The development of linguistic communication in 17 children with Rett syndrome was investigated by a parent questionnaire based on the Clinical Linguistic Auditory Milestone Scale in a study at the Department of Speech Pathology and Audiology, University of Alberta, Edmonton, Canada. From birth to 24 months, no child exceeded the stage of single word utterances, with a maximum of 4-6 single words, such as mama/dada. This milestone represents the transition from babbling to real words, normally occurring before the end of the first year. Gesture milestones involving pointing or showing and the beginning of communication were largely absent. Onset of regression had occurred for 14 of the 17 children. Sixteen children exhibited hand movement symptoms, generally during the second year of life. 
COMMENT. These findings contradict the observation that communication development in Rett syndrome before one year is essentially normal. Children with Rett syndrome may develop language to the mama/dada and other single word stage, but limited intentional gestural communication and lack of finger pointing is a potential early predictor of Rett syndrome.
Pervasive developmental disorders as a further cause of deficits in language and communication skills are reviewed from the Department of Neurology, Miami Children’s Hospital, FL . Of 421 children with PDD, referred because of language and behavioral disorders, 11% had chromosomal disorders, genetic syndromes, and familial occurrence. Motor deficits occurred in 18%, sleep problems in 20%, stereotypies in 71%, and regression of language in 28%. Abnormal EEGs were found in 29%, epilepsy in 13%, and MRI abnormalities in 19%. No patients in this study had classical Rett syndrome; 5% of girls had a “forme fruste” of Rett syndrome. Since the diagnosis of Rett syndrome is based on clinical criteria, girls presenting with autism should always be considered for possible Rett syndrome.