SLC24A5

SLC24A5 (solute carrier family 24, member 5) is a gene that is thought to be one of many genes that control skin pigmentation in humans, and therefore implicated in defining ethnic origin.

Research done by a large team at Penn State University and a number of other institutions discovered that the gene has two primary alleles that differ in only one nucleotide, changing the 111th amino acid from alanine to threonine.

The threonine allele was present in 98.7 to 100% among several European samples, while the alanine form was found in 93 to 100% of samples of Africans, East Asians and Indigenous Americans. The variation is a SNP polymorphism rs1426654, which had been previously shown to be second among 3011 tabulated SNPs ranked as ancestry-informative markers. They also showed that SLC24A5 explains between 25 and 38% of the European-African difference in skin melanin index.

The discovery of this gene may have interesting social consequences because of its bearing on the genetics of ethnic differences. It has obvious application to forensic science as well.

The SLC24A5 gene is located on the long (q) arm of chromosome 15 on position 21.1, from base pair 46,200,461 to base pair 46,221,881.

It is currently estimated that the threonine allele originated among Europeans 6,000 to 12,000 years ago.