Autistic disorders in Down syndrome: background factors and clinical correlates

A study of a clinic-based sample of 25 individuals (12 females, 13 males; a ge at diagnosis 14.4 years, SD 7.4 years; age range 4 to 33 years) with Dow n syndrome (DS) and autism spectrum disorders, demonstrates that autism is by no means rare in DS. Results showed that there was a considerable delay in the diagnosis of autism as compared with children with autism who did no t have DS. In 11 participants medical factors were identified that were lik ely to be of importance in contributing to the development of autism, and i n four further participants there were factors of possible significance. Su ch factors include a history of autism or antism-related disorders in first - or second-degree relatives (n=5), infantile spasms (n=5), early hypothyro idism. (n=3), evidence of brain injury after complicated heart surgery (n=2 ), or a combination of these factors. It is important that autism is recogn ised, identified, and fully assessed in individuals with DS in order for th em to receive appropriate education and support.