Researchers have discovered a protective gene variant that seems to shield people from severe cases of COVID-19.
In a new study, researchers compared information from people of different ancestries – looking at genetic datasets of people from both African and European lineages.
The aim was to see if they could narrow the search further within the OAS1/2/3 cluster and determine if this gene is protective for people who don’t carry the same complicated influx of Neanderthal and Denisovan genes in their own DNA, which makes identifying potentially causal variants much more problematic.
Scientists were successful. In an analysis of 2,787 COVID-19 cases alongside the genetic data of 130,997 individuals of African ancestry, the researchers identified an allele in the gene rs10774671 that confers protection against COVID-19 hospitalization in individuals of African ancestry.
“The fact that individuals of African descent had the same protection allowed us to identify the unique variant in the DNA that actually protects from COVID-19 infection,” states first author and genomics researcher Jennifer Huffman from the VA Boston Healthcare System.
The variant, rs10774671 G provides protection against COVID-19 severity independently of other associated alleles in non-African populations.
The common rs10774671 G variant exists today in both Africans and Europeans “as a result of their inheritance from the ancestral population common to both modern humans and Neanderthals,” the researchers write in their paper.
“Such variants have existed in modern humans on the order of approximately half a million years and therefore co-segregate with different variants than when they are derived from gene flow from Neanderthals into modern humans that occurred about 60,000 years ago.”
“This study shows how important it is to include individuals of different ancestries,” says senior researcher and evolutionary geneticist Hugo Zeberg from the Karolinska Institute in Sweden.
“If we had only studied one group, we would not have been successful in identifying the gene variant in this case.”
The researchers believe that the protective effect comes about due to the variant’s effect on the OAS1 gene, encoding a longer OAS1 protein that is more effective at breaking down SARS-CoV-2 than the unaltered form.
“That we are beginning to understand the genetic risk factors in detail is key to developing new drugs against COVID-19,” says senior researcher and geneticist Brent Richards from McGill University in Canada.
The findings are reported in Nature Genetics.