Study Report
Basic Info
Reference |
Misener VL, 2004 (b)15365221
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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.
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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
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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 |
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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...
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TDT results showed no evidence for biased transmission of alleles of this polymorphism to the ADHD-affected children |
Non-significant
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Genes reported by this study (count: 1)
Gene |
Statistical Values/Author Comments |
Result of Statistical Analysis |
IL1RN |
TDT results for the intron 2 86bp VNTR polymorphism did not ......
TDT results for the intron 2 86bp VNTR polymorphism did not support a role for the IL1RN gene in ADHD
More...
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Non-significant
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