Color: Dominant White cats are completely white, and may have blue eyes; white spotting (piebald) is responsible for a variable distribution of depigmented areas on the body.
Samples Accepted: Blood, Buccal Swabs
Locus Information: W
Test Information: Dominant White and white spotting in the cat are caused by two related mutations in the KIT gene. These mutations have been found responsible for Dominant White and white spotting in all breeds tested.
White Spotting is caused by the insertion of a retrovirus (FERV1) into the KIT gene. The mutation is dominant, but having two copies of the white spotting allele is correlated with having more white on the body.
Dominant White is caused by the insertion of a part of the FERV1 retrovirus (the long terminal repeat, or LTR) into the KIT gene. The mutation is dominant, meaning that only one copy of the allele is necessary for the cat to be white. If the cat has two copies of the allele, it is more likely to be deaf. A Dominant White cat can also have a white spotting allele; however, the effects of the spotting will not be seen due to the full depigmentation effect of the Dominant White allele.
David, V.A., Menotti-Raymond, M., Wallace, A.C., Roelke, M., Kehler, J., Leighty, R., Eizirik, E., Hannah, S.S., Nelson, G., Schäffer, A.A., Connelly, C.J., O’Brien, S.J., Ryugo, D.K.: Endogenous Retrovirus Insertion in the KIT Oncogene Determines White and White spotting in Domestic Cats. G3 (Bethesda) :, 2014. Pubmed reference: 25085922. Doi: 10.1534/g3.114.013425.
Further information is available at the Online Mendelian Inheritance in Animals (Dominant White) and Online Mendelian Inheritance in Animals (White Spotting) website.