Overview of the AAP autism spectrum disorders toolkit and guidelines

In 1997, a letter from an autism parent group landed on the desk of American Academy of Pediatrics' (AAP) leadership. It was a plea for guidelines targeting the diagnosis and care of children with autism. Three years later, the AAP published its first set of autism guidelines.^1,2 It was also during this time that the term "autism spectrum disorders" (ASDs) was coined to reflect the fact that autism is not a single disorder, but rather a family of symptoms with varying levels of severity.

Since then, the story of ASDs has continued to grow in leaps and bounds. Volumes of literature regarding screening, diagnosis, genetics, neurobiology, and efficacy of various interventions have been published. Mounting evidence has surfaced regarding the importance of early detection and intervention, and the need for primary care pediatricians (PCPs) to make referrals to intervention programs (even before a specialist confirms the diagnosis). New data has also shed light on which interventions (non-medical and medical) have been empirically demonstrated to be effective. Finally, public awareness of ASDs has swelled.

The landscape has indeed changed, and so then must our response. Hence, in 2007, the AAP's Council on Children with Disabilities elected not to reaffirm the 2001 guidelines, but rather revise them. Three 2007 ASD publications now exist, including two clinical reports-one reviewing identification³ and the other reviewing management.⁴ The guidelines are also accompanied by a resource toolkit,⁵ comprised of more than 100 documents (eg, screening and surveillance tools, practical forms, tables, physician fact sheets, and parent handouts) designed to assist PCPs with implementing the guidelines.

We encourage readers to review the three 2007 AAP publications for more detailed information and extensive bibliography.^3-5

Epidemiology and etiology

Given that there is no pathognomonic clinical sign or lab test to confirm the diagnosis of ASD, the best estimate of the current prevalence is approximately six per 1,000.⁶ Although this number is substantially higher than estimates prior to 1990, it may not reflect a true increase in biological prevalence. Indeed, it appears that some, if not most, of the rise in ASDs may be attributed to one or more of the following: heightened public and professional awareness due to increased media exposure, changing application of criteria and diagnostic categories, the appearance of standardized screening and diagnostic methodology, changing special education eligibility legislation, closure of large institutions and increased visibility (since children with ASDs live at home and attend community schools), and the acknowledgement that children with syndromes not usually associated with autism (ie, Down syndrome) may also meet criteria for an ASD.

In terms of etiology, we know now that ASDs are highly heritable. The recurrence rate for parents with one child with idiopathic ASDs is approximately 5% to 6%, while the recurrence rate for parents of a child with syndromic ASDs will vary depending on the syndrome. Approximately four times more males than females are affected.⁷

Although many genetic markers (especially those on chromosomes X, 2, 3, 7, 15, 17, and 22) and several neuropathologic abnormalities (eg, fewer Purkinje cells in the cerebellum, above-average head circumferences) have been described, no consistent nor ASD-specific abnormality occurs in all persons with ASDs. In fact, most cases of ASD are considered "idiopathic" such that these children have no recognizable etiology, usually look normal, and are somewhat more likely to have normal cognitive abilities and a better prognosis.

It is this confluence of these factors-lack of a pathognomonic sign and/or lab test, neurogenetic heterogeneity and phenotypic variation, and somewhat subjective diagnostic criteria-that has impeded and will continue to impede both the diagnosis and the determination of etiologic factors of ASDs.