If You’ve Resisted COVID So Far, You May Have Your Caveman Ancestors to Thank
A new study suggests that a genetic variant associated with reduced COVID-19 severity is inherited from Neanderthals.
Previously, a genetic factor associated with increased risk of contracting severe COVID-19 was shown to be inherited from Neanderthals.
Hugo Zeberg and Svante Pääbo analyzed new data from the Genetics of Mortality in Critical Care consortium, which includes more than 2,200 critically ill COVID-19 patients, and identified several additional genomic regions associated with COVID-19 hospitalization.
Using genomic data from published databases, the authors found that the sequence variations associated with COVID-19 hospitalization in one of these regions, located on chromosome 12, tended to be inherited together in Europeans.
This DNA segment is closely related to that found at the same location in all three Neanderthal genomes sequenced to date. The Neanderthal DNA segment is associated with a 22% reduction in the risk of requiring hospitalization for COVID-19.
In modern humans, the segment occurs at substantial frequencies in Eurasia and the Americas but is almost completely absent in sub-Saharan Africa. The DNA segment encompasses all or parts of three genes involved in cells’ response to RNA virus infection.
Neanderthals evolved in Europe and Asia while modern humans – our species, Homo sapiens – were evolving in Africa.
Judging from fossil evidence scattered across Europe and the British Isles, the Neanderthal lineage was already well-established in Europe by 400,000 years ago.
It is estimated that the proportion of Neanderthal-derived DNA in people of European descent ranges from 1% to 4%.
Africans also have some Neanderthal admixture in their DNA, however it accounts for a meager 0.3% of their genome.
According to the authors, the results suggest that the genetic contributions of Neanderthals to present-day humans are complex, conferring both increased and decreased risk of becoming severely ill during the current pandemic.