A 4-year-old boy has easy bruising since learning to walk, hemarthroses, and prolonged bleeding after dental extraction. His maternal uncle has a similar condition. Laboratory investigations: PT normal, aPTT markedly prolonged, bleeding time normal, platelet count normal. Mixing study corrects the aPTT. Factor VIII assay: 2% (severely reduced). What is the mode of inheritance and treatment of choice for acute bleeds?

• A X-linked recessive; treat with recombinant factor VIII concentrate ✓
• B Autosomal recessive; treat with fresh frozen plasma
• C X-linked dominant; treat with DDAVP
• D Autosomal dominant; treat with cryoprecipitate

Explanation

This is Hemophilia A (factor VIII deficiency), characterized by prolonged aPTT with normal PT and bleeding time, affecting males and transmitted through carrier females (X-linked recessive). The family history of a similarly affected maternal uncle confirms X-linked inheritance. Severe disease is defined as factor VIII activity less than 1% (here 2%, severe-moderate). The treatment of choice for acute hemorrhagic episodes is recombinant factor VIII concentrate, which is safer (no blood-borne infection risk) and more effective than cryoprecipitate or FFP. DDAVP is used only in mild-moderate hemophilia A.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.