GSE97356
Gene expression associated with PTSD in World Trade Center responders: An RNA sequencing study
The gene expression approach has provided promising insights into the pathophysiology of PTSD. However, few studies used hypothesis-free transcriptome-wide expression approach. Transcriptome-wide expression study using RNA sequencing (RNA-Seq) of whole blood was conducted in 324 World Trade Center responders (201 with never, 81 current and 42 past PTSD). The current and never PTSD samples were randomly split to form both discovery (N=195) and replication (N=87) cohorts. Differentially expressed genes identified in RNA-Seq were used in pathway analysis and to create a polygenic expression score. There were 448 differentially expressed genes in the discovery cohort, of which 99 remained significant in the replication cohort, and 5 (FKBP5, NDUFA1, CCDC85B, SNORD54, SNORD46) showed >1.2-fold difference in expression consistently between the discovery and replication cohorts. Several enriched biological pathways were found, including glucocorticoid receptor signaling and immunity-related pathways, but were not significant following FDR correction. The gene expression score achieved sensitivity of 0.917 and specificity of 0.508 for identifying PTSD cases in the replication cohort. It was similar in current and past PTSD, with both groups scoring higher than trauma-exposed controls. We confirmed the role of FKBP5 in PTSD and identified four additional differentially expressed genes that may constitute biomarkers for this condition. Together with the pathway analysis results, these findings point to HPA-axis and immune dysregulation as key biological processes underpinning PTSD. A novel polygenic expression aggregate that differentiates PTSD patients from trauma-exposed controls might be a useful screening tool for research and clinical practice, if replicated in other populations. Overall design: 324 human samples; 201 never,  82 current, 41 past with PTSD. Gene expression profiling by high throughput sequencing