Combined FV and FVIII deficiency is instead due to mutations in genes encoding proteins responsible for intracellular transport of the two coagulation factors (MCFD2 and LMAN1, respectively), while that of VKCFD to mutations in genes encoding necessary enzymes for post-translational change and vitamin K metabolism, namely Gamma-Glutamyl Carboxylase (GGCX) and Vitamin K epoxide reductase (VKOR) [53]. This evidence concerns the gene F5 and vitamin K-dependent clotting factors, combined deficiency of, type 1.