Congenital Erythropoietic Porphyria (CEP), also known as Gunther Disease, uroporphyrinogen III synthase defiency or UROS deficiency, is a rare autosomal recessive rare inborn error of metabolism (IEM). It is a disorder of the porphyrin metabolism pathway caused by a mutation in the UROS gene which encodes for uroporphyrinogen-III synthase. This enzyme catalyzes the dehydrogenation of hydroxymethylbilane into water and uroporphyrinogen III, which will undergo several more reactions to eventually form heme. This disorder is characterized by a large accumulation of porphyrins in the feces, urine and plasma, as well as in bones and teeth, potentially giving them a darkened or red appearance. Symptoms of this disorder include sensitivity to light, leading to potential skin damage as children, which can then lead to severe deformities. Red urine and teeth can also be seen in infancy. Treatment of CEP includes limiting or eliminating exposure to the sun, blood transfusions, and potentially bone marrow transplants or stem cell treatment. It is estimated that CEP affects less than 1 in 1,000,000 individuals.

Congenital Erythropoietic Porphyria (CEP) or Gunther Disease References

Porphyrin Metabolism References