This article reports on a project that genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region, including those previously associated with eye or skin pigmentation.
Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation, and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160–170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535–542, 2007; Anno et al. in Int J Biol Sci 4, 2008). The current project reports that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. The current project also observed that the derived allele of rs1800414 is essentially limited to East Asia, where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. This study also found evidence of selection at the derived allele of rs1800414 in East Asia. The data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and provide further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele. 10 figures, 3 tables, and 35 references (publisher abstract modified)