What is "haemophilia a"

n. hemophilia caused by a congenital deficiency of factor VIII; occurs almost exclusively in men [syn: hemophilia A, classical hemophilia, classical haemophilia]

Haemophilia A is a genetic deficiency in clotting factor VIII, which causes increased bleeding and usually affects males. In the majority of cases it is inherited as an X-linked recessive trait, though there are cases which arise from spontaneous mutations.