Why does COVID-19 kill some and not others, global study finds

Qatar Foundation’s Qatar Genome Programme is the first and only active participant from an Arab country in the COVID-19 Host Genetics Initiative, a global initiative to elucidate the role of host genetic factors in the susceptibility and severity of the SARS-CoV-2 virus pandemic.

Why does a 17-year-old with no underlying health conditions succumb to COVID-19 while a 75-year-old great grandmother makes a full recovery? The wide variation in severity makes it seem like they did not have the same disease, except they did. One of the most mysterious features of this disease, which has killed more than half a million people globally, is the difference in severity. Some people don’t even show symptoms, some die and many more are somewhere in the middle.

Age, sex, and underlying health conditions clearly play an important role. But geneticists believe the difference in severity could be linked to the natural variation in people’s genetic code. This is what launched the COVID-19 Host Genetics Initiative (HGI), led by Mark Daly and Andrea Ganna from the Finnish Institute for Molecular Medicine (FIMM) and the Broad Institute in Boston.

The initiative aims to bring together the scientific community to study the role of the human genome in explaining COVID-19 susceptibility and severity. Twenty countries are currently contributing to the study, with the majority of studies being conducted in Europe (55%) and the US (28%). United Kingdom (10%) and Italy (9%) being the top two countries in terms of genomes contributed from Europe.

Qatar Genome Programme (QGP), the initiative’s only active participant from the Middle East, has so far contributed with over 13,000 genomic results. “The contribution of Qatar Genome to COVID-19 HGI is very important because it adds diversity to the initiative and highlights the importance of including populations which are traditionally unrepresented in genetic research, but still highly impacted by the COVID-19 pandemic,”said Dr. Andrea Ganna, Co-founder of the COVID-19 HGI and Group Leader at the Institute for Molecular Medicine, Finland.

Results from the latest round of the global study show strong evidence of genetics playing a role in COVID-19 severity. A site on Chromosome 3 has been identified to have a solid link to COVID-19 severity. The identified site is home to six genes; hence it is not yet possible to say exactly which one of them influences the course of COVID-19. Further investigations are underway to pinpoint exactly which gene this is.

Dr. Hamdi Mbarek, a geneticist, who led QGP’s participation said, “These results are very interesting and timely. We now have a target region in the genome, and the next challenge is to understand the link between the six genes and COVID-19 severity. Identifying the gene linked to COVID-19 severity will be very valuable in drug development.

“Now that we now know that genetics is a big factor in determining COVID-19 severity, this information can help the healthcare sector prioritize which group of individuals should be first in line to get a vaccine once one is developed.”

If researchers are able to identify exactly which gene is responsible for COVID-19 severity, it could be a potential game-changer in swiftly determining which patients are high-risk and need more aggressive treatment. Previously, this study identified a variation at another spot in the human genome. The identified spot consisted of the gene that determines blood type. Patients with Type A blood, for example, were found to be at greater risk of being severely affected by COVID-19.

“We are glad to have contributed to this initiative with the genomes of an Arab population, which has added valuable diversity to the study. The diversity in the participating genomes strongly indicates that COVID-19 indiscriminately affects populations from all around the world,” added Dr. Said Ismail, Director of Qatar Genome Programme.

QGP’s participation in this study is a testament to QF’s commitment to doing meaningful research. The COVID-19 HGI is proof of how crucial research is in finding a way forward in uncertain times. How research must be resilient, and not be impeded by closed borders and travel restrictions. Despite the challenges, researchers worldwide have found ways to come together, build new ties and collaborate like never before, all motivated by a single, common goal: defeat COVID-19.