OMIA:001176-9940 : Porphyria cutanea tarda in Ovis aries (sheep)

In other species: pig

Categories: Homeostasis / metabolism phene

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

Links to MONDO diseases: No links.

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2005

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.

History: This disorder in sheep was first reported by Nezamzadeh et al. (2005).

Molecular basis: By cloning and sequencing a very likely comparative candidate gene (based on homologous clinical signs in other species), Nezamzadeh et al. (2005) identified the causative mutation of this disorder in a family of German Blackface sheep as a missense base substitution (C>T) in the UROD gene, resulting in L131P at the active cleft site of the peptide.

Genetic engineering: Unknown
Have human generated variants been created, e.g. through genetic engineering and gene editing

Breed: Scottish Blackface (Sheep) (VBO_0001598).
Breeds in which the phene has been documented. For breeds in which a likely causal variant has been documented, see the variant table below

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
UROD uroporphyrinogen decarboxylase Ovis aries 1 NC_056054.1 (19663992..19667360) UROD Homologene, Ensembl , NCBI gene


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WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Inferred EVA rsID Year Published PubMed ID(s) Acknowledgements
906 Scottish Blackface (Sheep) Porphyria cutanea tarda UROD missense Naturally occurring variant Oar_rambouillet_v1.0 1 g.20327971T>C c.392T>C p.(L131P) Oar_v3.1 position is g.19437840T>C; protein and cDNA positions are based on NP_001012341.1 and NM_001012341.1, respectively rs429214636 2005 16026339 Variant coordinates obtained from or confirmed by EBI's Some Effect Predictor (VEP) tool. The genomic location on Oar_rambouillet_v1.0 was determined by Katie Eager, EMAI, NSW Department of Primary Industries.

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2017). OMIA:001176-9940: Online Mendelian Inheritance in Animals (OMIA) [dataset].


2005 Nezamzadeh, R., Seubert, A., Pohlenz, J., Brenig, B. :
Identification of a mutation in the ovine uroporphyrinogen decarboxylase (UROD) gene associated with a type of porphyria. Anim Genet 36:297-302, 2005. Pubmed reference: 16026339. DOI: 10.1111/j.1365-2052.2005.01301.x.

Edit History

  • Created by Frank Nicholas on 15 Nov 2005
  • Changed by Frank Nicholas on 09 Dec 2011
  • Changed by Frank Nicholas on 03 Dec 2012
  • Changed by Frank Nicholas on 28 Sep 2015
  • Changed by Frank Nicholas on 11 Aug 2016
  • Changed by Frank Nicholas on 12 Dec 2017