Doctors are expressing cautious optimism regarding a groundbreaking gene therapy, developed by researchers in Manchester, for children afflicted by Hunter syndrome, a severe inherited disorder. This revolutionary treatment offers significant hope after showing positive initial results in three-year-old Oliver Chu from California, who became the first patient to receive the therapy nine months ago as part of a clinical trial.

Hunter syndrome, also known as mucopolysaccharidosis type II (MPS II), is caused by a faulty gene that impedes the body's ability to produce a vital enzyme crucial for breaking down complex sugar molecules. Over time, these sugar molecules accumulate in organs and tissues, leading to a range of debilitating symptoms including joint stiffness, hearing loss, breathing and heart problems, developmental delays, and cognitive decline resembling dementia. This life-limiting disorder typically results in a life expectancy of 10 to 20 years.

Currently, the only licensed treatment for children with Hunter syndrome is Elaprase, a weekly enzyme replacement therapy. This treatment requires a three-hour infusion and costs approximately £375,000 per patient annually, needing to be administered for life. While Elaprase can improve movement and alleviate some organ-related issues, it unfortunately does not penetrate the brain, rendering it ineffective in preventing the progressive cognitive decline associated with the condition.

The novel gene therapy, developed over a decade of research by scientists in Manchester, is a one-off procedure. In Oliver's case, doctors collected stem cells from his blood and, in collaboration with Great Ormond Street Hospital in London where the cells were modified, replaced the faulty gene with a working copy. These corrected stem cells were then re-infused back into his bloodstream. Once re-infused, these modified cells began producing high levels of the essential enzyme, crucially, this enzyme also reached his brain.

Since undergoing the therapy in February, Oliver no longer requires the weekly Elaprase infusions, which is a highly encouraging indicator of the treatment's efficacy. His father, Ricky Chu, expressed immense relief and excitement, stating that Oliver's life is no longer dominated by needles and hospital visits, and that his speech, agility, and cognitive development have dramatically improved, showing an exponential surge since the transplant.

Professor Simon Jones, a consultant in paediatric inherited metabolic disease at the Manchester Centre for Genomic Medicine (MCGM) at Saint Mary’s Hospital and a joint leader of the trial, acknowledged the promising progress but maintained a cautious outlook. He emphasized that while