DRPLA is observed relatively less frequently in other ethnic populations and an analysis of normal ATN1 alleles has demonstrated that CAG repeat length greater than 17 are significantly more frequent in the Japanese population.
Genetic recombination, refers to the recombining of alleles resulting in a new molecule of DNA
Epistasis: when the alleles at one locus change the phenotypic effects of genetic variation at another locus, the two genes are said to exhibit 'epistasis' in their interactions.
When found B*4601 segregates with only 2 HLA-Cw alleles, A limited number of HLA-A and HLA-DRB1 alleles suggesting that the allele recently expanded from a limited sized group within SE Asia.
The nuclear DNA results indicate about 30% of derived alleles in H. sapiens are also in the Neanderthal lineage.
In contrast, the activating receptors LILRA1 and LILRA3 prefer b2m-independent free heavy chains of MHC class I, and in particular HLA-C alleles.
Since the original study in the early part of the last century, in addition to the breeds identified as carrying the SW-1, -2 or -3 alleles, splashed white has also been identified, but not mapped, in American Saddlebreds, Morgan horses, the Irish Tinker or Gypsy horse, the Indian Kathiawari and feral Abaco Barbs of the Bahamas.
Another cause arises from the interaction between two alleles, also known as the epistatic effect between alleles.
Translocase of outer mitochondrial membrane 40 (TOMM40), a protein encoded by the TOMM40 gene, whose alleles differentially impact the risk for Alzheimer's disease