目的 了解多巴胺D4受体（DRD4）基因第3外显子48 bp可重复序列多态性（DRD4 exonⅢ 48 bp VNTR）与抽动秽语综合征（TS）共病抑郁的关系。方法 选取符合美国精神疾病诊断统计手册第4版TS诊断标准的112例儿童作为研究对象（TS组），以71名健康儿童作为正常对照组。采用聚合酶链反应(PCR)等位基因分型技术检测DRD4 exonⅢ 48 bp VNTR多态位点，分析该位点与TS的关联；采用儿童抑郁量表（CDI）测定TS儿童的抑郁水平。结果 112例TS儿童中29例（25.9%）共病抑郁。TS组及其亚组DRD4 exonⅢ 48 bp VNTR位点基因型及等位基因频率与正常对照组比较，差异均无统计学意义（P>0.05）。在TS组内，携带长重复等位基因组(61例)与短重复等位基因组（51例）CDI总分和因子分比较，差异均无统计学意义（P>0.05）。结论 DRD4 exonⅢ48 bp VNTR与TS共病抑郁之间可能不存在关联。

Objective To investigate the relationship between the polymorphism of repeatable sequence of DRD4 exonⅢ 48 bp gene and depressive symptoms in children with Gilles de la Tourette syndrome (TS). Methods A total of 112 children who were diagnosed as TS according to the criteria of the Fourth Edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (the TS group) and 71 healthy children (the control group) were selected. The polymorphous points of DRD4 gene were genotyped by the amplification refractory mutation system (ARMS) polymerase chain reaction (PCR) genotyping assay method and the depressive levels of children with TS were measured by the children's depression inventory (CDI). Results Among 112 children with TS, 29 (25.9%) were diagnosed with depression. The differences of genotype frequency and allele frequency of DRD4 exonⅢ 48 bp VNTR among the TS group, comorbid depression group, and control group were not statistically significant (P>0.05). The differences of CDI scores and factor scores between 61 children who carried long repeat allele group and 51 children who carried short repeat allele group were not statistically significant (P>0.05). Conclusion The DRD4 exonⅢ 48 bp VNTR may not correlate to the TS comorbid depression.