Hemophilia is a sex-linked inherited disorder in which the individual lacks the necessary blood-clotting factors to stop bleeding. The condition is transmitted via the X chromosome, but it is believed that some individuals are affected by hemophilia due to mutation of the genes on that chromosome. There are two forms of hemophilia: Type A (with the blood-clotting Factor VIII missing) and Type B (with the blood-clotting Factor IV missing). Hemophilia A and B are further defined by their severity and range from mild to severe.
Inherited blood disorder resulting in the absence of clotting factor IX.