This document discusses hemophilia, an inherited bleeding disorder caused by mutations in genes coding for blood clotting factors. It describes the history and genetics of the disease, including that hemophilia is X-linked recessive and mostly affects males. The main types are hemophilia A caused by factor VIII deficiency and hemophilia B caused by factor IX deficiency. Symptoms range from mild to severe bleeding. Treatment involves replacement of the missing clotting factor through therapies like fresh or concentrated plasma.