Gene Variants Linked to Severe COVID-19 Infection

Certain gene variants are common among patients who develop severe coronavirus infections, according to findings from a study recently published in Nature.

A team of European researchers conducted genome-wide association studies (GWAS) to compare the genomes of 2,200 patients with COVID-19 in intensive care units across Britain, comparing their genes to those of healthy individuals. The scientists identified eight variants that were common among patients with COVID-19 in intensive care. Five of these genetic signals were confirmed in further examination.

Some of the variants point to flaws in the immune system that could be targeted therapeutically. “Several of the new findings are able to point quite directly to genes with known functions of relevance to the immune system or antiviral responses,” said Tom Hemming Karlsen, MD, PhD, a physician from the University of Oslo in Norway and coauthor of a similar paper published in the New England Journal of Medicine earlier this year.

According to the Nature study, the gene IFNAR2 is among those linked to developing severe illness from the coronavirus. IFNAR2 enables cells to build a protein receptor for interferon as an early response against infection. A weak interferon response allows the virus to proliferate rapidly, which may lead to a potentially deadly overcorrection when later immune defenses kick in.

Despite the genetic links, “It’s unlikely that a single element is fully responsible for the development of severe COVID-19,” said study author Sara Clohisey, PhD, a researcher at the University of Edinburgh in Scotland. “It’s more likely to be a combination of factors.” Other factors associated with higher risk might include age, obesity, and male sex.

Source: The Washington Post, December 14, 2020; Pairo-Castineira E, Clohisey S, Klaric L, et al. Genetic mechanisms of critical illness in Covid-19. Nature. 2020 December 11. [Epub ahead of print]