Dominant White W4 - Camarillo

Acronym:	DW4C
Gene:	KIT
Mutation:	c.1805C>T
Inheritance:	Autosomal Dominant
Sample type:	WBE (Whole Blood EDTA), HA (Hairs - with roots)
Method:	Sanger sequencing

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Genetics and characteristics

Dominant White (W) is a general name given to a large number of white spotting patterns caused by mutations in the KIT gene in humans and other animals, including horses. There are up to 30 „W“ mutations that are currently known in horses and all are breed or line specific, having originated in one specific horse. All mutations in the KIT gene affect different signaling pathways influencing the development, migration, and proliferation of melanocytes. Dominant White W4 is a white spotting pattern that has been previously described in Camarillo White and Camarillo cross horse breeds and is caused by a single nucleotide change within the KIT gene. Horses with this specific mutation have a completely white coat, mane, and tail.

This type of dominant white W4 in horses is inherited as an autosomal dominant trait meaning horses with even one copy of the mutated KIT gene will have white spotting patterns. Horses with two mutated genes, so-called double mutants, are likely embryonic lethal because the reduction or absence of KIT signaling affects more than just the pigment cells. Early detection by genetic testing can help identify carriers of the mutation and help breeders in further selection of mating pairs.

 

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Results Reported As

 

 

 

 

 

 

 

 

 

 

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References:

Haase, B., Brooks, S. A., Schlumbaum, A., Azor, P. J., Bailey, E., Alaeddine, F., Mevissen, M., Burger, D., Poncet, P. A., Rieder, S., Leeb, T. (2007). Allelic heterogeneity at the equine KIT locus in dominant white (W) horses. PLoS genetics, 3(11), e195. https://doi.org/10.1371/journal.pgen.0030195