Hemophilia

haemophilia

(US), hemophilia

an inheritable disease, usually affecting only males but transmitted by women to their male children, characterized by loss or impairment of the normal clotting ability of blood so that a minor wound may result in fatal bleeding
www.hemophilia.org

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

hemophilia

[‚hē·mə′fil·ē·ə]

(medicine)

A rare, hereditary blood disorder marked by a tendency toward bleeding and hemorrhages due to a deficiency of factor VIII.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hemophilia

 

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.

REFERENCES

Kassirskii, 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

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.