Loss-of-function mutations in the genes encoding the enzymes involved in this so-called vitamin K cycle, such as GGCX and VKORC1, result in rare heritable disorders with extensive phenotypic variability, e.g., the PXE-like syndrome with multiple coagulation factor deficiency, and isolated vitamin K-dependent coagulation factor deficiencies (VKCFD1 and VKCFD2) [11]. The gene discussed is GGCX; the disease is vitamin K-dependent clotting factors, combined deficiency of, type 1.