Inherited DNA from our ancestors can play varying roles in immune response to disease. And this research suggests that some Neandertal genes in people today may protect against severe COVID-19. Technical speak: A Neandertal haplotype on chromosome 12 is protective for severe disease in the current SARS-CoV-2 pandemic.
We think that Neanderthals died out around 40,000 years ago. But their influence did not disappear, Neanderthals mated with the ancestors of modern humans, (see image below.) It’s estimated that almost half of the Neanderthal genome still survives, spread in small quantities among almost all modern people’s DNA. (The exception is those with mostly African ancestors, as Neanderthals seem not to have lived in Africa which was the land of Homo Sapiens.)
Such Neandertal genes have been associated with everything from hairiness to fat metabolism. Many seem to be related to the immune system, and to affect the risk of developing diseases including lupus, Crohn’s and diabetes. A pair of recent papers suggest covid-19 belongs on that list as well. Two long sections of DNA, both inherited from Neanderthals, appear to confer resistance or susceptibility to severe covid-19, depending on which is present. More at the Economist.
A Neandertal haplotype on chromosome 12 is protective for severe disease in the current SARS-CoV-2 pandemic. It is present in populations in Eurasia and the Americas at carrier frequencies that often reach and exceed 50%. The ancestral Neandertal OAS locus variants may thus have been advantageous to modern humans throughout Eurasia, perhaps due to one or many epidemics involving RNA viruses, especially given that the Neandertal haplotype has been found to be protective for at least three RNA viruses (West Nile virus, hepatitis C virus, SARS-CoV).