Novel variants in the KIT and PAX3 genes in horses with white-spotted coat colour phenotypes.

The research article focuses on the exploration of additional gene variants within horses that could lead to different white spotting patterns on their coats. Specifically, the study identified new variants in the KIT and PAX3 genes seen in horses with white-spotted coat color phenotypes not previously described.

About the Study

• The research examined EDNRB, KIT, MITF, PAX3, and TRPM1 genes, which are already known to trigger white spotting phenotypes in horses.
• The study included a sample of 169 horses with white spotting phenotypes, not accounted for by variants already described in past research.

Novel Variant in PAX3

• A novel missense variant, PAX3:p.Pro32Arg, was identified within Appaloosa horses.
• This variant is believed to be connected with the splashed white phenotype observed in these horses, which is also accompanied by leopard complex spotting patterns.

New Variants in KIT

• The research uncovered three novel variants within the KIT gene.
• A splice site variant (referred to as c.1346+1G>A), was detected in a Swiss Warmblood horse with a noticeable depigmentation phenotype.
• A missense variant, p.Tyr441Cys, was recognized within several part-bred Arabians that showed sabino-like depigmentation phenotypes.
• Furthermore, the study provides evidence that suggests the commonly widespread KIT:p.Arg682His variant has a subtle white-increasing effect on a horse’s coat. This effect is considerably less pronounced than those of the other described KIT variants.

Significance of the Findings

• All the new KIT variants discovered through this investigation have been labelled as W18-W20. This classification provides a simple and straightforward nomenclature which could be useful in future genetic testing applications.
• The study makes significant contributions to the existing body of knowledge pertaining to white-spotting and depigmentation patterns in horses, providing potential new avenues for genetic studies and breeding.