Genetic disorders of coagulation

Much of what is understood about specific coagulation proteins has emerged from the careful study of hereditary disorders of blood coagulation. Haemophilia is a familial X-linked disorder due to deficiency of either factor VIII (haemophilia A) or factor IX (haemophilia B), components of the intrinsic enzymatic complex that activates factor X. The severity of the disease correlates with predicted concentrations of activated factor protein, and those with activity levels below 1% are defined as having severe disease....