Disordered eating in early childhood: DRD2 and COMT gene polymorphisms and behavioral features in family trios

PURPOSE: This study examined the association between dopaminergic genetic variants and environmental factors in young children with disordered eating and their parents. METHODS: Single nucleotide polymorphisms of DRD2 (rs1800497) and COMT (rs4680) were analyzed in 57 undereating, 51 overeating, and 44 control children, and in their parents. The quality of mother-child interactions during feeding was evaluated by the Italian adaptation of the scale for the assessment of feeding interaction. Child externalizing, internalizing and dysregulation symptoms were assessed with the child behavior checklist, and parental psychological distress with the General Severity Index. Data were analyzed by χ2 tests, ANOVAs, and odds ratios. RESULTS: Children's undereating was associated with their DRD2 polymorphism; under- and over-eating patterns with DRD2 and COMT polymorphisms, including a gene x gene interaction. Eating behavior was strongly associated with the quality of mother-child interaction but not associated with parent's genotypes. Finally, parent's psychological distress correlated with children's eating behavior but not with genetic variables. CONCLUSIONS: Our findings suggest that DRD2 and COMT polymorphisms contribute to early vulnerability to disordered eating, while mother-child relational dynamics act independently of parental genetic factors. Level of evidence III Evidence obtained from well-designed case-control analytic study.