Summary
Hemophilia A, also known as classical hemophilia, is a genetic bleeding disorder caused by insufficient levels of a blood protein called factor VIII. Factor VIII is a clotting factor. Clotting factors are specialized proteins that are essential for proper clotting, the process by which blood clumps together to plug the site of a wound to stop bleeding. Individuals with hemophilia A do not bleed faster or more profusely than healthy individuals, but because their blood clots poorly, they have difficulty stopping the flow of blood from a wound. This may be referred to as prolonged bleeding or a prolonged bleeding episode. Hemophilia A can be mild, moderate or severe, depending on the baseline level of factor VIII made by that individual. In mild cases, prolonged bleeding episodes may only occur after surgery, dental procedures or trauma. In more severely affected individuals, symptoms may include prolonged bleeding from minor wounds, painful swollen bruises and unexplained (spontaneous) bleeding into vital organs as well as joints and muscles (internal bleeding).
Hemophilia A is caused by disruptions or changes (variants) to the F8 gene located on the X chromosome. A variant may be inherited or occur randomly with no previous family history of the disorder (spontaneously). Hemophilia A is mostly expressed in males but some females who carry a gene variant may have mild or, rarely, severe symptoms of bleeding. Although there is no cure for hemophilia, effective therapies have been developed; most affected individuals can lead full, productive lives by maintaining proper treatment and care.
Introduction
Hemophilia is a general term for a group of rare bleeding disorders caused by congenital deficiency of certain clotting factors. The most common form of hemophilia is hemophilia A. In rare cases, hemophilia A can be acquired during life (acquired hemophilia A) because of an autoantibody to factor VIII. Although both disorders involve deficiency of the same clotting factor, the bleeding pattern is quite different. The reason the bleeding patterns differ between these disorders is not fully understood. This report discusses the genetic form of hemophilia A.
