The diagnosis of ASD can be difficult since there are not specific recommendations for a medical test or tests to diagnose the disorder. An examination of the child’s behavior and development is typically employed to make a diagnosis. ASD can sometimes be detected at 18 months or younger. By age two, a diagnosis by an experienced professional can be considered very reliable. However, many children do not receive a final diagnosis until much older. This delay in early diagnosis may indicate that children with ASD might not get the early help they need.
Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria
The diagnosis of ASD is usually made by a developmental or general pediatrician, neurologist, psychologist, psychiatrist, or another specialist. A clinician may make a diagnosis of ASD after observing the behavior and language of a child and using the DSM-5 criteria for their evaluation. Since there is not a clear-cut blood test or imaging study (eg, MRIs) that can diagnose the condition, the diagnosis is typically accomplished using a behavioral approach by observing the behavior and language skills of the individual.
The American Academy of Pediatrics (AAP) recommends that all children be screened for developmental delays and disabilities during regular well-child doctor visits at nine months, 18, and 30 months, or whenever a concern is expressed. Additional screening might be needed if a child is at high risk for developmental problems because of preterm birth or low birth weight or is at high risk because of having a sibling with an ASD or if symptoms are present. Autism-specific screening is recommended at ages 18 and 24 months.
In recent years, there is increasing interest and support for the use of genetic testing to assess ASD and other developmental delay disorders. With the improvement in technology, several major laboratories, university-based testing centers, and diagnostic companies have developed specific genetic tests and gene panels for assistance in the diagnosis of ASD. In the following sections, we will discuss in more detail specific genetic tests for the assessment of ASD.
