Researchers identify protective gene variant against COVID-19

Global study co-authored by senior LDI investigator

In an effort to better understand and fight COVID-19, researchers at three international sites—including the Lady Davis Institute at the JGH—have identified a specific gene variant that protects against severe infection by the virus. The findings are based on a wider sample of humanity than has been examined up to this point.

The research, known as a meta-study, was conducted by the LDI, Karolinska Institutet in Sweden, and VA Boston Healthcare System in the United States. The results are described in a recent issue of the journal, Nature Genetics.

Before the research was conducted, scientists already knew that genetics—as well as old age and certain underlying diseases—can influence how severely or mildly an individual is affected by COVID-19.

Of particular interest was a specific segment of human DNA whose presence lowers the risk of developing a severe COVID-19 infection by 20 per cent. However, the earlier studies looked primarily at people of European ancestry, in whom the DNA segment also contains a large amount of genetic information that has no bearing on COVID-19.

The objective: to identify with greater precision the gene variant relevant to COVID-19. The solution: focusing on the DNA of individuals of predominantly African ancestry.

Since the DNA of people of African descent is not “cluttered” with genetic information that many Europeans inherited from Neanderthals (extinct humans who lived in prehistoric Europe), the researchers were able to compare both types of humans and pinpoint the COVID-related gene variant that is common to Europeans and Africans alike.

“That we are beginning to understand the genetic risk factors in detail is key to developing new drugs against COVID-19,” says the study’s co-author, Dr. Brent Richards, Senior Investigator at the LDI and Professor of Medicine at McGill University.

“This study shows how important it is to include individuals of different ancestries,” notes corresponding author Hugo Zeberg, Assistant Professor in the Department of Neuroscience at Karolinska Institutet. “If we had studied only one group, we would not have been successful in identifying the gene variant in this case.”

The analysis included a total of 2,787 hospitalized COVID-19 patients of African ancestry and 130,997 people in a control group from six cohort studies. Eighty percent of individuals of African ancestry carried the protective variant. The outcome was compared with a previous, larger meta-study of individuals of European heritage.

According to the researchers, the protective gene variant (rs10774671-G) determines the length of the protein encoded by the gene OAS1. Prior studies have shown that the longer variant of the protein is more effective at breaking down SARS-CoV-2, the virus causing the disease COVID-19.