Date of Conferral
Posttraumatic stress disorder (PTSD) is a psychiatric condition that presents with 3 main symptoms're-experiencing, avoidance/numbing, and hyper arousal'after an individual experiences a traumatic event. Recent evidence suggests a potential genetic basis for PTSD and a sub symptom of hyper arousal, sleep, as a potential pathway for PTSD development, but no study has identified candidate genes associated with specific symptoms such as sleep difficulty. Based on a conceptual framework in which specific genes are associated with the onset of PTSD, this study used a genome-wide association
study (GWAS) method with a case control study design to compare the genomes of individuals with and without PTSD. A secondary GWAS dataset from a study on alcohol dependence in European and African Americans was obtained from the National Center for Biotechnology Information. PTSD cases and controls were analyzed using PLINK software. Signals from 2 single nucleotide polymorphisms (SNPs), which have not been previously associated with PTSD, exceeded the established genome-wide threshold: SNP rs13160949 on chromosome 5 (p = 7.33x10-9, OR: 1.565) and SNP rs2283877 on chromosome 22 (p = 2.55x10-8, OR: 1.748). Neither SNP, though, maintained genomewide significance following corrected tests for multiple testing, population stratification, and false discovery, so the planned analysis for possible associations with PTSD by symptom category then by the sub symptom of sleep could not be completed. The results of this study suggest that PTSD may be the result of polygenic SNPs with weak effects, which supports a recent study indicating the disease may be highly polygenic. Positive social change implications include bringing attention to the clinical and research community that PTSD may involve complex polygenic factors in need of further study.