注意缺陷多动障碍多巴胺D4受体基因多态性与工作记忆的关系

Relationship between dopamine D4 receptor gene polymorphism and working memory in Chinese boys with attention deficit hyperactivity disorder

【目的】探讨中国汉族男童注意缺陷多动障碍(attention deficit hyperactivity disorder,ADHD)多巴胺D4受体基因(DRD4)第3外显子48bp可变数目串联重复(VNTR)多态性与工作记忆的关系。【方法】对80名ADHD男童DRD4 48bpVNTR多态性进行检测,并采用工作记忆任务(顺背数字、倒背数字、Corsi木块回忆、n-Back)测试,分长重复序列(4～6次)和短重复序列(2～3次)两组进行比较。【结果】ADHD男童DRD4 48bpVNTR次数是2～6次,最常见的等位基因是4次重复(73.125%)和2次重复序列(20%),未发现7次重复序列或更长的片段。ADHD男童DRD448bp长重复序列组在倒背数字中的总分及长度明显低于短重复序列组。【结论】ADHD男童DRD4 48bp长重复序列可能影响工作记忆功能。

【Objective】 To explore the relationship between the 48 bp variable number of tandem repeat（VNTR） polymorphism in the D4 receptor gene（DRD4） exon 3 and working memory in Han Chinese boys with attention deficit hyperactivity disorder.【Methods】 The polymorphism of 48 bp VNTR in DRD4 were tested in 80 boys with ADHD and working memory function was measured with digits forward,digits backward,Corsi block recall and visual spatial n-back.They were divided into two groups according to the long-repeat alleles（ranging from 4 to 6 repeats） or the short-repeat alleles（2 or 3 repeat） of DRD4.【Results】 The repeat numbers of the 48 bp VNTR at the DRD4 ranged from 2 to 6 repeats in boys with ADHD,with the most common being the 4-repeat（73.125%） and 2-repeat（20%） alleles.Neither the 7-repeat allele nor longer repeats were found.The total score and the number of the length in digit backward in ADHD boys with the long-repeat alleles were significantly lower than those with the short-repeat alleles.【Conclusion】 The long-repeat alleles of DRD4 may affect working memory function in Han Chinese boys with ADHD.