A large US study has found that having a faulty gene linked to dementia can double the risk of developing severe COVID-19.
The study by researchers from the University of Exeter Medical School and the University of Connecticut is published in the current Journals of Gerontology, Series A: Biological Sciences and Medical Sciences.
It analysed data from the UK Biobank, which contains health and genetic data from half a million people, and found a high risk of severe COVID-19 infection among people with two faulty copies of the APOE gene.
The APOE gene is known to increase the risk of Alzheimer’s disease 14-fold as well as raising the risk of heart disease. One in 36 people of European ancestry carry the genetic mutations.
Carrying the gene mutations doubles the risk of COVID-19, the researchers found, even the person is free from both diseases.
It’s not the first time a team has found link between dementia and COVID-19, with an earlier study indicating that people with dementia are three times more likely to get severe COVID-19.
The latest study suggests more could be at play, the researchers say.
Lead author David Melzer said the findings suggested that genetic factors, rather than the effects of dementia alone, may be responsible for increasing the risk of COVID in older people.
“Several studies have now shown that people with dementia are at high risk of developing severe COVID-19,” he said.
“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,” he said.
Hope for new treatments
Co-author Chia-Ling Kuo said the finding could lead to new ideas for treatments.
“This is an exciting result because we might now be able to pinpoint how this faulty gene causes vulnerability to COVID-19,” he said.
Australian geriatrician Dr Paul Yates of Austin Health said the findings of the study were interesting.
“APOE has many biological functions and so it is reasonable to consider whether it might influence susceptibility to COVID,” he told Community Care Review.
But Dr Yates said although the research suggested people with two copies of the faulty gene were twice as likely to have a positive test, it was possible that other conditions may have influenced their susceptibility to the virus.
Further research was needed before any “strong” conclusion could be made on a link, he said.
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