Hemophilia

1 Pages 226 Words

Hemophilia is a sex-linked disease in which the blood does not clot normally. People with hemophilia, called hemophiliacs, bleed excessively when injured because their blood clots extremely slowly.
Normally, blood must contain a certain number of substances called clotting factors for clotting to take place. A hemophiliac’s blood lacks the active form of one of these factors. People with hemophilia 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.
Hemophilia is caused by a defective gene on the X chromosome, one of the two chromosomes that determine a person’s sex. The Y chromosome, which has no genes for clotting factors, is the other. Males have one X and one Y chromosome, where females have two X chromosomes. Since hemophilia is carried on the X chromosome, it leaves females with a greater chance of not having the disease but will be a carrier. This is why almost all hemophiliacs are males.
Major types of hemophilia include classical hemophilia and Christmas disease; also known as hemophilia A and hemophilia B. Around 85% of all hemophiliacs have hemophilia A. Their blood lacks a protein called clotting factor number 8. Nearly all others have hemophilia B, which involves that lack of clotting factor number 9....