Von Willebrand disease (VWD) is a common inherited bleeding disorder in the general population affecting males and females equally, but women may be disproportionately impacted due to the bleeding challenges of menstruation and childbirth. There are three main types of VWD (VWD type 1, VWD type 2, and VWD type 3) each with differing degrees of severity and inheritance patterns. Unlike hemophilia which is characterized by joint bleeding, VWD is typically characterized by mucocutaneous bleeding. VWD is caused by a defect or deficiency in von Willebrand Factor (VWF), a large protein made up of multiple subunits. VWF binds to clotting factor VIII in the circulation and protects it from being broken down. VWF also helps platelets bind to the inside of injured blood vessels. This leads to the formation of a stable blood clot which plugs an injured blood vessel and stops bleeding. If there is an insufficient quantity of VWF or if it is defective, an individual may have difficulty forming a blood clot. Most affected individuals have the relatively mild form of the disease, VWD type 1, and are not diagnosed until adulthood. A small percentage of these individuals may have prolonged bleeding during infancy or early childhood. Symptoms can include nosebleeds, bleeding from the gums, and easy bruising. In women with VWD, heavy menses frequently occurs. Affected individuals may bleed easily after injury, childbirth, and/or surgery. Bleeding from the stomach and intestines can occur but is less common.Introduction
VWD was first described in the medical literature in 1926 by Dr. Erik von Willebrand, who differentiated the disorder from classic hemophilia. In addition to the genetic form, VWD can be acquired during life, often in relation to a separate underlying condition. This report deals specifically with the genetic forms. VWD types 1 and 3 may also be referred to as partial quantitative deficiency or total quantitative deficiency, respectively, because they are associated with low levels or near complete absence of VWF. VWD type 2 may also be referred to as qualitative VWD because VWF is present in normal or near normal levels, but doesn't function properly. In recent years, the understanding of the genetic factors and biochemistry associated with VWD has advanced considerably, especially for types 2 and 3. However, many questions and controversies still remain regarding the diagnosis and definition of VWD type 1 (see Causes section below).