Eating disorders with binge-eating behaviour are associated with the s allele of the 3′-UTR VNTR polymorphism of the dopamine transporter gene

Objective: The dopaminergic system is associated with feelings of pleasure and reward and with positive hedonic processes related to food, sexual activity and certain substances. Because it is recognized that patients who have eating disorders with binge-eating behaviour have a high comorbidity of substance dependence, we examined the association between the variable number of tandem repeats (VNTR) polymorphism in the 3' untranslated region of the dopamine transporter gene (DAT1) and eating disorders with binge-eating behaviour. Methods: The subjects were 90 female Japanese patients with eating disorders diagnosed using DSM-IV; they were compared with 115 healthy female controls. Genomic DNA was extracted from whole blood, and standard polymerase chain reaction testing was performed. We compared the frequencies of a short allele (7 or 9 repeats) and a long allele (10 or 11 repeats) in both groups. Results: In the group who had an eating disorder with binge-eating behaviour, the frequency of a short allele was significantly higher compared with the control group. Conclusion: It seems plausible that the association between the DAT1 VNTR and binge-eating behaviour indicates that dysregulation of dopamine reuptake may act as a common pathophysiologic mechanism in eating disorders with binge-eating behaviour and in disorders related to substance use.