James GallagherHealth and science correspondentBBC/Fergus WalshProfessors Ed Wild and Sarah Tabrizi led the UK part of the trialOne of the cruellest and most devastating diseases – Huntington's – has been successfully treated for the first time, say doctors.The disease runs through families, relentlessly kills brain cells and resembles a combination of dementia, Parkinson's and motor neurone disease.An emotional research team became tearful as they described how data shows the disease was slowed...