Fig. 1

Comparison of metabolites in neurotypical versus ASD cord blood. A) Volcano plot depicting significantly increased and decreased metabolites in cord blood of neurotypical versus ASD pregnancies. P value threshold = 0.05 (by Student’s t-tests); fold change threshold = 1.1 (ASD/Control) to allow for comprehensive exploration of the data. B) Hierarchical clustering heatmap depicting the top 20 (by t-test) significantly changed metabolites in neurotypical versus ASD pregnancies. Data are normalized, autoscaled, and Euclidean distances measured. Samples are clustered by the Ward method. C) Metabolite set enrichment analysis (MSEA) of ASD versus neurotypical control pregnancies reveals enrichment of select metabolic sets. Analyses utilized built-in MSEA library (99 entries). Only the top 15 significantly enriched metabolite sets containing more than one metabolite are displayed. Significant enrichment (P < 0.05) was determined relative to a reference metabolome containing 73 detected metabolites. D) Receiver operating characteristic (ROC) analysis was built on select features to predict ASD pregnancy. Features were those identified in the top-most significantly enriched metabolite set by GSEA (fructose and mannose degradation): Fructose 6-phosphate, D-Mannose, and D-Fructose. The area under the curve (AUC) was generated as the average of 100 cross validations utilizing a random forest algorithm. E) Scores plot of multivariate modeling by the orthogonal partial least-squares (OPLS) approach reveals highlight overlapping overall metabolome between ASD and neurotypical control pregnancies. Score plot depicts percentage of response variable explained by the first predictor only (T score[1]). R2 (percent variance explained by predictor) and Q2 (cross-validation) quality metrics are listed on the figure and indicate over-fitting. Variables were standardized (mean-centered, unit-variance scaled) prior to modeling. Ellipses correspond to 95% of the multivariate normal distribution with sample covariances for each class. Figures modified from MetaboAnalyst