The outcome of 18 children (13 males, 5 females) with severe developmental language delay and some features of autism (not fulfilling all criteria), examined at preschool age (mean age 4 years 4 months) and again 4 years later (mean age 8 years 7 months), was evaluated at the Institute of Child Health, London, UK. At follow-up, 5 children had continuing language disorder and fulfilled diagnostic criteria for childhood autism, 4 had atypical autism with associated language disorder, and 9 had atypical autism with improved language skills. Degree of social communication impairments and repetitive behaviors at preschool evaluation correlated with severity of autism symptoms at follow-up. Parents’ concerns initially were mainly about speech and language whereas at follow-up, social difficulties and social isolation were the primary concerns and inability to relate to peers. The presence of restricted, repetitive, and stereotyped behaviors in preschoolers with language delay is a negative prognostic indicator of a diagnosis of autism in later childhood. 
COMMENT. The relation between language delay and autism presents a diagnostic challenge in preschool children. Impairments of social interaction and repetitive behaviors reported by parents or preschool care-givers are considered risk factors for a diagnosis of autism in later childhood, especially in association with language delay. An early diagnosis of autistic spectrum disorder will permit access to appropriate interventional services.