ADHDgene Database

Hot Results

Quick Search

Keyword:
Type:

Large-scale studies

Data Summary

Published Variant
- SNP: 1391
- CNV: 398
- Others: 173
Published Gene: 359
Published Region: 128
Pathway by PBA: 8
Study: 361

Study Report

Basic Info

Reference	Jiang S, 200111803531
Citation	Jiang S., Xin R., Lin S., Qian Y., Tang G., Wang D. and Wu X. (2001) "Linkage studies between attention-deficit hyperactivity disorder and the monoamine oxidase genes." Am J Med Genet, 105(8): 783-8.
Study Design	family-based
Study Type	Candidate-gene association study
Sample Size	82 ADHD children and their parents
Predominant Ethnicity	Mongoloid
Population	China
Gender	60 male, 22 female
Age Group	Children/Adolescents : average age: 10.23 (SD=0.77) years

Detail Info

Summary	Their previous studies showed an association between ADHD and the DXS7 locus, which is located in close vicinity to the MAO genes on chromosome X. These findings suggest that there might be linkage between ADHD and MAO genes. To test this hypothesis, they used the transmission/ disequilibrium test (TDT) to test for linkage between a VNTR polymorphism at the MAOA(CA)n or MAOB(GT)n locus and DSM-III-R-diagnosed ADHD in 82 nuclear families of the Chinese population. The TDT analysis revealed linkage between ADHD and the MAOA(CA)n locus, but not the MAOB(GT)n locus. The data showed that ADHD was in linkage with the MAOA gene and suggested that MAOA might be a susceptibility factor for ADHD.
Total Sample	The subjects reported in this study were 82 ADHD children and their parents. Among the ADHD children, 60 were male and 22 were female. The average age of these ADHD children was 10.23 (SD=0.77) years and the average IQ was 96.07 (SD=18.46).
Sample Collection	These children were selected from the Hyperactivity, Attention, and Learning Problems School at Shanghai, China.
Diagnosis Description	The clinical diagnostic criteria for ADHD were from DSM-III-R [USAn Psychiatric Association, 1987]. To diagnose ADHD, a minimum of eight symptoms is required as well as the absence of pervasive developmental disorder. Each diagnosis was performed separately by at least two different psychiatrists. Diagnoses were considered positive only when DSM-III-R criteria were unequivocally met.
Technique	DNA was extracted from peripheral blood cells by standard procedure. Polymerase chain reaction (PCR) was used to amplify a dinucleotide tandem repeat sequence of the MAOA or the MAOB gene. The amplified sequence for the MAOA gene was named MAOA(CA)n because it contained CA repeats in this sequence [Black et al., 1991]. The PCR primers for the MAOA gene were 5'-AGAGACTAGACAAGTTGCAC-3' and 5'-CACTATCTTGTTAGCTCACT-3'. The amplified sequence for the MAOB gene contained GT repeats and was named MAOB(GT)n. The primer set for the MAOB gene was 5'-GAAGCATCGAAGTTAGGAGT-3' and 5'- ATTTGGCCTCATAGAGTTAGG-3' [Konradi et al., 1992].
Analysis Method	Allele frequencies of the MAOA(CA)n and MAOB(GT)n loci in ADHD children and their parents were obtained based on the size of PCR product and the Hardy-Weinberg equilibrium was calculated using these allele frequencies. Transmission/disequilibrium test [Spielman and Ewens, 1996] was performed to study the linkage between ADHD and the MAOA and MAOB genes.
Result Description	The TDT analysis revealed linkage between ADHD and the MAOA(CA)n locus (chis-quare =15.25, df=7, P<0.05), but not the MAOB(GT)n locus (chi-square=11.18, df=7, P>0.05). The data showed that ADHD was in linkage with the MAOA gene and suggested that MAOA might be a susceptibility factor for ADHD.

Other variant reported by this study (count: 2)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
MAOB (GT)n	170-194bp		TDT P-value>0.05, X²=11.18, df=7 TDT P-value>0.05, X²=11.18, df=7	TDT analysis did not reveal linkage between ADHD and the MAOB(GT)n locus	Non-significant
MAOA intron2 CA(n)	110-124bp		TDT P-value<0.05, X²=15.25, df=7 TDT P-value<0.05, X²=15.25, df=7	TDT analysis revealed linkage between ADHD and the MAOA(CA)n locus	Significant

Genes reported by this study (count: 2)

Gene	Statistical Values/Author Comments	Result of Statistical Analysis
MAOB	the results showed that ADHD was not in linkage with MAOB ge...... the results showed that ADHD was not in linkage with MAOB gene More...	Non-significant
MAOA	the results showed that ADHD was in linkage with MAOA gene the results showed that ADHD was in linkage with MAOA gene	Significant