Experts say that clinical trials for kidney disease treatment must include people living in Africa.
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Every minute, the kidneys filter around 200 litres of blood, removing waste, balancing salts and fluids, and regulating blood pressure — all without conscious effort.
But when they begin to fail, the effects can be severe: fatigue, fluid retention, cardiovascular complications, and in advanced cases, the need for dialysis or a transplant to survive.
Kidney disease is now one of the fastest-growing causes of death globally. Around 850 million people are living with some form of it — more than the combined number affected by diabetes and cancer. Chronic kidney disease causes about 1.5 million deaths annually, a toll that continues to rise.
The condition is often silent in its early stages, developing gradually with few warning signs until significant damage has already occurred.
The burden is also unevenly distributed. People of African ancestry are about four times more likely to develop end-stage kidney failure than people of European ancestry. In sub-Saharan Africa, where rates of hypertension and type 2 diabetes are increasing, the risk is compounded. Roughly 30% of adults in the region have high blood pressure, while about 25 million people — around one in 20 adults — live with diabetes, often undiagnosed or untreated.
Health systems across the continent are also under strain. Sub-Saharan Africa has far fewer kidney specialists, dialysis units and transplant services per capita than other regions. The continent averages fewer than one nephrologist per million people, compared with a global median of about 10 and up to 23 in high-income countries. In some countries, there are none at all.
For many patients, treatment simply does not exist.
Against this backdrop, early identification of those at risk has become critical.
New research from the KidneyGenAfrica consortium — a pan-African collaboration focused on kidney disease genomics — has begun to close major gaps in understanding how kidney disease develops in African populations.
The study identified previously unknown genetic variants linked to kidney disease risk in African populations, and found clear differences between genetic risk patterns in people living on the African continent and those of African ancestry living in North America and Europe.
Researchers say this highlights the importance of population-specific medical research rather than relying solely on data drawn from non-African groups.
Kidney disease does not emerge suddenly. It is shaped by a mix of factors: genetic variants that influence susceptibility, alongside environmental and health conditions such as high-salt diets, uncontrolled hypertension, diabetes, infections, and exposure to toxins, including some traditional herbal medicines and contaminated water sources.
Until recently, African populations have been significantly underrepresented in global genetic research, despite being the most genetically diverse populations on Earth.
That is now beginning to shift.
The study analysed genetic data from about 26,000 individuals across eastern, western and southern Africa, alongside around 81,000 individuals of African ancestry living outside the continent. It is the largest study of kidney function genetics in continental Africans to date.
Researchers used a genome-wide association study, a method that scans the full genetic code to identify variants linked to disease. The focus was estimated glomerular filtration rate, a standard measure of kidney function. Lower levels indicate reduced kidney performance and higher disease risk.
Among continental African populations, the study identified four genomic regions linked to kidney function, including two not previously reported. When African diaspora populations were included, the number rose to 19 regions, three newly discovered.
Four of these genetic locations were mapped with high precision, allowing researchers to identify likely causal variants rather than broader genomic regions. Each represents a potential target for future drug development or diagnostic tools.
The study also evaluated polygenic risk scores, which estimate overall disease risk based on multiple genetic variants. It found that scores built from genetically similar African datasets performed better than those derived from larger but more distant populations — a finding researchers say has major implications for medical prediction tools in Africa.
One key focus was the APOL1 gene, which contains variants known as G1 and G2. These variants are associated with higher kidney disease risk in African American populations. However, the study found that in continental Africa, these variants occur at lower and more regionally variable frequencies, and their association with kidney dysfunction appears weaker than in diaspora populations.
Researchers say this suggests the same genetic variants may not have identical effects across different environments and populations.
The finding carries implications for drug development and clinical trials, which researchers say must include participants from continental Africa, not only African-descended populations abroad.
The study’s authors argue that African health systems should prioritise early detection through affordable blood and urine tests, which can identify kidney damage before irreversible decline. Genetic risk tools, they say, could help target screening more effectively.
They also call for expanded pharmaceutical testing in African populations and sustained investment in genomic infrastructure across the continent.
Researchers say the study demonstrates the importance of African-led science in shaping global understanding of kidney disease — and in improving outcomes for populations most affected by it.
Segun Fatumo- Professor and Chair of Genomic Diversity, Queen Mary University of London