Study Report
Basic Info
Reference |
Wang G. X., 201222895683
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Citation |
Wang G. X., Ma Y. H., Wang S. F., Ren G. F. and Guo H. (2012) "Association of dopaminergic/GABAergic genes with attention deficit hyperactivity disorder in children." Mol Med Report, 6(5): 1093-8.
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Study Design |
case-control |
Study Type |
Candidate-gene association study |
Sample Size |
54 cases, 67 controls |
Predominant Ethnicity |
Mongloid |
Population |
Chinese |
Gender |
Case group: 40 males and 14 females; Control group: 49 males and 18 females |
Age Group |
Children/Adolescents
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Case group: aged 7-16 years, mean age=9.14 (SD=1.556); Control group: aged 7-16 years, mean age=9.06 (SD=1.732)
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Detail Info
Summary |
In this study, they investigated the association of five SNPs in dopaminergic/GABAergic genes with ADHD using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a group of 54 children with ADHD and 67 healthy controls. The distribution of AA genotype and A allele frequencies of rs5320 in the dopamine beta-hydroxylase gene in ADHD children differed significantly from that in healthy controls; however, no associations were found between four other polymorphisms in dopaminergic/GABAergic genes and ADHD. We also identified the best model consisting of four loci. We conclude that the rs5320 polymorphism may be considered as a genetic risk factor of ADHD, but the other four polymorphisms were not confirmed to be related directly to ADHD. The multilocus of dopaminergic/GABAergic genes acted in combination to affect susceptibility to ADHD in the children studied. |
Total Sample |
In all patients, 85.7% had the combined subtype and 14.3% the inattentive subtype of ADHD. All subjects were unrelated individuals. |
Sample Collection |
In total, 54 ADHD cases were recruited from the outpatient clinic of Qilu Children¡¯s Hospital of Shandong University between January 2009 and June 2010. The healthy control group included 67 healthy children (49 males and 18 females) who underwent a health examination in Qilu Chindren¡¯s Hospital of Shandong University. |
Diagnosis Description |
To be included in the study, children with ADHD had to meet the following three criteria: i) have a diagnosis of ADHD classified according to the DSM-IV; ii) be between the ages of 7 and 16 years and have a full scale IQ above 70 according to the Wechsler Intelligence scale for Chinese children; iii) originate from the Han population. Individuals were excluded for any evidence of major neurological conditions or a primary diagnosis of schizophrenia, affective disorder, pervasive developmental disorder or epilepsy. The control group was selected from the Han population and aged from 7 to 16 years. Subjects with relevant psychiatric/psychological or developmental illnesses were excluded. |
Technique |
Genomic DNA was extracted from the venous blood of each participant using a TIANamp blood DNA kit. PCR cycling was performed in a DNA thermal cycler with a 2X Hotstart Taq PCR Mastermix kit. PCR products were further purified, and then digested. The digested PCR products were confirmed by electrophoresis on 2.5% agarose gels. Genotypes were determined by gel image processing software. |
Analysis Method |
The data were statistically processed with SPSS 11.0 software. Allele and genotype frequencies were compared between two groups using the Chi-square test. Observed and expected allele frequencies within populations were compared by means of a Hardy-Weinberg test. To determine high- and low-risk genotype combinations, a multifactor dimensionality reduction (MDR) method was used. The fitness of an MDR model was assessed by estimating the testing accuracy; models that were true positive would have an estimated testing accuracy of 0.5. |
Result Description |
The distribution of the AA genotype and A allele frequencies of the rs5320 polymorphism in the DBH gene in ADHD children differed significantly from that in healthy controls. The genotype distribution and allele frequencies of rs6275 polymorphism in the DRD2 gene, the rs5326 polymorphism in the DRD1 gene and the rs4680 polymorphism in the COMT gene showed no significant difference between ADHD children and healthy controls. |
SNPs reported by this study (count: 4)
SNP |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
rs5326 |
G/A |
G |
Chi-square test: genotypic p>0.05; allelic p>0.05 |
The genotype distribution and allele frequencies of this SNP......
The genotype distribution and allele frequencies of this SNP showed no significant difference between ADHD children and healthy controls.
More...
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Non-significant
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rs6275 |
T/C |
T |
Chi-square test: genotypic p>0.05; allelic p>0.05 |
The genotype distribution and allele frequencies of this SNP......
The genotype distribution and allele frequencies of this SNP showed no significant difference between ADHD children and healthy controls.
More...
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Non-significant
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rs4860 |
A/G |
A |
Chi-square test: genotypic p>0.05; allelic p>0.05 |
The genotype distribution and allele frequencies of this SNP......
The genotype distribution and allele frequencies of this SNP showed no significant difference between ADHD children and healthy controls.
More...
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Non-significant
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rs5320 |
A/G |
A |
Chi-square test: genotypic P=0.016, OR=9.484, 95%CI=1.089-82.587; allelic P=0.014, OR=2.222, 95%CI=1.165-4.237 |
The distribution of the AA genotype and A allele frequencies......
The distribution of the AA genotype and A allele frequencies of the rs5320 polymorphism in the DBH gene in ADHD children differed significantly from that in healthy controls.
More...
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Significant
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Genes reported by this study (count: 4)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
DRD1 |
SNP rs5326 mapped to this gene showed no association with AD......
SNP rs5326 mapped to this gene showed no association with ADHD in this study.
More...
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Non-significant
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COMT |
SNP rs4860 mapped to this gene showed no association with AD......
SNP rs4860 mapped to this gene showed no association with ADHD in this study.
More...
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Non-significant
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DRD2 |
SNP rs6275 mapped to this gene showed no association with AD......
SNP rs6275 mapped to this gene showed no association with ADHD in this study.
More...
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Non-significant
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DBH |
SNP rs5320 mapped to this gene showed significant associatio......
SNP rs5320 mapped to this gene showed significant association with ADHD in this study.
More...
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Significant
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