**5.5. FX deficiency**

Factor X is a single chain polypeptide with a molecular weight of 58,900 kDa and circulates in plasma with a concentration of 10 μg/ml [77]. FX is encoded by FX gene present on chromosome 13 [78]. FX deficiency is characterized by central nervous system and gastro intestinal bleeding [79, 80]. FX deficiency is one of the very rare disorders observed in 1 in 500,000– 1000,000 [79, 80]. Treatments of FX deficiency include highly purified plasma FX, recombinant FX, fresh frozen plasma and prothrombin complex concentrates [79, 80].
