Three genes inherited from Neanderthals slash the risk of severe Covid-19 by 22 per cent, a new study has revealed.
The genes sit next to each other on chromosome 12, and this large chunk of genetic material includes 75,000 individual pieces of DNA.
Researchers compared the DNA of 2,200 Covid-19 patients from around the world with the genes of three Neanderthals that lived 50,000, 70,000 and 120,000 years ago.
They found people with Neanderthal versions of the genes OAS1, OAS2 and OAS3 were less likely to develop severe symptoms after infection with the coronavirus.
These genes produce enzymes which specifically target invading RNA viruses, and the Neanderthal version is thought to be more potent.
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Previous research has found eight genetic locations spread across five chromosomes (3, 6, 12, 19 and 21) which are ‘associated with risk of requiring intensive care upon SARS-CoV-2 infection’. However, the new analysis shows only those found at chromosome 3 and 12 come from Neanderthals (pictured). Chromosome 12 contains three genes which help fight Covi and slash risk of severe infection by 22%
Professor Hugo Zeberg and Dr Svante Pääbo from the Karolinska Institutet in Stockholm and the Max Planck Institute for Evolutionary Anthropology in Leipzig, respectively, conducted the study.
Previous research has found eight genetic locations spread across five chromosomes (3, 6, 12, 19 and 21) which are ‘associated with risk of requiring intensive care upon SARS-CoV-2 infection’.
However, the new analysis shows only those found at chromosome 3 and 12 originate from cross-species trysts between Homo sapiens and Neanderthals.
Researchers compared the DNA of 2,200 Covid-19 patients from around the world with the genomes of three Neanderthals that lived 50,000, 70,000 and 120,000 years ago. They found people with neanderthal versions of the genes OAS1, OAS2 and OAS3 were less likely to develop severe symptoms after infection with the coronavirus
The chromosome 3 gene was the subject of previous research from the same team of experts.
It revealed the Neanderthal version, which is present in around one in eight people today, actually doubles the risk of needing intensive care if a person catches Covid.
But the stretch of Neanderthal DNA on chromosome 12 is more common.
It was present in around one in ten humans that lived more than 20,000 years ago, and then increased to around 15 per cent up to 10,000 years ago.
The researchers estimate it continued to become more dominant, with around a third of people who lived between 3,000 and 1,000 years ago having it.
Pictured, the percentage of people in Eurasia with the Covid-fighting genes on chromosome 12 over time. It is now more than 30 per cent but experts say it often reaches and exceed 50 per cent in some populations
Pictured, a world map showing the percentage of people who have the Neanderthal versions of the OAS1, OAS2 and OAS3 genes (red portions of pie charts). Due to the ancient migratory patterns of Neanderthals and the fact they sparsely inhabited Africa before going extinct, very little Neanderthal DNA is seen in people living in sub-Saharan Africa today
Five genes make you more likely to die from coronavirus or be admitted to ICU
Five genes identified by the University of Edinburgh increase the likelihood of a Covid-19 patient being admitted to intensive care and dying.
A landmark study published in December gathered DNA from 2,700 Covid-19 patients in 208 intensive care units across the UK.
These are the most severe cases of Covid, and 22 per cent of patients studied died, with 74 per cent unable to breathe on their own and needing mechanical ventilation.
The genetic information of these patients was compared to 100,000 anonymous Britons, and five genes emerged as being extremely common in severe Covid cases.
Researchers say the discovery of five genes that appear so clearly to be linked to the disease is unprecedented in the field.
Knowing which genes are involved in severe cases of coronavirus infection can help scientists identify pre-existing drugs that could help treat Covid, the researchers say.
The genes were identified across the genome, with two on chromosome 19 called TYK2 and DPP9. One, called IFNAR2, is found on chromosome 21.
CCR2 is a gene found on chromosome four and OAS1 is located on the twelfth chromosome.
‘Intriguingly, the current allele frequency in Eurasia is around 30 per cent, suggesting that the Neandertal haplotype may have increased in frequency relatively recently,’ the researchers write in their paper.
They add: ‘It is present in populations in Eurasia and the Americas at carrier frequencies that often reach and exceed 50 per cent.’
Dr Pääbo says it is ‘striking’ that two Neanderthal variants can have such drastically different impacts on human immune response to SARS-CoV-2 infection.
‘This shows that our heritage from Neanderthals is a double-edged sword when it comes to our response to SARS-CoV-2,’ adds Professor Zeberg.
The researchers believe the location of the Neanderthal DNA on chromosome 12 is key, as it includes three genes (OAS1, OAS2 and OAS3) which play a critical role in fighting infection.
Specifically, they help produce enzymes which target and destroy invasive RNA, such as SARS-CoV-2 which causes Covid-19.
The new research, published in the journal PNAS, also found the Neanderthal variant makes more virus-fighting enzymes than the ancestral Homo sapien alternative.
‘One may speculate that, when modern humans encountered new RNA viruses outside Africa, the higher enzymatic activity of the ancestral variants that they acquired through genetic interactions with Neandertals may have been advantageous,’ the researchers write.
‘Intriguingly, there is evidence that the Neanderthal-like OAS haplotype may have recently increased in frequency in Eurasia, suggesting that selection may have positively affected the Neandertal-derived OAS locus in the last millennium.’
Due to the ancient migratory patterns of Neanderthals and the fact they sparsely inhabited Africa before going extinct, very little Neanderthal DNA is seen in people living in sub-Saharan Africa today.
In fact, the researchers say the Neanderthal Covid-fighting genes are ‘almost completely absent’ from these populations.
‘In the Americas, it occurs in lower frequencies in some populations of African ancestry, presumably due to gene flow from populations of European or Native American ancestry,’ they add in the paper.
The latest study backs up previous findings from a separate team of researchers from Canada, which also came to the conclusion the OAS1 gene reduces the risk of serious illness, hospitalisation and death from Covid-19.
Although they did not look at the gene’s origin, they did find five genes which increase the odds of severe infection.
Four of these genes — TYK2 and DPP9 on chromosome 19; IFNAR on chromosome 21 and OAS on chromosome 12 — were also studied by the latest study.
Neanderthals and Homo erectus went extinct due to bouts of sudden and intense climate change, study claims
Neanderthals and Homo erectus, both cousins of modern-day humans, went extinct due to sudden, and unexpectedly intense, bouts of climate change.
Scientists have long sought to understand the fate of our long-lost brethren, and previous studies have indicated climate change likely plays a major role.
Computer analysis, published today, reveals the hominins failed to adapt to a rapidly changing climate.
Researchers investigated temperature, rainfall and other data over the last five million years to get a gauge of the climate for every 1,000-year window.
They also modelled the evolution of Homo species’ through time by plundering an extensive database of more than 2,750 fossils.
The analysis revealed three Homo species – H. erectus, H. heidelbergensis and H. neanderthalensis – lost most of their ‘climatic niche’ just before going extinct.
Climactic niche describes a locale where conditions are just right for the species to survive, not too hot, dry, cold or barren.
According to the researchers, Neanderthals were wiped out around 40,000 years ago and Homo erectus went extinct 70,000 years before that.