Uroporphyrinogen Decarboxylase

**Definition:** An enzyme that catalyzes the decarboxylation of UROPORPHYRINOGEN III to coproporphyrinogen III by the conversion of four acetate groups to four methyl groups. It is the fifth enzyme in the 8-enzyme biosynthetic pathway of HEME. Several forms of cutaneous PORPHYRIAS are results of this enzyme deficiency as in PORPHYRIA CUTANEA TARDA; and HEPATOERYTHROPOIETIC PORPHYRIA.

**Tree numbers:** - D08.811.520.224.125.900

**Synonyms:** - Uroporphyrinogen Carboxy-Lyase - Uroporphyrinogen III Decarboxylase