Psychiatry Investig.  2009 Sep;6(3):216-221.

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

• Kim B
• Koo MS
• Jun JY
• Park IH
• Oh DY
• Cheon KA

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.

Keyword

Attention deficit hyperactivity disorder; Continuous performance test; Dopamine D4 receptor; 4 repeats allele; Commission errors

MeSH Terms

Alleles
Attention Deficit Disorder with Hyperactivity
Child
Dopamine
Exons
Humans
Minisatellite Repeats
Reaction Time
Receptors, Dopamine D4
Tandem Repeat Sequences
Dopamine
Receptors, Dopamine D4