In addition to diagnostic criteria, the authors cover the importance of early detection and appropriate assessment. From a clinical perspective, I appreciated the authors’ guidelines regarding medical assessment when a child is suspected of or diagnosed with an autism spectrum disorder. Along with a very thorough medical and family history, physical and neurologic examinations are considered the standard of care with a new autism diagnosis, and they are critical to recognizing genetic syndromes highly associated with autism spectrum disorders or other neurologic abnormalities. Solid history taking and physical examination may reveal a need for metabolic studies, hearing/vision examinations, or other findings that can direct care and significantly affect long-term prognosis. In psychiatry, it is rarely imperative to order genetic testing on every patient we diagnose. However, the authors do recommend obtaining a chromosomal microarray for all individuals diagnosed with an autism spectrum disorder, pointing out that chromosomal abnormalities and de novo copy number variants are implicated in 10%−20% of autism spectrum disorder cases. This may be a point of argument among providers and families wondering whether an abnormal microarray would affect treatment decisions. The authors do not expand on this recommendation further, although one can imagine that with ongoing research in autism genetics, chromosome studies will become more clinically relevant in the future and prove significant for affected families and treatments that emerge. They discourage routine MRIs and EEGs, acknowledging that while seizures may occur in 25%−30% of individuals with autism spectrum disorders, without clinically relevant symptoms these tests have not proven useful to aid diagnosis and management.