Study On The Relationship Between DRD4-521C/T,SNAP-25Mn/I,5-HTTLPR Single Nucleotide Polymorphisms And Response Inhibition In Children With ADHD

Objective: To respectively analyze the relationship among the single nucleotide polymorphisms of DRD4-521C/T,SNAP-25 Mn/I,5-HTTLPR,the interaction of the three genotypes on the response inhibition in children with ADHD,and to explore the etiology of impaired response inhibition in children with ADHD.Methods: Eighty-eight Han boys who met diagnostic criteria of ADHD in the fourth edition of Diagnostic and Statistical Manual of Mental Disorders(DSM-IV)were tested with Stroop color-word test and GO/no-go task to evaluate the response inhibition.PCR was used to detect the SNP of DRD4-521C/T,5-HTTLPR and SNAP-25 Mn/I.One-way ANOVA was used to compare the differences of genotypic response inhibition among DRD4-521C/T,5-HTTLPR and SNAP-25 Mn/I groups,the LSD method was used for pairwise comparisons.After controlling age and FSIQ,the general linear model was used to analyze the relationship between gene-gene interaction and response inhibition.Results:The score of SCWT error interference in DRD4-521C/T T allele homozygotes was significantly higher than that in C allele carriers(P<0.05).5-HTTLPR S allele homozygotes scored significantly higher than L allele homozygotes in the number of SCWT errors(P<0.05).After controlling age and FSIQ,there was gene-gene interaction between DRD4-521C/T and SNAP-25 Mn/I genes in response time interference score of ADHD children SCWT.TT-TT genotype suggested the worst inhibition function combination among all genotypic combinations(SCWT reaction time interference:0.96 ± 0.13,95%CI 0.69-1.22),but the difference was not significant.The TG+GG-CT+CC genotype indicated the best inhibition function combination among all genotypic combinations(SCWT reaction time interference:0.56±0.12,95%CI 0.39–0.81),and the difference was statistically significant(P <0.05).Conclusion: DRD4-521C/T T allele and 5-HTTLPR S allele may lead to the impairment of response inhibition in children with ADHD,and the single nucleotide polymorphism of DRD4-521C/T and SNAP-25 Mn/I gene had an interactive effect on the response inhibition in children with ADHD and had a gene cumulative effect on the impairment of response inhibition...