Scientist examines DNA models in modern Genetic Research Laboratory. Looking through laboratory glasswareCredit: janiecbros/E+/Getty Images
Africa’s underrepresentation in human genomics data is worse than previously reported because genetic and genomic studies are predominantly based on populations of European ancestry. A paper published in Nature Medicine warned that underrepresented populations may be excluded from better understanding of disease etiology, early detection and diagnosis, rational drug design and improved clinical care.
Segun Fatumo, from the London School of Hygiene and Tropical Medicine, who led the collaboration of researchers from South Africa, Uganda, the United Kingdom, and the United States told Nature Africa that because of the way genomics studies are structured, the proportion of the African population’s representation will continue to fall unless urgent action is taken.
The researchers found that about 86% of genomics studies have been conducted in individuals of European descent by June 2021, increasing from 81% in 2016 — suggesting that in spite of calls for more diversity in genomics studies, the gap continues to widen.
“This shows that progress toward diversification has been painfully slow. The genomic research community tends to extensively use resources with relatively straightforward access models, such the UK Biobank, which includes participants of mostly European descent, while other ancestry groups tend to have very few such resources and limited access models. Data from the International HundredK+ Cohorts Consortium (IHCC), a recently established consortium of international cohort studies, also show considerable ancestral disparities,” they reported.
“The proportion of the genomic studies that were done in Africa was 3% in 2016, now it's 1.1%. I think that this is shameful,” Fatumo said.
African Americans are not representing Africans
Fatumo noted that genomic studies conducted in African American populations are being wrongly categorized as expanding Africa’s genomic data. “African Americans don't represent Africa because they only represent a small portion of Africa.”
He said the number of initiatives intended to close the gap by only targeting African Americans would not diversify genomics studies and would continue to leave out the continent of Africa.
Fatumo’s co-author, Tinashe Chikowore, of the Sydney Brenner Institute for Molecular Bioscience, Faculty University of the Witwatersrand, in South Africa, said that the current genomics study structure, also prevent the world from benefiting from the continent’s genetic diversity.
He pointed to population-enriched clinically important variants that were only discovered in underrepresented populations. An example is the identification in populations with African ancestry, of loss-of-function variants in the PCSK9 gene that reduce low-density lipoprotein cholesterol, which led to the discovery of PCSK9 inhibitor drugs.
“They are highly concentrated in African individuals and have led to drugs which benefit everyone globally,” he said.
“To be successful in achieving equitable inclusion of underrepresented groups in genomic studies, the stakeholders must stimulate local participation, build trust and ensure mutual respect,” the researchers concluded.
