Hemophilia is a congenital disease, in which the correct clotting of the blood does not occur in the proper time, due to alterations in some actors of the clotting process. This interruption in the so-called coagulation cascade results in bleeding lasting longer than normal when there are open wounds. This condition is related to the X chromosome and can only be transmitted by women and suffered by men. There are three types of hemophilia: type A, where there is a deficiency of factor VIII, type B, where there is a deficit of factor IX, and type C, with a deficiency of Factor IX.
Hemophilia is strictly related to sex and chromosomes, especially the X. Every human being has two pairs of chromosomes, being that of women XX and that of men XY. This disease is suffered only by male individuals as a consequence of having only one X chromosome. Women, for their part, are the carriers, responsible for transmitting it genetically; however, it can be affected if the father is hemophiliac and the mother is a carrier of the disease, but these cases are rare.
Once hemophilia has been transmitted, it can be of three classes, already mentioned: hemophilia A, in which the deficit is localized in coagulation factor VIII, affecting one in 5000 healthy men and altering the processes of transformation of prothrombin into thrombin; hemophilia B, where the deficit affects factor IX, affecting 1 in every 100,000 healthy men; Leyden's hemophilia B, the least common of all, in which factor IX values are less than 1% in childhood, being quite severe; hemophilia C, where the deficit is in factor XI.
