One of the most common hereditary bleeding disorders, it is estimated that 20,000 people in the United States have Hemophilia in either a mild, moderate or severe form.
The two most common types of hemophilia are: hemophilia A, which is the result of a deficiency in the clotting factor VIII , and hemophilia B, which is caused by a deficiency of clotting factor IX. Other less common coagulation disorders treated are FV, FVII, FX, FXI, FXII, and FXIII.
Hemophilia is an X-linked genetic disorder, in which the hemophilia gene is carried by females on one of their X chromosomes. Women who are carriers of hemophilia have one normal X-chromosome, and one X-chromosome with an abnormal copy of the hemophilia gene. A woman who carries the abnormal hemophilia gene has a 50% risk of passing the gene on to a future son, who would then have hemophilia. There is also a 50% risk of passing the hemophilia gene on to a daughter, who would then be a carrier.
In about one-third of all cases, there is no family history of the disease, and hemophilia occurs as the result of a new or spontaneous mutation.