Carrasco Ximena, Rothhammer Paula, Moraga Mauricio, Henríquez Hugo, Aboitiz Francisco, Rothhammer Francisco
Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago.
Rev Med Chil. 2004 Sep;132(9):1047-52. doi: 10.4067/s0034-98872004000900004.
Genes for dopamine receptor DRD4 and dopamine transporter DAT1 have been implicated in attention deficit with hyperactivity disorder (ADHD). However, the findings are not conclusive. More studies in populations with different genetic backgrounds may contribute to solve the discrepancies observed.
To test the hypothesis that affected members of Chilean families exhibit higher frequencies of the DRD4/7R and DAT1/10R alleles then their healthy sibs.
The parents of 51 children belonging to families of the Metropolitan Region of Chile, were approached to obtain clinical histories and blood samples, after the signature of a written informed consent. ADHD was diagnosed according to DSM-IV criteria, ancd intellectual coefficient was tested using the WISC-R test. Genomic DNA was extracted from lymphocytes and amplified by PCR.
The 7R allele was identified in 13 out of 26 subjects diagnosed as ADHD and in 6 of 25 healthy sibs (p < 0.05). Parents with a history of ADHD, were conmpared with their healthy counterparts, exhibiting an identical tendency, that did not reach statistical significance. No significant differences in the frequencies of DAT1/10R alleles, were observed between cases and controls or their parents.
Our results showed that ADHD in Chilean families is associated with the presence of DRD4/7R allele.
多巴胺受体DRD4和多巴胺转运体DAT1的基因与注意力缺陷多动障碍（ADHD）有关。然而，研究结果并不确凿。对不同遗传背景人群进行更多研究可能有助于解决所观察到的差异。
检验智利家族中受影响成员的DRD4/7R和DAT1/10R等位基因频率高于其健康同胞这一假设。
在获得书面知情同意书后，联系了智利首都大区51名儿童的家长，以获取临床病史和血样。根据《精神疾病诊断与统计手册》第四版标准诊断ADHD，并使用韦氏儿童智力量表修订版（WISC-R）测试智力系数。从淋巴细胞中提取基因组DNA，并通过聚合酶链反应（PCR）进行扩增。
在26名被诊断为ADHD的受试者中，有13人检测到7R等位基因，在25名健康同胞中有6人检测到（p<0.05）。有ADHD病史的父母与其健康的对应者相比，表现出相同的趋势，但未达到统计学意义。在病例组和对照组及其父母之间，未观察到DAT1/10R等位基因频率的显著差异。
我们的结果表明，智利家族中的ADHD与DRD4/7R等位基因的存在有关。
