Hemophilia
Hemophilia is a hereditary disease in which the blood does not clot normally. People with hemophilia called hemophiliacs, bleed excessively when injured because their blood clots extremely slowly. Almost all hemophiliacs are males.
Blood must contain a number of substances called clotting factors for clotting to take place. A hemophiliac’s blood lacks the active form of one of these factors, Factor VIII (Anti-hemophilic factor). Hemophiliacs suffer most when internal blood vessels break, causing bleeding into such areas as the head or joints. Leaking blood accumulates in these areas, putting pressure on the surrounding tissues and causing pain, swelling and loss of function. Many hemophiliacs become crippled from repeated bleeding into joints.
Hemophilia is caused by a defective gene on the x chromosome, one of the two chromosome that determine a person’s sex. The y chromosome, which has no genes for clotting factor, is the other. Male has one x chromosome and one y chromosomes. Females have 2 x chromosomes.
A boy who inherits the hemophilia defect on his x chromosome will be a hemophiliac. A girl who inherits the defective gene on one of her x-chromosomes will be a carrier. She may transmit the defective gene to her children. But she will not be a hemophiliac because the normal gene of her other x chromosome provides enough of the essential clotting factor. In extremely rare cases, a girl inherits the defective gene on both x chromosome and will be a hemophiliac.
Major types of hemophiliac include classical hemophilia and Christmas disease. The name of Christmas disease comes from the last name of one of the first patients to be treated for it.
About 85% of all hemophiliacs have classified hemophilia. Their blood lacks a protein called clotting factor VIII. Nearly all others have Christmas disease, which involves the lacks of clotting factor IX.
Hemophiliacs depend on blood products such as cryoprecipitate and factor VIII concentrate for their survival.
A blood disorder called von willebrand’s disease is sometimes confused with hemophilia. Unlike hemophilia, van willebrand’s disease causes prolonged external bleeding and affects both sexes. However, few people with blood disorders suffer bleeding into the joints.
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