UROD is the fifth enzyme in the human heme biosynthetic pathway and is in charge for the transfer of uroporphyrinogen to coproporphyrinogen through the deletion of four carboxymethyl side chains. UROD Mutations and deficiency result in 3 autosomal disorders in humans: familial porphyria cutanea tarda(f-PCT), sporadic porphyria cutanea tarda(s-PCT) and hepatoerythropoietic porphyria(HEP).