Faulty dementia gene may double the risk of developing severe COVID-19

Researchers at the University of Exeter Medical School and the University of Connecticut School of Medicine have found in a large-scale study that having a faulty gene linked to dementia doubles the risk of developing severe COVID-19. The new research has been published in the Journal of Gerontology: Medical Sciences.

They analysed data from the UK Biobank, and found 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, and this is known to increase risks of Alzheimer's disease up to 14-fold* and also increases risks of heart disease.

Now, the research team has found that carrying these gene mutations doubles the risks of COVID-19 - even in people who had not developed these diseases.

The team has previously found that people with dementia are three times more likely to get severe COVID-19, yet they are 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.