OMIA 001249-9685 : Coat colour, brown, TYRP1-related in Felis catus

In other species: cattle , horse , dog , sheep , pig , golden hamster , North American deer mouse , goat , American mink , rabbit , Mongolian gerbil

Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 612271 , 203290 , 115501

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2005

Inheritance: As summarised by Lyons et al. (2005), "Brown, B, has a suggested allelic series, B > b > b1. The B allele is normal wild-type black coloration. Cats with the brown variation genotypes, bb or bb1, are supposedly phenotypically chocolate (aka chestnut) and the light brown genotype, b1b1, are supposedly phenotypically cinnamon (aka red)."

Molecular basis: By sequencing a very likely comparative candidate gene (based on the homologous traits in other mammals), Lyons et al. (2005) uncovered the molecular basis for several phenotypes at this locus in cats. The relevant gene is tyrosinase-related protein-1 (TYRP1). Specifically, they showed: "The C to T nonsense mutation at position 298 causes an arginine at amino acid 100 to be replaced by the opal (UGA) stop codon. This mutation is consistent with the cinnamon phenotype and is the putative light brown, b1, mutation. An intron 6 mutation that potentially disrupts the exon 6 downstream splice-donor recognition site is associated with the chocolate phenotype and is the putative brown, b, mutation." One month later, Schmidt-Küntzel et al. (2005) independently reported the same results.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
TYRP1 tyrosinase-related protein 1 Felis catus D4 NC_018735.3 (40068827..40087673) TYRP1 Homologene, Ensembl, NCBI gene


By default, variants are sorted chronologically by year of publication, to provide a historical perspective. Readers can re-sort on any column by clicking on the column header. Click it again to sort in a descending order. To create a multiple-field sort, hold down Shift while clicking on the second, third etc relevant column headers.

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.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
Chocolate TYRP1 b splicing p.Ala420_Asp421ins17/18 Lyons et al. (2005): "An intron 6 mutation that potentially disrupts the exon 6 downstream splice-donor recognition site" Li et al. (2018; Pigment Cell Melanoma Res., 1–10): "donor splice site mutation. p.Ala420_Asp421ins17/18" 2005 16104383
Cinnamon (light brown) TYRP1 b1 nonsense (stop-gain) c.298C>T p.R100* 2005 16104383


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.
2005 Lyons, LA., Foe, IT., Rah, HC., Grahn, RA. :
Chocolate coated cats: TYRP1 mutations for brown color in domestic cats. Mamm Genome 16:356-66, 2005. Pubmed reference: 16104383.
Schmidt-Küntzel, A., Eizirik, E., O'Brien, S.J., Menotti-Raymond, M. :
Tyrosinase and tyrosinase related protein 1 alleles specify domestic cat coat color phenotypes of the albino and brown loci. J Hered 96:289-301, 2005. Pubmed reference: 15858157. DOI: 10.1093/jhered/esi066.
1963 Todd, N.B. :
Independent assortment of Manx and three coat colour mutants in the domestic cat Journal of Heredity 54:266-272, 1963. Pubmed reference: 14098315.

Edit History

  • Created by Frank Nicholas on 26 Nov 2007
  • Changed by Frank Nicholas on 09 Dec 2011
  • Changed by Frank Nicholas on 26 Nov 2012