"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
A Red Arrows jet has crashed after an incident at RAF Valley in north Wales, the Ministry of Defence has said.
The Welsh Government has launched a consultation on how local councils could merge, despite the opposition to its plans three years ago.
46-year-old Anthony John Lowe has been sentenced to 18 years minimum for the murder of a young mother he met on a dating site.