An examination of the association between DRD4 and DRD2 polymorphisms and personality traits

To date, evidence supporting a positive association between the 7-repeat allele of the D4 dopamine receptor (DRD4) exon III 48 bp polymorphism and Novelty Seeking (NS) has been mixed, with some studies confirming and others refuting the association. A positive association between NS and the minor Taq1 A allele (A1) of the D2 dopamine receptor (DRD2) has also been reported. In the present study, we sought to replicate the associations between the DRD4 and DRD2 polymorphisms and various personality traits, as measured by the Multidimensional Personality Questionnaire. The sample consisted of 137 families (n=348) assessed as part of the ongoing Minnesota Twin Family Study. The data were analyzed at both the individual-level, to maximize comparability with previous studies, and at the family-level, to control for population stratification. The DRD4 and DRD2 polymorphisms were not associated with MPQ measures related to NS, results that may cast doubt on the generalizability of previous positive findings.