the name for several hereditary genetic illnesses that impair the body’s ability to control bleeding. People with hemophilia have low or absent levels of clotting proteins such as Factor VIII (Hemophilia A), Factor IX (Hemophilia B), or Factor XI (Hemophilia C). Hemophilia A and B are sex-linked disorders and affect one in 7,000 boys born in the U.S. Other rarer bleeding disorders include deficiencies of Fibrinogen, Prothrombin, Factor V, Factor VII, Factor X, and Factor XIII and may occur in both boys and girls.
Von Willebrand disease (VWD)
the most common hereditary bleeding disorder, although it can also be acquired as a result of other medical conditions. It is caused by deficiency or abnormalities of von Willebrand factor (vWD), a clotting protein that is required for platelet clumping and stabilization of Factor VIII. There are 3 main types of vWD, ranging from type 1, which is usually mild, and type 3, which is more severe.