Willebrandsyndrom

Willebrand syndrome is a hereditary bleeding disorder characterized by impaired blood clotting due to a deficiency or dysfunction of von Willebrand factor (VWF), a glycoprotein essential for platelet adhesion and coagulation. This condition is named after Erik Adolf von Willebrand, the Finnish physician who first described it in 1926. Willebrand syndrome is the most common inherited bleeding disorder, affecting approximately 1% of the general population, though many cases remain undiagnosed.

The disorder is classified into three main types based on genetic and clinical features: type 1, type 2, and type 3. Type 1, the mildest form, accounts for about 70% of cases and is caused by a quantitative deficiency of VWF. Symptoms may include prolonged bleeding after minor injuries, such as nosebleeds or excessive menstrual bleeding (menorrhagia). Type 2 involves qualitative abnormalities in VWF, leading to reduced clotting efficiency, while type 3 is the rarest and most severe form, characterized by near-complete absence of VWF, resulting in spontaneous bleeding episodes.

Diagnosis typically involves laboratory tests, including measurements of VWF antigen levels, VWF activity (ristocetin cofactor assay), and factor VIII levels. Genetic testing can confirm the underlying mutation in the *VWF* gene located on chromosome 12. Treatment depends on the severity of symptoms and may include desmopressin (DDAVP) for mild cases, which stimulates VWF release from endothelial cells. More severe cases may require replacement therapy with VWF-containing factor concentrates or recombinant VWF.

Management often involves avoiding aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), which can exacerbate bleeding. Patients with Willebrand syndrome should carry identification indicating their condition and receive appropriate medical advice before surgeries or dental procedures. While there is no cure, proactive management can significantly reduce bleeding complications and improve quality of life.