Association between GABA3 Gene Polymorphisms and Attention Deficit Hyperactivity Disorder in Korean Children

OBJECTIVE Attention deficit hyperactivity disorder (ADHD) is common disorder of the school-age population. ADHD is familial and genetic studies estimate heritability at 80-90%. The aim of the present study was to investigate the association between the genetic type and alleles for gamma-aminobutyric acid receptor subunit beta-3 (GABA3) gene in Korean children with ADHD. METHODS The sample consisted of 180 ADHD children and 159 control children. We diagnosed ADHD according to DSM-IV. ADHD symptoms were evaluated with Conners' Parent Rating Scales and Dupaul Parent ADHD Rating Scales. Blood samples were taken from the 339 subjects, DNA was extracted from blood lymphocytes, and PCR was performed for GABA3 rs2081648, rs1426217 and rs981778 Polymorphism. Alleles and genotype frequencies were compared using the chi-square test. We compared the allele and genotype frequencies of GABA3 gene polymorphism in the ADHD and control groups. RESULTS This study showed that there was a significant correlation among the frequencies of the rs2081648 (OR=0.71, 95% CI=0.51-0.98, p=0.040) of alleles of MAO, but the final conclusions are not definite. Follow up studies with larger patient or pure subgroups are expected. CONCLUSION These results suggested that GABA3 might be related to ADHD symptoms.