As scientists and doctors all over the world race to better understand COVID-19 and why certain people develop more severe symptoms than others, a major genetic discovery has been made. Researchers from the University of Exeter and the University of Connecticut have concluded that a faulty gene typically associated with dementia can double an individual’s risk of developing severe COVID-19 symptoms.
The research team analyzed data from the UK Biobank, a huge long-term genetic research project featuring samples from over 500,000 volunteers. Their investigation revealed that individuals of European heritage carrying two faulty copies of the APOE gene (called e4e4) are twice as likely to develop severe and life-threatening coronavirus symptoms upon COVID-19 infection. Most people carry the much more common e3e3 form of the APOE gene.
It’s estimated that about one in 36 people of European ancestry carries two faulty copies of the APOE gene, and that unlucky distinction is already linked to a 14 times greater likelihood of developing Alzheimer’s and an increased risk of heart disease. Now, this new study finds having this gene mutation also doubles one’s risk of suffering from severe COVID-19. To be clear, one doesn’t have to develop dementia or heart disease to be at a greater coronavirus risk; just carrying two faulty copies of this gene is enough.
Before making this discovery, the study’s authors had already concluded that people currently suffering from dementia are three times more likely to develop severe COVID-19 symptoms. This is especially noteworthy since most safety and awareness campaigns (stay home, social distancing) focusing on at-risk groups, like the elderly or physically ill, have failed to address those with dementia.
As far as why dementia patients are at a greater risk of harsh coronavirus symptoms, researchers originally theorized their observation probably had something to do with the high infection rates in care and nursing homes. However, now their newest findings suggest that genetics play a big role as well.
Within the analyzed dataset, a very small percentage (2.36%) of participants with a European heritage were carrying the APOE e4e4 faulty gene, but 5.13% of those who tested positive for COVID-19 had the faulty gene variant.
“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,” comments study co-author Dr. Chia-Ling Kuo, of the UConn School of Medicine, in a university release.
“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,” concludes study leader & professor David Melzer. “The effect could be partly due to this underlying genetic change, which puts them at risk for both COVID-19 and dementia.”
In the fight against COVID-19, knowledge is the ultimate advantage. If looking out for this gene variant can help physicians identify at-risk patients before severe symptoms appear, it can potentially save countless lives.
The full study can be found here, published in the Journal of Gerontology: Medical Sciences.
John Anderer is a frequent contributor to Ladders News.