한국인 주의력결핍 과잉행동장애 아동에서 도파민 D4 수용체 유전자의 Variable Number of Tandem Repeats (VNTR) 다형성과 Methylphenidate 치료 반응간의 연관성

Association of Dopamine D4 Receptor Gene(DRD4) VNTR Polymorphism and Response to Methylphenidate Treatment in Korean ADHD Children

Objectives：In the present study, we investigate the association between homozygosity of the 4-repeat allele (4/4) at the DRD4 and the response to the treatment with MPH in Korean children with ADHD. Methods：The present study included 71 children with ADHD (8.231.78 years) from two children’s psychiatric clinics in South Korea. All drug-naive children with ADHD were treated with MPH for about 8 weeks. The subjects who showed improvement of over 50% compared with the baseline ARS score after 8 weeks of treatment were termed as the ‘good response’ group. The subjects who showed an improvement of less than 50% were considered as the ‘poor response’ group. After genotyping for DRD4 were performed, we investigated correlation between homozygosity for 4-repeat allele at DRD4 and the response to MPH treatment. Results：We found that while 79.5% (31/39) of the subjects with homozygosity of 4-repeat allele at DRD4 showed good response to MPH treatment, 68.8% (22/32) of the subjects without homozygosity of 4-repeat allele at DRD4 showed poor response to MPH treatment according to ARS scores assessed by their parents (χ2=16.762, df=1, p<0.01). We also found that while 61.5% (24/39) of the subjects with homozygosity of4-repeat allele at DRD4 showed good response to MPH treatment, 87.5% (28/32) of the subjects without homozygosity of the 4-repeat allele at DRD4 showed poor response to MPH treatment according to ARS scores assessed by their teachers (χ2=17.698, df=1, p<0.01). Conclusion：Our findings support an association between the homozygosity of 4-repeat allele and a good response to MPH in ADHD of Koreans