Low levels of insulin‐like growth factor‐I in cerebrospinal fluid in children with autism

Autism is a behaviourally defined syndrome characterized by disturbances of social interaction and communication and restrictions of behaviour patterns and imagination. The pathogenesis of autism is unknown but it is suspected that a number of genetic factors may be involved. Neurotrophic factors such as insulin‐like growth factor‐I (IGF‐I) play a role in early brain development. The aim of this study was to determine whether IGF‐I levels might be associated with the development of autism. IGF‐I levels were measured in the CSF of 11 children with autism (4 females, 7 males; mean age 3.8 years, SD 1.1) using a sensitive radioimmunoassay method and compared with levels in 11 control participants (6 females, 5 males; mean age 3.8 years). Levels of IGF‐I in the CSF were statistically significantly lower in the children with autism than in the control children (p=0.03). IGF‐I may play a role in pathogenetic mechanisms of autism and the role of neurotrophic factors in autism and other neurodevelopmental diseases should be studied further.