OMIA 001176-9823 : Porphyria cutanea tarda in Sus scrofa

In other species: sheep

Possibly relevant human trait(s) and/or gene(s) (MIM number): 176100

Mendelian trait/disorder: unknown

Considered a defect: yes

Cross-species summary: Porphyrins are a class of organic compounds characterised by four pyrrole nuclei connected in a ring structure. When combined with iron, porphyrins form haem, which is a component of haemoglobin, cytochromes, catalases and peroxidases. Thus, porphyrins are constituents of many compounds that play a vital role in biological systems. The biosynthesis of porphyrins involves a six-step process, starting with aminolaevulinic acid (ALA) and ending with protoporphyrin. Each step is catalysed by an enzyme. A deficiency of any one of these enzymes results in a buildup of intermediates prior to the step for which the enzyme is lacking, and a deficiency of intermediates after that step. In much of the literature, these intermediates are loosely called porphyrins. Porphyria cutanea tarda results from a deficiency of the fourth enzyme, uroporphyrinogen decarboxylase, and a consequent buildup of intermediates (i.e. a buildup of porphyrins) that have been synthesised in the three previous steps.


1995 Roels, S., Hassoun, A., Hoorens, J. :
Accumulation of Protoporphyrin Isomers-I and Isomers-III, and Multiple Decarboxylation Products of Uroporphyrin in a Case of Porphyria in a Slaughtered Pig Journal of Veterinary Medicine Series A - Zentralblatt Fur Veterinarmedizin Reihe A - Physiology Pathology Clinical Medicine 42:145-151, 1995. Pubmed reference: 8592889.

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  • Created by Frank Nicholas on 06 Sep 2005