OCA2481Thr, a hypofunctional allele in pigmentation, is characteristic of northeastern Asian populations

Asians as well as Europeans have light skin, for which no genes to date are known to be responsible. A mutation, Ala481Thr (c.G1559A), in the oculocutaneous albinism type II ( OCA2 ) gene has approximately 70% function of the wild type allele in melanogenesis. In this study, the distribution of the mutation was investigated in a total of 2,615 individuals in 20 populations from various areas. OCA2*481Thr prevailed almost exclusively in a northeastern part of Asia. The allele frequency was highest in Buryat (0.24) in Mongolia and showed a north–south downward geographical gradient. These findings suggest that OCA2*481Thr arose in a region of low ultraviolet radiation and thereafter spread to neighboring populations.