A 9-year-old boy with recurrent hemarthroses has isolated prolonged aPTT that corrects on 1:1 mixing with normal plasma. Factor IX activity is 3%. Which statement about this disorder is correct?

• A It is called von Willebrand disease and is autosomal dominant
• B It is called Christmas disease and is X-linked recessive ✓
• C It is called Rosenthal syndrome and is autosomal recessive
• D It is called Stuart-Prower defect and is autosomal recessive

Explanation

Hemophilia A, historically called Christmas disease after the first described patient Stephen Christmas, results from factor IX deficiency and is inherited as an X-linked recessive trait like hemophilia B. Rosenthal syndrome refers to factor XI deficiency, an autosomal recessive condition common in Ashkenazi Jews. Stuart-Prower defect is factor X deficiency, which prolongs both PT and aPTT.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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