For Dr Anna Chellamuthu, a GP specialising in oncology, her daughter Rebecca’s illness was a nightmare that no amount of medical expertise could resolve. Rebecca, now 18, was just seven when a viral sore throat failed to clear up. Weeks turned into months, and the illness spiralled into Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) robbing her of her childhood and leaving her family devastated.