BackgroundAccumulating evidence suggests that genetic and environmental factors may influence aggression susceptibility. However, the etiology of aggressive behavior remains unknown. Compared to some extensively studied candidate genes of aggression, very little is known about the OXTR gene. The objective of this study was to determine whether OXTR genetic variants were associated with aggression risk and whether these polymorphisms showed interactive effects with childhood maltreatment on aggression in Chinese adolescents. MethodsA total of 996 participants including 488 cases and 488 controls were selected in our study. Aggression, childhood maltreatment were measured by self-reported questionnaire. Buccal cells were collected. Genotyping was performed using SNPscan. Logistic regressions were used to estimate both main effects of OXTR polymorphisms and the interactive effects with childhood maltreatment on aggressive behavior. ResultsParticipants who carried the rs237885 TT genotypes in OXTR had a higher risk of aggression compared to those who carried GG or GT genotypes under the recessive model (OR=1.40, 95% CI, 1.04–1.89) after controlling for potential confounders. In addition, we also found that the polymorphism had a synergic additive interaction with childhood physical abuse on the aggression risk. LimitationsThe subjects in the present study were only males, thus our findings and conclusions could not be generalized to females. ConclusionsThe present study provides evidence that OXTR genetic variants may contribute to aggression susceptibility. Moreover, this is the first study reporting significant interactive effects of OXTR polymorphism and childhood physical abuse on aggressive behavior in Chinese adolescents.