Four-year-old Darcy Holt and dad Simon both have Tuberous Sclerosis Complex (TSC), which causes mainly benign tumours to form around the body. As a result of the condition, around 20 youngsters a year develop inoperable brain tumours. The drug Everolimus can shrink the tumours, known as SEGAS, and stop them growing - but is not routinely available on the NHS. Darcy is on a clinical trial for Everolimus because she has epilepsy caused by the condition. Mum Jess Holt, 30, said: “Darcy has gone from having up to 90 seizures a day to one or two a week. She hasn’t been to hospital as much and we haven’t had to call ambulances. “We know that Darcy is going to have to come off it when the trial ends. I know after that if she needs it we’ll have to fight for it. It’s a ticking time bomb.” The Tuberous Sclerosis Association has also been urging the NHS to approve the drug.