Meta-analysis Report
Basic Info
| Reference |
Forero DA, 200919721846
|
| Citation |
Forero D. A., Arboleda G. H., Vasquez R. and Arboleda H. (2009) "Candidate genes involved in neural plasticity and the risk for attention-deficit hyperactivity disorder: a meta-analysis of 8 common variants." J Psychiatry Neurosci, 34(5): 361-6.
|
| Study Type |
Candidate association study |
| Summary |
The objective of the present study was to carry out a meta-analysis for 8 common variants located in 5 top candidate genes for ADHD (BDNF, HTR1B, SLC6A2, SLC6A4 and SNAP25). They performed a search for published genetic association studies that analyzed the candidate polymorphisms in different populations, and then applied state-of-the-art meta-analytical procedures to obtain pooled odds ratios (ORs) and to evaluate potential basis of heterogeneity. 75 genetic association studies were included in these meta-analyses. It turned out a major part of the previously postulated associations were nonconsistent in the pooled odds ratios. A weak significant association with a single nucleotide polymorphism (SNP) located in the 3'UTR region of the SNAP25 gene was observed. Limitations of this study include the retrospective nature of the meta-analysis with the incorporation of study-level data from published articles. Previously proposed cumulative associations with common polymorphisms in SLC6A4 and HTR1B genes were not supported. |
Detail Info
| Samples |
They included articles published in English in peer-reviewed journals that described results from case-control or transmission disequilibrium test (TDT) studies analyzing the association of the selected candidate polymorphisms with ADHD in children or adults in different ethnic populations. However, studies of quantitative measures of ADHD, response to medications or analyses of other markers (different from the selected candidate polymorphisms) in the candidate genes were not included. In total of 75 genetic association studies were involved in this study. For detail information, please refer to the original publication. Information about general features of the studies (e.g., sample sizes, phenotyping scales, genotyping methodologies, subtypes analyzed) was extracted from each article. In all cases of missing data, they contacted the respective authors to ask for allele frequencies that were not available in the main text of the papers or in their supplementary files. |
| Statistic Method |
For the meta-analysis procedures, they used the Catmap program which runs in the R statistical platform and allows for the joint analysis of case-control and family-based association studies and other advanced analysis approaches. They calculated the Q statistic for heterogeneity and random-effects models were used for the calculations of the pooled odds ratios (ORs). The evidence from the current meta-analysis was assessed by applying the Venice interim criteria. |
| Basic Result |
A major part of the previously postulated associations were nonconsistent in the pooled odds ratios. We observed a weak significant association with a single nucleotide polymorphism (SNP) located in the 3'UTR region of the SNAP25 gene (rs3746544). |
SNPs reported by this study: 7
| SNP |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
| rs6265 |
A/G |
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
| rs56164415 |
C/T |
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
| rs4795541 |
|
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
| rs3746544 |
A/C |
|
TDT P-value=0.028 (OR=1.15, 95% CI=1.01-1.31); Q statistic P-value=0.86, I2= 0%. |
Weak significant.
Weak significant.
|
Significant
|
| rs998424 |
C/T |
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
| rs6296 |
C/G |
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
| rs1051312 |
C/T |
|
|
Not significant for the total samples.
Not significant for the total samples.
|
Non-significant
|
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