Rett's syndrome: progression of symptoms from infancy to childhood.

The results of studies of seven girls with Rett's syndrome and two additional cases suggestive of Rett's syndrome are presented. After normal neurological development up to the age of 7 to 20 months, there was a rapid regression of higher cortical function. Rett's syndrome was initially manifested by a delay of further motor development and the appearance of autistic traits. As the disease progressed, there was a loss of ability to crawl, loss of purposeful hand movements, abnormal respirations, truncal ataxia, seizures, and spastic increase in muscle tone. Blood chemistries, including ammonia levels, were normal. Metabolic interference, a recently hypothesized form of inheritance, may occur in this syndrome.