W10 is one of the many different variations of white spotting.
¶ Phenotype
Horses with W10 exhibit a wide range of phenotypes; from belly spots, large face and leg markings, to nearly white horses. Horses may retain flecks or regions of pigmented skin and hair, mainly at the topline (especially ears and poll). Foals may be born with a pigmented topline, which then fades over time as the horse gets older. Typical white spotting characteristics are also present: the white patches often have irregular, jagged edges and white ticking is usually present in the pigmented areas.
W10 affects any base colour, but the presence of dilutions or grey may make the white pattern harder to see. When the pattern is very expressive, W10 may make it difficult to recognise the underlying colour of the horse without genetic testing.
| W10 - Quarter Horse |
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¶ Genotype
W10 is a white spotting mutation on the KIT locus (a frameshift mutation at exon 7). No horses homozygous for W10 have been recorded, therefore, it is suspected to be embryonic lethal in real life. In Horse Reality, breeding two horses together that both have any of the white spotting alleles (W/n), will result in a failed pregnancy on the 4th day if the foal is W/W (25% chance). A homozygous white spotting foal will, therefore, never be born.
Below, the resulting phenotype of each genotype is listed:
- W10/Wx = Failed pregnancy
- W10/n = White spotting 10
- n/n = No white spotting
W10 can be tested at the Laboratory.
W10 can of course also be present together with other KIT alleles - however, since they are located on the same gene, horses can only be heterozygous:
- TO/W10 = Tobiano white spotting 10
- SB1/W10 = Sabino1 white spotting 10
- RN/W10 = Roan white spotting 10
¶ Breeds
The founder of the W10 mutation was GQ Santana, a Quarter Horse born in 2000. The following table lists all breeds that can currently have the W13-allele in-game.
| Breeds |
| Akhal-Teke Horse |
| Arabian Horse |
| Brabant Horse |
| Brumby Horse |
| Camargue Horse |
| Cleveland Bay |
| Exmoor Horse |
| Finnhorse |
| Fjord Horse |
| Friesian Horse |
| Haflinger Horse |
| Icelandic Horse |
| Irish Cob Horse |
| Kladruber Horse |
| Knabstrupper |
| Lipizzaner |
| Lusitano |
| Mongolian Horse |
| Mustang Horse |
| Namib Desert Horse |
| Noriker Horse |
| Norman Cob |
| Oldenburg Horse |
| Pantaneiro Horse |
| Pura Raza Española |
| Quarter Horse |
| Shetland Pony |
| Shire Horse |
| Suffolk Punch |
| Thoroughbred |
| Trakehner Horse |
| Welsh Pony |
¶
References
- Bellone R., Sponenberg D. P., Equine Color Genetics, 4th Edition, 2017, Wiley-Blackwell,
- Castle N., Equine KIT Gene Mutations, Dun Central Station, 2009
- The University of Sydney, Online Mendelian Inheritance in Animals (OMIA); https://omia.org/OMIA000209/9796/; Access: December 2022
- GQ Santana horse pedigree; https://www.allbreedpedigree.com/gq+santana; Access: December 2022