A new study found that people who carry a version of a gene inherited from Neanderthals have a lower risk of serious illness, hospitalization and death from Covid-19.
The gene, known as OAS1, was incorporated into the human genome after our ancestors mated with the now extinct human relative about 60,000 years ago.
The OAS1 gene controls a protein of the same name, which is involved in the body’s response to viruses.
The version inherited from Neanderthals is less common in society, but offers increased protection against coronavirus, say researchers.
The finding contradicts previous research, which found that a group of genes inherited from Neanderthals may increase the risk of becoming seriously ill with Covid-19.
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A specific version of a gene, known as OAS1, which was inherited from Neanderthals reduces the risk of serious illness, hospitalization and death from Covid-19, a new study has found.
The study, led by McGill University in Canada, looked in detail at the genetic code that produces different versions of OAS1.
A position within the gene, known as rs10774671, has two main forms. The most common form is variant “A”, but the ancestral version from Neanderthals is called variant “G”.
“The ancestral variant (rs10774671-G) is the major allele of African populations and has become fixed in the Neanderthal and Denisovan genomes,” the researchers write.
The difference between the two genetic variants is that A leads to the production of many different types (or isoforms) of OAS1 proteins in varying amounts, while type G leads to a large amount of a specific isoform of the OAS1 protein, called p46.
“How much each of us has from any of the isoforms seems to be determined by a single change in the genetic code of the gene encoding the protein, that is, the region of the genome that contains the plan to build this protein,” said study author Dr. Maik Pietzner of at Cambridge University told MailOnline.
The p46 version of the protein is longer than the others and has higher antiviral activity than other types of OAS1, the researchers say.
When people have a high level of the p46 version of OAS1, which is produced by the Neanderthal gene, they have less than a third of the risk of becoming infected as a person with low levels of p46 OAS1, the data suggests.
And if they become infected, these people have only nine percent of the risk of hospitalization and five percent of the risk of developing “very severe” Covid as a person with low p46 levels.
This gene was incorporated into the human genomes after our ancestors mated with the now extinct human relative who lived about 60,000 years ago.
The G-shape of the gene originally entered Homo sapiens, through the interactions of our predecessor with our sister species millennia ago, and has survived to the present day.
It lasted so long due to its ability to fight disease, providing a survival benefit.
“This form of OAS protection1 is present in sub-Saharan Africa, but was lost when the ancestors of modern Europeans migrated from Africa,” study co-author Brent Richards of the Jewish General Hospital and McGill University in Montreal told Reuters.
“It was then reintroduced into the European population by mating with Neanderthals.”
Researchers believe that drugs that target the OAS1 gene and increase the amount of p46 in the system could lead to effective treatment for Covid-19.
A previous study from the University of Edinburgh identified five genes that can negatively affect a patient’s chances of survival after they caught Covid-19.
One of these was the usual version of OAS1 (variant A), reinforcing the suggestion that the type of OAS1 gene that a person inherits may play a significant role in the progression and severity of the disease.
Meanwhile, a previous study found that some genes inherited from Neanderthals can have a negative impact on the chances of survival of coronavirus patients.
Researchers in Germany and Sweden found that a specific group of Neanderthal genes were linked to an increased risk of Covid-19 death.
In a study of 3,199 hospital patients with coronavirus in Italy and Spain, they found that this genetic signature was linked to a more severe disease.
They found that people who developed a Covid-19 so bad that they needed a ventilator were 70% more likely to have genetic variation.