Ty Sperle started that morning feeling hopeless.
He'd been living with chronic granulomatous disease since the age of five — a rare genetic disorder that left his immune system unable to fight off serious infections. His whole life, doctors had been managing the condition with daily antibiotics and antifungal drugs, working to hold back the constant possibility of an infection that could turn fatal.
"People with this disease don't live long and healthy lives," said Dr. Stuart Turvey, the pediatric immunologist at BC Children's Hospital who treated Sperle for more than a decade.
Ty Sperle, now 19 and living in Kelowna, British Columbia, knew that. He'd grown up knowing it.
Then his doctor called with news that changed everything.
"He felt insane shock," Turvey said. "The news he was cured filled him with indescribable happiness."
Sperle had taken part in a clinical trial for a treatment called prime editing — a next-generation gene-editing technology developed by U.S.-based biotechnology company Prime Medicine. Unlike earlier approaches that cut DNA and sometimes cause unintended damage, prime editing works like a molecular word processor, finding the exact genetic 'spelling mistake' causing disease and rewriting it with precision.
The results were published in the peer-reviewed New England Journal of Medicine in December 2025. Ty Sperle is the first patient in the world known to have been treated and cured by prime editing.
For Sperle, this wasn't a last resort. It was a necessity. Chronic granulomatous disease can be treated with a combination of chemotherapy and bone marrow transplant — but that requires a well-matched donor. Sperle had none. The experimental therapy was the only viable path forward.
Turvey, who has treated Sperle since childhood, says he 'jumped' at the chance to register him for the trial. The only Canadian clinical site was at Montreal's Sainte-Justine university hospital.
"The era we're really in now is about translating those fundamental discoveries to helping patients," Turvey said. "Before, we could identify spelling mistakes in people's DNA. Now we can fix them."
Prime editing represents a significant leap from earlier gene therapies. It doesn't replace genes, it corrects them — making precise, targeted changes at the exact nucleotide level, with fewer off-target effects than previous techniques. For the many thousands of rare genetic diseases caused by specific DNA mutations, this approach could eventually offer a cure.
For one teenager in Kelowna, it already has.
The morning Ty Sperle got his results, he felt hopeless. By the afternoon, he knew something that will stay with him for the rest of his long, healthy life.
The spelling mistake in his DNA had been fixed. He was free. 🧬
