The Marsilis family are pretty much real-life superheroes. Six members of this Italian family have a rare genetic mutation that causes them to have an extremely low sensitivity to pain, meaning they’ve had broken bones and otherwise painful injuries without barely noticing. On top of this, they can also eat hot chili peppers with ease.
Scientists have recently been studying this fascinating family in the hopes of understanding the responsible genes and even creating new methods of pain relief. Their findings were published this week in the journal Brain.
“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,” study lead author Dr James Cox of University College London, said in a statement.
“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.”
The members of the family endowed with this gene variant include a mother (aged 78), her two daughters (aged 52 and 50) and their children (two boys and one girl, aged 24, 21, and 16). In homage to the family – the only known people with this genetic mutation – the researchers named the condition Marsili syndrome
Letizia Marsili, the 52-year-old family member with the condition, spoke to BBC News and explained how they have never seen the condition as a negative, although it does have its downsides. For one thing, they often damage the roof of their mouths on hot drinks because they are unaware they are burning themselves. Similarly, her 24-year-old son has extremely delicate ankles due to numerous microfractures acquired while playing soccer.
For the scientists, the family has proven to be an invaluable tool for understanding the genetics of pain and potentially inspiring a future treatment for chronic pain sufferers. They obtained DNA from each family member and mapped out the protein-coding genes in the genome, eventually identifying the novel point mutation in the ZFHX2 gene. They then bred mice that had the same mutation in the ZFHX2 gene. As you would imagine, these mice also gained a considerable tolerance to pain.
“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," said study co-author Professor Anna Maria Aloisi. "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.”