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	Cheuk DK, 2006(b)16402340
Citation	Cheuk D. K., Li S. Y. and Wong V. (2006) "No association between VNTR polymorphisms of dopamine transporter gene and attention deficit hyperactivity disorder in Chinese children." Am J Med Genet B Neuropsychiatr Genet, 141B(2): 123-5.
Study Design	case-control and family-based
Study Type	Candidate-gene association study
Sample Size	64 cases and 64 controls
Predominant Ethnicity	Mongoloid
Population	China
Gender	52 boys, 12 girls for cases and controls respectively
Age Group	Children/Adolescents : below 18 years

Detail Info

Summary	In this prospective family-based and case-control study during January to June 2004, they recruited consecutive Chinese children diagnosed with ADHD by DSM-IV criteria, their family members, and sex-matched controls admitted for acute upper respiratory infection, excluding those with perinatal brain insults, mental retardation, or neurological deficits. VNTR polymorphisms of the DAT gene were determined by standard PCR followed by agarose gel electrophoresis. Sixty-four ADHD cases (52 boys, 12 girls), their family members and 64 normal controls were recruited. The 10-repeat allele and the 10/10 repeat genotype were the most prevalent. Both family-based and case-control analyses showed no association between the DAT gene polymorphisms and ADHD.
Total Sample	Altogether 64 ADHD cases (52 boys (81.3%), 12 girls (18.7%); M:F=4.3:1) and 64 sex-matched normal controls were recruited.
Sample Collection	Chinese children
Diagnosis Description	The diagnosis of ADHD was made according to the diagnostic and statistical manual of mental disorders-IV (DSM IV) criteria after a structured interview, which incorporated parental and teachers' reports of behavioral symptoms, clinical observation of behaviors, aberrant behavioral checklist and tests of attention such as the Conners continuous performance test. Forty-three (67.3%) ADHD patients were classified to the combined subtype while 5 (7.7%) and 16 (25%) ADHD patients belonged to the predominantly hyperactive-impulsive and predominantly inattentive subtypes respectively.
Technique	Three milliliter of blood was taken from the cases and their parents and siblings and the controls for DNA analyses in the pediatric laboratory in the University of Hong Kong. Genomic DNA extraction was performed by traditional salting-out method. Primers used for amplification of variable number of tandem repeats in 30 untranslated region of DAT1 were as described by Young et al. [2002].
Analysis Method	Family-based allele transmission analysis was performed by the standard transmission dysequilibrium test (TDT) and the odds ratios of ADHD for the presence of the 10-repeat allele and various genotypes were determined by comparison between cases and controls and its significance determined by the chi-squared tests.
Result Description	Both family-based and case-control analyses showed no association between the DAT gene polymorphisms and ADHD (transmission dysequilibrium test: P-value=0.99; odds ratio of 10-repeat allele=0.89 (95%CI 0.35-2.28), P-value=0.81; odds ratio of 10/10 repeat genotype=0.69 (95%CI 0.26-1.84), P-value=0.46). They concluded that VNTR polymorphism of the DAT gene is not associated with ADHD in Chinese children.

Other variant reported by this study (count: 1)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
SLC6A3 3'-UTR VNTR	6, 9, 10, 11 repeat	10-repeat	TDT test for 10-repeat allele: P-value=0.99 for all ADHD sam...... TDT test for 10-repeat allele: P-value=0.99 for all ADHD sample, P-value=0.92 for combined subtype; Case-Control test for 10-repeat allele: OR=0.89, 95%CI = 0.35-2.28, P-value=0.81. More...	showed no significant association	Non-significant

Genes reported by this study (count: 1)