A specific gene variant that protects against severe COVID-19 infection has been identified by researchers.
An international team led by researchers at Sweden’s Karolinska Institutet identified the variant by studying people of various ancestries.
The study, published in the journal Nature Genetics, demonstrates that genes can influence whether we are severely affected by COVID-19 or only suffer mild illness.
Previous research, primarily on people of European ancestry, discovered that individuals carrying a specific segment of DNA have a 20% lower risk of developing a critical COVID-19 infection.
According to the researchers, this DNA segment encodes genes in the immune system and is inherited from Neanderthals by roughly half of all people outside of Africa.
However, this region of DNA is densely packed with genetic variants, making it difficult to isolate the precise protective variant, according to the researchers.
According to the researchers, identifying this variant could serve as a target for medical treatment against severe COVID-19 infection.
To find this specific gene variant, they looked for people who only had a portion of this DNA segment.
Because Neandertal inheritance occurred after the ancient migration out of Africa, the researchers concentrated on people with African ancestry who lacked Neanderthal heritage and thus the majority of this DNA segment.
However, a small portion of this DNA region is shared by people of African and European ancestry. Individuals of predominantly African ancestry had the same protection as those of European ancestry, allowing the researchers to pinpoint a specific gene variant of particular interest.
“Because people of African descent had the same protection, we were able to identify the unique variant in the DNA that actually protects from Covid-19 infection,” said Jennifer Huffman, a researcher at the VA Boston Healthcare System in the United States.
A total of 2,787 hospitalized COVID-19 patients of African ancestry and 130,997 people in a control group from six cohort studies were included in the analysis.
According to the researchers, the protective variant was carried by 80% of people of African ancestry.
The findings were compared to those of a previous, larger study of people of European ancestry.
According to the researchers, the protective gene variant (rs10774671-G) determines the length of the protein encoded by the gene OAS1.
Previous research has shown that the longer variant of the protein is more effective at breaking down the viruses that cause COVID-19 and SARS-CoV-2.
“The fact that we are beginning to understand the genetic risk factors in detail is critical to developing new drugs against COVID-19,” study co-author Brent Richards, a professor at McGill University in Canada, said.