von Willebrand disease in the developing world.

von Willebrand disease (VWD) is considered to be the most common inherited bleeding disorder. Data on its epidemiology and impact in developing countries are limited. The biologic heterogeneity and variable presentation of VWD make diagnosis difficult. Although there is no accurate estimate of the prevalence of VWD in developing countries, available data suggest that the proportion of diagnosed cases is lower than the expected number, often accounting for only 6% to 13% of patients with hereditary bleeding disorders. Although accurate subtyping is often not possible, the number with severe disease tends to be much higher, particularly in those parts of the world where consanguinity is common. Agents used to treat patients with VWD range from plasma to purified factor concentrates. Desmopressin (DDAVP) is commonly used. Preliminary data on molecular genetics suggests that there are significant population differences. There is inadequate awareness of this condition and lack of support for these patients from the health care system in many developing countries. Concerted efforts are needed at the scientific and social levels to improve this situation.