NCIt definition : A deficiency or abnormality of a blood coagulation factor characterized by the tendency
to hemorrhage. Hemophilia is typically a hereditary disorder but, rarely, may be acquired.
Inherited coagulation factor-deficient hemophilias include hemophilia A or classic
hemophilia (hereditary factor VIII deficiency) hemophilia B or Christmas disease (hereditary
factor IX deficiency), and hemophilia C (hereditary factor XI deficiency). Factor
VIII inhibitors may occur spontaneously as autoantibodies, resulting in acquired hemophilia
known as acquired factor VIII deficiency. Approximately 10% of patients with acquired
hemophilia have an underlying malignancy.;
Alternative definition : NCI-GLOSS: Group of hereditary disorders in which affected individuals fail to make
enough of certain proteins needed to form blood clots.; NICHD: A coagulation disorder characterized by the partial or complete absence of
factor VIII or IX activity in the blood.;