Association between Dopamine D4 Receptor Gene Polymorphism and Scores on a Continuous Performance Test in Korean Children with Attention Deficit Hyperactivity Disorder.

Abstract

OBJECTIVE:

The aim of this study was to evaluate the association between a variable number of tandem repeats polymorphism at the dopamine D4 receptor gene (DRD4) and the performance of children with attention deficit hyperactivity disorder (ADHD) in a continuous performance test (CPT).

METHODS:

This study included 72 ADHD children (mean age=9.39+/-2.05 years) who were recruited from one child psychiatric clinic. The omission errors, commission errors, reaction time and reaction standardization in the CPT were computed. The number of 48-base pairs tandem repeats in the exon III of DRD4 was analyzed in a blind manner.

RESULTS:

The homozygosity of the 4-repeat allele at DRD4 was significantly associated with fewer commission errors (t=2.364, df=28.685, p=0.025) and standard deviation of reaction time (t=2.351, df=24.648, p=0.027) even after adjusting for age. The results of analyses of CPT measured values among three groups showed that the group with higher frequency of the 4-repeat allele showed a lower mean score of commission errors (F=4.268, df=2, p=0.018).

CONCLUSION:

These results suggest a protective role of 4-repeat allele of the DRD4 polymorphisms on commission errors in the CPT in children with ADHD.

• Authors: Bora Kim, Min-Seong Koo, Jin-Yong Jun, Il Ho Park, Dong-Yul Oh, Keun-Ah Cheon
• Journal: Psychiatry investigation (Psychiatry Investig) Vol. 6 Issue 3 Pg. 216-21 (Sep 2009) ISSN: 1976-3026 [Electronic] Korea (South)
• PMID: 20046398 (Publication Type: Journal Article)