ABSTRACT
OBJECTIVES: The aim of our study was to investigate association of norepinephrine transporter gene (SLC6A2) polymorphism and side effects of osmotic-release oral system methylphenidate (OROS MPH) in children with attention-deficit hyperactivity disorder (ADHD). METHODS: We recruited drug naive children with ADHD (N=97). We administered OROS MPH by tolerable dosage. At week 8 of treatment, parents completed the Barkley's side effect rating scale. We analyzed two SLC6A2 single nucleotide polymorphisms (SNPs), rs192303 and rs3785143, with blood of subjects. We compared the frequency and severity of each side effect among SLC6A2 genotypes of 2 SNPs. RESULTS: In the analysis of frequency of each side effect, irritability differed according to rs192303 and rs3785143 genotype. In comparisons of severity, talking less and disinterest differed according to rs192303 genotype. In the case of rs3785143, severities of disinterest and irritability were involved with genotype. CONCLUSION: Side effects of OROS MPH showed an association with SLC6A2 genotype.
Subject(s)
Child , Humans , Genotype , Methylphenidate , Norepinephrine Plasma Membrane Transport Proteins , Parents , Polymorphism, Single NucleotideABSTRACT
OBJECTIVES: This study aimed to examine the association between norepinephrine transporter gene (SLC6A2) polymorphisms and attention-deficit hyperactivity disorder (ADHD) and to examine the relationship between the genotypes and allele variants of SLC6A2 and results of the Korean version of the parent ADHD rating scale (K-ARS). METHODS: We examined the association between ADHD and norepinephrine transporter gene polymorphism using DNA from 137 Korean children with ADHD and 120 normal controls. We compared the genotype distributions and allele frequencies of SLC6A2 polymorphism between the control group and the ADHD group. Then, we correlated the children's K-ARS mean totals, inattention scores, and hyperactivity/impulsivity scores with the genotypes and alleles for each SLC6A2 polymorphism. RESULTS: There were no significant differences in genotype and allele distribution for each SLC6A2 polymorphism, as shown by the Chi-square test (p>.01). There was a trend toward a difference in allele frequency in rs 5568, but it was not statistically significant after adjusting for multiple comparisons (p=.048). Also, there were no significant differences in K-ARS scores according to the genotypes and alleles for the SLC6A2 polymorphisms. CONCLUSION: Our study found no significant evidence of an association between SLC6A2 polymorphisms and ADHD.