However, most GWAS studies published to date represent European or East Asian populations. Despite making up around 400 million of the global population, Middle Eastern communities have been under-represented – until now.
The Qatar Genome Research Consortium – which brings together experts from various research institutes based in the Gulf country – has just published the world's largest study on Arab genetic risk factors.
Genomics and ethnic diversity
Twenty years ago, the International Genome Sequencing Consortium published the first detailed analysis of the human genome. Sequencing the entire human genome – which essentially means uncovering all of the genetic material in a person – was no mean feat.
Two decades later sequencing techniques have advanced greatly, and if the COVID-19 crisis has proven anything, it is that rapid sequencing is not only possible but crucial in the development of diagnostics.
Using genomic data, medical professionals have been able to identify patients who are at high risk of developing certain conditions and better plan for treatments. This approach has already seen great strides in cancer research and could be particularly helpful in proactively treating cognitive or neurodegenerative conditions, such as Alzheimer's, before people show signs of disease.
However, these advances have so far disproportionately benefited one group: the Caucasian population.
Genome databases do not represent the full range of human genetic diversity. In fact, it is thought that between 75-80 percent of the global genomic dataset represents people of European descent, followed by ten percent Asian, two percent African, one percent Hispanic, and less than one percent for all other groups.
So why is this significant?
For a start, the GWAS that have examined traits and complex diseases in Africans and Asians have indicated there are differences in the genetic architecture between different ethnic groups. Recent studies have also shown that polygenic risk scores – which can give us insights into an individual's susceptibility to different diseases – have lower predictive performance when derived from studies in European populations and applied to non-European populations. These polygenic risk scores are vital in finding personalised preventive healthcare measures, meaning its currently harder to find effective preventive measures for non-European populations.
Progress in Qatar
Researchers have recognised these challenges and are making efforts to boost diversity among participants in genetic studies. One of those studies has been taking place in Qatar. Together with experts from the Qatar Genome Program, Qatar Biobank, and Weill Cornell Medicine – Qatar, myself and a group of researchers at Qatar Foundations Hamad Bin Khalifa University (HBKU) have been working on the largest genetic association study in the Middle East.
Recently published in Nature Communications the study highlighted vital information to help us better understand genetic risk factors that are specific to the Arab population.
Our research explored whole-genome sequencing data of over 6000 Qatari individuals. By performing detailed assessments of genetic variants across the whole genome in these individuals, comprising data from 45 clinically relevant traits, the study identified about 300 independent genetic signals. Some of these signals were predominantly found in the Qatari population. Our observations were then confirmed in 7768 further subjects.
The findings tell us that there are novel trait associations that are predominant to the Middle Eastern population of Qatar, as well as differences in the heritability of certain lifestyle-related traits. They also confirm that genetic studies in European populations don't translate well when applied to Middle Eastern populations.
The results from this project have been shared publicly, to ensure that the specificities of the Arab genomes will be taken into consideration in future research on new treatments and therapies. However, this has also highlighted the need for more studies to be conducted not only in the Middle East but in other non-European regions too.
What this means for the future of healthcare
We are particularly excited about this research because it represents a foundation for the implementation of precision medicine in the Middle East.
Precision medicine, which delivers tailored treatments based on a person's genetic data, lifestyle, environment and physiology, is more likely to succeed when researchers consider that certain groups have worse health outcomes with respect to specific types of illness. For instance, Arab populations are more predisposed to genetic hemoglobinopathy diseases, such as sickle cell anaemia.
However, its full potential lies in enabling medical practitioners to access and evaluate more specific genetic information about their patients, so that they can identify disease predispositions and recommend the most effective therapies.
There is still progress to be made, but the Qatar Genome Program has given us the platform to make new genetic discoveries in this part of the world, which otherwise would be under-represented. As we continue to sequence more and more genetic profiles, we can expect to see significant near-future advances in a number of healthcare fields.