Autism and Rett syndrome: some notes on differential diagnosis.

Rett syndrome and infantile autism share the common symptom of autism, especially in the early stages of the disorders. In the later development of Rett syndrome autism sometimes becomes less prominent and there may also be clear differences as regards the quality of autistic behaviour in Rett syndrome and infantile autism. However, in infancy, the syndromes may be indistinguishable. The present paper deals briefly with this issue and suggests that in many girls referred in infancy for autistic symptoms Rett syndrome should be considered seriously as a primary diagnostic alternative.