IMAGINE the scene. Almost 60,000 years ago, a genetic variant was passed on to humans – us! – by crossbreeding between Neanderthals and modern humans. And today, in the midst of a pandemic, researchers are finding that this same variant may have played a role in circumscribing the numbers – to a certain extent – of those suffering from severe forms of Covid-19. Sounds like science fiction? Perhaps, but it's a real discovery.
Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST), in collaboration with German scientists, have made this surprising discovery: a group of genes, which would reduce the risk of a person becoming seriously ill from Covid-19 by about 20%, is inherited from the Neanderthals. In their study, the researchers specify that these genes are located on chromosome 12 and that they code for enzymes that play a crucial role in helping cells destroy the genomes of invading viruses – and thus of SARS-CoV-2.
One must keep in mind, however, that genetic factors – although important – are not the only factors to be taken into account when it comes to severe forms of Covid-19; advanced age and certain diseases also have a significant impact.
And contrary to what one might think, this genetic variant is rather frequent despite having been transmitted nearly 60,000 years ago. Researchers even indicate that it has increased in frequency over the last millennium to the point where it is now found in almost half of the people living outside Africa.
Is the Neanderthal legacy good or bad when it comes to fighting Covid-19?
Surprisingly, a study last year revealed that the greatest genetic risk factor doubling the risk of developing a severe form of Covid-19 had also been inherited from... Neanderthals. The newly identified genetic factor does the opposite, appearing to be protective... It's hard to tell which way is up.
"It's quite amazing that despite Neanderthals becoming extinct around 40,000 years ago, their immune system still influences us in both positive and negative ways today," said Professor Svante Pääbo, one of the study authors. "The rise in the frequency of this protective Neanderthal variant suggests that it may have been beneficial also in the past, maybe during other disease outbreaks caused by RNA viruses." – ETX Studio, February 19, 2021
