Research on human genome research still has a strong bias towards people of European descent, say scientists – and this could have harmful consequences for the interpretation and follow-up of research.
The statistics tell their own story: by 2018, 78% of Europeans, 10% of Asians, 2% of Africans, 1% of Hispanics and less than 1% of all other ethnic groups.
Because these GWAS studies are used to predict disease risk, develop medical treatments, and plan further research and studies, there is a risk that we will not see the full picture of the human population – even if the individual is self-studied scientifically founded.
"The exclusion of whole populations from human genetic studies is both scientifically harmful and unfair," says one of the researchers, the evolutionary geneticist Sarah Tishkoff of the University of Pennsylvania.
"We may miss genetic variants that play an important role in health and disease in ethnically diverse populations, which can have deleterious consequences for the prevention and treatment of disease."
Tishkoff and her colleague Agues looked at the thousands publications listed in the GWAS catalog to determine their numbers and to analyze the genetic risk associated with health problems such as kidney disease and schizophrenia.
Applying genetic risk assessments to Europeans may not work For non-Europeans, the team argues ̵
Some diseases are associated with a single gene variant, others are associated with many different genes as well as environmental factors – here the lack of a broad, unbiased set of samples becomes a real problem.
"The lack of diversity in human genome research is likely to worsen health inequalities," says one of the researchers behind the new research, Scott M. Williams from the School of Medicine at Case Western Reserve University in Ohio.
"For example, approaches are being developed to predict a person's risk for diseases such as Alzheimer's, heart disease or diabetes based on their status for multiple genes, but such calculations based on evidence from mainly European populations may not occur other people on ethnic backgrounds. "
The researchers cite the example of cystic fibrosis, about six times more likely to be of European descent than African descent. The most common causative allele in the first group accounts for 70 percent of the cases, but only 29 percent of the cases in the second group.
Specific genetic mutations may occur in populations that we have not studied enough, the team suggests, and together with the effects of genetic drift, when populations separate, this means that the end results of GWAS research may not be that way exactly as we would like.
The solution proposed by the researchers is to use, wherever possible, comprehensive biobanks for future studies: biobanks with ethnically diverse individuals that can be linked to comprehensive health records. This should lead to better health care for all.
"These initiatives require the political will to improve funding and infrastructure for the study of genomic and phenotypic diversity in global populations," says one of the researchers, Giorgio Sirugo of the University of Pennsylvania.
"The future success of genomic and precision medicine depends on it."
The research was published in Cell .