Using whole-genome sequencing, researchers have explored the breadth of genomic diversity across Africa, gaining further insight into human migration and health.
The African continent is home to the origins of modern humans and contains more genetic diversity than any other. Unfortunately, researchers have only surveyed a fraction of the genetic diversity among African individuals. Advances in genomics have empowered the interrogation of the human genome across populations. These studies have provided important insights into clinically relevant loci and advanced precision medicine. Currently, only a limited number of around 2,000 African ethnolinguistic groups have been genetically characterised. Researchers have predominantly done this through genotype arrays. These findings show that there are only a limited number of variants that are common with European populations.
Studying the genomes of individuals across Africa represents a unique opportunity for understanding the population demography of human disease. Established in 2010, the Human Heredity and Health in Africa (H3Africa) Consortium aims to address the lack of genomics research in Africa. To date, the Consortium support 48 projects across 34 countries.
Insights into migration and health
In a study, published in Nature, researchers performed whole-genome sequencing analysis in 426 individuals from ongoing H3Africa studies. This encompassed 50 ethnolinguistic groups from 13 countries across Africa. The team noted that some of these groups were studied for the first time, providing a unique overview of the diverse genomic landscape of Africa.
The team uncovered more than 3 million previously undescribed variants. Most of these were found among individuals from newly sampled ethnolinguistic groups. Additionally, they observed complex patterns of ancestral admixture and putative-damaging and novel variation within and between populations. They also found that pathogenic variants in genes currently characterised as medically relevant were uncommon. However, in other genes, researchers commonly found variants denoted as ‘likely pathogenic’.
These findings refine our understanding of continental migration. They also support the role of gene flow and response to human disease as key drivers of genome-level populations. Moreover, they emphasise the scientific necessity for broader characterisation of the genomic diversity of African individuals to gain more insight into human ancestry and improve health.
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