Lactase LCT

A single-nucleotide variant, C/T(-13910), located 14 kb upstream of the lactase gene (LCT), has been shown to be completely correlated with lactase persistence (LP) in northern Europeans.

The global distribution pattern of LP T(-13910) H98 supports the Caucasian origin of this allele.

Age estimates based on different mathematical models show that the common LP T(-13910) H98 allele (approximately 5,000-12,000 years old) is relatively older than the other geographically restricted LP alleles (approximately 1,400-3,000 years old).

Data about global allelic haplotypes of the lactose-tolerance variant imply that the T(-13910) allele has been independently introduced more than once and that there is a still-ongoing process of convergent evolution of the LP alleles in humans.

References

 Enattah NS, Trudeau A, Pimenoff V, Maiuri L, Auricchio S, Greco L, Rossi M, Lentze M, Seo JK, Rahgozar S, Khalil I, Alifrangis M, Natah S, Groop L, Shaat N, Kozlov A, Verschubskaya G, Comas D, Bulayeva K, Mehdi SQ, Terwilliger JD, Sahi T, Savilahti E, Perola M, Sajantila A, Jarvela I, Peltonen L. Evidence of still-ongoing convergence evolution of the lactase persistence T-13910 alleles in humans. Am J Hum Genet. 2007 Sep;81(3):615-25. PMID: 17701907