Doctors have reported a groundbreaking success in treating Huntington’s disease, a hereditary neurodegenerative disorder that combines symptoms of dementia, Parkinson’s, and motor neurone disease. A gene therapy trial at University College London slowed disease progression by an average of 75%. This means that a decline expected in one year would now take four, offering patients decades of improved quality of life. The therapy, delivered in a single dose through 12–18 hours of intricate brain surgery, permanently reduces production of the toxic huntingtin protein that kills brain cells. Early treatment may even prevent symptoms from developing. Among 29 trial participants, markers of brain cell death decreased instead of rising, and some patients regained independence: one returned to work after medical retirement. For families like Jack May-Davis’s, who lost his father to Huntington’s and carries the faulty gene himself, the breakthrough brings unprecedented hope. While the treatment will likely be costly, researchers call the results ‘spectacular’ and potentially life-changing.