OMIA 000815-9823 : Porphyria, unclassified in Sus scrofa

See the equivalent entry at NCBI

In other species: domestic cat

Possible human homologues (MIM numbers): 125270 , 176000 , 176090 , 176200

Mendelian trait/disorder: yes

Considered a defect: yes

Key mutation known: no

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 is a general term for disorders resulting from a deficiency in any one of the enzymes in the porphyrin pathway, and a consequent buildup of intermediates (i.e. a buildup of porphyrins). Each enzyme deficiency gives rise to a distinct disorder. The six enzymes (in order), together with their deficiency disorders are: ALA dehydratase (Doss porphyria); porphobilinogen deaminase (Acute intermittent porphyria); urporphyrinogen II cosynthetase (Porphyria, congenital erythropoietic); uroporphyrinogen decarboxylase (Porphyria cutanea tarda); coproporphyrinogen III oxidase (Hereditary coproporphyria); protoporphyrinogen oxidase (Varigate porphyria). Some porphyrins are extemely photoreactive. Because of this, photosensitivity is a clinical sign of some of these disorders. Another major common clinical sign is haemolytic anaemia, due to a deficiency of haemoglobin. In some cases, the buildup of porphyrins results in a characteristic red staining of teeth, bones and urine.

References


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.
1959 Jorgensen, S.K. :
Congenital porphyria in pigs British Veterinary Journal 115:160-175, 1959.
With, T.K., Clausin, H., Hojgaard-Olsen, N.J. :
Undersogelser over kongenet porphyria ros svin 310 Beretning fra Forsogslaboratoriet :?, 1959.
1956 Jorgensen, S.K. :
Congenital chronic porphyria in swine Nordisk Veterinaermedicin 8:562-580, 1956.
1944 Clare, T., Stephens, E.H. :
Congenital porphyria in pigs Nature 153:252-253, 1944.

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  • Created by Frank Nicholas on 06 Sep 2005