Congenital Erythropoietic Porphyria (CEP)

What Is Congenital Erythropoietic Porphyria?

Congenital Erythropoietic Porphyria (CEP) is caused by a deficiency of the enzyme uroporphyrinogen III synthase. 

Most cases of CEP are located on the UROS gene, however there are reports of CEP that is located on the x-linked GATA1 gene.

hemizygous pathogenic variant in the X-linked gene GATA1 (

In most individuals with congenital erythropoietic porphyria (CEP) severe cutaneous photosensitivity begins in early infancy; the first manifestation is often pink to dark red discoloration of the urine. Hemolytic anemia is common and can be mild to severe, requiring chronic blood transfusions in some. The phenotypic spectrum ranges from severe (non-immune hydrops fetalis) to milder disease (adult-onset with isolated cutaneous manifestations [Warner et al 1992]). (See Genotype-Phenotype Correlations for predictors of disease severity.)

What Are the Symptoms of Congenital Erythropoietic Porphyria?

  • Pink to dark red discoloration of the urine

  • Hemolytic anemia

  • Severe cutaneous photosensitivity with onset usually in infancy or early childhood

  • Blisters and vesicles in light-exposed areas, which are prone to rupture and infection

  • Scarring and deformities (photomutilation) of digits and facial features, caused by recurrent blistering, infections, and bone resorption

  • In light-exposed areas: friable skin, skin thickening, hypo- and hyperpigmentation

  • Reddish-brown discoloration of teeth (fluoresce on exposure to long-wave ultraviolet light), also called erythrodontia

  • Corneal ulcers and scarring

  • Hypertrichosis of face and extremities 


How Is Congenital Erythropoietic Porphyria Diagnosed?

A complete diagnostic evaluation for congenital erythropoietic porphyria consists of biochemical testing, enzyme testing, and genetic testing.



Markedly increased levels of uroporphyrin I and coproporphyrin I isomers in erythrocytes, urine, or amniotic fluid as well as coproporphyrin I in stool (