Objectives: ASD-risk biomarkers expressed early in life could significantly impact diagnosis and treatment, but no transcriptome-wide biomarker classifiers derived from fresh blood samples from autistic children have yet emerged.
Methods: Using a community-based, prospective, longitudinal method, we identified infants and toddlers at-risk for ASDs (autistic disorder and pervasive developmental disorder), language delay (LD), or global developmental delay (DD), as well as two groups of typically developing (TD) comparison children. Diagnoses were confirmed via longitudinal follow-up. Each child’s mRNA expression profile in peripheral blood mononuclear cells (PBMCs) was determined by microarray.
Results: 61 potential ASD biomarkers were discovered in one half of the sample and used to build a classifier with high diagnostic accuracy for sorting the subjects in the remaining half of the sample.
Conclusions: The mRNA expression abnormalities reliably observed in PBMCs, which are safely and easily assayed in babies, offer the first potential peripheral blood-based early biomarker of risk for autism in infants and toddlers; future work should verify these biomarkers and evaluate if they may also serve as indirect indices of deviant molecular neural mechanisms in autism.