A newborn presents with umbilical cord bleeding. Laboratory tests show: PT markedly prolonged, aPTT markedly prolonged, thrombin time prolonged, platelet count normal, fibrinogen level undetectable, and bleeding time prolonged. Which inheritance pattern applies to this condition?

• A Autosomal dominant
• B Autosomal recessive ✓
• C X-linked recessive
• D Mitochondrial

Explanation

Afibrinogenemia is autosomal recessive. Absent fibrinogen prolongs PT, aPTT, thrombin time, and bleeding time (since fibrinogen is needed for both clot formation and platelet aggregation). Hemophilia A and B are X-linked recessive, and von Willebrand disease is usually autosomal dominant.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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