Variation in SLC1A1 is related to combat-related posttraumatic stress disorder

Candidate gene studies have yet to investigate the glutamate system, the primary excitatory neurotransmitter of the HPA-axis related to PTSD risk. We investigated 13 SNPs in the glutamate transporter gene (SLC1A1) in relation to PTSD among combat-exposed veterans. Participants (n = 418) completed a diagnostic interview and provided a blood sample for DNA isolation and genotyping. A subset of participants (n = 391) had severity and combat exposure data available. In the primary logistic regression gender and rs10739062 were significant predictors of PTSD diagnosis (OR = 0.50; OR = 1.43). In the linear regression analysis, combat exposure was the only significant predictor (β = 0.16) of severity. A computed genetic risk sum score was significant in relation to PTSD diagnosis (OR = 1.15) and severity scores (β = 0.14) above and beyond the effects of combat exposure. This study provides preliminary support for the relationship of glutamate transporter polymorphisms to PTSD risk and the need for further genetic studies within this system.