COVID-19 decoded: Scientists find genes making people vulnerable to coronavirus

The new finding suggests TLR7 role is essential for protection from coronavirus.

Coronavirus treatment: In a major positive development during the prevailing grim scenario triggered by the coronavirus outbreak, scientists have detected a gene in the human body which could be an important performer in the immune response against the coronavirus, reported PTI, citing a research paper published in the Journal of the American Medical Association. This development may help doctors and scientists understand the virus better and further helping in the treatment of COVID-19 patients.

In this study scientists from the Radboud University Medical Center in the Netherlands explored the presence of genetic variants associated with primary immune deficiency among young COVID-19 patients. They studied the genetic structure of four young male COVID-19 patients from two families; they didn’t have any previous medical complications that made them predisposed to the deadly disease.

“In this case series of four young male patients with severe COVID-19, rare putative loss-of-function variants of X-chromosomal TLR7 were identified that were associated with impaired type I and II IFN responses,” the scientists wrote in the paper, as reported by PTI.

According to them, TLR-genes help produces a family of protein receptors on the surface of human cells which play an important role in the recognition of pathogens. “These receptors recognise infectious agents like bacteria and viruses in the body and activate the immune system,” they said in the paper, adding “TLR7 triggers the production of so-called interferons, signalling proteins that are essential in the defense against virus infections.”

Till now TLR7 function had never been associated with an inborn error of immunity. But scientists say the new finding suggests TLR7 role is essential for protection from coronavirus.

Geneticist Alexander Hoischen, a co-author of the study, said, “It seems the virus can replicate undisturbed because the immune system does not get a message that the virus has invaded,” as reported by PTI. He said because TLR7, which should identify the intruder and then activate the defense, was hardly present…could be the reason for the severity of the disease in these brothers.”

The study found that the variants of the TLR7 gene in the patients had a loss-of-function. “TLR7 loss-of-function mutations can lead to an immunodeficiency with a strong predisposition to develop a severe form of COVID-19 in young male patients, he said.

The findings provide more insight into the fundamental workings of the human body’s immune system, say the scientists. This could further help in the treatment of severely ill coronavirus patients.