Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations

TLDR

The EPIGEN Brazil Project is the largest Latin‑American initiative to study genomic diversity in admixed populations and its phenotypic effects. The authors use whole‑genome data to show that continental admixture is the main determinant of deleterious genotypes in admixed individuals. They studied 6,487 Brazilians from three population‑based cohorts with diverse geographic and demographic backgrounds. The study identified ancestry components at unprecedented geographic resolution, uncovered an African ancestry component likely derived from Bantu/eastern African slave trade, and demonstrated that continental admixture is the primary determinant of deleterious genotypes in admixed Brazilians.

Abstract

Significance The EPIGEN Brazil Project is the largest Latin-American initiative to study the genomic diversity of admixed populations and its effect on phenotypes. We studied 6,487 Brazilians from three population-based cohorts with different geographic and demographic backgrounds. We identified ancestry components of these populations at a previously unmatched geographic resolution. We broadened our understanding of the African diaspora, the principal destination of which was Brazil, by revealing an African ancestry component that likely derives from the slave trade from Bantu/eastern African populations. In the context of the current debate about how the pattern of deleterious mutations varies between Africans and Europeans, we use whole-genome data to show that continental admixture is the main and complex determinant of the amount of deleterious genotypes in admixed individuals.