Hemophilia is a rare hereditary disorder in which the blood does not clot normally, caused when one or more clotting factors (substances in the blood that help form a clot) are missing. The types of hemophilia disorders include hemophilia A, hemophilia B and von Willebrand disease.
- Hemophilia A
Hemophilia A, also known as factor VIII deficiency or classic hemophilia, is the most common type of hemophilia. In most cases, it is an inherited disorder in which one of the proteins needed to form blood clots is missing or reduced. In about 30% of cases, there is no family history of the disorder and the condition is the result of a spontaneous gene mutation.
Standard treatment involves replacing the missing clotting factor. The amount of factor VIII concentrates needed depends on how severe the bleeding is, the site of the bleeding, and the size of the patient .
- Hemophilia B
Hemophilia B, sometimes known as Christmas disease, is a less common form of hemophilia, much rarer than hemophilia A. A hereditary disorder, it is caused by a deficiency of blood plasma protein called factor IX, without which the blood cannot clot properly.
Hemophilia B is typically treated by infusing factor IX concentrates to replace the defective clotting factor. The amount infused depends upon the severity of bleeding, the site of the bleeding, and the size of the patient .
- Von Willebrand Disease (VWD)
Although referred to as a single disease, von Willebrand disease (VWD) is in fact a family of bleeding disorders caused by an abnormality of the von Willebrand factor (VWF). A congenital bleeding disorder characterized by a lifelong tendency toward easy bruising, frequent epistaxis, and menorrhagia, von Willebrand disease is the most common hereditary bleeding disorder.
The two main treatment options for patients with VWD are DDAVP and infusion of plasma-derived factor VIII (FVIII) concentrates that contain von Willebrand factor in high molecular weight.