Having Neanderthal genes could make you more at risk from severe coronavirus, a study has found.
A genetic quirk inherited from the extinct human species, who lived 40,000 to 400,000 years ago, could make people more susceptible to Covid-19.
This genetic variation is present in modern-day humans because our ancestors had sex with Neanderthals about 60,000 years ago, researchers say.
And those who have the variant, found on chromosome three, are up to three times more likely to need ventilation if they catch the virus.
In a study of 3,199 hospital patients with coronavirus in Italy and Spain, researchers found the genetic signature was linked to a more severe illness.
People infected with Covid-19 who carry a specific snippet of genetic coding bequeathed by Neanderthals are three times more likely to need mechanical ventilation. Pictured: Svante Pääbo, director at the Max Planck Institute for Evolutionary Anthropology in Germany and study author
WHO WERE NEANDERTHALS?
Neanderthals were a close human ancestor that mysteriously died out around 40,000 years ago.
The species lived in Africa with early humans for millennia before moving across to Europe around 300,000 years ago.
They were later joined by humans, who entered Eurasia around 48,000 years ago.
These were the original ‘cavemen’, historically thought to be dim-witted and brutish.
But in recent years, evidence points to a more sophisticated and multi-talented kind of ‘caveman’.
It now seems likely that Neanderthals buried their dead, painted and even interbred with humans.
Lead author Professor Hugo Zeberg, from the Karolinska Institutet in Sweden, said: ‘The increase in risk is 60-70 per cent if you carry one copy of the Neanderthal variant and three times the risk if you have two copies – one from your father and one from your mother.
‘Later studies estimate the risk increase to be even higher, with twice the risk if you have one copy and up to a five-fold increase if you have two copies.’
The gene variant had first been found in the remains of a Neanderthal in Croatia from some 50,000 years ago, and continues to be found in millions of modern day humans.
Neanderthals were a species that lived alongside humans tens of thousands of years ago and were very similar in appearance and size but were generally stockier and more muscular.
This primitive relative of humans existed for around 100,000 years – much of that time alongside people and breeding with them – before going extinct around 40,00 years ago.
It is not yet known why the Neanderthal gene is associated with an increased risk of becoming severely ill, while scientists say it is something to be investigated ‘as quickly as possible’.
Not everyone has this variant – it is most common among people of South Asian ethnicity, of whom around 50 per cent have it.
It is less common in Europe, where about 16 per cent of people carry it.
Bangladesh has the highest number of carriers at 63 per cent.
Professor Zeberg and his fellow study author Dr Svante Pääbo said the Neanderthal genes are most common in people of South Asian ethnicity, particularly Bangladeshis, and considerably less common in Europeans (Pictured: A map of where the genes are most common)
This difference may contribute to the differences in severity of Covid-19 that have been observed between different populations.
For example, individuals of Bangladeshi descent in the UK have about two times higher risk of dying from Covid-19 than the general population.
The researchers wanted to know whether the quirk had been passed over from Neanderthals or whether it had been inherited by both Neanderthals and present-day people through a common ancestor.
They concluded it must have come from inbreeding between Neanderthals and present-day humans because the last common ancestor between the groups would have lived 550,000 years ago – during which time the genetic variant probably would have been altered.
Neanderthals were a species that lived alongside humans tens of thousands of years ago and were very similar in appearance and size but were generally stockier and more muscular (Pictured: A replica of a male Neanderthal head in London’s Natural History Museum)
Author Professor Svante Paabo, from the Okinawa Institute of Science and Technology, said: ‘It is striking that the genetic heritage from Neanderthals has such tragic consequences during the current pandemic.’
The scientists are keen to point out that there are also other factors that can influence a person’s susceptibility to having a severe reaction to the virus, including their age and the existence of other medical conditions.
Professor Zeberg, said: ‘Obviously, factors such as your age and other diseases you may have also affect how severely you are affected by the virus.
‘But among genetic factors, this is the strongest one.’
GENES THAT DICTATE BLOOD TYPE COULD AFFECT RISK OF SEVERE CORONAVIRUS
Another genetic difference that may put people at higher risk of developing severe coronavirus could be one that dictates someone’s blood group, a study in June suggested.
Researchers at genetic testing company 23andMe found that people with type O blood were up to 18 percent less likely to test positive for COVID-19, the disease caused by the virus.
Additionally, those who had the blood type, and had been exposed, were up to 26 percent less likely to contract coronavirus.
The team says this indicates a link between the genes that determined blood type and the severity of the virus. People who become seriously ill are the ones who are most likely to test positive, while milder patients may not realise they’re ill.
For the study, the team recruited more than 750,000 participants, including 10,000 who reported having COVID-19.
Individuals with type O blood were between nine and 18 percent less likely than those with other blood types to test positive.
About 1.3 percent of 23andMe research participants with type O blood tested positive for COVID-19.
By comparison, 1.4 percent of those with type A blood and 1.5 percent of people with type B or type AB blood were confirmed to have the virus.
People with O-type blood who had been exposed to the virus, such as frontline health workers, were between 13 and 26 percent less likely to test positive.
Among those exposed, 3.2 percent with type O blood tested positive compared to 3.9 percent of people with type A blood, four percent with type B blood and 4.1 percent with type AB blood.
The findings, which have yet to be peer reviewed or published in a medical journal, held true when adjusted for factors such as age, sex, body mass index and underlying health conditions.
Researchers identified a variant in the ABO gene, responsible for difference blood types, that was associated with a lower risk.
‘The study and recruitment are ongoing, with the hope that we can use our research platform to better understand differences in how people respond to the virus,’ a statement on the 23andMe blog read.
‘Ultimately, we hope to publish our research findings in order to provide more insight into COVID-19 for the scientific community.’