Ancestry informative markers in indigenous populations from Brazil

Brazil has more than one million Indigenous people, with the highest populations concentrated in the North and Center-West regions. These regions have significant Indigenous populations, so this provides essential insights into their genetic heritage. This study aimed to investigate the genomic ancestry of Indigenous groups in these areas by ten Ancestry Informative Markers (AIMs) described with frequency differential > 30% between parental populations. By analyzing these markers, we determined the ancestral genetic profile for European (EUR), African (AFR), and Amerindian (AME) ancestry within indigenous (IND) from the North (Tiriyó and Waiampi) and Center-West (Jaguapiru and Bororó) of Brazil. Peripheral blood samples were collected from three hundred and two indigenous people, and genomic DNA was extracted to identify AIMs through PCR. The genomic ancestry results showed that Tiriyó was AME: 74.1, EUR: 14.7, AFR: 11.2; Waiampi, AME: 49.3, EUR: 35.7, AFR: 15.0; Jaguapiru and Bororó AME: 47.1, EUR: 42.8, AFR: 10.2. These findings indicate that indigenous populations have preserved mainly their Amerindian ancestral contributions, despite varying levels of European and African admixture. While the AIMs effectively distinguished between AFR and IND ancestries, they were less precise in differentiating between EUR and IND. Understanding the genetic profile of indigenous Brazilians is essential to identifying genetic predispositions and specific health risks, allowing for personalized interventions and more inclusive public health policies.