Why do young and healthy people end up in intensive care after contamination by SARS-CoV-2 while other people, who are a priori more fragile, get by with a simple cold? The answer may well be in our genes!
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[EN VIDÉO] Interview: Could genetics reverse aging? Slowing down aging, or even reversing it, is what genetics could offer in the years to come. But where is the current research on this subject? Futura-Sciences interviewed Vera Gorbunova, researcher in biology, during her speech at TEDxCannes, in order to find out more.
Covid-19 disease is very mysterious. Some will be asymptomatic or will have a mild cold while others will stay in intensive care or even die of the disease. If risk factors have been identified, such as obesity, diabetes or age, some young and healthy patients are struck down by the SARS-CoV-2 incomprehensibly.
Our genetic heritage could well explain these interindividual differences. A study recently revealed a gene that doubles the risk of dying from a contamination by SARS-CoV-2. This gene is present in 61% of Asians while it is present in only 16% of Europeans. Another one study suggests that people who express the most Genoa TYK2 and CCR2, involved in the inflammatory response, are more likely to die from Covid-19. A new article was published on January 13, 2022 in the prestigious journal Nature. This time, it’s a segment of DNA coding for genes in the immune system which would protect serious forms of Covid-19 that has been identified.
A segment of DNA that protects against severe forms
The relevant DNA segment, located on the chromosome 12, in the chromosomal region 12q24.13, would be inherited from Neanderthals. To identify the protective DNA segment, the researchers looked at 20,779 records of hospitalized patients, including patients of African and European descent. This is the first study of this scale that has succeeded in integrating patients of African origin. Having the protective segment reduces the risk of developing a critical form of the disease by 23%. More interestingly, 80% of people of African descent are carriers of the protective fragment. Which could explain why the virus is less devastating on this continent.
A segment involved in the immune response
The protective segment is 75 kb and codes for three genes: OAS1, OAS2 and OAS3, immune system genes. In people with the protective variant, the protein from the OAS1 gene would be 60% longer. Its mission is to dissect SARS-CoV-2. The longer it is, the more effective it is in its fight against the virus.
Better understanding the genetic mechanisms explaining why some people defend themselves better than others against SARS-CoV-2 could allow:
- on the one hand to identify in advance the people who are going to have a serious form of the disease for better care, more targeted to patients in need
- on the other hand to develop new drugs curative.
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