Autism in Down's syndrome: family history correlates

Although the association of autism with Down's syndrome is said to be uncommon, several reports have described the co-occurrence of the two disorders. This report describes three additional cases of Down's syndrome with autism. In all the patients, a history suggestive of the broader phenotype of autism was obtained in parents. This suggests that familial factors specific to autism may play an important role even when autism complicates a known medical condition such as Down's syndrome.