Rett syndrome: case reports and review.

Rett syndrome consists of a progressive encephalopathy and psychomotor deterioration in young females who have appeared clinically normal until between six and eighteen months of age. The syndrome has incidence similar to that of phenylketonuria and autism in females. It has been widely recognised only since 1983. After six months of age head growth decelerates associated eventually with severe dementia, and autism, apraxia, stereotypic "hand washing" movements and loss of previously acquired skills occurs. Supportive symptoms may include breathing dysfunction, seizures, EEG abnormalities, and growth retardation. Occurrence indicates sporadic new mutations as a cause. The case histories of two patients diagnosed in New Zealand are described.