THURSDAY, Dec. 14, 2017 (HealthDay News) -- Six members of a family in Italy live a strangely pain-free life, and scientists want to know why.
The Marsili clan "can burn themselves or experience pain-free bone fractures without feeling any pain," explained study lead researcher Dr. James Cox of University College London.
The family can't even feel the burn from hot chili peppers.
It's not that the Marsilis lack the nerves responsible for sensing and transmitting pain, the researchers noted.
"They have a normal intraepidermal nerve fiber density, which means their nerves are all there, they're just not working how they should be," said Cox, who works at the university's Wolfson Institute for Biomedical Research.
His team hopes that insights into the family that doesn't feel pain could help people who feel far too much of it.
Moderate to severe chronic pain affects an estimated 10 percent of people, the study authors explained. It's often difficult to treat, and people may turn to dangerously addictive opioid painkillers for help.
Cox and his colleagues believe they might develop newer, safer drugs by understanding why some people -- the Marsilis, for example -- can tolerate pain better than others.
"We're working to gain a better understanding of exactly why [this family doesn't] feel much pain, to see if that could help us find new pain-relief treatments," Cox said in a university news release.
The investigators said they've already identified the rare genetic mutation that's responsible for the family members' pain-free state.
For the new study, the researchers examined the genomes of affected family members, and spotted a mutation in a key gene. They then studied the effects of the gene by breeding mice without it.
As expected, mice with the altered DNA appeared insensitive to high heat, the researchers reported Dec. 13 in the journal Brain.
The mouse study suggests that the mutant gene the Marsili family members carry affects other DNA linked to pain signaling.
According to study co-author Anna Maria Aloisi, of the University of Siena in Italy, "By identifying this mutation and clarifying that it contributes to the family's pain insensitivity, we have opened up a whole new route to drug discovery for pain relief." She was part of the team that initially identified the Marsili family's condition.
"With more research to understand exactly how the mutation impacts pain sensitivity, and to see what other genes might be involved, we could identify novel targets for drug development," Aloisi added.
There's more on pain relief at the Arthritis Foundation (http://www.arthritis.org/toolkits/better-living/about/managing-pain/ ).
SOURCE: University College London, news release, Dec. 13, 2017