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	Misener VL, 2004 (b)15365221
Citation	Misener V. L., Schachar R., Ickowicz A., Malone M., Roberts W., Tannock R., Kennedy J. L., Pathare T. and Barr C. L. (2004) "Replication test for association of the IL-1 receptor antagonist gene, IL1RN, with attention-deficit/hyperactivity disorder." Neuropsychobiology, 50(3): 231-4.
Study Design	family-based
Study Type	Candidate-gene association study
Sample Size	178 families with 220 children
Predominant Ethnicity	Caucasian
Population	Canada
Age Group	Children/Adolescents : 7-16 years

Detail Info

Summary	Recently, Segman et al. tested the IL-1Ra gene, IL1RN, as a candidate for involvement in ADHD. Using the transmission/disequilibrium test (TDT) to examine 77 nuclear ADHD families for the inheritance of alleles of an intronic 86-bp VNTR polymorphism, they found significant evidence for biased transmission of the 4-repeat allele and non-transmission of the 2-repeat allele. Here, they sought to replicate this in an independent sample of families. In contrast to the previous findings, their analysis of 178 ADHD families showed no evidence for biased transmission of these alleles. Their lack of evidence for association of this IL1RN polymorphism with ADHD, based on a much larger sample of families, suggests that the original finding may have been a spurious result.
Total Sample	In this study, 178 nuclear families ascertained through an ADHD proband were analyzed. In addition to the probands, 42 affected siblings were also identifi ed, giving a total of 220 children in the study.
Sample Collection	Probands and their affected siblings were ascertained through the Child Development and Neuropsychiatry Clinics at the Hospital for Sick Children in Toronto.
Diagnosis Description	Subject assessment and diagnostic criteria for inclusion in this study are described in detail elsewhere. The children were between 7 and 16 years of age and met DSM-IV criteria for ADHD, as determined through clinical assessment and interviews with both parents and teachers.
Technique	DNA was extracted from peripheral blood using a high salt extraction method, and genotyped by PCR using primers flanking the IL1RN intron 2 86-bp VNTR site.
Analysis Method	TDT analysis was carried out using the extended TDT (ETDT) program.
Result Description	In contrast to the previous findings, their analysis of 178 ADHD families showed no evidence for biased transmission of these alleles (p=0.81 and p=1.00, respectively). Their lack of evidence for association of this IL1RN polymorphism with ADHD, based on a much larger sample of families, suggests that the original finding may have been a spurious result.

Other variant reported by this study (count: 1)

Variant Name	Allele Change	Risk Allele	Statistical Values	Author Comments	Result of Statistical Analysis
IL1RN intron2 VNTR			TDT two-sided P-value=0.813, X²=0.056, df=1 for 4...... TDT two-sided P-value=0.813, X²=0.056, df=1 for 4 repeat allele; TDT two-sided P-value=1.00, X²=0.00, df=1, for 2 repeat allele; TDT two-sided P-value=0.491, X²=0.474, df=1 for 5 repeat allele More...	TDT results showed no evidence for biased transmission of alleles of this polymorphism to the ADHD-affected children	Non-significant

Genes reported by this study (count: 1)