Rett syndrome is a genetically linked form of autism spectrum disorder (ASD) accompanied by intellectual disability (ID). The disorder is also characterized by cardiorespiratory dysregulation, disturbance in muscle tone, reduced brain growth and scoliosis. Over 300 studies have been published on the disorder, most of which has focused on identification of causative factors, which appears to be the result of mutations of gene MECP2. Rarely have adults with Rett syndrome been studied, and behavioral characteristics in these individuals are largely unknown. The present study aimed to extend what little is known about behavioral characteristics of Rett syndrome in adults, with particular emphasis on social, communicative, and adaptive behavior. Rett syndrome adults with severe ID were matched to autistic adults with ID and ID only controls. The implications of these data for more fully describing and diagnosing the condition in adults are discussed.

We report a summary of Portuguese families and siblings research under the umbrella of the Portuguese Healthy Family Project. Families lived in mainland Portugal, as well as in the Azores and Madeira islands. All samples comprise children and adolescents (9–20 years) and their parents (27–57 years). Recruitment procedures and phenotypes were detailed. Familial resemblance in body shape and composition, metabolic syndrome, physical fitness, physical activity and sedentary behaviors are presented, as well as future research avenues.