Published 13 January 2022 at 18.09
Domestic. A new international meta-study has identified a specific gene variant that protects against severe covid-19. The researchers succeeded in identifying the variant by comparing Africans and Europeans and their different gene sets.
– If we had only studied one group, we would not have been able to identify the gene variant in this case, says researcher Hugo Zeberg.
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Previous studies on mainly white people have shown that individuals who carry a special piece of DNA have a 20 percent lower risk of being admitted to the intensive care unit at covid-19.
This piece of DNA encodes genes in the immune system against viruses and is inherited from Neanderthals in about half of all people outside Africa.
However, the DNA fragment is long and contains many different gene variants, which has made it difficult to know exactly which gene variant protects and could possibly be a target in drug treatment for severe covid-19 infection.
To identify the specific gene variant, the researchers in the current study looked for individuals who carried only parts of this piece of DNA. Since the inheritance from Neanderthals took place after the emigration from Africa, the researchers saw a potential in targeting individuals of African descent who have no inheritance from Neanderthals and thus also the majority of this DNA segment. However, a small part of this DNA is the same in both Africans and Europeans.
The researchers found that individuals of mainly African descent had the same protection as Europeans, which allowed them to point out a specific gene variant as particularly interesting.
– The fact that individuals of African descent had the same protection allowed us to identify the unique difference in the DNA that actually protects against covid-19 infection, says the study's lead author Jennifer Huffman, researcher at VA Boston Healthcare System in the United States, in a press release.
The analysis included a total of 2,787 hospitalized covid-19 patients of African descent and 130,997 people in a control group from six cohort studies. 80 percent of individuals of African descent wore the protective variant. The effect was compared with a previous larger meta-study of individuals of European descent.
According to the researchers, the protective gene variant (rs10774671-G) affects how far the protein encoded by the gene OAS1 becomes. Other studies have shown that the longer variant of the protein is better at breaking down the virus sars-cov-2, which causes the disease covid-19.
– That we begin to understand the genetic risk factors in detail is a key to develop new drugs against covid-19, says co-author Brent Richards, professor at the Lady Davis Institute of the Jewish General Hospital and McGill University in Canada.
The Covid-19 pandemic has led to extensive collaborations between researchers from different parts of the world, which has made it possible to study genetic risk factors in a wider group of individuals than in many previous studies. However, the majority of all research is still done on individuals of mainly European descent.
– This study shows how important it is to include individuals with different backgrounds. If we had only studied one group, we would not have been able to identify the gene variant in this case, says the study's corresponding author Hugo Zeberg, assistant professor at the Department of Neuroscience at Karolinska Institutet.