Von Willebrand's disease is caused by congenital deficiency of vWF, a protein cofactor essential for normal platelet adhesion and for the transport of Factor VIII. Bleeding time is prolonged, platelets show reduced adhesion and levels of Factor VIII are low. Inheritance is autosomal, usually dominant, but in the severe forms it may be recessive.
The severity of the bleeding tendency is variable. Most patients are mildly or moderately affected but some may present like severe haemophilia.
Aspirin should be avoided.