hemophilia definition a and b
Haemophilia B (or hemophilia B) is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX. It is the second-most common form of haemophilia, rarer than haemophilia A. It is sometimes called Christmas disease, named after Stephen Christmas, the first patient described with this disease.
Hemophilia A: Classic hemophilia, which is due to a profound deficiency in the activity of clotting factor VIII. Affected individuals suffer hemorrhage into joints and muscles, easy bruising, and prolonged bleeding from wounds. The disease is inherited as an X-linked trait, so males are affected and females carry the gene.