Hemophilia B and factor IX deficiency
People with hemophilia B have a deficiency in clotting factor IX. Hemophilia B is sometimes called Christmas disease after Stephen Christmas, the first patient described with this disease. It is the second most common form of hemophilia, occurring in about 1 in 20,000 to 50,000 people.
Treating hemophilia B
It's important to manage hemophilia B by taking steps to stop bleeds as soon as they start. There are several therapies available to treat hemophilia B.