Hemophilia is a rare genetic blood disorder in which the blood does not clot properly. It is usually an inherited bleeding disorder caused by a mutation or change in one of the genes that provide instructions for making the clotting factor proteins needed to form a blood clot. Hemophilia is caused by low levels of either factor VIII (8) or factor IX (9) . The severity of hemophilia that a person has is determined by the amount of factor in the blood. The lower the amount of the factor, the more likely it is that bleeding will occur which can lead to serious health problems. Hemophilia is classified into three types: Hemophilia A, Hemophilia B, and Hemophilia C. Hemophilia A is the most common type and is associated with a low level of factor 8, while Hemophilia B is associated with a low level of factor 9. Hemophilia C is a rare type of hemophilia that is associated with a low level of factor 11.

People with hemophilia can experience spontaneous bleeding as well as bleeding following injuries or surgery. The bleeding can occur in any part of the body, but it is most common in the joints, muscles, and soft tissues. Hemophilia can cause joint damage from repeated bleeds, pseudotumors, and fractures. The best way to treat hemophilia is to replace the missing blood clotting factor so that the blood can clot properly. This is done by infusing commercially prepared factor concentrates. People with hemophilia can learn how to perform these infusions themselves so that they can stop bleeding episodes and, by performing the infusions on a regular basis, prevent bleeding episodes from occurring.

Hemophilia is much more common in people who were born male since they can get it with a change to the gene on their X chromosome. Females inherit two X chromosomes, one from their mother and one from their father, and they can develop hemophilia if they inherit the altered gene from both parents[[6...