AUG 04, 2021 11:34 AM PDT

Variants May Predict Which Young People Are at Risk for Severe COVID-19

WRITTEN BY: Carmen Leitch

While people carry mostly the same genes, there are many small changes in the sequences of those genes, and small variations throughout the genome that can add up to have huge biological effects. Since the beginning of the pandemic, researchers have been trying to determine why some people experience more severe COVID-19 cases than others. There may be many reasons, such as pre-existing health conditions, or age. But genetics may help explain why some young, healthy people end up with serious health problems when most other young people do not.

Transmission electron micrograph of a variant strain of SARS-CoV-2 virus particles (UK B.1.1.7), isolated from a patient sample and cultivated in cell culture. Image captured at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. / Credit: NIAID

Some studies have suggested that remnants of the Neanderthal genome that are still carried by some modern humans have an influence on the severity of COVID-19 if a person gets infected.

Scientists have been searching massive genetic databases, like those maintained by the commercial genetic sequencing company 23AndMe, to identify specific gene variants that play a role in the seriousness of a COVID-19 case.

Now reporting in Frontiers in Immunology, researchers have suggested that variants in a gene called TLR7 impact COVID-19 cases. TLR7 is a gene that encodes for an immune receptor called toll-like receptor 7, which is thought to be involved in some aspects of the immune defense against RNA viruses, which includes COVID-19. Earlier studies have linked mutations in TLR7 to severe COVID-19 cases, one was a case study, and another investigated the genetics of COVID-19 patients in Italy who were over the age of 60.

In the latest research, the genomes of fourteen otherwise healthy men under age 50 that had severe COVID-19 were investigated. In two of these patients, the researchers found mutations in TLR7 that had not been previously identified. Further work showed that two young relatives of one of these TLR7 mutation carriers also carried the same mutation.

“As far as we know, these family members had not yet been exposed to the coronavirus. We therefore decided to vaccinate them preventively, in order to greatly reduce the risk of serious illness from COVID-19," explained study co-author and geneticist Alexander Hoischen of Radboud University Medical Center. Hoischen noted that though the study is small, it suggested that TLR7 screening could help identify young COVID-19 patients that will need additional treatment.

A large study done by Regeneron that included over half a million people has recently reported that they did not find variants in protein-coding genes that could predict whether or not a case of COVID-19 would be severe. However, that research did find that genetic variations in a pathway called type I/III interferon (IFN) were associated with changes in COVID-19 severity. This pathway can include TLR7.

Sources: AAAS/Eurekalert! via Radboud University Medical Center, Frontiers in Immunology

 

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUL 22, 2021
Microbiology
Researchers Discover 15,000-Year-Old Viruses in Glacial Ice
JUL 22, 2021
Researchers Discover 15,000-Year-Old Viruses in Glacial Ice
As the climate warms and long-frozen surfaces begin to thaw, scientists are finding ancient animals and organisms. In so ...
AUG 03, 2021
Neuroscience
Is it the zombie apocalypse? Nope, just some zombie genes
AUG 03, 2021
Is it the zombie apocalypse? Nope, just some zombie genes
Scientists trace the time duration of postmortem cell activity and gene expression in brain tissue to facilitate researc ...
AUG 21, 2021
Genetics & Genomics
Like Some People, Isolated Flies Will Eat More and Sleep Less
AUG 21, 2021
Like Some People, Isolated Flies Will Eat More and Sleep Less
Over the past year and a half, may people have been isolated and have spent far more time alone than usual. For some, th ...
AUG 29, 2021
Genetics & Genomics
Archaeological Site Reveals DNA Belonging to an Ancient Human Relative
AUG 29, 2021
Archaeological Site Reveals DNA Belonging to an Ancient Human Relative
The Wallacean Islands served as stepping stones for the first modern humans as they migrated from Eurasia to Oceania, pr ...
AUG 29, 2021
Cell & Molecular Biology
Learning More About How a microRNA is Involved in ALS
AUG 29, 2021
Learning More About How a microRNA is Involved in ALS
The loss of a microRNA might be interfering with neuromuscular synapse function, causing breathing muscle paralysis, sug ...
SEP 07, 2021
Cell & Molecular Biology
Genetic Influences That Help Make the Human Brain Unique
SEP 07, 2021
Genetic Influences That Help Make the Human Brain Unique
For years, many researchers have been trying to answer the question "What makes us human?" from both a biological and ph ...
Loading Comments...