Study Report
Basic Info
Reference |
Banoei MM, 200817582621
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Citation |
Banoei M. M., Majidizadeh T., Shirazi E., Moghimi N., Ghadiri M., Najmabadi H. and Ohadi M. (2008) "No association between the DAT1 10-repeat allele and ADHD in the Iranian population." Am J Med Genet B Neuropsychiatr Genet, 147B(1): 110-1.
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Study Design |
case-control |
Study Type |
Candidate-gene association study |
Sample Size |
100 cases and 130 controls |
Predominant Ethnicity |
Iranian |
Population |
Iran |
Gender |
70 males for cases, 80 males for controls |
Age Group |
Children/Adolescents
:
mean age 10,SD=4 for cases, mean age 12,SD=5 for controls
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Detail Info
Summary |
Association studies between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a polymorphism (a 40 bp variable number of tandem repeats) in the dopamine transporter gene (DAT1) have resulted in mixed findings in different populations. They performed a case/control study to clarify the contribution of this allele with ADHD in the Iranian population. No association was observed between the 10-allele and disease (x2=0.081, P-value<0.9). Furthermore, no significant difference was observed in the homozygosity of this allele between the case and control groups (x2=0.022, P-value<0.9). Implication of the dopamine transporter gene in the pathophysiology of ADHD warrants investigation of other functional polymorphisms within this gene in the Iranian ADHD patients. |
Total Sample |
One hundred unrelated Iranian subjects (70 males) with ADHD were recruited for the study from the Child Psychiatry Clinic of the Rassool Akram Hospital-Iran Medical Sciences University and two private clinics in Tehran. One hundred thirty unrelated Iranian children (80 males) were randomly selected as controls. |
Sample Collection |
Iranian |
Diagnosis Description |
All the patients in this study met the following criteria using Diagnostic and Statistical Manual of Mental Disorders (DSM-IV): six symptoms of inattention and/or hyperactivity/ impulsiveness either in the home or school setting as determined by clinical interview; evidence of pervasiveness, defined as a minimum of four symptoms in the noncriterion setting, and onset before 7 years of age. |
Technique |
A 10 ml buccal sample was drawn from each subject. DNA was extracted using standard techniques and subsequently used as a template for the determination of DAT1 VNTR alleles by polymerase chain reaction as described previously [Holmes et al., 2000]. Approximately 100 ng of amplified DNA were analyzed by electrophoresis on a 4% polyacrylamide gel and visualized following silver staining. |
Analysis Method |
The Chi-square test was employed to compare frequency differences of the VNTR alleles and genotypes between the groups studied. A P-value of <=0.02 was considered significant; implementing the Bonferroni 0.5 mean correction to the conventional significant P-value of <0.05. |
Result Description |
No association was observed between the 10-allele and disease. Furthermore, no significant difference was observed in the homozygosity of this allele between the case and control groups. |
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 |
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|
chi-square P-value=0.9, X2=0.081
chi-square P-value=0.9, X2=0.081
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no association between 10-allele and ADHD |
Non-significant
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Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
SLC6A3 |
no association between the SLC6A3 10-repeat allele and ADHD
no association between the SLC6A3 10-repeat allele and ADHD
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Non-significant
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