title: Convergent adaptation of human lactase persistence in Africa and Europe.
abstract: A SNP in the gene encoding lactase (LCT) (C/T-13910) is associated with the ability to digest milk as adults (lactase persistence) in Europeans, but the genetic basis of lactase persistence in Africans was previously unknown. We conducted a genotype-phenotype association study in 470 Tanzanians, Kenyans and Sudanese and identified three SNPs (G/C-14010, T/G-13915 and C/G-13907) that are associated with lactase persistence and that have derived alleles that significantly enhance transcription from the LCT promoter in vitro. These SNPs originated on different haplotype backgrounds from the European C/T-13910 SNP and from each other. Genotyping across a 3-Mb region demonstrated haplotype homozygosity extending >2.0 Mb on chromosomes carrying C-14010, consistent with a selective sweep over the past approximately 7,000 years. These data provide a marked example of convergent evolution due to strong selective pressure resulting from shared cultural traits-animal domestication and adult milk consumption.
authors.affiliation: Department of Biology, University of Maryland, College Park, Maryland 20742, USA. Tishkoff@umd.edu
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Tishkoff
authors.forename: Floyd A
authors.initials: FA
authors.lastname: Reed
authors.forename: Alessia
authors.initials: A
authors.lastname: Ranciaro
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Voight
authors.forename: Courtney C
authors.initials: CC
authors.lastname: Babbitt
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Silverman
authors.forename: Kweli
authors.initials: K
authors.lastname: Powell
authors.forename: Holly M
authors.initials: HM
authors.lastname: Mortensen
authors.forename: Jibril B
authors.initials: JB
authors.lastname: Hirbo
authors.forename: Maha
authors.initials: M
authors.lastname: Osman
authors.forename: Muntaser
authors.initials: M
authors.lastname: Ibrahim
authors.forename: Sabah A
authors.initials: SA
authors.lastname: Omar
authors.forename: Godfrey
authors.initials: G
authors.lastname: Lema
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Nyambo
authors.forename: Jilur
authors.initials: J
authors.lastname: Ghori
authors.forename: Suzannah
authors.initials: S
authors.lastname: Bumpstead
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Pritchard
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wray
authors.forename: Panos
authors.initials: P
authors.lastname: Deloukas
mesh_terms: D000220:Adaptation, Biological; D000328:Adult; D000349:Africa; D000818:Animals; D018938:Caco-2 Cells; D005060:Europe; D019143:Evolution, Molecular; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D043322:Lactase / Q000235:genetics*; D007785:Lactose / Q000097:blood / Q000378:metabolism*; D007789:Lactose Tolerance Test; D008892:Milk / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic
chemical_list: D043322:Lactase; D007785:Lactose