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Leif Groop

Leif Groop

Principal investigator

Leif Groop

Independent introduction of two lactase-persistence alleles into human populations reflects different history of adaptation to milk culture


  • Nabil Sabri Enattah
  • Tine G. K. Jensen
  • Mette Nielsen
  • Rikke Lewinski
  • Mikko Kuokkanen
  • Heli Rasinpera
  • Hatem El-Shanti
  • Jeong Kee Seo
  • Michael Alifrangis
  • Insaf F. Khalil
  • Abdrazak Natah
  • Ahmed Ali
  • Sirajedin Natah
  • David Comas
  • S. Qasim Mehdi
  • Leif Groop
  • Else Marie Vestergaard
  • Faiqa Imtiaz
  • Mohamed S. Rashed
  • Brian Meyer
  • Jesper Troelsen
  • Leena Peltonen

Summary, in English

The T-13910 variant located in the enhancer element of the lactase (LCT) gene correlates perfectly with lactase persistence (LP) in Eurasian populations whereas the variant is almost nonexistent among Sub-Saharan African populations, showing high prevalence of LP. Here, we report identification of two new mutations among Saudis, also known for the high prevalence of LP. We confirmed the absence of the European T-13910 and established two new mutations found as a compound allete: T/G(-13915) within the -13910 enhancer region and a synonymous SNP in the exon 17 of the MCM6 gene T/C-3712, -3712 bp from the LCT gene. The compound allele is driven to a high prevalence among Middle East population(s). Our functional analyses in vitro showed that both SNPs of the compound allele, located 10 kb apart, are required for the enhancer effect, most probably mediated through the binding of the hepatic nuclear factor 1 alpha (HNF1 alpha). High selection coefficient (s) similar to 0.04 for LP phenotype was found for both T-13910 and the compound allele. The European T-13910 and the earlier identified East African G(-13907) LP allele share the same ancestral background and most likely the same history, probably related to the same cattle domestication event. In contrast, the compound Arab allele shows a different, highly divergent ancestral haplotype, suggesting that these two major global LP alleles have arisen independently, the latter perhaps in response to camel milk consumption. These results support the convergent evolution of the LP in diverse populations, most probably reflecting different histories of adaptation to milk culture.


  • Genomics, Diabetes and Endocrinology

Publishing year







American Journal of Human Genetics





Document type

Journal article


Cell Press


  • Medical Genetics



Research group

  • Genomics, Diabetes and Endocrinology


  • ISSN: 0002-9297