Diseases Studied
The Rare Diseases Clinical Research Network is an NIH-funded research network of 21 active consortia or research groups working to advance treatment for diseases that are rare. Use the search tools on this page to find the diseases we currently study. You can reach out to the indicated consortia or research groups for more information on those diseases and studies underway.
This network focuses on clinical research and does not generally support clinical care outside of research activities. To learn about other rare diseases, please visit the Genetic and Rare Diseases Information Center (GARD), which is an NIH program that helps the public find reliable information about rare and genetic diseases. Their staff are specialists. Contact them at 1-888-205-2311 or email GARDinfo@nih.gov.
All Diseases > Hepatoerythropoietic porphyria
Hepatoerythropoietic porphyria (HEP)
Disease Category: Porphyrias
A rare, inherited, metabolic disorder characterized by profound deficiency of the enzyme uroporphyrinogen decarboxylase (UROD), which allows for build-up of porphyrins. Porphyrins are substances that bind metals to form complexes, such as the iron found in red blood cells. A child must inherit genetic mutations from both parents (autosomal recessive) for disease manifestation. The hallmark symptom is cutaneous photosensitivity (skin hyperreactivity to light), resulting in painful, blistering skin lesions that may become infected, scar, and/or develop discoloration. Other symptoms include hypertrichosis (excessive hair growth) on affected skin, mild anemia (low red blood cell level), and hepatosplenomegaly (enlarged liver and spleen).