ADHDgene Database

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Large-scale studies

Data Summary

Published Variant
- SNP: 1391
- CNV: 398
- Others: 173
Published Gene: 359
Published Region: 128
Pathway by PBA: 8
Study: 361

Study Report

Basic Info

Reference	Wang Y, 200718762727
Citation	Wang Y., Wang Z., Yao K., Tanaka K., Yang Y., Shirakawa O. and Maeda K. (2007) "Lack of association between the dopamine transporter gene 3' VNTR polymorphism and attention deficit hyperactivity disorder in Chinese Han children: case-control and family-based studies." Kobe J Med Sci, 53(6): 327-33.
Study Design	case-control and family-based
Study Type	Candidate-gene association study
Sample Size	54 children with ADHD, consisting of 42 boys and 12 girls, and their biological parents; 66 healthy individuals, consisting of 46 boys and 20 girls.
Predominant Ethnicity	Mongoloid
Population	China
Gender	42 boys and 12 girls for cases, 46 boys and 20 girls for controls
Age Group	Children/Adolescents : mean 9.4,SD=2.2 for cases, mean 8.6, SD=2.2 for controls

Detail Info

Summary	Attention deficit hyperactivity disorder (ADHD) is the most common childhood onset neurodevelopment disorder. The etiology is unclear, but is suspected to involve the dopamine system. In this study they used the haplotype-based haplotype relative risk (HHRR) analysis and the transmission disequilibrium test (TDT) to investigate the potential contribution of dopamine transporter (DAT1) gene variants to ADHD. DAT1 gene polymorphisms were assessed in 54 ADHD Chinese Han children and all 108 of their parents and 66 normal child controls. No differences were found in either genotype or allele distributions. The HHRR analysis of the DAT1 polymorphisms suggests that the transmission of this polymorphism is not significantly associated with ADHD. And the TDT result showed that ADHD was not in linkage with the DAT1 gene. These findings do not support the hypothesis that DAT1 gene variants contribute to the pathogenesis of ADHD in Chinese Han population.
Total Sample	The current study included 54 children with ADHD (mean 9.4,SD=2.2 years), consisting of 42 boys and 12 girls, aged 6-16 years, and their biological parents, who visited the outpatient clinic of Child Development and Behavior Institute of the Second Affiliated Hospital, Xi'an Jiaotong University in Xi'an, PRC. In addition to a family-based design, they included a control group to allow for a case-control design. The control group included 66 healthy individuals (mean 8.6,SD=2.2 years), consisting of 46 boys and 20 girls, aged 6-14 years, who visited the hospital for health examinations, and were confirmed to have no evidence of medical or psychiatric illness.
Sample Collection	Han Chinese
Diagnosis Description	Children were diagnosed as ADHD if they met DSM-IV criteria for ADHD: six symptoms of inattention and/or hyperactivity-impulsivity either in the home or school setting determined by clinical interview, evidence of pervasiveness defined as a minimum of four symptoms in the non-criterion setting, and onset of symptoms before 7 years of age. Thirty-seven (68.5%) children met the criteria for the ADHD combined type (ADHD-C), 5 (9.3%) met the criteria for the ADHD hyperactive-impulsive type (ADHD-HI), and 12 (22.2%) met the criteria for the ADHD inattentive type (ADHD-I). Subjects were excluded if their IQ scored below 70, or showed evidence of neurological or chronic medical illness, bipolar affective disorder, psychotic symptoms, Tourette syndrome, or chronic physical disability. Children were free of medication for a minimum of 24hr before their assessment.
Technique	Peripheral blood was drawn from the ante cubical vein, and genomic DNA was extracted from whole blood using a standard DNA isolation procedure from 54 ADHD cases and 108 their biological parents, in addition to 66 controls. DNA was resuspended in 20 ul of water and stored at 4^oC (concentration range 25-100 ng L-1). The primer sequence used to amplify the 40-bp sequence of the VNTR polymorphic loci was described in the original article.
Analysis Method	In the case-control association analysis, allele and genotype frequencies in different groups of subjects were compared using the Chi-square test. For the family-based analysis, the transmission disequilibrium test (TDT), and the haplotype-based haplotype relative risk (HHRR) method were used to avoid any potential population stratification.
Result Description	No differences were found in either genotype or allele distributions. The HHRR analysis of the DAT1 polymorphisms suggests that the transmission of this polymorphism is not significantly associated with ADHD. And the TDT result showed that ADHD was not in linkage with the DAT1 gene. These findings do not support the hypothesis that DAT1 gene variants contribute to the pathogenesis of ADHD in Chinese Han population.

Other variant reported by this study (count: 1)

Genes reported by this study (count: 1)