Imagine going through life and never feeling any physical pain at all due to a disorder. That’s the reality for one Italian family, and scientists have published a new study examining them in detail to determine what’s causing it, and how it might be relevant to research into painkillers in the future.

The findings, published in the neurology journal Brain, showed that the family had a “reduced capacity to detect tissue-damage causing stimuli,” but is otherwise normal. Of course, pain can be pretty useful at alerting us to when something is wrong, and as the study noted one of the members of the family broke her shoulder skiing but kept enjoying the rest of her day and didn’t get checked out until a day later.

Scientists called it Marsili syndrome, and understanding this genetic disorder that allows people to live entirely without pain could potentially lead to breakthroughs in painkillers. Since many painkillers are addictive and harmful, finding another way to do it would be a tremendous boon to the medical community.

“The members of this family can burn themselves or experience pain-free bone fractures without feeling any pain. But they have a normal intraepidermal nerve fibre density, which means their nerves are all there, they’re just not working how they should be. We’re working to gain a better understanding of exactly why they don’t feel much pain, to see if that could help us find new pain relief treatments,” said the study’s lead author, Dr James Cox (UCL Wolfson Institute for Biomedical Research).