Genetic Link Between Alzheimer’s and Severe COVID Identified

An anti-viral gene that impacts the risk of both Alzheimer’s disease and severe COVID-19 has been identified by a UCL-led research team. The findings, published in Brain, could open the door for new targets for drug development or tracking disease progression in either disease. 

For the study the research team sought to build on their previous work, which found evidence from a large dataset of human genomes, to suggest a link between the OAS1 gene and Alzheimer’s disease. Investigating the gene’s link to Alzheimer’s further, they sequenced genetic data from 2,547 people, half of whom had Alzheimer’s disease. Their findings add OAS1, an anti-viral gene, to a list of dozens of genes now known to affect a person’s risk of developing Alzheimer’s disease. The researchers investigated four variants of the OAS1 gene, all of which dampen its expression. They found that the variants increasing the risk of Alzheimer’s disease are linked with OAS1 variants recently found to increase the baseline risk of needing intensive care for COVID-19 by as much as 20%.

As part of the same research, in immune cells treated to mimic the effects of COVID-19, the researchers found that the gene controls how much the body’s immune cells release pro-inflammatory proteins. They found that microglia cells where the gene was expressed more weakly had an exaggerated response to tissue damage, unleashing what they call a 'cytokine storm,' which leads to an autoimmune state where the body attacks itself.

OAS1 activity changes with age, so further research into the genetic network could help to understand why older people are more vulnerable to Alzheimer’s, COVID-19, and other related diseases. “Our findings suggest that some people may have increased susceptibility to both Alzheimer’s disease and severe COVID-19, irrespective of their age, as some of our immune cells appear to engage a common molecular mechanism in both diseases,” researcher Naciye Magusali concluded.