AUTHOR=Guimarães Alves Ana Cecília , Sukow Natalie Mary , Adelman Cipolla Gabriel , Mendes Marla , Leal Thiago P. , Petzl-Erler Maria Luiza , Lehtonen Rodrigues Souza Ricardo , Rainha de Souza Ilíada , Sanchez Cesar , Santolalla Meddly , Loesch Douglas , Dean Michael , Machado Moara , Moon Jee-Young , Kaplan Robert , North Kari E. , Weiss Scott , Barreto Mauricio L. , Lima-Costa M. Fernanda , Guio Heinner , Cáceres Omar , Padilla Carlos , Tarazona-Santos Eduardo , Mata Ignacio F. , Dieguez Elena , Raggio Víctor , Lescano Andres , Tumas Vitor , Borges Vanderci , Ferraz Henrique B. , Rieder Carlos R. , Schumacher-Schuh Artur , Santos-Lobato Bruno L. , Chana-Cuevas Pedro , Fernandez William , Arboleda Gonzalo , Arboleda Humberto , Arboleda-Bustos Carlos E. , O’Connor Timothy D. , Beltrame Marcia Holsbach , Borda Victor TITLE=Tracing the Distribution of European Lactase Persistence Genotypes Along the Americas JOURNAL=Frontiers in Genetics VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.671079 DOI=10.3389/fgene.2021.671079 ISSN=1664-8021 ABSTRACT=

In adulthood, the ability to digest lactose, the main sugar present in milk of mammals, is a phenotype (lactase persistence) observed in historically herder populations, mainly Northern Europeans, Eastern Africans, and Middle Eastern nomads. As the –13910∗T allele in the MCM6 gene is the most well-characterized allele responsible for the lactase persistence phenotype, the –13910C > T (rs4988235) polymorphism is commonly evaluated in lactase persistence studies. Lactase non-persistent adults may develop symptoms of lactose intolerance when consuming dairy products. In the Americas, there is no evidence of the consumption of these products until the arrival of Europeans. However, several American countries’ dietary guidelines recommend consuming dairy for adequate human nutrition and health promotion. Considering the extensive use of dairy and the complex ancestry of Pan-American admixed populations, we studied the distribution of –13910C > T lactase persistence genotypes and its flanking haplotypes of European origin in 7,428 individuals from several Pan-American admixed populations. We found that the –13910∗T allele frequency in Pan-American admixed populations is directly correlated with allele frequency of the European sources. Moreover, we did not observe any overrepresentation of European haplotypes in the –13910C > T flanking region, suggesting no selective pressure after admixture in the Americas. Finally, considering the dominant effect of the –13910∗T allele, our results indicate that Pan-American admixed populations are likely to have higher frequency of lactose intolerance, suggesting that general dietary guidelines deserve further evaluation across the continent.