Kyle Sieniawski was just 14 years old when motor neurone disease (MND) claimed his life, making him the youngest known person in the UK to die from the rare, degenerative condition. His story, both heartbreaking and remarkable, has become a rallying cry for greater awareness and support for those affected by MND—regardless of age.
Kyle, from Pontypridd in Rhondda Cynon Taf, was a typical teenager: he loved taekwondo, enjoyed school, and relished time with his friends. But in March 2024, his family noticed something was wrong. He began losing mobility in his left arm, a symptom that set off a chain of hospital visits and medical tests. On January 17, 2025, at just 13 years old, Kyle was diagnosed with MND, a disease that, according to BBC News, typically affects people over 50 and is all too rare in children.
"It can affect anybody at any age, at any time," Kyle's mother, Melanie Sieniawski, told BBC Breakfast. She stressed the urgent need for fundraising and awareness, hoping for a cure before more families have to endure the devastation her own has faced. Her words echo the family’s experience: “To be honest what Melanie and I went through was horrific,” Kyle’s father, Mark, explained. He described watching his son’s rapid decline as “horrendous to watch.”
Kyle's symptoms worsened quickly. By October 2025, he was unable to use any of his limbs and relied on a breathing mask and feeding tube. His family spent over nine months living with him at Noah's Ark Children's Hospital in Cardiff, unable to bring him home because their property could not be adapted to his complex care needs. Melanie said they found themselves “in the middle” of a gap in the system, struggling to access the support Kyle so desperately needed.
Despite these challenges, Kyle’s spirit shone through. His family described him as “brilliant” and a “troublemaker,” someone whose personality was undimmed by his illness. “He touched so many people, to be honest. He was amazing,” Mark said. “He had banter and laughter with everybody. We had so many strangers come to visit him. They all thought he was amazing.” Even as his body weakened, Kyle’s smile never faded. His aunt, Heather Jones, told WalesOnline that he was “such a happy child” who “always has a smile on his face.”
In late October or November 2025, Kyle developed an infection and was moved into intensive care. He died on November 27, 2025, less than a year after his diagnosis. His family announced the news with heartbreaking candor: “We’re absolutely heartbroken to announce that our little superhero has very sadly lost his battle with MND,” they wrote on the Facebook page chronicling his journey. “Kyle fought with everything he had but in the end it all became too much for him and he very sadly passed away yesterday evening. There’s no way for us to describe how we’re feeling.... we’re just completely heartbroken... Kyle... we’ll miss you so very much buddy and we love you more than words could ever possibly say.”
Kyle’s passing has resonated far beyond his family and friends. On December 3, 2025, former rugby league star Kevin Sinfield met with the Sieniawski family at Gorseinon Rugby Club in Swansea. Sinfield, who has become a leading advocate for MND awareness, was in the midst of his “7 in 7: Together” challenge—seven ultramarathons in seven days, each at least 45 kilometers, to raise funds for MND research and support. The challenge honors his late friend and teammate Rob Burrow, who died from MND in June 2024, and aims to raise £777,777 in recognition of Burrow’s iconic number seven shirt.
During the emotional meeting, Sinfield pledged to dedicate the Swansea leg of his run to Kyle. “We’ve got to make sure that Kyle is always remembered and that families who come next get more support than what you guys have had,” Sinfield told the family, as reported by WalesOnline. He promised to run “faster and harder” in Kyle’s honor and expressed pride in dedicating the day’s effort to the young boy’s memory. “I hope you can feel that the whole MND community is with you,” Sinfield said, vowing to do all he could to prevent other families from experiencing such heartache.
The Sieniawski family’s ordeal has highlighted the gaps in support for young people with MND and their families. After Kyle’s diagnosis, the family was “desperate” to bring him home, but the lack of suitable housing and adequate support left them living in the hospital for months. Melanie and Mark’s call for more fundraising and research is not just about their loss—it’s about preventing others from facing the same struggles. “We really need to get awareness out there and keep pushing it because what my child went through was horrific and horrendous to watch,” Mark told BBC Breakfast.
Motor neurone disease is a rare condition, affecting about 5,000 adults in the UK at any one time, with a lifetime risk of one in 300. It attacks nerves in the brain and spinal cord, leading to muscle weakness, stiffness, and ultimately, loss of the ability to walk, talk, eat, and breathe. The disease is most commonly diagnosed in people over 50, making Kyle’s case exceptionally rare and all the more tragic.
Yet, even in loss, Kyle’s legacy endures. His family’s willingness to share their story—through the media, online, and in person—has brought national attention to the reality that MND can strike anyone, at any age. Their message is clear: more needs to be done to fund research, improve care, and support families facing the unimaginable.
Kevin Sinfield’s ongoing efforts, and the outpouring of support from the MND community, offer hope that Kyle’s fight was not in vain. As Sinfield and hundreds of well-wishers run through cities and towns, the memory of a boy with a bright smile and indomitable spirit inspires a movement for change.
In the words of his family: “We’ll think of you every single day, beautiful boy… until we meet again.”
