A Dopamine Receptor genetic variant enhances perceptual speed in cognitive healthy subjects

Cognition is under strong genetic control, yet the specific genes are unknown. To investigate genetic influences on specific cognitive domains, 153 cognitive healthy subjects of European ancestry from the Reference Abilities Study (RANN) were genotyped for 1,160 variants within 446 neuropsychiatric genes. Adjusted linear regression models evaluated the association between the genetic variants and four reference abilities, which capture variance in age-related cognitive function (Vocabulary, Episodic Memory, Perceptual Speed, and Reasoning). 159 variants nominally significant in the RANN cohort were then re-evaluated in an independent cohort of 868 cognitive healthy subjects from the Religious Orders Study and Rush Memory Aging Project. Meta-analysis yielded a Bonferroni adjusted statistically significant association between perceptual speed and a variant located in the promoter of the dopamine receptor D4 gene, rs3756450 (β=0.23, SE=0.05, P =2.3 × 10^-5). Our data suggest that genetic variation in a dopamine pathway gene influences perceptual speed performance in cognitively healthy individuals.