Aug. 10 (UPI) -- Researchers have identified a mutation in a sensor that the immune system uses to detect viruses capable of turning the chickenpox virus deadly in rare cases.
The study, published this week in the Journal of Clinical Investigation, found that for two out of every 10,000 people with the genetic mutation, it can lead to inflammation of the brain, and for 20 out of every 10,000 people it can lead to severe pneumonia.
Researchers identified a mutation of what is known as the POL III sensor, which the immune system uses to identify the genome of varicella zoster virus, known as chickenpox.
In patients with this mutation, their cells do not detect the infection and did not activate the immune system's response allowing the virus to spread to the brain.
"We cannot yet put an exact figure on how much the risk of complications is increased when you have this new immunodeficiency, since we have looked at relatively few patients in our study," Professor Trine Hyrup Mogensen, from the Department of Clinical Medicine and the Department of Biomedicine at Aarhus University in Denmark, said in a news release.
"Neither do we know how large a proportion of all those who have inflammation of the brain and pneumonia have the defect. But we do know that this applies to both children and adults."
Patients with mutations in POL III have an increased risk of developing serious, life-threatening illness with the chickenpox virus.
"Today it is possible to map the entire genomic composition of an individual. At the same time the last few decades have seen an explosion in our knowledge of the immune system. Together this means we are now slowly becoming able to understand the individual differences in susceptibility to infections at both the genetic and molecular level," Søren Riis Paludan, professor at the Department of Biomedicine at Aarhus University said.