Autism spectrum disorders in Down syndrome: A review

While it had been claimed that the association of autism spectrum disorders (ASDs) and Down syndrome was uncommon there are now a substantial number of studies demonstrating that a subgroup of those with Down syndrome will also reach the diagnostic criteria for an ASD. This review examines published research on the prevalence of ASDs in Down syndrome. The manifestation of ASDs in the Down syndrome population is also examined with regard to published case studies and profiles on ASD screening and diagnostic instruments. Possible correlates of ASDs in Down syndrome including level of cognitive functioning, medical factors, gender, and family history are also reviewed. Issues regarding the diagnostic assessment of ASDs in Down syndrome and suggestions for future research are discussed.