Researchers from the University of Exeter, England, and the University of Connecticut have found that people carrying faulty gene APOE e4e4 are more likely to have severe symptoms from COVID-19 than those with a different variant.
The gene has previously been linked to Alzheimer's disease in Caucasian people. Having two faulty copies of the gene, common to 1 in 36 people of European descent, has been known to increase one's risk of Alzheimer's by 15 times, as well as increase one's risk of heart disease.
For their study, the researchers analyzed data from the UK Biobank study, a collection of health and genetic data of 500,000 people. They found that while most people in the population had not been exposed to the virus, 2.36% of those with European ancestry had the APOE e4e4 gene, whereas 5.13% of those tested positive for COVID-19 had this gene variant. Meanwhile, those with the e3e3 variant of the same gene were less than half as likely to test positive for the virus.
The researchers concluded that the APOE e4e4 gene's presence might increase one's chances of developing severe COVID-19 symptoms. These results match their previous findings showing that people with dementia are three times as likely than those without to get severe COVID-19 symptoms.
"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 aging 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 sixties." says co-author of the study, Dr. Chia-Ling Kuo.
Professor David Melzer, lead author if the study, says, "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."