There are moments in this documentary that are like a Little Britain sketch. Except this isn't funny. It follows five British teenagers with the incurable neurological disorder Tourette syndrome as they spend a week in a special American summer camp. Here there's no need to suppress the random verbal outbursts, uncontrollable twitches and strange noises that society finds so unacceptable. Everyone's doing it. The kids are accepted, not ostracised, so they can relax and find new ways to manage their antisocial tics. For us it's a rare chance to see past the offensive behaviour, understand how difficult this inherited condition makes their life and feel a sympathy we may not have had at the outset.