PTSD is a commonly occurring psychiatric consequence of exposure to extreme, life threatening stress. We report herein the results from MVP of the first GWAS of the PTSD re-experiencing (REX) symptom cluster, which reflects the most characteristic set of PTSD symptoms. Our approach of using severity of the core PTSD phenotype – REX symptoms – for GWAS obviates the reliance on a categorical phenotype such as DSM or ICD-defined PTSD; these have changed with various iterations to the diagnostic criteria and as a result have proven to identify individuals with varying levels of symptom severity.10 Our SNP results support eight separate GWS regions; our gene-based results point to CRHR1 as well as several other genes expressed in brain; and our LD score regression results support genetic overlap with multiple psychiatric, behavioral and other medical phenotypes. While these data identify numerous biological mechanisms that may be associated with REX scores, two patterns stand out. The first pattern relates to steroid response or metabolism. We identified a GWS association mapped to a well-known 900 kb inversion region (MAF ~0.2 in Europeans)11 that
