A group of researchers has performed a study that found that some people could have genes inherited from Neanderthals that reduce the risk of severe COVID-19 by 22 percent. These inherited genes are said to be more common in people of European and Asian ancestry. Neanderthals are a human species that went extinct about 40,000 years ago.
Neanderthals are believed to have passed along some genetic material to modern humans through interbreeding. Researchers believe Neanderthal DNA makes up between one and two percent of the genomes of people of European and Asian descent. While the percentage of DNA inherited from the Neanderthals is small, the small fraction of DNA could hold clues about the immune system’s response to pathogens.
The DNA advantage comes from a single haplotype, a long block of DNA, on chromosome 12. That haplotype has been shown in the past to protect people against West Nile, hepatitis C, and SARS. It may also help provide some immunity to SARS-CoV-2, which shares many genetic similarities with the virus’s original strain.
In the study, the team relied on genomes of three Neanderthal specimens, with the remains of two found in Siberia and one found in Croatia. The DNA used dates for between 50,000 and 120,000 years ago. Researchers compared the genomes of those specimens to the DNA of thousands of people with severe COVID-19. The haplotype associated with less severe COVID-19 was found in all three Neanderthal genomes.
The haplotype in question specifically codes for proteins that activate enzymes helping to degrade RNA viruses. Strangely while this particular haplotype helps fight COVID, the same researchers found in another study that an inherited haplotype from Neanderthals on chromosome 3 could put people at higher risk for respiratory failure due to COVID-19. That DNA gene cluster was discovered in the Neanderthal from Croatia.