Tuberous sclerosis--an unusual cause of seizures in an 18 year old.

An 18 year old man presenting with seizures was found to have hypomelanotic macules and a cardiac rhabdomyoma. These features suggested a diagnosis of tuberous sclerosis (TS) but there were no other clinical signs, no family history and cranial imaging failed to reveal the characteristic appearances. The diagnostic criteria for TS are reviewed and the importance of thorough clinical examination and appropriate investigation in this disease is stressed.