The rs387907171 SNP in TYRP1 is not Associated with Blond Hair Color on the Island of Bougainville

Objectives: The aims of this study are to characterize the frequency of the derived allele at rs387907171 in populations from the islands of New Britain and Bougainville in Northern Island Melanesia, to confirm its association with lighter hair color, and to refine hypotheses regarding its evolutionary history. Methods: rs387907171 was genotyped in 93 individuals from New Britain and 101 from Bougainville for whom quantitative assessments of skin and hair pigmentation were available. Combining these with existing data from other Melanesian islands we tested for differences in allele frequencies between islands and for associations with skin and hair pigmentation using ANOVA, including sex, age, and island affiliations as covariates. Results: The derived allele at rs387907171 was observed in a single copy in the New Britain and Bougainville populations genotyped here. Its frequency differs significantly among islands in the region (chi(2) = 206.5, df = 3, P < 0.001). rs387907171 remains significantly, although weakly, associated with lighter hair pigmentation (F = 10.28, R-2 = 0.0125, P = 0.0014). This association increases when sex and age (F = 20.68, R-2 = 0.074, P < 7.92 x 10(-13)) are included as covariates. Conclusions: The rs387907171 SNP exhibits strong allele frequency differences among islands in Northern Island Melanesia. Its absence from Bougainville, as well as the weak association with decreased hair color, indicates that additional alleles contribute to the blondism phenotype. Its geographic distribution suggests that a Lapita-mediated model for the dispersal of the derived allele at rs387907171 remains a viable evolutionary scenario. (C) 2015 Wiley Periodicals, Inc.