3-year-old makes big strides after 1st-ever gene therapy for Hunter syndrome
Three-year-old Oliver Chu, who has the rare genetic disorder Hunter syndrome, is showing huge progress after getting the world's first gene therapy for this condition at Royal Manchester Children's Hospital in February 2025.
Before treatment, Oliver couldn't make a key enzyme—now his body produces it at super high levels, and he's developing just like other kids nine months later.
How this new treatment works
Doctors took Oliver's stem cells, fixed the faulty gene in them, and put them back into his body.
The upgraded enzyme these cells make can reach his brain as well as his body—helping with both physical and mental symptoms of Hunter syndrome.
Why it matters
This breakthrough could mean kids with Hunter syndrome may not need lifelong weekly treatments anymore—a single therapy might be enough.
Since starting gene therapy, Oliver has stopped needing weekly infusions and is talking, moving, and learning better than ever.
If trials go well for other kids around the world too, this could open doors to more one-time cures for rare diseases.