COMT and post-traumatic stress disorder: Other gene variants that have been studied in the context of G×E interactions for PTSD include COMT (Rwandan genocide),[107]GABRA2 (child abuse),[108]RGS2 (hurricanes),[109, 110]APOE4 (combat exposure),[111]DAP1 (tsunami and psychosocial factors),[112]ADRB2 (child abuse),[113] and CNR1 (child abuse)[114] (Table 1).