Several meta-analytical studies have pointed to the 7R allele of the DRD4 as a risk allele for attention-deficit hyperactivity disorder (ADHD; Faraone et al., 2001; DiMaio et al., 2003), a disorder characterized by high dysfunctional impulsivity (Young et al., 2007). The gene discussed is DRD4; the disease is attention deficit-hyperactivity disorder.