hemophilia

Hemophilia is divided into A and B types. Hemophilia A (hemophilia A) is a bleeding disorder caused by a deficiency of factor VIII, accounting for about 85% of congenital bleeding disorders. According to a 1990 joint meeting of the World Health Organization (WHO) and the World Federation of Hemophilia (WHF), the incidence of hemophilia A is about 15-20 / 100,000 population, and statistics from Europe and the United States are about 5-10 / 100,000 people, the incidence of hemophilia A in China is about 3-4 per 100,000 population. Hemophilia B (hemophilia B), called factor IX deficiency or Christmas disease, has an incidence of about 1.0 to 1.5 / 105, accounting for 15% to 20% of hemophilia. The gene of Factor IX is 34 kb long and is located on the long arm of X chromosome. It has 8 exons and 7 introns. Factor IX is a vitamin K-dependent plasma protein with a relative molecular weight of 56,000 and is synthesized in the liver. Hemophilia A and B are treated similarly, and alternative therapies are used, including plasma, prothrombin complex (PCC), factor IX concentrates, and recombinant factor IX products.