What is the difference between hemophilia A and hemophilia B?

Question

What is the difference between hemophilia A and hemophilia B?

Answer 1

Hemophilia A (classical hemophilia) and hemophilia B (sometimes called Christmas disease). Both are caused by a low level or absence of one of the proteins in the blood (called factors) that control bleeding. Hemophilia A is caused by a deficiency of factor VIII, and hemophilia B is caused by a deficiency of factor IX.

There is no difference between the two types of hemophilia, except that hemophilia B is about five times less common than hemophilia A.