Toward a biology of autism: possible role of certain neuropeptides and neurotrophins

Autism is a behaviorally defined syndrome for which there is no known biologic marker. Although autism is thought to be a disorder of brain development, there have been few efforts to study early regulators of brain development in this disorder. This paper describes a recent study of neonatal blood of children with later-diagnosed of autistic spectrum disorders comparing them with two groups of affected children, those with mental retardation without autism, or with cerebral palsy. and unaffected control children, using recycling immunoaffinity chromatography. We measured concentrations of four neuropeptides and four neurotrophins, finding that neonatal concentrations of the neuropeptides vasoactive intestinal peptide. calcitonin gone-related peptide, and the neurotrophins brain derived neurotrophic factor and neurotrophin 415 were higher in children in the autistic spectrum. and in those with mental retardation without autism, than in children with cerebral palsy or healthy control children. In 99% of children with autism and 97% with mental retardation, levels of at least one of these substances exceeded those of all control children. Concentrations were similar in subgroups of the autistic spectrum (core syndrome with or without mental retardation, other autistic spectrum disorders with or without mental retardation), and in the presence or absence of a history of regression. Two other neuropeptides and two neurotrophins were present in similar concentrations in all groups examined. Thus overexpression of certain neuropeptides and neurotrophins was observed in neonatal blood of children with later diagnoses of autism or cognitive disability. (C) 2001 Association for Research in Nervous and Mental Disease. Published by Elsevier Science B.V.