F2 and hemorrhagic disease: The autosomal recessive deficiencies of fibrinogen, prothrombin, FV, FVII, FX, FXI and FXIII, also referred to as rare bleeding disorders, display a variable prevalence ranging from 1:500,000 (FVII deficiency) to 1:2,000,000 (prothrombin and FXIII deficiency).