Yet almost nine in 10 genomics studies are conducted in individuals of European descent – while Africa represents a tiny 1.1%.
These stark statistics hint at an untapped opportunity to conduct research that can benefit all populations, according to Segun Fatumo, associate professor of genetic epidemiology and bioinformatics at the London School of Hygiene and Tropical Medicine.
“We are doing ourselves harms if genomic study is not diversified to include Africans and other underrepresented populations,” he told Vitafoods Insights.
Disparity between Europeans and underrepresented populations on the rise
A 2022 paper in Nature Medicine on which Fatumo was lead author showed that in 2021, 86.3% of genomics studies were conducted in individuals of European descent, followed by East Asian (5.9%), African (1.1%), South Asian (0.8%), and Hispanic/Latino (0.08%) populations.
This represents an increase in the proportion of samples from individuals of European ancestry – which stood at 81% in 2016 – while the proportion of samples from underrepresented populations has stagnated or decreased.
Asked why this disparity was continuing to widen, Fatumo said: “Despite the warning [about the lack of diversity in genomics research], people are studying even more European populations – so even if African and other underrepresented populations try to catch up, they cannot.”
However, the need to equitably study all populations remains paramount, he said – particularly in the case of African individuals, who harbour far greater genetic and linguistic diversity than other populations.
As many as 90% of African ethnolinguistic groups have no representative genetic data to date; studying a small number of diaspora populations and grouping participants into one broad category of African ancestry will continue to promote imbalance and widen health disparities.
“If you don't study Africa, you are not going to capture [that] diversity and capture those genetic variants that might be important for maybe the next [miracle] drug,” Fatumo said.
Intersecting identities and the challenge of representation
Intersecting identities also have implications for how different people respond to health interventions, Fatumo explained.
“Apart from including different ethnic group in genomics studies, we also need to think about if we are also including representation of different genders,” he said.
Race, ethnicity, and gender all have an influence on how compounds are metabolised in the body, meaning that some individuals may require different dosages of some medications to achieve the same effects as others.
“If we don't study different kinds of people, different kinds of genders, different kinds of ancestry, you would not know how to administer the appropriate [amount] of medication,” Fatumo said.
Closing ethnicity data gap would benefit all populations
Fatumo highlighted some breakthroughs in our understanding of metabolic disease that could never have been made without research in diverse populations.
For example, a treatment for lowering low-density lipoprotein (LDL) cholesterol could not have been developed without a study on the enzyme PCSK9 – which plays a role in the regulation of LDL receptors – that included individuals of African ancestry, in whom the researchers discovered a genetic variant.
Fatumo said: “Because they included African ancestry individuals, now we have a class of drug from this PCSK9 that is very useful for all populations.”
Another example is a drug targeting the APOL1 gene variant, which is implicated in kidney disease. This variant is between three and five times more frequent in Africa than in other populations, particularly in West Africa and Central Africa, Fatumo explained, putting people of African descent at an increased risk of developing kidney disease.
Meanwhile, research published in Nature earlier this year identified a genetic variant that may explain why some people of African ancestry have naturally lower viral loads of HIV. This variant, near the CHD1L gene, holds potential as a drug target for HIV, Fatumo said.
UK diabetes testing fails to account for sickle cell traits
Fatumo used a personal example from several years ago when he went to the GP and was told he had diabetes. In the UK, the most commonly used blood test for diabetes is HbA1c; however, Fatumo knew that this was not appropriate for him “because I have sickle cell traits, which is not very common in the UK”.
In Africa, about 20% of people have sickle cell traits, and this is a factor taken into consideration during testing. However, it took many months before the British doctor asked Fatumo to do a different test and established that he did not, in fact, have diabetes.
Fatumo said this was just one example of why the shift towards precision medicine, wherein patients’ healthcare takes into consideration their characteristics – “most importantly, their genomics and epigenetics” – is so important.
The current one-size-fits-all model results in treatment that is only effective for about 20% of the population, he said – “whereas if we have a tailored approach for precision medicine… people have more appropriate treatment. The future is precision medicine”.
Industry has ‘a lot to do’ to address ethnicity data gap
Asked about industry attitudes towards addressing these disparities, Fatumo said some pharmaceutical companies were looking to play a role in supporting study in African populations – for example, via providing funding for African Centres of Excellence.
“For some companies, they have a lot to do,” he said. “I think now they realise that.”
However, he admitted that there was reluctance from other players, which most probably came down to the question of profit.
“If you have medication for the UK or the West, for example, you make your money, but if you are dreaming of Africa, maybe they don't see any big markets there,” he said. “But I think we are in the era where we need to think beyond that.
“We need to … think about how many lives can we save and maybe think about long-term profits in terms of people living longer.”