von Willebrand disease (VWD) is the most common inherited bleeding disorder, with an estimated prevalence of 0.6 to 1.3% in the general population.1, 2However, the proportion of patients with symptomatic VWD who require treatment is rare, with a prevalence of 23 to 113 per million population, or up to 1 in 1,000 in certain clinical settings.3, 4VWD is caused by a deficiency or dysfunction of von Willebrand factor (VWF).5, 6VWF is essential for primary hemostasis as it mediates platelet adhesion to the subendothelium at sites of vascular injury. The gene discussed is VWF; the disease is platelet-type von Willebrand disease.