Combined Factor V and Factor VIII Deficiency

Combined deficiency of factor V (FV) and factor VIII (FVIII) (F5F8D, or FV+FVIII) is a autosomal recessive bleeding disorder caused by mutations in genes encoding two components of the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC-53), that is, lectin mannose binding protein (LAMN1) and multiple coagulation factor deficiency 2 (MCFD2), involved in the FV and FVIII intracellular transport rather than by DNA defects in the genes that encode the corresponding coagulation factors. F5F8D is estimated to be extremely rare (1:1,000,000) in the general population, but an increased frequency is observed in regions where consanguineous marriages are practiced. F5F8D is characterized by concomitantly low levels (usually between 5% and 20%) of both FV and FVIII and is associated with a mild to moderate bleeding tendency. Treatment of bleeding episodes requires a source of both FV and FVIII; replacement of FV is achieved only through use of fresh-frozen plasma (FFP) and replacement of FVIII by FFP and desmopressin or specific FVIII concentrates (plasma-derived or recombinant FVIII products).