Dopamine D2 receptor and N-methyl-D-aspartate receptor 2B subunit genetic variants and intelligence.

The dopaminergic and glutamate systems have been implicated in cognitive function. We tested the associations between the dopamine D2 receptor (DRD2) and N-methyl-D-aspartate receptor 2B subunit (GRIN2B) gene variants and intelligence quotient (IQ). Subjects with the DRD2 A1/A1 genotype had a significantly higher mean performance IQ than A2/A2 carriers, while no significant differences in IQ scores were determined for the three GRIN2B genotype groups. These results suggest that genetic variants of the DRD2 gene may play a role in cognitive function. Considering the major role played by the dopaminergic system in general cognitive function, genetic variants of the dopamine receptors and those involved in metabolism and modulation of reuptake should be tested to improve gene-based prediction of general cognitive function.