Genetic Ancestry Strongly Impacts MAPT (17q21.31) Haplotype Frequencies of South American Populations

Document Type

Article

Authors

• Miguel A. Alfonso-Sánchez, Universidad del Pais Vasco (UPV/EHU)Follow
• José E. Dipierri, Instituto de Biología de la Altura, Universidad Nacional de Jujuy, San Salvador de Jujuy, ArgentinaFollow
• Ibone Espinosa, Departamento de Genética, Antropología Física y Fisiología Animal. Facultad de Ciencia y Tecnología. Universidad del País Vasco (UPV/EHU), SpainFollow
• Luis Gómez-Pérez, Departamento de Genética, Antropología Física y Fisiología Animal. Facultad de Ciencia y Tecnología. Universidad del País Vasco (UPV/EHU), SpainFollow
• José A. Peña, Departamento de Genética, Antropología Física y Fisiología Animal. Facultad de Ciencia y Tecnología. Universidad del País Vasco (UPV/EHU), SpainFollow

Open Access Pre-Print

https://digitalcommons.wayne.edu/humbiol_preprints/233/

Abstract

Genetic and archaeological studies indicate that the American continent has undergone multiple waves of human migration, shaping a complex population genetic structure comprising three major ethnic groups—Native American, European, and African—unevenly distributed across the continent. In this study, we examined MAPT (17q21.31) haplotype and subhaplotype frequencies by analyzing two single nucleotide polymorphism markers (rs10514879 and rs199451) in three South American groups from distinct countries: Waorani (Ecuadorian Amazon), Jujuy (northwestern Argentina), and Afro-Colombian (northwestern Colombia). To broaden the scope, we also genotyped four short tandem repeats within the 17q21.31 chromosomal region and compiled H2 haplotype and subhaplotype frequency data for 97 worldwide populations (Africa: 26; Asia: 37; Europe: 19; America: 15). We used the publicly available genome-wide databases 1000G and ALFRED. Genetic heterogeneity among population clusters, classified by geographic region, was examined by hierarchical analysis of molecular variance. Likewise, we explored genetic affinities between the Waorani, Afro-Colombian, and Jujuy samples and worldwide collections using factorial correspondence analysis. The H1 haplotype predominated in all study populations. Notably, H2 varied among them: In Afro-Colombians, H2 was found at a frequency of 0.058, with equal representation of subhaplotypes H2’ and H2D. Among Native American groups (Waorani and Jujuy), the H2 haplotype was virtually absent, with only H2D detected in Jujuy at a very low frequency (0.007). Analysis of a set of short tandem repeats from the MAPT region identified distinct genetic features in Native American groups, characterized by markedly low heterozygosity. Waorani and Karitiana exhibited strikingly low genetic diversity, reflecting a significant degree of population isolation and, consequently, a potentially strong impact of genetic drift. In summary, our analyses demonstrate the utility of MAPT haplotypes in detecting the effects of population isolation, genetic drift, and admixture on the gene pool of the South American samples examined. MAPT haplotypes may serve as reliable lineage markers, given their ability to differentiate ethnic groups and trace ancestral chromosomes. They have proved to be an informative and cost-effective tool for exploring ancestry, geographic origins, and demographic history in anthropological studies.

Recommended Citation

Alfonso-Sánchez, Miguel A.; Dipierri, José E.; Espinosa, Ibone; Gómez-Pérez, Luis; and Peña, José A. (2026) "Genetic Ancestry Strongly Impacts MAPT (17q21.31) Haplotype Frequencies of South American Populations," Human Biology: Vol. 96: Iss. 2, Article 1.
Available at: https://digitalcommons.wayne.edu/humbiol/vol96/iss2/1