"This research is one of the first clinical trials to assess whether a drug can improve brain function in people with an inherited disorder.
"The potential benefits of this treatment include an improved quality of life for affected patients and wider benefits for their families and carers.
"If it works it will benefit patients directly and could provide clues as to whether this class of drugs (called mTOR inhibitors) might have wider benefits in problems like autism."
More top news
Fire crews have been responding to reports of flash flooding in Carmarthenshire. Some homes have been affected.
Medication designed for animals was taken from the building in Abertillery on Thursday night.
More than a thousand riders will be taking part in a series of events in and around the town.