Dominant White (W3, W5, W10, W13 and W20)
White coat color or de-pigmentation phenotype in horses is inherited as a monogenic autosomal dominant trait showing a variable expression of coat depigmentation. Dominant white” refers to a class of white spotting patterns in which a horse with one copy will display markings on 50-100% of the body. Unlike other extreme white patterns, this trait generally leaves the eyes dark. Dominant White markings are a result of various mutations occurring in the Kit gene.
|W1||Franches Montagnes||Cigale, 1957|
|W2||Thoroughbred||KY Colonel, 1946|
|W3||Arabian||R Khasper, 1996|
|W4||Camarillo White Horse||Sultan, 1912|
|W9||Holstein Horse||not published|
|W10||Quarter Horse||GQ Santana, 2000|
|W11||South German Draft Horse||not published|
|W13||Quarter Horse||Haase B et al.|
|W20||Gypsy and many other breeds||Hauswirth R et al.|
Dominant White is a dominant physical trait, so if a horse has one or two copies of the Dominant White gene, the horse will display the pattern associated with the gene mutation. Testing can determine if the coat pattern of a horse is actually Dominant White (W3, W5, W10, W13 and W20) or if a different modifier is present. This can be particularly useful in horses that have additional patterns, such as Frame Overo and Tobiano. DNA testing for Dominant White (W3, W5, W10, W13 and W20), also identifies if a horse has 1 or 2 copies of the gene, which can be an informative tool for breeders.
If you believe your horse is included in one of these 11 families identified as carrying a Dominant White allele and you would like to confirm if it carries the specific KIT mutation, Animal Genetics has developed genetic tests for many of these alleles and can verify whether or not the horse carries the suspected allele. Please call our office or email us for more information.
Animal Genetics offers DNA testing for Dominant White (W3, W5, W10, W13 and W20). The genetic test verifies the presence of the W3, W5 or W10 mutation and presents results as one of the following:
|W#/W#||Affected||Indicate that the horse carries two copies of the specific Dominant White KIT mutation.|
|n/W#||Carrier||Horse carries one copy of the specific Dominant White KIT mutation that was tested for. Horse will usually exhibit a coat pattern phenotype associated with the particular mutation which could vary greatly from a completely white coat to small areas of white, depending on which mutation is involved.|
|n/n||Negative||This horse does not carry the specific Dominant White gene mutation that was tested.|