What is Hemophilia B?
Hemophilia is a disorder in which the blood does not clot properly. The two most common types, hemophilia A and hemophilia B, are caused by defective or missing proteins that are part of the system that causes the blood to clot. In hemophilia B the defective or missing protein is called factor IX. Both hemophilias affect males almost exclusively. There is a number of other hemophilias, most caused by defects in or absence of other proteins of the clotting system. The most common of these is von Willebrand disease. All of the others are rare. Although one might think that the danger for a person with hemophilia would be bleeding to death from even a small injury, that is not usually the problem. The blood of a person with hemophilia clots much more slowly than normal, but the blood clotting system has a lot of redundancy, so it will eventually cause the blood to clot by alternate mechanisms. Most of the danger comes from bleeding internally. For instance, without treatment, many people
Hemophilia B is a hereditary blood coagulation disorder. It is caused by a deficiency of a blood plasma protein called factor IX that affects the clotting property of blood. Hemophilia is a hereditary bleeding disorder of specific blood clotting factors. There are several types of Hemophilia, including Hemophilia A and B. Hemophilia A is 7 times more common than Hemophilia B. How do you get Hemophilia B? The disorder is caused by an inherited sex-linked recessive trait with the defective gene located on the X chromosome. Females carry two copies of the X chromosome, so if the factor IX gene on one chromosome is defective, the other can compensate. Males, however, carry only one X chromosome, so if the factor IX gene on that chromosome is defective, they have the disease. Females with one defective factor IX gene are carriers of this trait. Fifty percent of the male offspring of female carriers will have the disease, and 50% of their female offspring will be carriers. All female childre
