Having a faulty gene linked to dementia doubles the risk of developing severe COVID-19, according to a large-scale study.
Researchers at the University of Exeter and the University of Connecticut analysed data from the UK Biobank, and found a high risk of severe COVID-19 infection among European ancestry participants who carry two faulty copies of the APOE gene (termed e4e4).
One in 36 people of European ancestry have two faulty copies of this gene, which is known to increase the risk of Alzheimer’s disease up to 14-fold and also the risk of heart disease.
Now the research team has found that carrying these gene mutations doubles the risk of COVID-19 – even in people who have not developed these diseases.
The team previously found that people with dementia were three times more likely to get severe COVID-19, yet they were not one of the groups advertised to shield – or shelter in place – on health grounds.
Part of the increased risk effect may have been exposure to the high prevalence of the virus in care homes. However, the new study indicates that a genetic component may also be at play.
The team found that people with the APOE e4e4 genotype were at double the risk of developing severe COVID-19, compared to those with the common e3e3 form of the APOE gene.
The team used data from the UK Biobank study, which collects health and genetic data on 500,000 people.
The majority of people in the population, and in the sample size, have not yet been exposed to the virus.
In this analysis, 2.36 per cent of participants with European ancestry had the APOE e4e4 faulty gene, but 5.13 per cent of those who tested positive for COVID-19 had this gene variant, suggesting the risk is doubled compared to e3e3 (410 per 100,000 versus 179 per 100,000).
Co-author Dr Chia-Ling Kuo said: “This is an exciting result because we might now be able to pinpoint how this faulty gene causes vulnerability to COVID-19. This could lead to new ideas for treatments.
“It’s also important because it shows again that increasing disease risks that appear inevitable with ageing might actually be due to specific biological differences, which could help us understand why some people stay active to age 100 and beyond, while others become disabled and die in their 60s.”
Professor David Melzer, who led the team, said: “Several studies have now shown that people with dementia are at high risk of developing severe COVID-19. This study suggests that this high risk may not simply be due to the effects of dementia, advancing age or frailty, or exposure to the virus in care homes.
“The effect could be partly due to this underlying genetic change, which puts them at risk for both COVID-19 and dementia,” Prof Melzer explained.
Have you been tested for your future risk of developing dementia? Does this study make you more concerned about catching COVID-19?
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