The goal of this project is to identify specific miRNAs that are increased or decreased in the saliva of children with developmental delay and are useful for screening toddlers for ASD. Such a screening tool would improve the specificity of diagnosis, streamline referrals to developmental specialists, and expedite the arrangement of early intervention services.

The central aim of this project is to characterize the expression of exosomal microRNA (miRNA) in children with autism spectrum disorder (ASD). Currently, the CDC estimates the prevalence of ASD in U.S. children to be 1 in 68. Yet, the biological causes, diagnosis, and treatment of this disease remain ambiguous. Growing evidence implicates a genetic role in ASD. miRNAs regulate genetic expression and are altered in lymphocytes, neurons and serum of patients with ASD. Recent studies of miRNAs have shown that they can be packaged into exosomal vessels and extruded from neurons as extracellular signaling tools. This knowledge provides a novel approach for examining the genetic regulation of the central nervous system.

We propose to measure the expression of extracellular miRNA in children with ASD. Expression levels of miRNA from blood and saliva will be compared between children with autism and normally developing controls. The goal of this study will be to identify genetic regulatory mechanisms involved in ASD and provide potential biomarkers for diagnostic screening.

The primary endpoints of this study are as follows:

1. Characterization of brain-related miRNA in the saliva of children with ASD and typically developing control children between the ages of two and five years.
2. Identification of sets of miRNAs in saliva and plasma that are predictive of both ASD diagnosis and severity of ASD symptoms. This aim will enroll ASD and control children age 12-24 months (inclusive).

Secondary endpoints include the identification of miRNA expression patterns that correlate with ASD symptom severity measured with standardized neuropsychologic testing and to characterize parental knowledge and attitudes towards epigenetic testing in the context of ASD..

Inclusion Criteria:

• • Age at enrollment: 18 months and 6 years (inclusive)

  • Control group documented negative ASD screening on M-CHAT-R
  • ASD group: established DSM-5 diagnosis
  • Parent/guardian must be fluent in written and spoken English (required to complete study specific questionnaires etc)

Exclusion Criteria:

For autistic subjects study exclusion criteria will include:

• Autistic subjects with known syndromic autism (attributed to a known genetic mutation)

Control subjects only exclusion criteria will include:

• A diagnosis of autism

For both groups: wards of the state, active periodontal infection, active upper respiratory infection

The study will compare salivary miRNA in 2 groups of children between the ages of 18 months and 6 years, 11 months of age:

Group 1: Children with autism spectrum disorder (ASD), diagnosed by a qualified clinical specialist using DSM-5 criteria and confirmed with ADOS, CASD, or some additional semi-structured evaluation measure. ASD will not be attributable to an underlying genetic phenotype.

Group 2: Healthy controls with negative MCHAT-R screening not meeting DSM-5 criteria for ASD

IPD will not be made available