Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/9594
Appears in Collections:Management, Work and Organisation Journal Articles
Peer Review Status: Refereed
Title: Absence of the 7-repeat variant of the DRD4 VNTR is associated with drifting sustained attention in children with ADHD but not in controls
Authors: Johnson, Katherine A
Kelly, Simon P
Robertson, Ian H
Barry, Edwina
Mulligan, Aisling
Daly, Michael
Lambert, David
McDonnell, Caroline
Connor, Thomas J
Hawi, Ziarih
Gill, Michael
Bellgrove, Mark A
Contact Email: michael.daly@stir.ac.uk
Keywords: endophenotype
response variability
reaction time
executive function
dopamine
Issue Date: 5-Sep-2008
Publisher: Wiley-Blackwell
Citation: Johnson KA, Kelly SP, Robertson IH, Barry E, Mulligan A, Daly M, Lambert D, McDonnell C, Connor TJ, Hawi Z, Gill M & Bellgrove MA (2008) Absence of the 7-repeat variant of the DRD4 VNTR is associated with drifting sustained attention in children with ADHD but not in controls, American Journal of Medical Genetics Part B: Neuropsychiatric Genetics, 147B (6), pp. 927-937.
Abstract: Many genetic studies have demonstrated an association between the 7-repeat (7r) allele of a 48-base pair variable number of tandem repeats (VNTR) in exon 3 of the DRD4 gene and the phenotype of attention deficit hyperactivity disorder (ADHD). Previous studies have shown inconsistent associations between the 7r allele and neurocognitive performance in children with ADHD. We investigated the performance of 128 children with and withoutADHDon the Fixed and Random versions of the Sustained Attention to Response Task (SART). We employed timeseries analyses of reaction-time data to allow a fine-grained analysis of reaction time variability, a candidate endophenotype for ADHD. Children were grouped into either the 7r-present group (possessing at least one copy of the 7r allele) or the 7r-absent group. The ADHD group made significantly more commission errors and was significantly more variable in RT in terms of fast moment-to-moment variability than the control group, but no effect of genotype was found on these measures. Children with ADHD without the 7r allele made significantly more omission errors, were significantly more variable in the slow frequency domain and showed less sensitivity to the signal (d') than those children with ADHD the 7r and control children with or without the 7r. These results highlight the utility of time-series analyses of reaction time data for delineating the neuropsychological deficits associated with ADHD and the DRD4 VNTR. Absence of the 7-repeat allele in children with ADHD is associated with a neurocognitive profile of drifting sustained attention that gives rise to variable and inconsistent performance.
Type: Journal Article
URI: http://hdl.handle.net/1893/9594
DOI Link: http://dx.doi.org/10.1002/ajmg.b.30718
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Affiliation: Trinity College, Dublin
Nathan S. Kline Institute, New York
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Socio-Management
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin

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