von Willebrand disorder

von Willebrand factor has important functions in haemostasis linking platelets to the vessel wall and protecting FVIIIC. Reductions in quantity or functional activity can predispose to bleeding. Moderate and severe reductions in von Willebrand factor are generally caused by von Willebrand factor gene mutations (autosomal inheritance), but borderline values may be related to other factors such as blood group (perhaps ‘disorder’ rather than ‘disease’). The overall haemostatic balance of an individual determines bleeding risk which should be assessed by a thorough bleeding history including a scoring system. Appropriate testing should be performed in a haemophilia centre and routine screening tests are often normal. Family history may be helpful in children who have never had a haemostatic challenge. In addition to education, several strategies are available for treatment.