F8 and hemophilia A: Hemophilia A is an X-linked bleeding disorder caused by deficiency in factor VIII (FVIII) coagulation protein activity.1 People with hemophilia A are susceptible to spontaneous and trauma-induced bleeding in soft tissues and joints, resulting in painful, disabling arthropathy, impaired quality of life, possible life-threatening complications such as intracranial hemorrhage, and early death.1,2