OMIA:002139-9796 : Coat colour, Leopard Complex Spotting in Equus caballus (horse)

Categories: Pigmentation phene , Vision / eye phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 613216 (trait) , 603576 (gene)

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal incomplete dominant

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2013

Species-specific description: As summarised by Bellone et al. (2013): "Leopard complex spotting is a group of white spotting patterns in horses caused by an incompletely dominant gene (LP) . . . homozygotes (LP/LP) are also affected with congenital stationary night blindness". Thus, a single mutation is autosomal incompletely dominant for Leopard Complex/Appaloosa and autosomal recessive for stationary congenital night blindness (OMIA:001341-9796).

Molecular basis: Bellone et al. (2013) reported that a retroviral insertion in TRMP1 was complete associated with Leopard spotting in 511 horses from a range of breeds.

Breeds: American Miniature Horse (Horse) (VBO_0000896), Appaloosa (Horse) (VBO_0000904), British Spotted Pony, Spotted Pony, United Kingdom of Great Britain and Northern Ireland (Horse) (VBO_0011461), English Spotted Pony, Australia (Horse) (VBO_0011165), Knabstrupper (Horse) (VBO_0001008), Noric (Horse) (VBO_0001030), Pony Of the Americas, Germany (Horse) (VBO_0011370), Thoroughbred (Horse) (VBO_0001083).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
TRPM1 transient receptor potential cation channel, subfamily M, member 1 Equus caballus 1 NC_009144.3 (109301575..109109527) TRPM1 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.

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 Year Published PubMed ID(s) Acknowledgements
725 American Miniature Horse (Horse) Appaloosa (Horse) British Spotted Pony, Spotted Pony, United Kingdom of Great Britain and Northern Ireland (Horse) English Spotted Pony, Australia (Horse) Knabstrupper (Horse) Noric (Horse) Pony Of the Americas, Germany (Horse) Thoroughbred (Horse) Stationary congenital night blindness & Leopard Complex/Appaloosa spotting TRPM1 insertion, gross (>20) Naturally occurring variant EquCab3.0 1 NC_009144.3:g.109211964_109211965insN[1378] "a 1378 bp retroviral LTR insertion in intron 1 of TRPM1", EquCab2.0: g.108297929_108297930insN[1378] 2013 24167615 Coordinates in EquCab3.0 kindly provided by Haley Rutstein, working under the guidance of Professor Ernie Bailey.

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2024). OMIA:002139-9796: Online Mendelian Inheritance in Animals (OMIA) [dataset].


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.

2024 McFadden, A., Vierra, M., Martin, K., Brooks, S.A., Everts, R.E., Lafayette, C. :
Spotting the pattern: A review on white coat color in the domestic horse. Animals (Basel) 14:451, 2024. Pubmed reference: 38338094. DOI: 10.3390/ani14030451.
2021 Derks, M.F.L., Steensma, M. :
Review: Balancing selection for deleterious alleles in livestock. Front Genet 12:761728, 2021. Pubmed reference: 34925454. DOI: 10.3389/fgene.2021.761728.
2019 Grilz-Seger, G., Druml, T., Neuditschko, M., Mesarič, M., Cotman, M., Brem, G. :
Analysis of ROH patterns in the Noriker horse breed reveals signatures of selection for coat color and body size. Anim Genet 50:334-346, 2019. Pubmed reference: 31199540. DOI: 10.1111/age.12797.
2017 Druml, T., Grilz-Seger, G., Neuditschko, M., Neuhauser, B., Brem, G. :
Phenotypic and genetic analysis of the leopard complex spotting in Noriker horses. J Hered 108:505-514, 2017. Pubmed reference: 28453641. DOI: 10.1093/jhered/esx039.
2016 Holl, H.M., Brooks, S.A., Archer, S., Brown, K., Malvick, J., Penedo, M.C., Bellone, R.R. :
Variant in the RFWD3 gene associated with PATN1, a modifier of leopard complex spotting. Anim Genet 47:91-101, 2016. Pubmed reference: 26568529. DOI: 10.1111/age.12375.
2015 Ludwig, A., Reissmann, M., Benecke, N., Bellone, R., Sandoval-Castellanos, E., Cieslak, M., Fortes, G.G., Morales-Muñiz, A., Hofreiter, M., Pruvost, M. :
Twenty-five thousand years of fluctuating selection on leopard complex spotting and congenital night blindness in horses. Philos Trans R Soc Lond B Biol Sci 370:20130386, 2015. Pubmed reference: 25487337. DOI: 10.1098/rstb.2013.0386.
2013 Bellone, R.R., Holl, H., Setaluri, V., Devi, S., Maddodi, N., Archer, S., Sandmeyer, L., Ludwig, A., Foerster, D., Pruvost, M., Reissmann, M., Bortfeldt, R., Adelson, D.L., Lim, S.L., Nelson, J., Haase, B., Engensteiner, M., Leeb, T., Forsyth, G., Mienaltowski, M.J., Mahadevan, P., Hofreiter, M., Paijmans, J.L., Gonzalez-Fortes, G., Grahn, B., Brooks, S.A. :
Evidence for a retroviral insertion in TRPM1 as the cause of congenital stationary night blindness and leopard complex spotting in the horse. PLoS One 8:e78280, 2013. Pubmed reference: 24167615. DOI: 10.1371/journal.pone.0078280.
2012 Sandmeyer, L.S., Bellone, R.R., Archer, S., Bauer, B.S., Nelson, J., Forsyth, G., Grahn, B.H. :
Congenital stationary night blindness is associated with the leopard complex in the Miniature Horse. Vet Ophthalmol 15:18-22, 2012. Pubmed reference: 22051042. DOI: 10.1111/j.1463-5224.2011.00903.x.
2010 Bellone, RR., Forsyth, G., Leeb, T., Archer, S., Sigurdsson, S., Imsland, F., Mauceli, E., Engensteiner, M., Bailey, E., Sandmeyer, L., Grahn, B., Lindblad-Toh, K., Wade, CM. :
Fine-mapping and mutation analysis of TRPM1: a candidate gene for leopard complex (LP) spotting and congenital stationary night blindness in horses. Brief Funct Genomic Proteomic 9:193-207, 2010. Pubmed reference: 20353955. DOI: 10.1093/bfgp/elq002.
2007 Sandmeyer, LS., Breaux, CB., Archer, S., Grahn, BH. :
Clinical and electroretinographic characteristics of congenital stationary night blindness in the Appaloosa and the association with the leopard complex. Vet Ophthalmol 10:368-75, 2007. Pubmed reference: 17970998. DOI: 10.1111/j.1463-5224.2007.00572.x.
2004 Terry, RB., Archer, S., Brooks, S., Bernoco, D., Bailey, E. :
Assignment of the appaloosa coat colour gene (LP) to equine chromosome 1. Anim Genet 35:134-7, 2004. Pubmed reference: 15025575. DOI: 10.1111/j.1365-2052.2004.01113.x.
1990 Sponenberg, D.P., Carr, G., Simak, E., Schwink, K. :
The Inheritance of the Leopard Complex of Spotting Patterns in Horses J Hered 81:323-31, 1990. Pubmed reference: 2177073. DOI: 10.1093/oxfordjournals.jhered.a110997.

Edit History

  • Created by Frank Nicholas on 29 Jan 2018
  • Changed by Frank Nicholas on 29 Jan 2018
  • Changed by Frank Nicholas on 06 May 2019
  • Changed by Imke Tammen2 on 18 Jan 2022
  • Changed by Imke Tammen2 on 03 Jun 2024
  • Changed by Imke Tammen2 on 04 Jun 2024
  • Changed by Imke Tammen2 on 05 Jun 2024