All under the age of 60, young Covid patients who had two things in common: a severe stage of the disease and a genetic variation that could have caused it. A genetic variation (which differs from the genetic mutation because it arises spontaneously, while the latter can also be induced) could therefore be linked to the severity of the disease: this was shown by a study conducted on 156 patients. A study that led to a second conclusion: those affected by a rare genetic variation, which decreases the innate immune response to SARS-CoV-2, could benefit from genetic screening and treatment with interferon. With the result of avoiding many deaths.
Covid in severe form? It’s written in the genes
by Giuseppe del Bello
“Although advanced age and the presence of previous conditions, such as cardiovascular disease or diabetes are known as risk factors, taken individually they do not fully explain the differences in the severity of the disease itself. Chiara Fallerini, researcher at the University of Siena – for some young men without pre-existing medical conditions it is more likely to be hospitalized, enter intensive care and even die of Covid-19, highlighting how some factors cause defects in their immune system “.
Covid, found five mutations that alter two genes
Recent research has shown that the genes that control interferon are important for regulating the immune response against Covid-19. Interferon is produced by immune cells during viral infection; it works together with molecules on the surface of immune cells called Toll-like receptors (TLRs) that are true sensors of viruses and initiate the immune response.
“When a recent study identified rare mutations in a TLR gene, TLR7, in young men affected by Covid-19, we wanted to investigate if it was a very rare situation or if it was the tip of the iceberg”, underlines Mario Mondelli, Director of Infectious Diseases 2 of the Policlinico San Matteo of Pavia and professor of the University of Pavia, co-senior author of the study.
From the Neanderthals, the geniuses who decide if we will become seriously ill with Covid
by Valentina Arcovio
The team analyzed 156 patients affected by Covid-19, all male and under 60, in turn selected by a larger Italian study, launched on March 16, 2020, called GEN-Covid. It is a network of over 40 Italian hospitals coordinated by the professor Alessandra Ranieri, director of the Medical Genetics Unit at the University Hospital of Siena.
From the study, the TLR7 gene was identified as one of the most important genes linked to disease severity. In fact, it emerged that out of 79 patients 5 had missense mutations of the TLR7 gene with very severe Covid-19, while on the other 77 patients no similar mutation was detected.
Covid: for men it is more serious than for women
by Claudia Carucci
To confirm the impact of the mutations on the Covid response, the team of researchers decided to study two brothers, one with the interferon gene mutation and the other without. The reactivity levels of the interferon gene were much lower in the sibling with the missense mutation when compared to the other sibling. Furthermore, the one with the mutation had Covid in severe form, while the sibling with normal interferon genes was asymptomatic.
The study shows that young men with severe coronavirus, with further loss of function of the genes that regulate interferon, represent a small but important group of more vulnerable patients. Furthermore, these mutations could potentially justify the up to 2% increase in the severity of Covid in young men. That is why the control of these mutations, present in patients with acute Covid, and their immediate treatment with interferon, could avoid many deaths.