目的：研究多巴胺D4受体(dopamine D4 receptor ，DRD4)基因的多态性及其组合分布与原发性夜间遗尿症（PNE）的相关性。方法：选取无亲缘关系的PNE儿童86例以及无亲缘关系的健康儿童100例为对照组，提取静脉血白细胞基因组DNA，采用聚合酶链反应及等位基因特异性扩增技术检测DRD4基因-1240L/S，-521C/T与-616C/G 3个位点的基因型。结果：PNE组与对照组DRD4-616C/G的等位基因频率及基因型频率差异存在显著性（ χ2=8.13，P＜0.05；χ2=6.23，P＜0.05）。等位基因组合分布研究发现DRD4-1240 L/S-616 C/G-521 C/T组合的单倍型LCT分布频率在PNE组明显高于正常对照组（χ2=5.88，P＜0.05）。结论：PNE儿童DRD4基因-616位点由G到C的转换可能影响DRD4基因的诱导及转录，DRD4基因启动子区3个功能多态位点构成的单倍型LCT可能进一步协同抑制了DRD4基因的转录活性，可能使DRD4蛋白表达降低，注意力缺陷，睡眠觉醒障碍，引起夜间遗尿。

OBJECTIVE: To study polymorphisms of dopamine D4 receptor (DRD4) in children with primary nocturnal enuresis (PNE) and explore the relationship between DRD4 gene polymorphisms and PNE. METHODS: Genomic DNA was isolated from leukocytes in 86 unrelated children with PNE and in 100 healthy unrelated children (controls). Polymorphisms of DRD4-1240L/S, -616C/G and -521C/T were genotyped by allele-specific primer PCR. RESULTS: There were significant differences in allele frequencies (χ2=8.13, P<0.05) and genotypes frequencies (χ2=6.23, P<0.05) of DRD4-616C/G between PNE patients and healthy controls. The frequency of haplotype LCT consisting of 3 function polymorphic sites DRD4-1240L/S, -616C/G and -521C/T in PNE patients was statistically higher than that in healthy controls (χ2=5.88, P<0.05). CONCLUSIONS: The change of C to G of DRD4-616 may affect the induction and transcription of DRD4 gene. The haplotype LCT consisting of 3 function polymorphic sites DRD4-1240L/S, -616C/G and -521C/T may synergistically inhibit the transcription activity of DRD4 gene. This might lead to a reduction of DRD4 protein expression and cause nocturnal enuresis.