An international team of researchers has isolated five genes that are more active in young people with severe COVID-19 symptoms than in those with less severe symptoms. In their paper published in the journal Science Translational Medicine, the group describes their genetic analysis of young infected people with no known contributing factors for the disease.

Some healthy young people, despite having no apparent underlying conditions, still develop very serious COVID symptoms. Why this happens remains a mystery. In this new effort, the researchers found a possible cluegenes that appear to reduce the body's ability to fight the disease when activated.

The work involved collecting plasma samples from 72 young, hospitalized COVID patients, 47 of whom were critically ill. None of those sampled had any underlying conditions that might explain their symptoms. The team also collected samples from 22 infected young people who had few or no symptoms to serve as a control group. The researchers noted at the outset that those patients who were the most ill also suffered from increased inflammation and coagulation. They then conducted whole-genome sequencing on the samples, along with RNA sequencing, cell proteomics, cytokine profiling and immunophenotyping. They also used a machine-learning application to spot patterns in the genes. Their analysis revealed five genes that were more active in the patients with severe symptoms. One, ADAM9, was found to be the most prevalent.

The team found that when ADAM9 was blocked in human lung tissue in vitro, the virus was less efficient at duplicating itself. The researchers suggest that all five of the genes they identified need to be studied in more depth, particularly ADAM9. Doing so could lead to therapeutics to disable the activity of such genes, and in so doing, reduce symptoms of COVID-19.

—Bob Yirka , Medical Xpress