New Delhi, Sept. 24 -- Huntington's disease, one of the most devastating inherited brain disorders, has been treated successfully for the first time. A gene therapy trial led out of the UK has shown dramatic results, slowing the disease's progress by three-quarters after three years.

The illness, which is passed down through families, is triggered by a single faulty gene. Once active, it steadily destroys brain cells, leading to mood changes, uncontrolled movements, dementia, and, in time, death. Until now, there has been no treatment that could slow it down.

"This is absolutely huge. I'm really overjoyed," said Prof. Sarah Tabrizi, who directed the trial at University College London's Huntington's Disease Centre. "We now have a treatme...