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Hemophilia 2016-11-07T21:10:06+00:00

WHAT IS HEMOPHILIA?

An inherited blood disorder passed from a parent to their child through genes. Hemophilia delays the clotting of the blood, causing difficulty in controlling bleeding due to lack of clotting factor protein in the blood. There are 13 main factors (identified by roman numerals) in blood that work together to produce a clot.  If one factor is missing, the chain reaction is broken and clots will not form properly, causing a person with hemophilia not to bleed faster, but to bleed for longer periods of time. If not treated early on, hemophilia can lead to crippling pain, internal bleeding into muscles and joints, severe joint damage, disability, and early death. There are various levels of severity. A mild form of hemophilia may be having few bleeding episodes, but may require taking precautions if having surgery, or after a serious injury. Severe hemophilia can lead to bleeding spontaneously when there is no obvious cause for the bleeding. Hemophilia affects mostly males.

HOW IS IT DIAGNOSED?

Hemophilia is diagnosed by measuring the level of factor activity in the blood. If the mother is a carrier, testing can be done before a baby is born. Prenatal diagnosis can be done at 9 to 11 weeks by chorionic villus sampling (CVS) or fetal blood sampling at a later stage (18 or more weeks). Hemophilia A is diagnosed by testing the level of factor VIII coagulation activity in the blood. Hemophilia B is diagnosed by measuring the level of factor IX activity.

GENETICS OF HEMOPHILIA

Men with hemophilia pass the gene on to their daughters, but not to their sons. Men are generally more effected than women. Women who are carriers have a 50 percent chance of having a boy with hemophilia and a 50 percent chance of having a girl who is a carrier.

About one third of new cases are caused by a spontaneous mutation of the gene, which means that there was no history of hemophilia in the family before. Hemophilia usually affects men because the hemophilia gene is carried on the same chromosome that determines whether a person is male or female. Men have an X and a Y chromosome and women have two X chromosomes. The genes for hemophilia A and B are on the X chromosome. Since women have two X chromosomes, if one does not work properly, the other X chromosome makes up for it. However, if the hemophilia gene is on both X chromosomes, then the women will have hemophilia.