Chronic hepatic porphyria is caused by a deficiency in URO-D that leads to an accumulation of porphyrins in the liver. The enzyme deficiency is caused by heterogeneous mutations, in the case of porphyria cutanea tarda, of the URO-D gene coding for URO-D. The disease is chronic hepatic porphyria (Experimental Factor Ontology entry EFO_0700114). Also known as: acute hepatic porphyria, chronic, chronic acute hepatic porphyria.