Background: Exposure to life-threatening events is common and everyone will most likely experience this type of trauma during their lifetime. Reactions to these events are highly heterogeneous and seems to be influenced by genes as well. Some individuals will develop posttraumatic stress disorder (PTSD), while others will not. In this study, our aim was to analyze the correlation between single nucleotide polymorphisms (SNPs) within the oxytocin receptor (OXTR) gene (rs53576 and rs2254298), the RAR-related orphan receptor A (RORA) gene (rs8042149) and the cannabinoid receptor 1 (CNR1) gene (rs1049353) and PTSD. All candidate genes have been previously associated with stress related disorders and the reaction to traumatic events.
Subjects and methods: Participants (N=719) have been exposed to war-related trauma during the war in South-Eastern Europe (Bosnia and Herzegovina, Croatia and Kosovo). We correlated the presence and absence of current and lifetime PTSD as well as PTSD severity (Clinician Administered PTSD scale (CAPS)) and current psychopathology (Brief Symptom Inventory (BSI) score) with the mentioned SNPs. DNA was isolated from whole blood and genotyped for OXTR rs2254298 and rs53576 following previously published protocols, for RORA rs8042149 via PCR-RFLP and CNR1 rs1049353 via KASP.
Results: Nominally significant results were found for OXTR rs53576 in connection with the CAPS and BSI scores within lifetime PTSD patients. The additive allelic model indicated that G allele carriers achieved lower CAPS (p=0.0090) and BSI (p=0.0408) scores than participants carrying one or two copies of the A allele. These results did not withstand correction for multiple tests. No significant results were observed for OXTR rs2254298, RORA rs8042149 and CNR1 rs1049353 although the results for RORA showed a slight tendency that rs8042149 may influence the level of BSI scores in current PTSD patients.
Conclusions: This study points to a role of the OXTR gene in PTSD and the related psychopathology following war related trauma.