Rett syndrome is a rare progressive neurodevelopmental disorder with an incidence of about 1 in 10000 births. It occurs almost exclusively in girls may be lethal in males. It is characterized by early neurological regression that severely affects cognitive communication and motor skills leading to emergence of autistic features stereotyped hand movements other motor abnormalities and often associated with seizures says Dr Anaita Hegde Consultant Pediatric Neurologist at Jaslok Hospital and Research Centre. She also tells you about the treatment. Everything about it Stage 1 - The symptoms begin between 6 to 18 months of age with subtle slowing of development.