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Possible association of the alpha‐2A‐adrenergic receptor gene with response time variability in attention deficit hyperactivity disorder
Author(s) -
Cho SooChurl,
Kim JaeWon,
Kim BoongNyun,
Hwang JunWon,
Park Mira,
Kim Soon Ae,
Cho DaeYeon,
Yoo HeeJeong,
Chung UnSun,
Son JungWoo,
Park TaeWon
Publication year - 2008
Publication title -
american journal of medical genetics part b: neuropsychiatric genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.393
H-Index - 126
eISSN - 1552-485X
pISSN - 1552-4841
DOI - 10.1002/ajmg.b.30725
Subject(s) - haplotype , genotype , allele , transmission disequilibrium test , polymorphism (computer science) , endophenotype , genetics , neurocognitive , medicine , biology , gene , neuroscience , cognition
Previous studies have demonstrated that the Msp I and Dra I polymorphisms at the alpha‐2A‐adrenergic receptor gene (ADRA2A) are associated with ADHD. However, few studies have been designed to ascertain the association between the ADRA2A genotypes and the performance on neurocognitive measures in ADHD. The aims of this study were to examine the association of the ADRA2A Msp I and Dra I polymorphisms with ADHD in Korean subjects, and to determine the relationship between the genotypes of these two polymorphisms and the candidate endophenotypes, as measured by the continuous performance test (CPT). In a case–control study, we assessed 186 ADHD probands and 150 normal controls. One hundred eight trios were studied in a family based association analysis. The transmission disequilibrium test (TDT) analysis showed preferential transmission of the C allele of the Dra I polymorphism ( χ 2 = 5.88, P = 0.015). In the haplotype analyses, a trend of over‐transmission of haplotype C/C was observed ( χ 2 = 3.80, P = 0.051). The homozygous subjects for the C allele (C/C genotype) at the Dra I polymorphism showed a trend toward a higher mean T‐score with respect to the response time variability profiles of the CPT than did those with the other genotypes (C/T + T/T genotypes; P = 0.042). The homozygous subjects for the G allele (G/G genotype) at the Msp I polymorphism showed a tendency to have a lower mean T‐score with respect to the response time variability profiles of the CPT ( P = 0.068). The results of this study provide important evidence for the involvement of the ADRA2A Msp I and Dra I polymorphisms in the etiology of ADHD in Korean subjects. In addition, our results provide evidence for the possible role of these two polymorphisms in ADHD symptom expression, such as increased response time variability. © 2008 Wiley‐Liss, Inc.