A pensioner who feels no pain or fear could open the door to a new generation of pain-relief and anxiety medications after scientists discovered the genetic mutations that make her so rare.
For decades Jo Cameron has been cheerfully bumping, burning and bruising herself in all manner of mishap, yet she never stopped to ask why her injuries did not hurt.
She gave birth to both her children without once resorting to drugs; she laughs off offers of anaesthetic during dental work, and when she burns herself while cooking on the Rayburn in her Scottish Highlands home, often the first she knows about it is the smell of her own burning flesh.
Virtually nothing worries her. When a wayward white van careered into her car on a remote country road, leaving her upside down in a ditch, it was she, totally unfazed, who found herself comforting the driver.
It was not until Mrs Cameron's sixties, as she was preparing for an arthritis operation on her hand, that she - or anyone in the medical profession - first suspected she was different.
“My anaesthetist said “you will definitely need strong pain-killers after this because it can be a very brutal”,” she told The Telegraph.
“I said “I bet I won’t”. When he came round after the operation and saw that I was right he said “This really isn’t normal”.”
This followed an operation to repair severe joint degeneration on her hip, which specialists had refused her twice because the key diagnostic criterion was pain.
Now 71, Mrs Cameron, who lives with her husband Jim near Loch Ness, has become the focus of intense research by scientists eager to establish if her sky-high pain threshold can be traced to the same location in her genome as her fearless and optimistic qualities.
The researchers were further spurred on to investigate a genetic explanation by Mrs Cameron’s recollection of her late father as a man who “hardly ever complained” and was never seen to take a pain-killer in his life.
Led by University College London (UCL), the team has now alighted on two mutations - dubbed FAAH-OUT - of a gene known to play a role in endocannabinoid signalling, which is central to pain sensation, mood and memory.
Further tests revealed that Mrs Cameron’s 41-year-old son, Jeremy, also has an unusual mutation to his FAAH gene, although neither the mutation nor his relatively high pain threshold are as pronounced as those of his mother.
“It makes a lot of sense and puts everything into perspective,” she said.
“I’ve always been covered in bumps and burns and bruises.
“I used to think I was just clumsy, but now I know I’m not. I just don’t get the pain signals that others learn from.”
Despite enjoying a near total absence of pain her entire life, Mrs Cameron’s unusual disposition has caused her to delay seeking treatment for injuries, meaning they are often more complicated to heal.
Eighteen months ago she smashed her knee on the ground after tripping on a pothole.
The impact would have been agony for most people, yet Mrs Cameron thought nothing of it and it was only hours later when she could not stand up from dinner that she sought medical help.
It turned out she was suffering significant internal bleeding which could have been prevented with immediate help.
However, the up-side is an almost total fearlessness and optimistic outlook.
This was clinically evidenced when she scored the lowest possible mark on a standard anxiety test.
It served her well during her 42-year career working with severely physically and mentally disabled children and adults, as well as on one camping holiday when, on the first day, she tripped headfirst into a rock, knocking her front teeth out.
“My husband assumed that would be the end of the holiday, but I stood up and carried on," she said.
“People think I’m being a martyr but I’m not, it’s just the way I am.”
Now the research team, which included experts at the universities of Oxford and Calgary, believe their genetic discovery, published in the British Journal of Anaesthesia, can begin the development of a new class of drugs capable of treating both pain and anxiety.
“We hope that with time, our findings might contribute to clinical research for post-operative pain and anxiety, and potentially chronic pain, PTSD (post-traumatic stress disorder) and wound healing, perhaps involving gene therapy techniques,” said Dr James Cox, one of the lead authors.
“People with rare insensitivity to pain can be valuable to medical research as we learn how their genetic mutations impact how they experience pain, so we would encourage anyone who does not experience pain to come forward.”
Dr Devjit Srivastava, the NHS consultant anaesthetist who originally spotted Mrs Cameron’s rare status, added: “The implications for these findings are immense.”
Mrs Cameron said: “I would be elated if any research into my own genetics could help other people who are suffering. I had no idea until a few years ago that there was anything that unusual about how little pain I feel – I just thought it was normal. Learning about it now fascinates me as much as it does anyone else.”
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