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hemophilia (hēˌməfĭlˈēə, –fēlˈyə), genetic disease in which the clotting ability of the blood is impaired and excessive bleeding results. The disease is transmitted through females but almost invariably affects male offspring only. A male born to a carrier mother has a 50% chance of having the disease. A hemophiliac cannot pass the disease to his sons, but all his daughters will be carriers. There are two diseases usually classified as hemophilia: hemophilia A (classical hemophilia, or Factor VIII deficiency) and hemophilia B (Christmas disease, or Factor IX deficiency).
Small wounds and punctures are usually not a problem for hemophiliacs and can be treated as in a nonhemophiliac. Uncontrolled internal bleeding, however, can result in pain and swelling and permanent damage, especially to joints and muscles. The symptoms often first appear in toddlers as their joints begin to bear weight.
Treatment and Screening
See S. Pemberton, The Bleeding Disease: Hemophilia and the Unintended Consequences of Medical Progress (2011).
a hereditary disease manifested by increased bleeding. The inheritance of hemophilia is associated with a disorder of the genes of the female X chromosome, which determine the formation of factor VIII (antihemophilic globulin) and factor IX (Christmas). Women are only the carriers of hemophilia, and they transmit the disease to some of their sons. However, a few cases of hemophilia have occurred in women born to a mother-carrier and a hemophiliac father. An insufficiency of factor VIII in the blood causes the development of hemophilia A (80 to 90 percent of the patients). If there is a deficiency of factor IX, hemophilia B arises (10 to 15 percent of the patients). Hemophilia C is caused by a deficiency of factor XI and occurs in only 5 percent of the cases. This form of the disease also occurs in women.
Bleeding in cases of hemophilia is manifested from early childhood, but it becomes less pronounced with age. Even slight bruises cause extensive hemorrhages, both subcutaneous and intramuscular. Repeated hemorrhages in the joints result in serious changes in them that are characteristic of hemophilia (hemarthrosis and its residual effects). Cuts and tooth extraction are accompanied by life-threatening bleeding, and they may promote the development of anemia. Bleeding sometimes does not begin until hours or even days after an injury or surgical operation. The main diagnostic signs of hemophilia are prolonged blood coagulation time and deficiency of antihemophilic globulin in the plasma (0.02-0.03 percent in healthy persons). A mixture of blood from a known hemophiliac and a person suspected of having the disease is also tested for coagulability. Treatment for bleeding includes transfusion of blood and plasma. (Blood and plasma stored for only a few hours are used for hemophilia A, or blood is transfused directly from a donor to the patient.) General action hemostatic agents, antihemophilic globulin (AHG), and dried fresh plasma are also used, and bleeding may be arrested locally. Preventive measures include avoiding surgery, which should be undertaken only when it is absolutely indicated. If surgery (including the extraction of teeth) is needed, the patients must be hospitalized, if possible in a specialized institution. Hemophiliacs must be protected against injury. Children suffering from hemophilia should be kept under observation in specialized clinics.
REFERENCESKassirskii, I. A., and G. A. Alekseev. Klinicheskaia gematologiia, 4th ed. Moscow, 1970.
Grozdov, D. M., and M. D. Patsiora. Khirurgiia zabolevanii sistemy krovi. Moscow, 1962.
Stefanini, M., and W. Dameshek. The Hemorrhagic Disorders. New York-London, 1962. (Bibliography.)
A. M. POLIANSKAIA