Hemophilia A is a heredity bleeding disorder that is caused by a lack of clotting factor VIII. As a result, individuals with this condition suffer from bleeding into joints and other complications. For the most part, men have hemophilia A as the defective gene is found on the X chromosome. A woman who has the defective gene is considered a carrier and any male offspring have a 50% chance of having hemophilia A and female offspring a 50% chance of being a carrier. It affects one in 10,000 people. With treatment, individuals are able to lead relatively normal lives.
Hemophilia B is a blood clotting disorder caused by a mutation of the Factor IX gene. It is rarer than hemophilia A and affected royal families in both Europe and Russia. It affects one in 25,000 men. Replacement of Factor IX through recombinant therapy allows individuals to lead relatively normal lives.
Von Willebrand Disease
The most common bleeding disorder, Von Willebrand affects about 1.25 million men and women worldwide, although it is estimated that as many as 3 million are undiagnosed. Common symptons include excessive menstrual bleeding and nosebleeds. There are several kinds of VWD and symptom severity varies. With proper treatment, individuals may live relatively normal lives.
Antithrombin III Deficiency
Antithrombin III is a protein that prevents blood clots from forming. It is caused by an abnormal gene that may lead to blood clots. Data on incidence is uncertain.