 There are 27 identified variants of dominant white as of 2017, plus sabino 1, each corresponding to a spontaneously-white foundation animal and a mutation on the "KIT" gene.Researchers have suggested that at least some forms of dominant white result in nonviable embryos in the homozygous state, though others are known to be viable as homozygotes.While homologous mutations in mice are often linked to anemia and sterility, no such effects have been observed in dominant white horses.