Alzheimer’s and Covid-19 share a genetic risk factor

A gene that impacts the risk of both Alzheimer's disease and severe Covid-19 has been identified by a UCL-led research team. The researchers estimate that one genetic variant of the OAS1 gene increases the risk of Alzheimer's disease by about 3-6% in the population as a whole, while related variants on the same gene increase the likelihood of severe Covid-19 outcomes. The findings, published in Brain , could open the door for new targets for drug development or tracking disease progression in either disease, and suggest that treatments developed could be used for both conditions. The findings also have potential benefits for other related infectious conditions and dementias. Lead author Dr Dervis Salih (UCL Queen Square Institute of Neurology and UK Dementia Research Institute at UCL) said: "While Alzheimer's is primarily characterised by harmful build-up of amyloid protein and tangles in the brain, there is also extensive inflammation in the brain that highlights the importance of the immune system in Alzheimer's. "In patients with severe Covid-19 infection there can also be inflammatory changes in the brain. Here we have identified a gene that can contribute to an exaggerated immune response to increase risks from both Alzheimer's and Covid-19." 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.