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	Kent L, 2001(a)11803515
Citation	Kent L., Green E., Holmes J., Thapar A., Gill M., Hawi Z., Fitzgerald M., Asherson P., Curran S., Mills J., Payton A. and Craddock N. (2001) "No association between CHRNA7 microsatellite markers and attention-deficit hyperactivity disorder." Am J Med Genet, 105(8): 686-9.
Study Design	family-based
Study Type	Candidate-gene association study
Sample Size	206 trios
Predominant Ethnicity	Caucasian
Population	United Kingdom, Ireland
Gender	187 (91%) were male and 19 (9%) were female
Age Group	Children/Adolescents : 5-16 years (mean age: 10.5, SD=3.4)

Detail Info

Summary	Three known microsatellite markers (D15S165, D15S1043, and D15S1360) near the nicotinic acetylcholine alpha 7 receptor gene, CHRNA7, were studied in 206 ADHD parent-proband trios of children aged 5-16 with ADHD according to DSM-IV criteria. Children with known major medical or psychiatric conditions or mental retardation (IQ <70) were excluded from the study. Markers D15S165 and D15S1360 were in linkage disequilibrium. The extended Transmission Disequilibrium Test analyses demonstrated no evidence that variation at the microsatellite markers D15S1360, D15S1043, and D15S165 influences susceptibility to ADHD. However, it remains possible that the CHRNA7 gene and other nicotinic system genes may be involved in conferring susceptibility to ADHD.
Total Sample	The sample was recruited from several child psychiatry clinics in the U.K. and Ireland and consisted of 206 parent-proband trios. Probands were Caucasian born in the U.K. or Ireland and were aged 5-16 years (mean age=10.5, SD=3.4). Of the 206 probands, 187 (91%) were male and 19 (9%) were female.
Sample Collection	The sample was recruited from several child psychiatry clinics in the U.K. and Ireland.
Diagnosis Description	The sample was recruited from several child psychiatry clinics in the U.K. and Ireland and consisted of 206 parent-proband trios who were interviewed employing the Child and Adolescent Psychiatric Assessment (CAPA) [Angold et al., 1995]. Consistent interview procedures were employed across the four centers, with researchers from each center receiving a common training in the use of the CAPA All probands fulfilled DSM-IV [USAn Psychiatric Association, 1994] diagnostic criteria for ADHD. Of these, 83% were combined subtype, 7% were inattentive subtype, and 10% were hyperactive impulsive subtype.
Technique	High-molecular-weight genomic DNA was extracted from either whole blood or cheek swab according to routine procedures. PCR primers were labeled with either 6-Fam or Hex phophoramidites and amplified using true allele PCR mix (Applied Biosytems, Cheshire, U.K.). All genotyping was performed by the Birmingham laboratory.
Analysis Method	The extended Transmission Disequilibrium Test (TDT) [Sham and Curtis, 1995] was employed to test for association. Parental haplotypes between marker pairs were constructed where phase could be determined. Evidence for linkage disequilibrium between markers was examined by chi-square analysis in addition to calculating D, the coefficient of disequilibrium, and D', the normalized disequilibrium coefficient.
Result Description	The extended Transmission Disequilibrium Test analyses demonstrated no evidence that variation at the microsatellite markers D15S1360, D15S1043, and D15S165 influences susceptibility to ADHD. However, it remains possible that the CHRNA7 gene and other nicotinic system genes may be involved in conferring susceptibility to ADHD.

Other variant reported by this study (count: 3)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
CHRNA7 upstream D15S1360			TDT P-value=0.19, allele-wise X²=4.69, df=3 TDT P-value=0.19, allele-wise X²=4.69, df=3	The extended TDT analyses demonstrated no evidence that variation at the microsatellite marker influences susceptibility to ADHD	Non-significant
CHRNA7 upstream D15S165			TDT P-value=0.5, allele-wise X²=12.32, df=13 TDT P-value=0.5, allele-wise X²=12.32, df=13	The extended TDT analyses demonstrated no evidence that variation at the microsatellite marker influences susceptibility to ADHD	Non-significant
CHRNA7 upstream D15S1043			TDT P-value=0.31, allele-wise X²=5.97, df=5 TDT P-value=0.31, allele-wise X²=5.97, df=5	The extended TDT analyses demonstrated no evidence that variation at the microsatellite marker influences susceptibility to ADHD	Non-significant

Genes reported by this study (count: 1)