Association between Dopamine Transporter Gene (DAT1) Polymorphisms and Eating Disorders with Binge Eating Behavior

Objectives: Dyshomeostasis of the dopaminergic system is implicated in the pathophysiology of eating disorders (EDs). We have previously reported an association between 3'-UTR VNTR (three prime untranslated region variable number of tandem repeat) of the Dopamine Transporter 1 (DAT1) gene and ED with binge eating behavior (EDBEB). Here we investigated whether variants in the coding region of the DAT1 gene also associate with EDBEB. Methods: The coding region and exon-intron junctions of the DAT1 gene were screened by direct sequencing using genomic DNA from EDBEB patients (n = 90) and healthy subjects (n = 114) on whom 3'-UTR VNTR variants had been previously determined. Results: rs2270912 and rs28363130, two of five known polymorphisms found by this screen, were significantly associated with EDBEB patients by genotype (p = 0.003, p = 0.011, respectively) and allele (p = 0.003, p = 0.012, respectively) frequency compared with healthy subjects. Interestingly, these polymorphisms associate with the risk 3'-UTR VNTR variant of EDBEB. Conclusion: Although our sample size was small, we show here that rs2270912 and rs28363130 associates with EDBEB and might act with 3'-UTR VNTR as a haplotype. These findings support the notion that the DAT1 gene plays a key role in the dopaminergic system of EDBEB.