The D-2 dopamine receptor (DRD2) gene and family stress; Interactive effects on cognitive functions in children

TaqI A D-2 dopamine receptor (DRD2) alleles, family stress, and cognitive markers, including visuospatial ability (Benton's Line Orientation) and event-related potentials (P300 amplitude and latency), were obtained in preadolescent boys of alcoholic and nonalcoholic fathers. In the presence of the DRD2 minor allele (A1(+)), the Family Stress score negatively correlated with the Line Orientation score and P300 amplitude. No significant correlations were found in boys lacking this allele (A1(-)). The interaction of the A1(+) allele and the Family Stress score produced significant regression coefficients for both Line Orientation score (p = .002) and P300 amplitude (p = .04). Together, these two cognitive markers account for 37% of the variance in the Family Stress score of 47 A1 allele boys (p = .0002) but less than 1% in 71 A1(-) allele boys (p > .9). This provides the first evidence of a specific gene-environment interaction involving human cognitive functioning.