epistatic variation

In genetics, epistatic variation refers to the phenomenon where one gene masks or modifies the expression of another, non-allelic gene. This means that the presence or absence of a particular gene can determine whether a trait, influenced by a different gene, will be observable.123

An epistatic gene is the gene that suppresses the effect of another gene, which is then called the hypostatic gene. A classic example is the gene for albinism in humans. The dominant allele for albinism can prevent the expression of genes responsible for skin pigmentation, resulting in an albino individual regardless of their other pigment genes. This interaction of genes at different loci is a complex aspect of genetic variation, often observed in traits like coat color in mice and in the expression of certain inherited human diseases.2314