Epidemiology
VWD is the most common inherited bleeding disorder, affecting 66 to 100 people per million of the general population, if patient referral for clinical manifestations is used as the basis for diagnosis.[3] Laboratory studies have suggested a prevalence of VWD as high as 1%, although the clinical significance of this finding is unclear and many such patients are asymptomatic. von Willebrand factor (VWF) levels are on average 30% lower in blood group O people than in those with non-O blood group. The disorder is transmitted in an autosomal pattern, although there is variable penetrance and expressivity. Males and females are affected equally, but because of the prominent symptom of menorrhagia, adolescent and adult women are more often diagnosed. VWF levels are higher in black people than in white people.[4] The diagnosis of VWD is less common in developing countries. This is likely to be due to lack of medical resources. The most common form of VWD is type 1, which constitutes approximately 75% of cases.[5] Severe (type 3) VWD accounts for only 5% of cases and has an overall prevalence of 1 to 3 per million of the general population, but is relatively more common in countries or regions where consanguineous relationships are accepted.[6] The remaining 20% is composed of the type 2 variants.[1]
Use of this content is subject to our disclaimer