Children's Autism Metabolome Project

Inclusion Criteria: * Age of greater or equal to 18 months and less than or equal to 48 months * Fulfills the definition of an autism spectrum disorder, developmentally delayed, or typically developing child in the age range 18-48 months, as determined by a clinician or certified practitioner of the appropriate tests and who is knowledgeable in the field; and * Has parental (or other legal guardian ) informed consent to participate. Exclusion Criteria: * Diagnosis with a chronic condition that could interfere with a diagnosis of ASD or DD, (e.g.: a known history of Fragile X, Rett syndrome, Down syndrome, tuberous sclerosis, trisomy 21, inborn errors of metabolism or other genetic disorder that includes some symptoms of autism) * Fetal alcohol syndrome, or other serious neurological disorder * Other serious metabolic disorder, psychiatric disorder, or medical condition involving the liver, kidney, pulmonary, cardiovascular or endocrine systems * A second child within a family in which a sibling has already been enrolled. * A child who has previously participated in the CAMP-01 study