Reactive and proactive subtypes of aggression have been recognized to help parse etiological heterogeneity of this complex phenotype. With a heritability of about 50%, genetic factors play a role in the development of aggressive behavior. Imaging studies implicate brain structures related to social behavior in aggression etiology, most notably the amygdala and striatum. This study aimed to gain more insight into the pathways from genetic risk factors for aggression to aggression phenotypes. To this end, we conducted genome-wide gene-based cross-trait meta-analyses of aggression with the volumes of amygdala, nucleus accumbens and caudate nucleus to identify genes influencing both aggression and aggression-related brain volumes. We used data of large-scale genome-wide association studies (GWAS) of: (a) aggressive behavior in children and adolescents (EAGLE, N = 18,988); and (b) Magnetic Resonance Imaging (MRI)-based volume measures of aggression-relevant subcortical brain regions (ENIGMA2, N = 13,171). Second, the identified genes were further investigated in a sample of healthy adults (mean age (SD) = 25.28 (4.62) years; 43% male) who had genome-wide genotyping data and questionnaire data on aggression subtypes available (Brain Imaging Genetics, BIG, N = 501) to study their effect on reactive and proactive subtypes of aggression. Our meta-analysis identified two genes, MECOM and AVPR1A, significantly associated with both aggression risk and nucleus accumbens (MECOM) and amygdala (AVPR1A) brain volume. Subsequent in-depth analysis of these genes in healthy adults (BIG), including sex as an interaction term in the model, revealed no significant subtype-specific gene-wide associations. Using cross-trait meta-analysis of brain measures and psychiatric phenotypes, this study generated new hypotheses about specific links between genes, the brain and behavior. Results indicate that MECOM and AVPR1A may exert an effect on aggression through mechanisms involving nucleus accumbens and amygdala volumes, respectively.

Additional Metadata
Keywords Aggression, Brain imaging, Genetics, MRI, Neurobiology
Persistent URL dx.doi.org/10.3389/fnbeh.2018.00061, hdl.handle.net/1765/106333
Journal Frontiers in Behavioral Neuroscience
Grant This work was funded by the European Commission 7th Framework Programme; grant id fp7/278948 - Translational Adolescent and Childhood Therapeutic Interventions in Compulsive Syndromes (TACTICS), This work was funded by the European Commission 7th Framework Programme; grant id fp7/602450 - IMAging GEnetics for MENtal Disorders (IMAGEMEND), This work was funded by the European Commission 7th Framework Programme; grant id fp7/602805 - Aggression subtyping for improved insight and treatment innovation in psychiatric disorders (AGGRESSOTYPE), This work was funded by the European Commission 7th Framework Programme; grant id h2020/643051 - Mastering skills in the training Network for attention deficit hyperactivity and autism spectrum Disorders (MiND), This work was funded by the European Commission 7th Framework Programme; grant id h2020/667302 - Comorbid Conditions of Attention deficit / hyperactivity disorder (CoCA)
Citation
Van Donkelaar, M.M.J, Hoogman, M, Pappa, M, Tiemeier, H.W, Buitelaar, J.K, Franke, B, & Bralten, L.B.C. (2018). Pleiotropic contribution of MECOM and AVPR1A to aggression and subcortical brain volumes. Frontiers in Behavioral Neuroscience, 12. doi:10.3389/fnbeh.2018.00061