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Hereditary coproporphyria


Other Names for this Disease
  • Coproporphyria
  • Coproporphyria hereditary
  • Coproporphyrinogen oxidase deficiency
  • CPO deficiency
  • CPRO deficiency
More Names
Related Diseases
More Related Diseases
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Cause


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What causes hereditary coproporphyria?

Hereditary coproporphyria is due to a combination of a genetic enzyme defect and acquired causes that become symptomatic in rare cases. In patients with coproporphyria, the function of coproporphyrinogen oxidase is only 40-60% of normal. Most patients with defects in coproporphyrinogen oxidase never have any symptoms. The classic inducers of porphyria are chemicals or situations that boost heme synthesis. This includes fasting and many medications.[1] Tables which list medications which are safe and unsafe can be accessed by clicking here.

The deficient enzyme in hereditary coproporphyria is coproporphyrinogen oxidase, which is responsible for the sixth step in heme production.[2][3][1][4] This enzyme speeds the conversion of coproporphyrinogen to protoporphyrinogen. In coproporphyria, the porphyrin precursors porphobilinogen and amino-levulinic acid (ALA) accumulate, as well as the formed porphyrin coproporphyrin.[1]

The predominant problem is neurologic damage that leads to peripheral and autonomic neuropathies and the psychiatric manifestations. Skin disease may also be present, though not as often as the neurovisceral symptoms. The etiology of the skin disease may be the deposition of formed porphyrins in the skin that react with sunlight and lead to skin damage. Although patients with acute neurovisceral attacks always have elevations of porphobilinogen and ALA, researchers still are unclear about how this leads to the symptomatic disease because most patients with the genetic defect have excessive porphyrin secretion but no symptoms.[1]
Last updated: 11/11/2010

References
  1. DeLoughery TG. Porphyria, Hereditary Coproporphyria. eMedicine. 2009; http://emedicine.medscape.com/article/205374-overview. Accessed 11/11/2010.
  2. Porphyria, Hereditary Coproporphyria. National Organization for Rare Disorders (NORD). 2007; http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Porphyria%2C%20Hereditary%20Coproporphyria. Accessed 11/11/2010.
  3. Learning about Porphyria. National Human Genome Research Institute (NHGRI). 2010; http://www.genome.gov/19016728. Accessed 11/11/2010.
  4. Hereditary Coproporphyria (HCP). American Porphyria Foundation. 2009; http://www.porphyriafoundation.com/about-porphyria/types-of-porphyria/HCP. Accessed 11/11/2010.