DRD4 and obesity due to melanocortin 4 receptor deficiency: Since the DRD2 and DRD4 genes have been associated with susceptibility to obesity and anomalous eating behaviour, and given that polymorphisms of these genes seem to affect the performance of executive functions, which appear to be altered in obesity, it would seem logical to ask whether there is any relationship between these polymorphisms and executive function in obese subjects.