5-HT_(2C)基因多态与共患学习困难的儿童注意缺陷多动障碍的相关性

Association between serotonin 2C gene polymorphisms and attention deficit hyperactivity disorder comorbid or not comorbid with learning disorder

目的 :探讨共患与不共患学习困难 (learningdisorder,LD)的儿童注意缺陷多动障碍 (attentiondeficithyperac tivitydisorder,ADHD)与 5 HT2C受体基因 (HTR2C)C 75 9T和G 6 97C两种多态之间的关联。方法 :检测 1 89个共患LD的ADHD核心家系 (ADHD +LD)和 2 99个不共患LD的ADHD核心家系 (ADHD -LD)的C 75 9T和G 6 97C两种多态 ,并对各等位基因和单体型进行传递不平衡检验 (TDT)。结果 :在ADHD -LD家系中 , 75 9C(χ2 =6 .96 1 ,P =0 .0 0 8)和 6 97G(χ2 =8.346 ,P =0 .0 0 4 )等位基因优先传递 ,就单体型而言 , 75 9C/ 6 97G传递较多 (χ2 =9.0 0 0 ,P =0 .0 0 2 7) ,而 75 9T/ 6 97C传递较少 (χ2 =7.784 ,P =0 .0 0 5 3) ;但是 ,在ADHD +LD家系中未发现任何等位基因和单体型的传递不平衡现象。结论 :ADHD共患LD与否在HTR2C基因C 75 9T和G 6 97C两种多态水平上有明显的遗传差别。HTR2C基因与ADHD

Objective: To investigate the relationship between two HTR2C gene polymorphisms, that is C 759T and G 697C polymorphisms, and attention deficit hyperactivity disorder (ADHD) comorbid or not comorbid learning disorder (LD). Methods: Blood samples were taken from 189 trios with probands of ADHD comrbid LD (ADHD+LD) and 299 trios with probands of ADHD not comorbid LD (ADHD-LD). DNA was extracted and PCR was performed to amplify the fragments containing both C 759T and G 697C polymorphisms. Aci Ⅰ was used to detect different alleles of the two polymorphisms. Allele based and haplotype based TDT analysis were used to test the association of the two polymorphisms of HTR2C gene and ADHD-LD and ADHD+LD. Results: 759C(χ 2= 6.961 , P =0.008), 697G(χ 2=8.346, P =0.004), as well as 759C/ 697G haplotype were over transmitted(χ 2=9.000, P = 0.002 7), while haplotype 759T/ 697C was under transmitted(χ 2= 7.784 , P =0.005 3) to probands with ADHD-LD. No biased transmission of any allele and haplotype were found in families with probands of ADHD+LD. Conclusion: ADHD-LD and ADHD+LD are different at the level of HTR2C gene polymrohisms of C 759T and G 697C. HTR2C is related to ADHD-LD, while not related to ADHD+LD.