W20 is a rather unique white spotting variation; rather than causing white patterns by itself, it seems to act as a modifier or booster for other white patterns, namely white spotting.In combination with certain white spotting variations, this can even lead to a nearly-white phenotype, making the base colour difficult to recognise. On Horse Reality, it also boosts hidden sabino and white markings. If no white is present, W20 won't have any effect on a horse.
W20 is a white spotting mutation on the KIT locus (a missense mutation in exon 14). Homozygous W20 (W20/W20) is viable but has the same effect as heterozygous W20 (W20/n); there is no additional increase in the amount of white.
Below, the resulting phenotype of each genotype is listed:
W20/W20 = Boosted white markings and hidden sabino (if present)
W20/n = Boosted white markings and hidden sabino (if present)
n/n = Regular white markings and hidden sabino (if present)
Note: W20 testing at the Laboratory is not fully functional at the moment.
When all KIT alleles have been tested, the following results indicate the presence of W20: ?/? = W20/W20 ?/n, n/? = W20/n RN/?, ?/RN = RN/W20 n/n = n/n
The W20 allele is an old mutation found in many different horse breeds in real life. On Horse Reality, W20 has currently only been added to the Lipizzaner Horse.
The following table lists all breeds that can currently have the W20 allele in-game.
