Learn More - Overview of the Porphyrias
The Cutaneous Porphyrias
Cutaneous porphyrias primarily affect the skin. Areas of skin exposed to the sun become fragile and blistered, which can lead to infection, scarring, changes in skin coloring (pigmentation), and increased hair growth. Cutaneous porphyrias include congenital erythropoietic porphyria, erythropoietic protoporphyria and X-linked protoporphyria, porphyria cutanea tarda, and hepatoerythropoietic porphyria.
Congenital Erythropoietic Porphyria (CEP)
What is Congenital Erythropoietic Porphyria?
CEP is a severe disorder caused by a deficiency of the enzyme uroporphyrinogen III synthase (URO-synthase). CEP is one of the most severe porphyrias, symptoms usually begin soon after birth or in early childhood. Some severe cases have been diagnosed before birth as a cause of anemia and fluid accumulation in the fetus (fetal hydrops). Less severe cases may occur in adults in association with another bone marrow condition.
Skin photosensitivity results in severe blistering and scarring, often with mutilation and loss of facial features and fingers. Increased hair growth (hypertrichosis) on sun-exposed skin, brownish-colored teeth (erythrodontia), and reddish-colored urine are common. There may be bone fragility due to expansion of the bone marrow and vitamin deficiencies, especially vitamin D. Red blood cells have a shortened life-span, and mild or severe hemolytic anemia often results. Synthesis of heme and hemoglobin is actually increased to compensate for the shortened red blood cell survival and is associated with splenomegaly. Bacteria may infect the damaged skin and contribute to mutilation and scarring.
Who gets Congenital Erythropoietic Porphyria?
CEP is very rare, with only several hundred cases reported. This is an autosomal recessive disorder, meaning that each parent of an affected individual must have a mutation in one of their UROS genes and both must pass their mutation on to their child. Each parent is, ttherefore, a "carrier", but neither will have any symptoms of CEP.
What causes Congenital Erythropoietic Porphyria?
CEP is caused by a deficiency of the enzyme uroporphyrinogen III synthase (URO-synthase) due to mutation in both of an individual’s UROS gene.
How is Congenital Erythropoietic Porphyria diagnosed?
Porphyrins accumulate first in the bone marrow, are deposited in the teeth and bones, and are markedly increased in red blood cells, plasma, urine, and feces. Uroporphyrin I and coproporphyrin I usually predominate in red blood cells, plasma, and urine. Coproporphyrin I is strikingly increased in feces. In some milder cases, zinc protoporphyrin may predominate in red blood cells. Identifying the mutations confirms the diagnosis.
- Also see FAQ: What diagnostic tests are available?
What are treatments for Congenital Erythropoietic Porphyria?
Avoidance of sunlight is most important. Vitamin and mineral deficiencies should be prevented. Blood transfusions to correct anemia are required in severe cases, and this may reduce porphyrin production by the marrow. Removing the spleen is sometimes considered. Identifying the mutations in a family enables diagnosis before birth in subsequent pregnancies. Gene therapy may be an option in the future.