Since childhood, Stuart Flett was incredibly muscular, but often experienced severe cramps and spasms in his muscles.
The 60-year-old former police officer from Barrow-in-Furness, Cumbria, has spent his life trying to figure out what is wrong with him.
Researchers believe the answers may lie in his roots in the Orkney Islands, his father's homeland.
They suspect that the family may have a unique genetic trait that causes their unusually strong physique, as well as a predisposition to a rare genetic disorder called neuromyotonia.
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In 2024, the Viking Genes project began studying members of the Flett family from Flotta Island in Orkney to identify a suspected inherited muscle and nerve disorder.
Neuromyotonia can cause severe cramping, delayed muscle relaxation after movement, and enlargement of the muscles.
Both of Stuart's paternal grandparents were from the Orkney Islands. His grandmother's family was from the Isle of Westray, and his grandfather's family was from the Isle of Flotta.
His father was born in the Orkney Islands but moved to England. It was there that he met Stuart's mother.
«"So I'm 50% Orkney," said Stewart.
He said he first noticed unusual symptoms around age seven, and as his muscles developed, other problems began to emerge.
Stuart Flett's incredibly developed physique was achieved without going to the gym. [Stuart Flett]
«"I kind of felt it when I hit early adulthood and started putting on muscle," he told BBC Radio Orkney.
«"My father was always incredibly strong, not just big, but very strong. People would say, 'You look like your dad.' But I thought people looked like their dads, it was just genetics.".
He explained: "I had the same physique when I was younger, but I didn't go to the gym or exercise.".
«"I was accused of using steroids. People said, 'You can't have that physique without training.' I didn't think there was anything unusual about myself until people started pointing it out to me.".
Stewart added jokingly: "Now that I'm getting older and flabby, it's not so relevant anymore.".
However, his enviable physique was accompanied by some unpleasant symptoms.
«"When I tense a muscle, it doesn't feel like a cramp; the muscle just stays tense," he said. "Then there's a pulsating sensation. I've lived with this my whole life.".
«"The most difficult symptom to deal with is the stroke, which causes spasms throughout the body, so I have to be very careful.".
Arnold Schwarzenegger became famous worldwide thanks to his muscles [Getty Images]
He said that at some point he consulted a specialist in hereditary diseases.
«"He called his colleague and said, 'There's a very interesting gentleman sitting in front of me who looks like Arnold Schwarzenegger.'".
Stewart called the comparison to Arnie "a bit of a stretch.".
But ultimately, receiving a diagnosis of genetic neuromyotonia was "the defining moment.".
It was an excuse, he said, not a fictitious condition.
The piper William Arnot Flett was said to be renowned for his strength. [The Flett family]
In the family tradition, the bagpipe tune "Flett fae Flotta" (Flett from Flotta) is named after the piper William Arnot Flett, who played the bagpipes in Flotta.
He was well known for his physical strength and distinctive gait, which are symptoms of this disease. The rhythm of the melody is said to mimic his gait.
Stewart knows that many of his father's relatives in Flott had muscle problems, as well as a relatively high incidence of ALS and Parkinson's disease.
Now his daughter, Dr. Chloe Flett, a medical biochemist who specializes in rare diseases, has also been diagnosed with neuromyotonia.
She said further research could help understand why the condition might contribute to the development of large muscles.
The knowledge gained could help develop future gene therapies to prevent muscle wasting or weakening in a range of other diseases.
«"That's why finding the gene is so important," she said.
Stewart hopes this research can also provide clarity for future generations of the Flett family.
The photo shows Stuart (centre) and his daughter Chloe with Professor Jim Flett Wilson [the Flett family].
Professor Jim Flett Wilson, who leads the Viking gene research, said focusing on the Flett family could be key.
«"It's such a rare disease, one of the rarest I've ever worked with, so it's a whole other level," he said.
«"It's quite possible that the cause of this condition in Stuart Flett's family will be unique worldwide, we just don't know yet.".
They use volunteers from the Orkney Islands and also recruit members of Stewart's extended family.
«"We can use the DNA of all these people and compare them to try to find the gene that causes this disease," he explained.
«"We're pretty sure it's a genetic condition, and similar symptoms have been seen in four or five generations of his family.".
«We are still only at the first stage of this process.».
Stewart said his family was "strongly supportive" of the project and "extremely grateful for the tireless work" of Professor Wilson and his team.
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