Genetic Ancestry in Three Colombian Population Groups through AIM-Indels. Marked Variability in Ancestry among Afro-Colombian Samples from Chocó

Abstract

Introduction: Colombia is a multi-ethnic and multicultural country. Its population is predominantly composed of a blend of various ethnicities derived from Europeans, African populations brought during colonial times, and indigenous Amerindian populations, which are the second largest in the Americas after Brazil, as the original inhabitants. Few studies have analyzed the genetic ancestry of Afro-Colombians and Amerindians.

Materials and Methods: With prior consent, we analyzed genetic ancestry using AIM-Indels in 165 Afro-Colombian individuals from five cities and towns along the Chocó region on the Pacific coast of Colombia. We also examined 159 individuals of Amerindian origin belonging to 28 different tribes, along with 149 mixed-race Colombians from the central Andean region.

Results: For the mixed Colombian population, the average proportion of European ancestry was 54.7%, Amerindian ancestry was 38.2%, and African ancestry was 7%. Among Colombian Amerindians, the average Amerindian ancestry was 89.7%, European ancestry was 7.1%, and African ancestry was 3.2%, although there were geographic variations. For the Afro-Colombian population, the average African ancestry was 67.4%, European ancestry was 19.7%, and Amerindian ancestry was 12.9%. However, a significant mixture with European ancestry ranging from 10% to 30% and Amerindian ancestry ranging from 6% to 22% was observed.

Conclusions: Among Amerindians, Amerindian ancestry is higher in the regions of the Orinoco and the Amazon compared to the tribes in the northern and western parts of the country. For Afro-Colombians, different patterns of mixing exist in the Chocó region, where European and Amerindian mixing began during the colonial period and has continued to the present day, resulting in a 10% to 30% European presence and 6% to 22% Amerindian population. These results are highly valuable for population genetics, anthropological, forensic, and pharmacogenetic studies.