Effect of the Dopamine D2 Receptor T Allele on Response Latency After Mild Traumatic Brain Injury

Section of Neuropsychiatry, Department of Psychiatry, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH 03756. .
American Journal of Psychiatry (Impact Factor: 12.3). 10/2005; 162(9):1749-51. DOI: 10.1176/appi.ajp.162.9.1749
Source: PubMed


The authors tested the hypothesis that the dopamine D2 receptor T allele (formerly described as the A1 allele) would be associated with poorer performance on memory and attention tasks following mild traumatic brain injury.
Thirty-nine patients with mild traumatic brain injury and 27 comparison subjects were genotyped. All subjects completed memory and attention tests, including the California Verbal Learning Test recognition task and the Continuous Performance Test.
In both groups the T allele was associated with poorer performance on the California Verbal Learning Test recognition task. There was also a significant diagnosis-by-allele interaction on measures of response latency (Continuous Performance Test): the subjects with mild traumatic brain injury and the T allele had the worst performance.
Genetic polymorphisms modulating central dopaminergic tone can affect cognitive outcome following mild traumatic brain injury.

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Available from: C. Harker Rhodes, Sep 01, 2015
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    • "The presence of a single copy of the A1 allele (A1+) is associated with a 30–40% reduction in D2 receptor density [38]; but see [39] and reduced cognitive performance when compared to participants lacking this polymorphism (A1−). Carriers of the A1 allele perform worse on the California Verbal Learning Test of memory [40], [41] and other cognitive tasks (reviewed in [20], [42]. "
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    • "This suggests that individuals in whom the number of D2 receptors is smaller due to genetic variation might perform less well on similar mnemonic tasks. Consistent with this suggestion, individuals with the T allele have been found to have lower levels of recognition memory performance on the California Verbal Learning Test, relative to individuals without this genetic variation (McAllister et al., 2005). "
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