Combinations of genes.
The KIT gene consists of roan, tobiano, sabino, and dominant white. Since all of these patterns are alleles of a single gene, only two at most can be present on a horse. If a horse is homozygous for one of those patterns, it wont have any of the others.
If a horse is recessive for all KIT traits, KIT can simply be written as "n" for none, or with a + sign. If referencing just one KIT trait, it is written as a lowercase version with a plus sign (to+, rn+).
The KIT gene consists of roan, tobiano, sabino, and dominant white. Since all of these patterns are alleles of a single gene, only two at most can be present on a horse. If a horse is homozygous for one of those patterns, it wont have any of the others.
If a horse is recessive for all KIT traits, KIT can simply be written as "n" for none, or with a + sign. If referencing just one KIT trait, it is written as a lowercase version with a plus sign (to+, rn+).