52-year-old Letizia Marsili realized from an early age that she was different. She hardly felt any pain and could easily overlook burns or fractures. Five members of her family also don’t feel pain in situations where an ordinary person would need pain relief.
“We lead a perfectly normal life, maybe even better than others, because we rarely feel unwell and hardly experience pain,” says Letizia Marsili. “Actually, we do feel pain, but it only lasts a few seconds,” she adds.
Scientists believe that some nerve cells in the Marsili family members work differently from those in other people. Researchers hope to identify the gene mutation responsible for such a high pain threshold. Understanding the nature of this phenomenon is believed to aid in the treatment of people suffering from chronic pain syndromes.
“We are on the path to discovering a new way to treat pain syndromes,” claims Professor Anna Maria Aloisi of the University of Siena.
Fractures and burns without pain
Letizia’s mother, two of her sons, her sister, and niece—all live with a similar syndrome named after their family: the Marsili pain syndrome.
As noted by Anna Maria Aloisi, pain is an important signal that something is wrong with the body. Since members of the Marsili family only feel pain for a few seconds, often they simply don’t notice the injury until the inflammatory process begins. Consequently, they often seek medical help quite late.
According to Letizia, her 24-year-old son Ludovico, who is passionate about soccer, often sustains injuries.
“He rarely stops, even when he’s knocked down. However, he has problems with his ankle joint and often gets microtraumas. Recently, he had X-rays of his joints showing many microcracks in his ankle,” says Letizia.
Her younger son, 21-year-old Bernardo, broke his elbow joint falling off his bike. But he didn’t even notice it: after the fall, he got up and rode another 14 kilometers. The injury was discovered when the bone had already started to heal.
Letizia herself recalls fracturing her shoulder while skiing. Instead of seeing a doctor, she thought everything was fine and continued skiing all day. She only visited the doctor the next morning because she felt uncomfortable tingling in her fingers.
She also didn’t notice when she broke a bone in her elbow joint while playing tennis.
But the most unpleasant incident, she says, was when she didn’t notice a problem with her dental implant. Letizia’s mother, 78-year-old Maria Domenica, has also had several fractures, didn’t notice them, and didn’t seek medical attention in time, resulting in misaligned bone fusion. She also often gets burns.
Letizia’s sister almost constantly burns her mouth with hot drinks, and her daughter Virginia once frostbitten her hand. She held her hand on ice for 20 minutes and felt no pain.
Hindrance or help?
Despite all these incidents, Letizia doesn’t complain about the absence of pain and doesn’t believe it interferes with normal life. James Cox from University College London says that the Marsili family has “all the nerves in place,” but they don’t function as they should.
“We are trying to understand why exactly they don’t feel pain. Understanding this, we can find out if this discovery will help find a new pain reliever,” says James Cox.
The researchers’ work, in which they attempted to determine the clinical manifestations of the genetic condition of this family, was published in the scientific journal Brain.
The Marsili syndrome means that a patient with this genetic mutation is less sensitive to hot or cold, and bone fractures in such a patient do not come with a pain syndrome.
By creating genetic maps of the Marsili family members, scientists found a mutation in the ZFHX2 gene. They then conducted two experiments with mice. In the first case, scientists raised mice without this gene. In this case, the pain sensitivity threshold in mice changed significantly. In the second experiment, they raised mice with a similar mutation in the ZFHX2 gene, which led to the mice’s insensitivity to high temperatures.
Scientists intend to continue their research to understand which other genes may be involved in those suffering from the Marsili syndrome. The Marsili family is considered to be the only one in the world with such a genetic mutation that prevents feeling pain.
