title: Novel variants in the KIT and PAX3 genes in horses with white-spotted coat colour phenotypes.
abstract: Variants in the EDNRB, KIT, MITF, PAX3 and TRPM1 genes are known to cause white spotting phenotypes in horses, which can range from the common white markings up to completely white horses. In this study, we investigated these candidate genes in 169 horses with white spotting phenotypes not explained by the previously described variants. We identified a novel missense variant, PAX3:p.Pro32Arg, in Appaloosa horses with a splashed white phenotype in addition to their leopard complex spotting patterns. We also found three novel variants in the KIT gene. The splice site variant c.1346+1G>A occurred in a Swiss Warmblood horse with a pronounced depigmentation phenotype. The missense variant p.Tyr441Cys was present in several part-bred Arabians with sabino-like depigmentation phenotypes. Finally, we provide evidence suggesting that the common and widely distributed KIT:p.Arg682His variant has a very subtle white-increasing effect, which is much less pronounced than the effect of the other described KIT variants. We termed the new KIT variants W18-W20 to provide a simple and unambiguous nomenclature for future genetic testing applications.
authors: Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland; DermFocus, University of Bern, 3001, Bern, Switzerland.
authors: Regula
authors: R
authors: Hauswirth
authors: Rony
authors: R
authors: Jude
authors: Bianca
authors: B
authors: Haase
authors: Rebecca R
authors: RR
authors: Bellone
authors: Sheila
authors: S
authors: Archer
authors: Heather
authors: H
authors: Holl
authors: Samantha A
authors: SA
authors: Brooks
authors: Teruaki
authors: T
authors: Tozaki
authors: Maria Cecilia T
authors: MC
authors: Penedo
authors: Stefan
authors: S
authors: Rieder
authors: Tosso
authors: T
authors: Leeb
mesh_terms: D000818:Animals; D006197:Hair / Q000502:physiology*; D006736:Horses / Q000235:genetics* / Q000502:physiology; D020125:Mutation, Missense / Q000235:genetics; D051761:Paired Box Transcription Factors / Q000235:genetics*; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*
chemical_list: D051761:Paired Box Transcription Factors; D019009:Proto-Oncogene Proteins c-kit
keywords: Equus caballus; leucism; melanocyte; piebaldism; pigmentation; white spotting