A Neanderthal DNA segment raises the risk of severe COVID

Geneticists at the Max Planck Institute and Karolinska Institutet traced a risk variant on chromosome 3 back through the human genome's history. They compared it against the genome of a Neanderthal who lived in Croatia around 50,000 years ago.

The risk segment matched the Neanderthal genome almost exactly, confirming it had entered modern humans through interbreeding roughly 60,000 years ago and survived in some populations ever since. Carrying it raises the risk of respiratory failure and needing a ventilator if infected with the coronavirus.

The variant is carried by about 16 percent of people with European ancestry and by about half of people in South Asia, a striking difference the researchers are still trying to explain. It sits near genes involved in the immune response, and later work found the same ancient variant is also linked to a lower risk of HIV infection.

Ancient DNA, a modern risk.