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Genetic Similarity Between COVID-19 and Alzheimer’s Disease

by Karishma Abhishek on Oct 8 2021 11:55 PM

Genetic Similarity Between COVID-19 and Alzheimer’s Disease
Anti-viral gene that influences both COVID-19 and Alzheimer’s risk has been identified by a study “A genetic link between risk for Alzheimer's disease and severe COVID-19 outcomes via the OAS1 gene”, at the University College London, published in the journal Brain.
Alzheimer's disease (AD) is a neurodegenerative disease that leads to gradual memory loss and behavioral changes. It is characterized by the pathological hallmark formation of beta-amyloid plaques and the tau proteins in the brain tissues, long (almost 20 to 30 years) before the actual symptoms occur.

The study demonstrates that a specific genetic variant of the OAS1 gene escalates the risk of Alzheimer’s disease by 3-6%. Following it, related variants on the same gene also increase the possibility of severe COVID-19 outcomes.

This may help formulate new drug targets against both the disease and its progression. The findings may also hold probable benefits against dementia and other similar infections.

OAS1 gene and Risk of AD & COVID-19

“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. We have found that some of the same immune system changes can occur in both Alzheimer’s disease and COVID-19. 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 of both Alzheimer’s and COVID-19”, says Lead author Dr. Dervis Salih (UCL Queen Square Institute of Neurology and UK Dementia Research Institute at UCL).

The gene OAS1 is found to be expressed in immune cells of the brain – microglia. The study sequenced genetic data from 2,547 people, among which, half of them had Alzheimer’s disease.

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The study team found that the baseline risk of Alzheimer’s increased by 11-22% in people with a particular variation, called rs1131454, of the OAS1 gene. Moreover these OAS1 variants were also found to increase the baseline risk of needing intensive care for COVID-19 by as much as 20%.

As the OAS1 activity changes with age, further genetic research is required to understand why older people are more vulnerable to Alzheimer’s, COVID-19, and other related diseases.

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“If we could develop a simple way of testing for these genetic variants when someone tests positive for COVID-19, then it might be possible to identify who is at greater risk of needing critical care, but there is plenty more work to be done to get us there”, says, Dr. Salih.

Source-Medindia


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