Study Report
Basic Info
Reference |
Brookes KJ, 2005 (a)16143039
|
Citation |
Brookes K. J., Xu X., Chen C. K., Huang Y. S., Wu Y. Y. and Asherson P. (2005) "No evidence for the association of DRD4 with ADHD in a Taiwanese population within-family study." BMC Med Genet, 6: 31.
|
Study Design |
family-based |
Study Type |
Candidate-gene association study |
Sample Size |
216 ADHD probands and available parents |
Predominant Ethnicity |
Mongoloid |
Population |
China |
Gender |
192 (83.6%) were males |
Age Group |
Children/Adolescents
:
5-15 years
|
Detail Info
Summary |
Here they investigated two markers within the DRD4 gene in a Taiwanese population, the exon 3 variable number tandem repeat (VNTR) and a 5' 120 base-pair duplication. Within-family transmission disequilibrium tests of association of the 5' 120 base-pair duplication, and exon 3 VNTR in a Taiwanese population. No evidence of association of ADHD with either polymorphism in this population was observed. The DRD4 gene markers investigated were not found to be associated with ADHD in this Taiwanese sample. |
Total Sample |
216 ADHD probands between the ages of 5-15 years and available parents were recruited into the study from the Child Psychiatric Clinics in the Chang Gung Memorial Hospital in Taipei area, Taiwan. A total of 192 (83.6%) were males. |
Sample Collection |
216 ADHD probands between the ages of 5-15 years and available parents were recruited into the study from the Child Psychiatric Clinics in the Chang Gung Memorial Hospital in Taipei area, Taiwan. |
Diagnosis Description |
The diagnosis of ADHD was made according to DSM-IV criteria following completion of a standard maternal interview (Kiddie-SADS) and completion of parent and teacher Conner's revised rating scales. In all 78% had the combined subtype and 22% the inattentive subtype of ADHD. |
Technique |
Genotyping was carried out using standard PCR methods and analysed on 2% agarose. Detection rate of DRD4 genotypes was 87.5% for the VNTR and 96% for the 5' 120 bp duplication. |
Analysis Method |
The family genotypes were analysed by single marker transmission disequilibrium test (TDT), and haplotype-based haplotype relative risk test (HHRR) run in UNPHASED http://portal.litbio.org/Registered/Menu. UNPHASED was also used to calculate haplotype associations for phase-certain haplotypes (TDTPHASE) and for uncertain haplotypes (HHRR) in addition linkage disequilibrium between the markers. |
Result Description |
No evidence of association of ADHD with either polymorphism in this population was observed. The DRD4 gene markers investigated were not found to be associated with ADHD in this Taiwanese sample. |
Other variant reported by this study (count: 2)
Variant Name |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
DRD4 promoter duplication 120bp |
|
120bp |
allelic TDT P-value=0.71; HHRR P-value=0.73
allelic TDT P-value=0.71; HHRR P-value=0.73
|
global and allele-specific tests of association were non-significant |
Non-significant
|
DRD4 exon3 VNTR |
|
|
allelic TDT P-value=0.55; HHRR P-value=0.55
allelic TDT P-value=0.55; HHRR P-value=0.55
|
global and allele-specific tests of association were non-significant |
Non-significant
|
Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
DRD4 |
two-marker haplotype, TDT P-value=0.45; HHRR P-value=0.45; d......
two-marker haplotype, TDT P-value=0.45; HHRR P-value=0.45; did not find either global or haplotype-specific evidence for association
More...
|
Non-significant
|