Neanderthal gene variants can both increase and decrease the risk of severe Covid-19 courses
Last year, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig and the Karolinska Institutet in Sweden discovered that we inherited the most important genetic risk factor for a severe course of the disease Covid-19 from Neanderthals. Now the same researchers describe study that Neanderthals contributed not only harmful but also protective variants to our genome.
Some people get seriously ill when they contract the Sars-CoV-2 virus, while others have mild or no symptoms. In addition to risk factors such as advanced age and diabetes, there are also certain gene variants that make people more or less susceptible to a severe course of Covid-19. The most important genetic risk factor is found in the human genome on chromosome 3 and dramatically increases the risk of having to be ventilated or even dying. Last year Hugo Zeberg and Svante Pääbo from the Karolinska Insitutet in Sweden and the Max Planck Institute for Evolutionary Anthropology discovered that we inherited this risk variant from the Neanderthals.
Now the two researchers show that the Neanderthals passed on protective variants in addition to the harmful ones. In an article they describe that a region on chromosome 12 that reduces the risk of becoming seriously ill with an infection by about 20 percent comes from the Neanderthal. The genes in this region will be OAS called and regulate the activity of an enzyme that breaks down viral genomes, and the Neanderthal variant of the enzyme appears to be more efficient at doing this. “It shows that our Neanderthal heritage is a double-edged sword. It has given us variants for which we can both thank the Neanderthals and curse them, ”says Hugo Zeberg.
The study also shows that the protective Neanderthal variant has continued to gain acceptance since the last Ice Age, so that around half of all people outside Africa now have it in their genome. “It is noticeable that this Neanderthal variant has established itself in many parts of the world. It may have been useful not only in the current pandemic, but also in the past, ”says Svante Pääbo. “It is also noticeable that two genetic variants that we inherited from Neanderthals are associated with such opposing effects for the course of Covid-19. The Neanderthals’ immune system obviously still influences us today – both positively and negatively. “