Hemophilia

Hemophilia is a blood-clotting disorder that causes prolonged bleeding.1 Blood contains coagulation factor proteins that help stop bleeding; people with hemophilia have low levels or no coagulation factor proteins. The lower the level of coagulation factor— they are numbered from I through XIII—the more serious the condition and the more likely it is that bleeding will occur without an obvious cause or after injury or surgery.2 Classic hemophilia is an inherited blood disorder, whereas acquired hemophilia is a rare condition caused by the production of autoantibodies in adult life.3,4 Acquired hemophilia is most frequently associated with inactive coagulation factor VIII proteins.4

Hemophilia occurs in 1 of every 5,000 male births. About 400 babies are born with hemophilia each year. Approximately 20,000 men in the United States are living with  hemophilia.2 The incidence of acquired hemophilia has been estimated to be 0.2 to 1.0 case per 1 million individuals per year in the United States, but because of difficulty in diagnosis, the incidence may be much higher. Unlike classic hemophilia, acquired hemophilia has no known genetic inheritance pattern and occurs equally in men and women.3 Acquired hemophilia usually...