Autism: Definition, Neurobiology, Screening, Diagnosis

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Autism (ie, the autism spectrum disorders) is now recognized in 1 in 150 children. This article highlights the definition, neurobiology, screening, and diagnosis of autism. The genetics, immunology, imaging, and neurophysiology of autism are reviewed, with particular emphasis on areas that impact pediatricians. Early recognition of the social deficits that characterize autism is key to maximizing the potential of these children.

Section snippets

Definition

Articles from the medical and lay press about clinical aspects of autism bombard pediatricians virtually every day. Therefore, this review focuses on recent developments and some of the less well known aspects of this disorder. The authors emphasize up front that autism is not a “disease.” Rather it is a symptom of atypical development of the immature brain. Its diagnosis is not biologic, and responsible diagnosable etiologies are numerous but infrequent. Autism is a behaviorally distinct

Neurobiology

Parent-initiated advocacy groups, the largest of which in 2008 is Autism Speaks, which fused with Cure Autism Now and National Alliance for Autism Research, have not only raised money to support pilot research over the past 15 years or so but also publicized autism so effectively that it is now fully in the public eye. The result is an enormous increase in federal funding for research and state funding for specialized education services. Among the many areas of progress in unraveling the

Screening

The definition of autism as a spectrum disorder, the limitations of our present understanding of the neurobiology of autism, and the heterogeneity at a clinical and biologic level of children who have autism challenge our ability to screen for autism. Nevertheless, recognition of the early signs of autism has progressed significantly. Screening instruments like the Modified Checklist for Autism in Toddlers65 use social behaviors to identify toddlers at risk for autism and distinguish autism

Diagnosis

The rigorous phenotyping of autism or phenotyping subgroups of children who have autism is essential. At a clinical level, there are many signs and symptoms of autism that also occur in other developmental disorders. Table 3 outlines some of the most salient diagnostic features that differentiate the diagnosis of ASDs from other developmental disorders. The authors emphasize that the one feature that differentiates autism from other developmental disorders is the social deficit. Although autism

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