B. Autosomal dominant – Explanation

Although type 3 von Willebrand disease is actually autosomal recessive, majority of von
Willebrand’s disease is autosomal dominant.

Von Willebrand disease
The 3 important points you need to know in Von Willebrand disease in PLAB is:
1. It presents with mucosal bleeding → Epistaxis, menorrhagia (behaves like a platelet
disorder)
2. AAutosomal dominant (type 3 is recessive)
3. Role of Von Willebrand’s factor is:
a. Promotes platelet aggregation
b. Carrier molecule for factor VIII

Investigation
• Bleeding time → prolonged
• APTT → prolonged
• Factor VIII levels may be moderately reduced
• Defective platelet aggregation with ristocetin

Management
• Tranexamic acid for mild bleeding
• Desmopressin (DDAVP): raises levels of vWF by inducing release of vWF
• Factor VIII concentrate

Comparing the 3 important bleeding disorders in PLAB