Rett syndrome is a neurodevelopmental disorder primarily affecting females. The disorder is characterized by apparent normal development in early infancy (6-18 months), followed by a period of regression with onset of systemic and neurological signs. The CNS symptoms of Rett syndrome include learning disability, autism symptomatology and epilepsy and these can be severe and highly debilitating. Affected individuals also show signs of autonomic dysfunction, reflected in cardiovascular and respiratory abnormalities. There is no currently effective treatment for Rett syndrome.