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	Barr CL, 199910581494
Citation	Barr C. L., Wigg K., Malone M., Schachar R., Tannock R., Roberts W. and Kennedy J. L. (1999) "Linkage study of catechol-O-methyltransferase and attention-deficit hyperactivity disorder." Am J Med Genet, 88(6): 710-3.
Study Design	family-based
Study Type	Candidate-gene association study
Sample Size	77 nuclear families
Predominant Ethnicity	96% Caucasian
Population	Canada
Age Group	Children/Adolescents : 7-16 years

Detail Info

Summary	In this study, they have tested for linkage in ADHD families using the functional polymorphism at codon 158 that determines COMT activity [Lachman et al., 1996] and analyzed the data with the transmission disequilibrium test (TDT). A total of 77 nuclear families collected from Toronto were genotyped. They find no evidence for linkage of this polymorphism and ADHD in their sample.
Total Sample	This sample consisted of 77 nuclear families consisting of 59 probands with both parents, 18 parent/child pairs, and 19 affected siblings.
Sample Collection	Subjects were recruited from referrals for clinical assessment of attention, behavior, and learning problems to two clinics at an urban pediatrics hospital.
Diagnosis Description	Children were included if they met DSM-IV criteria for one of the three ADHD subtypes (inattentive, hyperactive-impulsive, combined) and were excluded if they scored below 80 on both the Performance and Verbal Scales of the WISC-III, had evidence of neurological or complex medical illness, Tourette syndrome, chronic multiple tics, bipolar affective disorder, psychotic symptoms, or had a comorbid anxiety, depressive, or developmental disorder that could better account for the behaviors (as specified by DSM-IV).
Technique	Genomic DNA was extracted from whole blood as described [Miller et al., 1988]. The amplification of the COMT polymorphism was conducted using PCR.
Analysis Method	Following the assignment of genotypes for each individual, statistical analysis was performed using the extended TDT [Sham and Curtis, 1995].
Result Description	They find no evidence for linkage of rs4680 (COMT_Val158Met) and ADHD in their sample.

SNPs reported by this study (count: 1)

Genes reported by this study (count: 1)