A team of local researchers have conducted a research study aimed at unlocking the unique genetic character of Southern African populations.
The study highlights the potential implications for disease susceptibility in Africans.
Called the Southern African Human Genome Programme (SAHGP), the study has revealed a high level of genetic diversity in individuals after the researchers sequenced 24 South African individuals of different ethnolinguistic origins.
According to the South African Medical Research Council (SAMRC), the study funded by the National Department of Science & Technology (DST), is the first government-funded human genomics research study performed on African soil.
“This study supports our understanding that African genomes are likely to yield many more unique genetic variants,” said Director and Research Chair from Human Genetics and the Sydney Brenner Institute for Molecular Bioscience (SBIMB) at Wits University, Professor Michèle Ramsay.
“The next step of progress is to use this knowledge to decipher what potential impact the genetic variants can have on the health of individuals when we conduct health related research,” added Unit Director of the SAMRC Stem Cell Research and Therapy Unit at the University of Pretoria, Professor Michael Pepper.
The focus of the SAHGP was to capture a full spectrum of diversity in under-represented populations and therefore included ethnically self-identified individuals of different ancestries.
Whole-genome sequencing was used to study the differences in some of the major ethnolinguistic groups in the country. In this pilot project, eight admixed or Coloured individuals from the Western Cape, seven Sotho speakers from the Free State, eight Xhosa speakers from the Eastern Cape and one Zulu speaker from Gauteng constituted the sample group of the study.
The study aimed to use novel whole-genome sequence data to study possible correlations between language groups and genetic clustering and investigate the ancestral compositions of these individuals, including maternal and paternal lineages. The results indicate that despite a short period of geographic and cultural separation between the Nguni and Sotho-Tswana speakers there are measurable genetic differences between them. These are in part the result of varying regional ancestral contributions, but also of a random process of genetic drift.
“We have a richer understanding of the past as the study confirms general historical accounts of African migration and admixture,” said Senior Scientist at the SBIMB at Wits University, Dr Ananyo Choudhury (PhD).
African populations harbour the greatest genetic diversity and have the highest per capita health burden, yet they are rarely included in large genome studies of disease association. This diversity provides both a challenge and an opportunity for biomedical research and the hope that Africans will one day benefit from genomic medicine.
“South Africa has cemented a critical stone in the foundation to advance precision medicine for its people,” concluded Director for Health Innovation at DST, Glaudina Loots.