Association between dopamine D4 receptor gene exon Ⅲ 48bp VNTR polymorphism and temperament in school-aged children

Abstract:

Objective To investigate the association between dopamine D4 receptor gene DRD4 exon Ⅲ 48bp variable number of tandem repeat (VNTR) polymorphism and temperament in school-aged children.Methods Randomized cluster sampling was used to select 350 healthy children aged 8-12 years, and a questionnaire survey was performed. Oral epithelial samples were collected from half of these children. The complete questionnaire data of 164 children with a high level of DNA in oral epithelial samples were included in this study. PCR was used for the typing of DRD4 exon Ⅲ 48bp VNTR, and the effect of this gene and its interaction with the environment on temperament was analyzed.Results Compared with the children with S-DRD4 genotype, the children with L-DRD4 genotype had significantly lower scores on the four dimensions of activity level, reaction intensity, emotion essence, and persistence (P < 0.05). The main effects of mother's rejection/denial (OR=2.281, P < 0.05) and sex (OR=2.766, P < 0.05) and the interaction between sex and DRD4 exon Ⅲ 48bp VNTR (OR=0.582, P < 0.05) had an influence on activity level. The main effect of DRD4 exon Ⅲ 48bp VNTR (OR=0.314, P < 0.01) and the interaction between this gene and mother's rejection/denial (OR=1.872, P < 0.01) had an influence on reaction intensity. The main effect of DRD4 exon Ⅲ 48bp VNTR (OR=0.420, P < 0.05) and mother's rejection/denial (OR=2.236, P < 0.05) had an influence on persistence.Conclusions DRD4 exon Ⅲ 48bp VNTR and its interaction with other factors may affect the activity level and reaction intensity of school-aged children.