Genes passed down from our Neanderthal ancestors may increase our risk of contracting a more severe form of Covid-19, a study has concluded.
The research, published in Nature, suggests that a gene thought to triple an infected individual’s chance of developing serious coronavirus symptoms was passed on by Neanderthals more than 50,000 years ago.
Around 16% of Europeans and 50% of South Asians currently carry the gene.
The DNA strand, found on chromosome 3, was discovered by Swedish and German scientists comparing genetic data from seriously ill Covid-19 patients with that of 50,000-year-old Neanderthal skeletons found in Croatia and Siberia, CNN reports.
About 2% of all DNA found in European and Asian populations can be traced back to the now-extinct humanoid species, but it is almost completely absent in African populations.
The six-gene cluster at the center of the study was found to be most prevalent in Bangladesh, “where 63% of the population carry at least one copy of the sequence”, The New York Times says.
The strand “may account in part for why people of Bangladeshi descent are dying at a high rate of Covid-19 in the United Kingdom”, the paper adds.
Svante Paabo, who also worked on the study, has posited that around 100,000 “additional” coronavirus deaths have so far occurred as a result of the now-extinct humanoid’s genetic code.
“The genes in this region may well have protected the Neanderthals against some other infectious diseases that are not around today” Paabo said. “And now when we are faced with the novel coronavirus these Neanderthal genes have these tragic consequences.”
Despite the breakthrough, the precise feature of Neanderthal DNA that causes the increase in risk is currently unknown, which has led experts to warn against jumping to conclusions.
“Covid-19 is a complex disease, the severity of which has been linked to age, gender, ethnicity, obesity, health, virus load among other things” University College London Professor Mark Maslin told The Guardian.
“Lots of different populations are being severely affected, many of which do not have any Neanderthal genes,” Maslin added. “We must avoid simplifying the causes and impact of Covid-19.”