Background: Individuals with fragile-X syndrome exhibit developmental delay, hyperexcitation and social anxiety; they also show lack of attention and hyperactivity. Few studies have investigated whether levels of functioning change with increasing age. Here, we explored developmental changes across adolescence in the cognitive and behavioural…

There is uncertainty about the proportion of children with autism spectrum disorders who do not develop phrase speech during the preschool years. The main purpose of this study was to examine this ratio in a population-based community sample of children. The cohort consisted of 165 children (141 boys, 24 girls) with autism spectrum disorders aged…

Aim: There is a lack of investigation into the functional developmental profile of children with Down syndrome. On the basis of current international health paradigms, the purpose of this study was to assess the developmental profile of these children. Method: Sixty children (33 males, 27 females) with Down syndrome (age range 6-16y; mean age 9y…

Background: Little is known about trajectories of cognitive functioning as individuals with Williams syndrome (WS) move though adulthood. Method: The present study investigated cognitive, linguistic and adaptive functioning in adults with WS aged 19-55 years, using both cross-sectional and longitudinal approaches. Results: Data from the…