Study Report
Basic Info
Reference |
Cho SC, 2008(a)18835330
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Citation |
Cho S. C., Kim J. W., Kim B. N., Hwang J. W., Shin M. S., Park M., Kim S. A., Cho D. Y., Yoo H. J., Chung U. S., Son J. W. and Park T. W. (2008) "Association between the alpha-2C-adrenergic receptor gene and attention deficit hyperactivity disorder in a Korean sample." Neurosci Lett, 446(2-3): 108-11.
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Study Design |
case-control and family-based |
Study Type |
Candidate-gene association study |
Sample Size |
184 ADHD probands, 150 normal controls, and 98 trios |
Predominant Ethnicity |
Mongoloid |
Population |
Korea |
Gender |
162 boys for cases, 131 boys for controls, unknown in the trios |
Age Group |
Children/Adolescents
:
mean 9.2,SD=2.3 years
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Detail Info
Summary |
The aims of this study were to examine the association between the ADRA2C (GT)n repeat polymorphism (STR marker adra2c1) and ADHD in a Korean sample. In this case-control and family-based association study, they assessed 184 ADHD probands, 150 normal controls, and 98 trios. There were no significant differences in the allele frequencies of the ADRA2C polymorphism between the ADHD and control groups (p>0.05). The overall allele-wise transmission disequilibrium test (TDT) analysis showed statistical significance (X2=19.07, P-value=0.025). They found a trend for preferential transmission of the 183-bp allele (X2=3.72, P-value=0.054), and a significantly lower-than-expected rate of transmission of the 187-bp allele (X2=6.26, P-value=0.012). The findings provide important evidence that the ADRA2C polymorphism is involved in the etiology of ADHD in Korean subjects. |
Total Sample |
family sample included 186 children with ADHD (mean age 9.2,SD=2.3 years), consisting of 162 boys and 24 girls, and their parents, who agreed to participate in the study. The control group included 150 normal children (mean age 9.4,SD=0.6 years), consisting of 131 boys and 19 girls. For this study, 184 ADHD subjects, 150 normal controls, and 98 trios were successfully genotyped. |
Sample Collection |
Korean |
Diagnosis Description |
The diagnosis of ADHD was based on the DSM-IV criteria using the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version. For clinical and neuropsychological evaluation of the ADHD subjects, the Child Behavior Checklist, ADHD Rating Scale-IV, Children's Depression Inventory, State-Trait Anxiety Inventory for Children, Junior Temperament and Character Inventory, and computerized continuous performance test were administered. |
Technique |
Genomic DNA was extracted from lymphocytes (stored frozen), using a G-DEXTM II Genomic DNA Extraction Kit (Intron, Korea) according to the manufacturer's protocol. Oligonucleotide primers (ADRA2C-F primer 5 -6FAM-CGC TGC CTC CCT TCC ACC TGT TG and ADRA2C-R primer 5 -AGT GGG CAG GGC GGG GCA GGT) were used to generate the ADRA2C (GT)n polymorphic region. |
Analysis Method |
The allele frequencies were estimated by counting, and the Hardy-Weinberg equilibrium was calculated based on these allele frequencies, using the goodness-of-fit X2(Chi-square) test. For the family-based association analysis of the ADRA2C polymorphisms with ADHD, the transmission disequilibrium test (TDT) was performed using the extended transmission disequilibrium test (ETDT) program. |
Result Description |
The findings provide important evidence that the ADRA2C polymorphism is involved in the etiology of ADHD in Korean subjects. |
Other variant reported by this study (count: 1)
Variant Name |
Allele Change |
Risk Allele |
Statistical Values |
Author Comments |
Result of Statistical Analysis |
ADRA2C upstream (TG)n |
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allele frequencies P-value>0.05 between the ADHD and control......
allele frequencies P-value>0.05 between the ADHD and control groups; TDT P-value=0.025, X2=19.07; 183-bp allele P-value=0.054, X2=3.72; 187-bp allele P-value=0.012, X2=6.26
More...
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showed significant associations with ADHD |
Significant
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Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
ADRA2C |
ADRA2C(GT)n repeat polymorphism is involved in the etiology ......
ADRA2C(GT)n repeat polymorphism is involved in the etiology of ADHD
More...
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Significant
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