OMIA 001249-9615 : Coat colour, brown, TYRP1-related in Canis lupus familiaris

In other species: cattle , horse , domestic cat , 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 Recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2002

Species-specific name: This is the classic B (Brown) locus described by Little (1957)

Species-specific symbol: B locus

Molecular basis: By cloning and sequencing a very likely comparative candidate gene (based on the gene corresponding to the brown locus in mice), Schmutz et al. (2002) were the first to sequence the TYRP1 gene in dogs. They identified three likely causal variants, namely "a premature stop codon in exon 5 (Q331ter) [named allele b^s], . . .a [deletion of a] proline residue in exon 5 (345delP) [named allele b^d] . . . [and] A third variant in exon 2 (S41C) [named allele b^c). . . . All 43 of the brown group carried two or more of these sequence variants likely to interfere with TYRP1 function, whereas 0 of 34 in the black group carried two or more of these variants (10 carried one variant)". The authors concluded that "all three [mutations] affect eumelanin production and alter black pigmentation to brown".

Gerding et al. (2011) showed that the typical "grey" coat colour in Weimaraners is due to homozygosity for a non-functional allele (or heterozygosity for different non-functional alleles) at the TYRP1 locus; and that the "blue" coat colour in the same breed is due to the presence of one or two functional alleles at this locus. Thus, "blue" is dominant to "grey". By studying haplotypes, they were also able to show that the funcational allele is not a "reversion" from within the breed.

Letko and Drögemüller (2017) identified alleles b^c and b^d in Leonberger dogs.

Hrckova Turnova et al. (2017) reported a new allele (c.555T>G; p.Tyr185*) in a single pedigree of Australian Shepherd dogs.

Jancuskova et al. (2018) reported the same c.555T>G allele as being more widespread in the Australian Shepherd breed and "also its close relative Miniature American Shepherd".

Wright et al. (2019) reported a likely causal variant (CFA11:33326719; c.1025T>G; p.Phe342Cys) strongly associated with liver colour in Lancashire Heelers.

Van Buren et al. (2021) reported a 6th variant: "(NM_001194966.1, c.125G>A, p.Cys42Tyr) in exon 1 of the husky and husky‐mixes whose brown phenotype could not be explained by the previously known b‐variants." They named this variant b^h.

Prevalence: Van Buren et al. (2021): "All genotyped brown husky and husky‐mixes carrying the b^h allele were compound heterozygotes with either the bs or bc alleles, consistent with two mutant alleles required for a brown coat. No unrelated huskies had the b^h allele."

Breeds: Australian Shepherd, German Shepherd Dog, Leonberger, Miniature American Shepherd.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
TYRP1 tyrosinase-related protein 1 Canis lupus familiaris 11 NC_051815.1 (34222689..34240515) 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
Numerous breeds Brown TYRP1 b^c missense CanFam3.1 11 g.33317810T>A c.121T>A p.Cys41Ser 2002 12140685 Variant coordinates obtained from or confirmed by EBI's Some Effect Predictor (VEP) tool. Correction to genomic details provided by professor Claire Wade August 2018. Correction to g and c. details provided by Professor Tosso Leeb 11 Feb 2020.
Siberian Husky Brown TYRP1 b^h missense CanFam3.1 11 g.33317814G>A c.125G>A p.Cys42Tyr NM_001194966.1, c.125G>A, p.Cys42Tyr (Van Buren et al., 2021) 2021 33421162
Australian Shepherd Brown TYRP1 nonsense (stop-gain) CanFam3.1 11 g.33319349T>G c.555T>G p.Tyr185* 2017 28497851
Numerous breeds Brown TYRP1 b^s nonsense (stop-gain) CanFam3.1 11 g.33326685C>T c.991C>T p.Gln331* rs850566878 2002 12140685 Variant coordinates obtained from or confirmed by EBI's Some Effect Predictor (VEP) tool
Lancashire heeler Liver TYRP1 b^e missense CanFam3.1 11 g.33326719T>G c.1025T>G p.Phe342Cys 2019 31468558
Numerous breeds Brown TYRP1 b^d deletion, small (<=20) CanFam3.1 11 g.33326727_33326729del c.1,033_1,035del p.Pro345del rs851422848 2002 12140685


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.
2021 Van Buren, S.L., Mickelson, J.R., Minor, K.M. :
A novel TYRP1 mutation associated with brown coat color in Siberian huskies. Anim Genet :, 2021. Pubmed reference: 33421162. DOI: 10.1111/age.13037.
2019 Wright, H.E., Schofield, E., Mellersh, C.S., Burmeister, L.M., Wright, H.E., Schofield, E., Mellersh, C.S., Burmeister, L.M. :
A novel TYRP1 variant is associated with liver and tan coat colour in Lancashire Heelers. Anim Genet :, 2019. Pubmed reference: 31468558. DOI: 10.1111/age.12839.
van Rooy, D., Wade, C.M. :
Association between coat colour and the behaviour of Australian Labrador retrievers. Canine Genet Epidemiol 6:10, 2019. Pubmed reference: 31798910. DOI: 10.1186/s40575-019-0078-z.
2018 Jancuskova, T., Langevin, M., Pekova, S. :
TYRP1:c.555T>G is a recurrent mutation found in Australian Shepherd and Miniature American Shepherd dogs. Anim Genet :, 2018. Pubmed reference: 30109695. DOI: 10.1111/age.12709.
2017 Hrckova Turnova, E., Majchrakova, Z., Bielikova, M., Soltys, K., Turna, J., Dudas, A. :
A novel mutation in the TYRP1 gene associated with brown coat colour in the Australian Shepherd Dog Breed. Anim Genet 48:626, 2017. Pubmed reference: 28497851. DOI: 10.1111/age.12563.
Letko, A., Drögemüller, C. :
Two brown coat colour-associated TYRP1 variants (b(c) and b(d) ) occur in Leonberger dogs. Anim Genet 48:732-733, 2017. Pubmed reference: 28983931. DOI: 10.1111/age.12612.
2015 Monteagudo, L.V., Tejedor, M.T. :
The b(c) allele of TYRP1 is causative for the recessive brown (liver) colour in German Shepherd dogs. Anim Genet 46:588-9, 2015. Pubmed reference: 26370740. DOI: 10.1111/age.12337.
2012 Schmutz, S.M., Melekhovets, Y. :
Coat color DNA testing in dogs: theory meets practice. Mol Cell Probes 26:238-42, 2012. Pubmed reference: 22507852. DOI: 10.1016/j.mcp.2012.03.009.
2011 Gerding, WM., Schreiber, S., Dekomien, G., Epplen, JT. :
Tracing the origin of 'blue Weimaraner' dogs by molecular genetics. J Anim Breed Genet 128:153-60, 2011. Pubmed reference: 21385230. DOI: 10.1111/j.1439-0388.2010.00888.x.
2005 Cargill, E.J., Famula, T.R., Schnabel, R.D., Strain, G.M., Murphy, K.E. :
The color of a Dalmatian's spots: linkage evidence to support the TYRP1 gene. BMC Vet Res 1:1, 2005. Pubmed reference: 16045797. DOI: 10.1186/1746-6148-1-1.
2002 Schmutz, S.M., Berryere, T.G., Goldfinch, A.D. :
TYRP1 and MC1R genotypes and their effects on coat color in dogs Mammalian Genome 13:380-387, 2002. Pubmed reference: 12140685. DOI: 10.1007/s00335-001-2147-2.
1957 Little, C.C. :
The Inheritance of Coat Color in Dogs Comstock Publishing Associates, Cornell University Press, Ithaca, NY :, 1957.

Edit History

  • Created by Frank Nicholas on 04 Jun 2011
  • Changed by Frank Nicholas on 12 Dec 2011
  • Changed by Frank Nicholas on 20 Sep 2012
  • Changed by Frank Nicholas on 24 Nov 2012
  • Changed by Frank Nicholas on 24 Nov 2017
  • Changed by Frank Nicholas on 24 Jan 2018
  • Changed by Frank Nicholas on 17 Aug 2018
  • Changed by Frank Nicholas on 17 Sep 2019
  • Changed by Frank Nicholas on 18 Sep 2019
  • Changed by Tosso Leeb on 30 Jan 2020
  • Changed by Frank Nicholas on 12 Jan 2021