Recommendation Diagnosis and Testing for Autism Spectrum Disorder
American Academy of Neurology and the Child Neurology Society Clinical Practice Recommendations:
- Genetic testing in children with autism, specifically high-resolution chromosome studies (karyotype) and DNA analysis for Fragile X, should be performed in the presence of intellectual disability (or if intellectual disability cannot be excluded), if there is a family history of Fragile X or undiagnosed intellectual disability, or if dysmorphic features are present. However, there is little likelihood of positive karyotype or Fragile X testing in the presence of high-functioning autism.
- Selective metabolic testing should be initiated by the presence of suggestive clinical and physical findings such as the following: evidence of lethargy, cyclic vomiting, or early seizures; presence of dysmorphic or coarse features; evidence of intellectual disability cannot be ruled out; or if occurrence or adequacy of newborn screening is questionable.
- There is inadequate evidence to recommend an electroencephalogram study in all individuals with autism. Indications for an adequate sleep-deprived electroencephalogram with appropriate sampling of slow wave sleep include clinical seizures or suspicion of subclinical seizures and a history of regression (clinically significant loss of social and communicative function) at any age, but especially in toddlers and preschoolers.
- Recording of event-related potentials and magnetoencephalography are research tools at the present time, without evidence of routine clinical utility
- There is no clinical evidence to support the role of routine clinical neuroimaging in the diagnostic evaluation of autism, even in the presence of megalencephaly.
- There is inadequate supporting evidence for hair analysis, celiac antibodies, allergy testing (particularly food allergies for gluten, casein, Candida, and other molds), immunologic or neurochemical abnormalities, micronutrients such as vitamin levels, intestinal permeability studies, stool analysis, urinary peptides, mitochondrial disorders (including lactate and pyruvate), thyroid function tests, or erythrocyte glutathione peroxidase studies.