People from minority ethnic backgrounds are set to lose out on medical benefits of genetics research due to an overwhelming bias towards studying white European populations, Prof David Curtis, a geneticist, and psychiatrist at University College London, has warned.
He has called on funding bodies to do more to address the emerging issue that genetic tests developed using samples from white Europeans can give meaningless results when applied to other ethnic groups. The problem could intensify as the clinical applications of genetics expand over the next decade.
In a letter to the leaders of the Medical Research Council (MRC) and the Wellcome Trust in December, Curtis said the current situation was so acute that “UK medical science stands at risk of being accused of being institutionally racist”.
According to Curtis, the problem is most striking in the case of so-called polygenic risk scores, in which a person’s risk of a disease is calculated by aggregating the contributions of thousands of genes. The tests can be used to predict the likelihood of conditions like schizophrenia or high blood pressure, where a vast number of genes contribute to risk rather than just a handful.
Prof Eske Willerslev, a geneticist at the University of Cambridge and director of the GeoGenetics centre at the University of Copenhagen, accused funding agencies of appearing reluctant to invest in sequencing samples from people of non-European descent. Willerslev, who is studying the genetics of indigenous groups, said he had recently failed to secure funding to analyse samples that had already been collected at great expense. “There simply does not seem to be a lot of interest for it from funding bodies,” he said.
Doug Speed, a statistician working on the genetics of disease at Aarhus University in Denmark, said: “Certainly there is a bias towards European samples. It definitely stands to reason that European populations will be first to benefit.”
According to Curtis, the problem is most striking in the case of so-called polygenic risk scores, in which a person’s risk of a disease is calculated by aggregating the contributions of thousands of genes. The tests can be used to predict the likelihood of conditions like schizophrenia or high blood pressure, where a vast number of genes contribute to risk rather than just a handful.
In a recent study, published in Psychiatric Genetics, Curtis found that a commonly used genetic test to predict schizophrenia risk gives scores that are 10 times higher in people with African ancestry than those with European ancestry. This is not because people with African ancestry actually have a higher risk of schizophrenia, but because the genetic markers used were derived almost entirely from studies of individuals of European ancestry.
“This means that in the UK today we can test a white British subject and tell them their risk of diabetes or schizophrenia, but if they are of a different ethnicity we cannot offer them the test,” said Curtis.
Such tests are not yet used clinically, but in the future, they could help identify those at risk of health problems in order to provide preventive treatment. Beyond clinical settings, some predict that such tests could be used to gauge the academic potential of school pupils.
A recent international inventory of more than 3,000 papers describing polygenic scores found that 78% of the sequences used in research had come from individuals of European ancestry, up from 76% between 2011 and 2016. Individuals of east Asian descent accounted for 9% of samples, and non-European and non-Asian groups combined accounted for less than 4%.
Ethnic minorities are also underrepresented in the UK Biobank, which is aiming to genotype 500,000 individuals. In comparison with population data from the 2011 census, black participants are underrepresented by a third (making up 1.6% versus 2.4% in the census), people of Indian and Chinese origin are underrepresented by more than a third and people of Pakistani and Bangladeshi origin by more than half. White British participants make up 94.6% of Biobank samples, compared to 91.3% of the general population.
“It seems grossly unfair to me that people from ethnic minorities are funding this research through paying their taxes but are then not receiving the full benefits from it,” said Curtis.
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