Stability or variation? Patterns of lactase gene and its enhancer region distributions in Brazilian Amerindians
Version of Record online: 23 JAN 2012
Copyright © 2012 Wiley Periodicals, Inc.
American Journal of Physical Anthropology
Volume 147, Issue 3, pages 427–432, March 2012
How to Cite
Friedrich, D. C., Callegari-Jacques, S. M., Petzl-Erler, M. L., Tsuneto, L., Salzano, F. M. and Hutz, M. H. (2012), Stability or variation? Patterns of lactase gene and its enhancer region distributions in Brazilian Amerindians. Am. J. Phys. Anthropol., 147: 427–432. doi: 10.1002/ajpa.22010
- Issue online: 13 FEB 2012
- Version of Record online: 23 JAN 2012
- Manuscript Accepted: 7 DEC 2011
- Manuscript Received: 10 AUG 2011
- Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil
- Amerindian populations;
- genetic structure;
- LCT gene
Lactase persistence (LP) is the phenotypic trait in which lactase secretion is maintained during adulthood. LP is due to mutations in the LCT enhancer region, located 14-kb upstream of the gene. In Europeans, the −13910*T allele is associated with LP. In Africans this allele is rare while other mutations in this same region were related to LP. The LCT is highly polymorphic in human populations, but so far Brazilian Amerindians had not been investigated for these polymorphisms or for the presence of LP mutations. We describe the genetic diversity of the LCT region and the presence of LP enhancer mutations in four native Brazilian populations (Guarani-Kaiowá, Guarani–Ñandeva, Kaingang, and Xavante). Twelve polymorphisms were genotyped by PCR-based methods. The −13910*T allele varied from 0.5% in the Xavante to 7.6% in the Guarani–Ñandeva. These frequencies probably derive from European sources and they correlate with non-native admixture proportions previously estimated for these groups. But since admixture is virtually absent in the Xavante, we suggest that the presence of the LP allele could have been determined by a de novo mutation. No other mutations in the −14 kb enhancer region were found. The LCT was highly polymorphic in the present sample showing 15 haplotypes with a heterogeneous distribution among the four Amerindian populations. This diversity could be due to drift, as indicated by the neutrality test performed. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.