Three studies have investigated whether the Taq1A polymorphism interacts with environmental factors to influence drinking outcomes. In a longitudinal study of adolescent drinking in the Netherlands, van der Zwaluw et al. (2010) found that parental permissiveness toward drinking interacted with Taq1 A1 genotype. For example, adolescents who reported high parental rule setting at one assessment had relatively low levels of alcohol use (< 1 drink in the prior week) one year later regardless of genotype. However, adolescents who reported low levels of parental rule setting consumed significantly more alcohol at follow-up only if they had the A1 allele (5.5 drinks); those with the A2A2 genotype were similar to the high parental rule setting groups (1.5 drinks in past week).
