Which of the following feature may be used to differentiate hemophilia A from von Willebrand disease
Bleeding time
Prothrombin time
Paial thromboplastin time
Factor VIII levels
Answer is A (Bleeding time) : Bleeding time is prolonged in von Willebrand disease, but normal in Hemophilia A Both conditions present with decreased levels of factor VIII normal PT and elevated PTT and hence these features cannot be used to differentiate between hemophilia A and von Willebrand disease. Features of VWF and differences with Haemophilia A Feature Hemophilia A Von Willebrand Disease Inheritance Sex linked Autosomal (Most common is A.dominant) Factor VIIIc Decreased Decreased VWF Normal Decreased Ristocetin cofactor Normal Decreased Common Presentation Features of clotting disorder Skin/Mucosal bleeding -- Hemahrosis ++ Features of bleeding disorder +- clotting disorder Skin/Mucosal bleeding + Hemohrosis+ Bleeding Time Normal Prolonged APTT Prolonged Prolonged (may be normal) PT Normal Normal Thrombin Time Normal Normal Fibrinogen Normal Normal Platelet aggregation in Response to Ristocetin Normal Decreased