Perturbations in the development of infants with Rett disorder and the implications for early diagnosis.

The gene discovery in Rett disorder has opened the way for the development of clinical intervention. Initial recognition of affected infants will depend on observation by clinicians and the development of key diagnostic criteria is of crucial importance. Perturbations in the development of very young infants are emerging in studies of home videos. Observations from experienced health practitioners and home video transcriptions are presented which indicate the nature of early clues to the disorder and their fluctuating nature. Early diagnosis is likely to be available before the development of effective treatment. Most children are not diagnosed before regression and, currently, no therapies are equipped to offer support to pre-regression infants and their families. When earlier diagnosis becomes available, parents of the newly-diagnosed infant will be aware of their infant's difficult future before her problems are fully apparent. Practitioners in regular contact with families will have the sensitive task of supporting infants in early infancy and into regression.