Genetics of hair and skin color.
Differences in skin and hair color are principally genetically determined and are due to variation in the amount, type, and packaging of melanin polymers produced by melanocytes secreted into keratinocytes. Pigmentary phenotype is genetically complex and at a physiological level complicated. Genes determining a number of rare Mendelian disorders of pigmentation such as albinism have been identified, but only one gene, the melanocortin 1 receptor (MCR1), has so far been identified to explain variation in the normal population such as that leading to red hair, freckling, and sun-sensitivity. Genotype-phenotype relations of the MC1R are reviewed, as well as methods to improve the phenotypic assessment of human pigmentary status. It is argued that given advances in model systems, increases in technical facility, and the lower cost of genotype assessment, the lack of standardized phenotype assessment is now a major limit on advance.
Rees
Jonathan L
JL
Systems Group, Dermatology, University of Edinburgh, Lauriston Buildings, Lauriston Place, Edinburgh, EH3 9YW, United Kingdom. jrees@staffmail.ed.ac.uk
D054366:Agouti Signaling Protein; D014644:Genetic Variation; D005838:Genotype; D006200:Hair Color / Q000235:genetics*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008543:Melanins / Q000096:biosynthesis*; D008544:Melanocytes / Q000378:metabolism*; D010641:Phenotype; D044102:Receptor, Melanocortin, Type 1 / Q000235:genetics / Q000378:metabolism; D012880:Skin Pigmentation / Q000235:genetics*; D013329:Structure-Activity Relationship; D000521:alpha-MSH / Q000378:metabolism
D054366:Agouti Signaling Protein; D036341:Intercellular Signaling Peptides and Proteins; D008543:Melanins; D044102:Receptor, Melanocortin, Type 1; D000521:alpha-MSH