ABSTRACT
Autism spectrum disorders (ASDs) are common heterogeneous neurobehavioral syndromes that result from abnormal neural development and present before 3 years of age. Known etiologies are detectable in up to 10% of patients, although the causes in most children are still unknown. Children typically present with the triad of delayed or disordered language development, abnormal social relatedness, and repetitive odd behaviors. Autistic symptoms and cognitive deficits vary widely among patients in their age of onset, severity, and clinical course. Regression in previously acquired language and social skills occurs in approximately 30%, usually between 18 and 24 months. ‘‘Classic’’ or Kanner-type autism is grouped with other ASDs (or pervasive developmental disorders, PDDs, in DSM-IV), including Asperger syndrome and PDD=NOS (not otherwise specified). Childhood disintegrative disorder and Rett syndrome are related disorders that also have autistic symptoms.
