The Enzymatic Defect in Porphyria Cutanea Tarda

Abstract

The porphyrias are a group of disorders resulting from specific enzymatic defects in the heme biosynthetic pathway. The compound excreted in excess in the various porphyric syndromes is generally the substrate of the defective enzyme. The inherited nature of a specific enzymatic defect has been established in all forms of porphyria with the exception of porphyria cutanea tarda (PCT).Because of its association with alcoholic liver disease and hepatic siderosis, PCT used to be considered an acquired form of porphyria. The accumulation of uroporphyrin and partially decarboxylated porphyrins in the liver and the excretion of these compounds in the urine . . .