any of several hereditary disorders, nearly always of males, in which one of the normal blood-clotting factors is deficient, causing serious internal or external hemorrhage from minor cuts and injuries: females with this defective gene are, normally, only carriers
These individuals have had the unfortunate occurrence of a spontaneous mutation, meaning that in their early development, some random genetic accident affected their X chromosome, resulting in the defect that causes hemophilia A or B.
These include the coagulation disorders hemophilia A and hemophilia B, and von Willebrand's disease, a bleeding disorder caused by a deficiency in von Willebrand factor, an essential component of the coagulation system.
By 1997, approximately 800 different diagnostic tests were available, most of them for hereditary genetic disorders such as Tay-Sachs disease, sickle cell anemia, hemophilia, muscular dystrophy, and cystic fibrosis.
The most commonly known coagulation disorder is hemophilia, a condition in which a critical component of blood coagulation is missing, causing individuals to bleed for long periods of time before clotting occurs.
About 20 percent of all individuals with hemophilia A begin to produce antibodies in their blood against the specific factor protein; the presence of antibodies may then rapidly destroy infused factor VIII.