DRD2 and obesity due to melanocortin 4 receptor deficiency: Regarding genetic variants in dopamine D2/D3 receptors (DRD2), which may relate to obesity via differences in reward processing [54, 55], only one study investigated the link with white matter microstructure and found that a genetic variant in strong linkage disequilibrium with Taq1A correlated with higher structural connectivity of striatal-frontal tracts in a sample of young, normal-weight participants [25].