A meta-analysis of two high-risk prospective cohort studies reveals autism-specific transcriptional changes to chromatin, autoimmune, and environmental response genes in umbilical cord blood.

The study was not adequately powered to detect moderate differences at a single gene level after correcting for multiple comparisons. The individual gene differences used for enrichment did not meet multiple comparison-corrected significance. All children were siblings of children with ASD, so findings may not apply to children without that family risk. Cord blood is a mixture of cell types, and cell type composition, gestational age, birth weight, and paternal age explained much of the expression variability. Microarray did not cover all transcripts, and validation in the general population would be needed before any use as a biomarker. Cell type estimates used an adult blood reference panel because a cord blood panel was unavailable. ASD is heterogeneous, and the analysis did not further break ASD into subtypes.

Funded by the National Institute of Environmental Health Sciences, the National Center for Environmental Assessment, the National Institute of Child Health and Human Development, and the NIH Office of the Director. The supplied text does not state author conflicts of interest.

Do not infer that these genes caused ASD or that cord blood testing can diagnose ASD. No individual transcript passed the strict multiple-comparison threshold, and the gene-set findings relied on nominally significant differences in high-risk siblings.