosis. On further questioning, the patient’s parents say that he bruises easily and that it took several days for the bleeding to completely stop after losing a tooth 1 month ago. His maternal uncle had similar bleeding difficulties. After further testing, the patient is diagnosed with an X-linked recessive disorder.

Which of the following laboratory test results corresponds to the patient’s disorder?

A. A
B. B
C. C
D. D
E. E

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