Hemophilia is a hereditary bleeding disorder where essential factors needed to make blood clot are missing. The abnormal hemophilia gene is found on the X sex chromosome. This abnormal gene is there in place of the factor VIII gene. People without the factor VIII gene have hemophilia A. Also, the hemophilia gene can be in place of the factor IX gene as well. People without the factor IX gene have hemophilia B. Hemophilia B is also known as the Christmas disease. (Marshall Cavendish Limited)
             When these factors are missing the body cannot make fibrinogen, the substance that makes the fibers that make blood clot.
             80% of hemophiliacs have the hemophilia A disease, while only 20% have the hemophilia B disease. 80% of all cases of hemophilia have an identifiable family history. Hemophilia may also come from the spontaneous mutation of genes. (Microsoft Encarta online Encyclopedia 2000) Hemophilia is the oldest known hereditary bleeding disorder. There are around twenty thousand patients in the US with hemophilia. Four hundred babies are born each year with hemophilia. 70% of hemophilia A patients have less than 1% of the normal person's clotting factor. (www.nhlbi.nih.gov/health/public/blood/other/hemophel.htm.)
             The inheritance of the hemophilia gene is controlled by a recessive sex linked factor carried by the mother on the X chromosome. (Microsoft Encarta online
             Encyclopedia 2000) Females have two X chromosomes. Males have an X and a Y
             chromosome. Because of this, if a female gets an X chromosome with the hemophilia gene, they still have the other X chromosome with the factor VIII and XI genes on them
             and will not get hemophilia. But, they will become carriers of the disease. And female carriers are usually symptom free. In some rare cases if both of the parents have the hemophilia gene, the female will get hemophilia. While if a male gets an X chromosome with the hemophilia gene he will have the d
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