Worldwide polymorphism at the MC1R locus and normal pigmentation variation in humans

While there have been many advances in our understanding of the genetics of pathological skin pigmentation in humans, our knowledge about what determines variation in normal skin color is still incomplete. Variation in one gene, melanocortin I receptor (MCIR), has been associated with red hair and fair skin in Europeans. However, this gene might also play an important role in shaping pigmentation of other human populations, where it experiences different selective pressures. Below we review what is currently known about polymorphism and selection at the MCIR coding and promoter regions in human populations, the pattern of MCIR evolution in nonhuman primates, and the interaction of MCIR with other genes. (c) 2005 Elsevier Inc. All rights reserved.