The COVID-19 pandemic has become the central focus of the scientific world in 2020. With mountains of rigorous research into the origin, evolution, spread, diagnosis, and treatment of the disease, lots of researchers in a variety of disciplines have jumped on board to help.
One of the strangest mysteries of COVID-19 is that it causes severe illness and death in some individuals, while others display only mild symptoms or do not appear to show any at all. Of course, there are some known risk factors, such as advanced age, obesity, smoking, existing respiratory illness, and having a compromised immune system. Other environmental and societal factors are also likely to influence individual susceptibility to such infectious diseases. However, various unknown factors seem to render some fit and healthy individuals extremely vulnerable to severe illness with COVID-19.
Could variation in our DNA holds the answer? DNA contains the blueprint for the function of every cell in our body. Therefore, it seems obvious that differences in an individual’s DNA sequences could affect how they respond to the virus. The evidence that variation in our genetic makeup contributes to our risk of suffering from infectious disease is well established 1. As such, ongoing research studies are aiming to link genetic variation with differences in COVID-19 susceptibility and severity. Such information could allow clinicians to identify those most at risk of experiencing severe complications of infection.
Scientists have been quick to establish international consortia aiming to tackle this problem, enhancing research outcomes by sharing resources and expertise. For example, the COVID-19 Host Genetic Initiative is a collection of researchers involved in over 100 studies across the world who are trying to uncover the relationship between the host genome and SARS-CoV-2 infection 2.
A new benefit of genetic testing companies
Commercial direct-to-consumer DNA testing companies hold a wealth of our genetic data. For example, the two largest firms (23andme and Ancestry.com) have a combined database of around 30 million samples.
Their possession of such a vast resource of DNA information data puts them in a unique position to uncover how our genes impact certain traits. If they had information about the COVID-19 status of each individual, they could piece together how variation at specific regions of the genome correlates with how people respond to potential exposure to SARS-Cov-2.
Not only do these companies have access to a huge pool of samples that they have already collected, saving researchers time and money, but they also have the necessary resources and capital to recruit a vast number of additional participants to take part in their studies.
23andme leads the way
23andme is one of the market leaders in at-home genetic testing. They have used their position to generate preliminary data about genetic variation and COVID-19 from 750,000 study participants. One observation they made was an association between an individual’s blood type and the likelihood of contracting COVID-19.
The findings from their preliminary research suggest that individuals with the O blood type are 9-18% less likely to test positive for COVID-19 than those with other blood types. This indicates that type O blood could be protective against SARS-CoV-2 infection. Alternatively, belonging to blood group O could reduce the likelihood of displaying symptoms; if these individuals were never tested, they would never know they were infected.
Importantly, these observations are also consistent with genetic data. A variant in the ABO gene (which determines blood type) is associated with a reduced risk of being diagnosed with COVID-19, as shown in their recent preliminary article 3.
23andme is still recruiting for their study. Specifically, they are looking for individuals who have been diagnosed and hospitalized with COVID-19. If you are interested, you can participate here.
Coronagenes – putting this data to use
In another example of research collaboration, the University of Edinburgh is calling on people who have participated in direct-to-consumer DNA tests with 23andMe, Ancestry.com, or FamilyTreeDNA to join their “Coronagenes” investigation. By using existing data gathered by commercial companies, will significantly increase the speed at which they can collect meaningful findings and publish their results.
Coronagenes is a research study aiming to uncover gene variants linked to COVID-19 infectious risk, symptoms, and severity. It will also look at the long-term health consequences of infection and self-isolation. Should you wish to participate, you can read more about the study here.
In the fight against the global COVID-19 pandemic, pooling together and utilizing existing data is essential in optimizing efficiency. Commercial genetic testing companies are in a unique position to be able to further these advances and provide large amounts of data to research teams, as well as performing their own studies. Their ability to contribute to faster and more robust research should not be ignored. However, others have warned of the potential ramifications of such studies 4, and due care and consideration must be taken at all stages of such research to avoid discrimination and undermining the public health response.
1. Chapman, S. J. & Hill, A. V. S. Human genetic susceptibility to infectious disease. Nature Reviews Genetics vol. 13 175–188 (2012).
2. The COVID-19 Host Genetics Initiative. The COVID-19 Host Genetics Initiative, a global initiative to elucidate the role of host genetic factors in susceptibility and severity of the SARS-CoV-2 virus pandemic. Eur. J. Hum. Genet. 28, 715–718 (2020).
3. Ellinghaus, D. et al. The ABO blood group locus and a chromosome 3 gene cluster associate with SARS-CoV-2 respiratory failure in Italian-Spanish genome-wide association analysis. medRxiv 2020.05.31.20114991 (2020) doi:10.1101/2020.05.31.20114991.
4. Milne, R. Societal considerations in host genome testing for COVID-19. Genetics in Medicine vol. 22 1464–1466 (2020).
Katy is a freelance science writer with expertise in genetics and molecular biology.
She received her PhD in Molecular Medicine from the University of Edinburgh and her BSc (First Class Honours) in Genetics from the University of Glasgow.
She recently completed a post-doctoral research position at the University of Edinburgh, where her work dissected the interplay between genetics, epigenetics and development.