Study Report
Basic Info
Reference |
Wohl M, 200818214864
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Citation |
Wohl M., Boni C., Asch M., Cortese S., Orejarena S., Mouren M. C., Gorwood P. and Purper-Ouakil D. (2008) "Lack of association of the dopamine transporter gene in a French ADHD sample." Am J Med Genet B Neuropsychiatr Genet, 147B(8): 1509-10.
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Study Design |
family-based |
Study Type |
Candidate-gene association study |
Sample Size |
146 affected children with 106 trios and 40 duos |
Predominant Ethnicity |
Caucasian |
Population |
French |
Gender |
87% boys |
Age Group |
Children/Adolescents
:
6-16 years
|
Detail Info
Summary |
They analyzed a sample of 146 ADHD children and their parents, with a transmission disequilibrium test (TDT) design, assessing age, inattention, and hyperactivity dimensions and total score of the ADHD Rating Scale, the number of errors and the total score at Stroop Color-Word test, and the total score at the Trail Making Test. The TDT for 10-repeat (10-R) allele shows a perfect lack of transmission bias and PBAT analyses showed no role of this polymorphism for any of the studied endophenotypes. Lack of statistical power is always a possibility, but with a sample size above the average of the majority of previous studies, and an odds ratio (number of transmitted versus untransmitted 10-R allele) of 1.00 exactly, this possibility may be considered as not very likely. |
Total Sample |
The final sample consisted of 146 affected children with 106 trios and 40 duos (82% child-mother). Main characteristics of the samplewere: 86% Caucasians, 73% combined ADHD subtype, 87% boys. |
Sample Collection |
86% Caucasians |
Diagnosis Description |
They recruited a French clinical sample of ADHD children aged 6-16, assessed for diagnostic subtype and comorbidity (DSM IV-TR), the severity of ADHD symptoms (ADHD Rating Scale), cognitive function after at least 24 hr off methylphenidate medication (Stroop Color-Word test and Trail Making Test). |
Technique |
Probands and their parents were genotyped for the 40 bp VNTR polymorphism of the DAT1 gene. |
Analysis Method |
a TDT design was used, including trios and duos |
Result Description |
The TDT for 10-repeat allele shows a perfect lack of transmission bias and PBAT analyses showed no role of this polymorphism for any of the studied endophenotypes. Lack of statistical power is always a possibility, but with a sample size above the average of the majority of previous studies, and an odds ratio of 1.00 exactly, this possibility may be considered as not very likely. |
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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TDT P-value=1.00, Mc Nemar X2=0.00 (df=1)
TDT P-value=1.00, Mc Nemar X2=0.00 (df=1)
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showed a perfect lack of transmission bias |
Non-significant
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Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
SLC6A3 |
The TDT for 10-R allele shows a perfect lack of transmission......
The TDT for 10-R allele shows a perfect lack of transmission bias
More...
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Non-significant
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