Ineffective anger expression has been associated with essential hypertension (EH) and with blood pressure (BP) reactivity to stress. The ET-1/Lys198Asn polymorphism has been associated with increased resting BP and exaggerated vasoconstrictive mediated BP reactivity. African Americans (AAs) are at particular risk for development of EH, report greater anger difficulties, and exhibit greater vasoconstrictive reactivity than their European American (EA) counterparts.The objective is to investigate a gene-environment model of stress reactivity in which anger expression, particularly in combination with ET-1 T allele carrier status and AA ethnicity, would be associated with the greatest vasoconstrictive reactivity in response to a behavioral stressor.One hundred ninety-one AA and 197 EA normotensive young adults (M age=18.8+/-2.5 years) participated in the study. Total peripheral resistance index (TPRI) reactivity was assessed during a 10-min video game challenge. Anger expression was measured using Spielberger's Anger Expression Scale.A multiple regression model with TPRI reactivity as the dependent variable revealed a three-way interaction effect for anger management (i.e., AM=anger control minus anger out scores), ethnicity, and ET-1 polymorphism. Specifically, AA carriers of the ET-1 polymorphism with poor AM skills exhibited the greatest TPRI reactivity.Individuals with a genetic predisposition for exaggerated vasoconstriction who also display low AM skills may be at particular risk for development of stress-induced EH. Such individuals may particularly benefit from anger management training.