Association of Genetic Factors and Gene-Environment Interactions With Risk of Developing Posttraumatic Stress Disorder in a Case-Control Study.

Abstract

The dopamine receptor D2 (DRD2) and serotonin transporter (5-HTT) genes are associated with posttraumatic stress disorder (PTSD). However, it remains largely unknown whether these genes interact with environmental factors to affect the development of PTSD. The purpose of this study was to examine the associations of gene polymorphisms and gene-environment interactions with the risk of developing PTSD among adolescent earthquake survivors. A total of 183 adolescent survivors from an earthquake-stricken area participated in this study. Measures included a questionnaire about demographic characteristics and earthquake exposure, the PTSD Checklist-Civilian Version and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, fourth edition disorders. Genotypes were analyzed by using the polymerase chain reaction-based restriction fragment length polymorphism. The 5-HTTLPR and 5-HTTVNTR polymorphisms and earthquake exposure had statistically significant positive effects on PTSD. The interaction effects of 5-HTTLPR × Earthquake Exposure and 5-HTTVNTR × Earthquake Exposure were statistically significant. The development of PTSD is the result not only of a genetic effect and environmental factors but also of the interactive effect between gene and environment.