On May 26, 2020, researchers at the University of Exeter Medical School and the UConn School of Medicine analyzed data from the UK Biobank, and found a high risk of severe COVID-19 infection among participants of European ancestry 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 the risk of heart disease. 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. Part of the increased risk effect may have been exposure to the high prevalence of the virus in nursing homes. However, the new study, published in the Journal of Gerontology: Medical Sciences, 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.

In this analysis, 2.36% (n=9,022) of participants with European ancestries (n=382,188) had the ApoE e4e4 faulty gene, but 5.13% (n=37) of those who tested positive for COVID-19 (n=721) had this gene variant, suggesting the risk is doubled compared to e3e3 (410 per 100,000 versus 179 per 100,000).