Genetic variants and skin colour in Danes

Abstract

In this study, 33 single nucleotide polymorphisms (SNPs) in known pigmentation genes were tested for association to objective spectrophotometric reflectance measurements of the upper-inner arm and the buttock in 188 unrelated Danes. The 188 Danes were typed for 33 SNPs by two multiplex PCRs, two multiplex single base extension reactions and capillary electrophoresis. To further investigate the role of the SNPs, their allelic distribution was compared to those in a population of 36 Somalis. Four MC1R SNP alleles (R151C, R160W, D294H and 29insA) showed significant associations to light skin pigmentation in individuals who were either homozygous or compound heterozygous. This confirms the regulatory role of MC1R in skin pigmentation. SNP loci in SLC45A2, SLC24A5 and TYR showed large allele frequency differences between Somalis and Danes, which suggested a possible role in skin pigmentation. The average buttock pigmentation was significantly lighter than the average upper-inner arm pigmentation. Therefore, the buttock reflectance measurements better resemble the constitutive skin colour compared to upper-inner arm reflectance measurements and will be used in future studies.