OBJECTIVES: Dysregulation of the central noradrenergic system may be involved in the pathophysiology of attention-deficit hyperactivity disorder (ADHD). The aim of this study was to examine the differences in pre- and post-treatment cerebral perfusion according to the MspI polymorphisms of the alpha-2A-adrenergic receptor gene (ADRA2A) in children with ADHD. METHODS: Thirty seven drug-naive ADHD children (8.9+1.8 years old, M=32, F=5) were genotyped. Baseline single-photon emission computed tomography (SPECT) and clinical assessments were performed for ADHD children. After treatment with methylphenidate for eight weeks, SPECT and clinical assessment were repeated. RESULTS: No differences in baseline clinical assessments or cerebral perfusion were observed according to the MspI genotype. However, after treatment, ADHD children with the G/G genotype at the MspI polymorphism showed hyperperfusion in the right cerebellar declive (p=.001, uncorrected) and hypoperfusion in the left lentiform nucleus and left cingulate gyrus (p<.001 and p=.001, uncorrected), compared to children without the G/G genotype. CONCLUSION: Although the results of this study should be interpreted cautiously, they suggest a possible role of the MspI polymorphisms of the ADRA2A gene in methylphenidate-induced changes in cerebral perfusion.
Brain ; Child ; Corpus Striatum ; Genotype ; Gyrus Cinguli ; Humans ; Methylphenidate ; Perfusion ; Pharmacogenetics ; Receptors, Adrenergic, alpha-2 ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon

OBJECTIVE: The purpose of this study was to investigate the association between the T102C polymorphism in the serotonin 2A receptor gene and attention-deficit/hyperactivity disorder (ADHD) in Korean patients. METHODS: A total of 189 Korean children with ADHD as well as both parents of the ADHD children and 150 normal children participated in this study. DNA was extracted from blood samples from all of the subjects, and genotyping was conducted. Based on the allele and genotype information obtained, case-control analyses were performed to compare the ADHD and normal children, and Transmission disequilibrium tests (TDTs) were used for family-based association testing (number of trios=113). Finally, according to the significant finding which was showed in the case-control analyses, the results of behavioral characterastics and neuropsychological test were compared between ADHD children with and without the C allele. RESULTS: In the case-control analyses, statistically significant differences were detected in the frequencies of genotypes containing the C allele (chi2=4.73, p=0.030). In the family-based association study, TDTs failed to detect linkage disequilibrium of the T102C polymorphism associated with ADHD children. In the ADHD children, both the mean reaction time and the standard deviation of the reaction time in the auditory continuous performance test were longer in the group with the C allele compared to the group without the C allele. CONCLUSION: The results of this study suggest that there is a significant genetic association between the T102C polymorphism in the serotonin 2A receptor gene and ADHD in Korean children.
Alleles ; Case-Control Studies ; Child ; DNA ; Genotype ; Humans ; Linkage Disequilibrium ; Neuropsychological Tests ; Parents ; Reaction Time ; Receptor, Serotonin, 5-HT2A ; Serotonin

OBJECTIVE: Communication problems are a prevalent symptom of autism spectrum disorders (ASDs), which have a genetic background. Although several genome-wide studies on ASD have suggested a number of candidate genes, few studies have reported the association or linkage of specific endophenotypes to ASDs. METHODS: Forty-two Korean ASD patients who showed a language delay were enrolled in this study with their parents. We performed a genome-wide scan by using the Affymetrix SNP Array 5.0 platform to identify candidate genes responsible for language delay in ASDs. RESULTS: We detected candidate single-nucleotide polymorphisms (SNPs) in chromosome 11, rs11212733 (p-value=9.76x10(-6)) and rs7125479 (p-value=1.48x10(-4)), as a marker of language delay in ASD using the transmission disequilibrium test and multifactor dimensionality reduction test. CONCLUSION: Although our results suggest that several SNPs are associated with language delay in ASD, rs11212733 we were not able to observe any significant results after correction of multiple comparisons. This may imply that more samples may be required to identify genes associated with language delay in ASD.
Autistic Disorder ; Child ; Autism Spectrum Disorder ; Chromosomes, Human, Pair 11 ; Endophenotypes ; Genome-Wide Association Study ; Humans ; Language Development Disorders ; Multifactor Dimensionality Reduction ; Parents ; Polymorphism, Single Nucleotide

OBJECTIVES: This study was conducted to examine the prevalence and characteristics of savant skills and the relationship between the savant skills and autistic symptoms in Korean ASD children. METHODS: 141 ASD subjects participated in this study and they were divided in to two groups based on the presence or lack of savant skills. The domain scores and total scores of the K-ADI-R, K-ASDS and SRS were used for evaluating the ASD symptoms between the groups. RESULTS: Memory (n=47) was the most prevalent savant skill in the savant ASD group (n=60). The savant ASD group had a statistically higher mean age and IQ score than did the nonsavant ASD group. Despite their high IQ profile, the savant ASD group showed a higher restricted, repetitive and stereotype behavior score on the K-ADI-R and higher language and cognitive scores on the K-ASDS than did the nonsavant ASD group. CONCLUSIONS: These results suggest savant syndrome in ASD might be related to the severity of some subdomain of autistic symptoms even though their IQ scores were higher than nonsavant ASD patients.
Autistic Disorder ; Child ; Autism Spectrum Disorder ; Humans ; Memory ; Prevalence

OBJECTIVES: This study was conducted in order to develop and obtain the normative data of the computerized Comprehensive Attention Test (CAT) in Korean children and adolescents. It also aimed to evaluate the reliability and validity of the CAT. METHODS: We developed the computerized CAT which includes the selective attention task, the sustained attention to response task, the flanker task, the divided attention task, and the spatial working memory task. We investigated the testretest reliability and the construction validity of this computerized version by using the data from 21 children, and gathered the normative data of 912 subjects, aged 4 to 15 years, dwelling in the Metropolitan Seoul area in 2008. RESULTS: No statistical differences between means of the tests and retests of the CAT were observed. The mean of the correlation coefficient of the test-retest scores was 0.715. The results from the factor analyses explained 51.7% of the cumulative variance. In addition, the normative data for all of the CAT subtests were obtained. CONCLUSION: The computerized CAT can be used as a reliable and valid tool in both clinical and research settings for Korean children and adolescents with or without neuropsychiatric conditions such as attention deficit.
Adolescent ; Aged ; Animals ; Cats ; Child ; Humans ; Memory, Short-Term ; Reproducibility of Results

OBJECTIVES: The aim of this study was to investigate the association between Korean ADHD patients and the l/s polymorphism of serotonin transporter(5-HTTLPR). METHODS: The study sample consisted of 189 Korean ADHD children diagnosed by Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version(K-SADS-PL), both parents of ADHD children, and 150 normal children. DNA were extracted from the blood of all samples, and genotyping was done. Based on the allele and genotype information, not only the case-control analysis between ADHD and normal children but also the family-based association test among ADHD children and their parents. Transmission disequilibrium test(TDT) were performed for family-based associated test(number of trio=113). The results of the clinical rating and neuropsychological tests were compared according to the l/s genotype of ADHD children. RESULTS: In case-control analysis, there were no statistically significant difference of l/s gene polymorphism between ADHD and normal children in various kinds of analysis condition. In family-based association study, TDT failed to detect linkage disequilibrium between l/s gene polymorphism and ADHD in whole ADHD families. However, in the families of ADHD inattentive type only(number of trio=23), l allele was transmitted more preferentially in the proband with ADHD even if the number of families was small(chi-square=4.57, p=.032). In the analysis of the results from the clinical scales and neuropsychological tests in ADHD children, the score of the Novelty- Seeking of ADHD children with l/l genotype was significantly lower than with the other genotypes(F=3.15, p=.047), and that of Self Transcendence was significantly higher(F=4.25, p=.017). CONCLUSION: The results of this study suggest there were no significant genetic association between the 5- HTTLPR gene polymorphism and Korean ADHD.
Alleles ; Case-Control Studies ; Child ; DNA ; Genotype ; Humans ; Linkage Disequilibrium ; Mood Disorders ; Neuropsychological Tests ; Parents ; Serotonin ; Serotonin Plasma Membrane Transport Proteins ; Weights and Measures

BACKGROUND AND OBJECTIVES: Recent works have demonstrated the existence of ocular vestibular evoked myogenic potentials (OVEMPs), which reflects otolith-ocular reflex. The purpose of this study was to identify an appropriate gaze position to detect OVEMPs produced by air-conducted sound stimulation in healthy subjects. SUBJECTS AND METHOD: Twenty four healthy subjects (35 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used to activate the vestibular end-organs. RESULTS: Sound stimulation evoked negative-positive biphasic responses on both ipsilateral and contralateral eyes, while responses were contralateral eye-dominant. Contralateral eye responses had higher response incidence and larger amplitudes. Altering the direction of gaze generally changed the incidence and size of the inter-peak amplitudes. The higher incidence and larger amplitudes were recorded when the eyes are directed to the superior and ipsilateral side to the sound stimulation. In that gaze position, the amplitude was 5.3 micronV, the first negative peak latency was 10.5 ms and the following positive peak latency was 15.4 ms on the average. CONCLUSION: OVEMPs can be evoked using an air-conducted 500 Hz tone burst and are best recorded contralaterally with a upward gaze towards the source of sound stimulation. Further changes of the test parameters are needed for higher and consistent responses.
Electrodes ; Evoked Potentials ; Eye ; Incidence ; Reflex ; Reflex, Vestibulo-Ocular ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials

BACKGROUND AND OBJECTIVES: The ocular vestibular evoked myogenic potential (OVEMP) is a recently discovered test of labyrinthine function, analogous to the cervical VEMP. Recent works have demonstrated the existence of OVEMPs, which likely reflect otolith-ocular reflex. The purpose of this study was to identify the optimal plateau and rise/fall times of short tone bursts to detect OVEMPs in healthy subjects. MATERIALS AND METHODS: Thirteen healthy subjects (26 ears) were included in this study. Surface electromyographic activity was recorded from active electrodes placed inferior to each eye. Stimulation with 500 Hz short tone bursts was used. We used a variety of plateau and rise/fall times. Three different plateau times (1, 2, and 3 ms) and rise/fall times (0.5, 1, and 2 ms) were used. The incidence, amplitudes and latencies were compared. RESULTS: VEMP responses were clearly observed in all 26 ears at the plateau time of 2 ms and two rise/fall times (0.5 and 1 ms). The amplitudes in the individual ears tested were lower at the rise/fall time of 2 ms than at the other conditions. The amplitudes were lower at the plateau time of 3 ms compared to the other conditions. When the rise/fall time was prolonged from 0.5 to 2 ms, the n1 and p1 latencies were prolonged in parallel. However, there was no such change in latencies according to the plateau times. CONCLUSIONS: Our findings show that the ideal stimulation pattern for evoking OVEMP is at the rise/fall times of 0.5 or 1 ms and the plateau time of 2 ms. The waveform morphology of the VEMP responses observed with this stimulation pattern was simultaneously the most constant and marked.
Ear ; Electrodes ; Evoked Potentials ; Eye ; Incidence ; Otolithic Membrane ; Reflex ; Reflex, Vestibulo-Ocular ; Vestibular Evoked Myogenic Potentials

OBJECTIVES: Neurobiological and pharmacological research has suggested that the dysregulation of the central noradrenergic systems might be involved in the pathophysiology of ADHD. The aim of this study was to examine the association of the alpha- 1C-adrenergic receptor gene (ADRA1C) with ADHD in Korean subjects. METHODS: In a case-control study, we assessed 186 DSM-IV ADHD probands and 150 normal controls. One hundred and eight trios were studied in a family-based association analysis. Psychiatric diagnoses were derived through structured diagnostic interviews. For the clinical evaluation of the ADHD subjects, the Child Behavior Checklist (CBCL), the ADHD Rating Scale-IV (ARS) and the Junior Temperament and Character Inventory (JTCI) were administered. A computerized continuous performance test (CPT) was used to measure the inattention and impulsivity of the ADHD children. RESULTS: There were no significant differences in the genotype or allele frequencies of the ADRA1C PstI polymorphism between the ADHD and control group (p<0.05). The transmission disequilibrium test (TDT) analysis observed no evidence for biased transmission of any of the alleles of the PstI polymorphism. There were no significant differences in the CPT or JTCI profiles between those ADHD subjects with the CC genotype and those with the other (CT+TT) genotypes at the PstI polymorphism. CONCLUSION: The results of this study do not support the ADRA1C as a major genetic susceptibility factor in ADHD.
Alleles ; Attention Deficit Disorder with Hyperactivity ; Bias (Epidemiology) ; Case-Control Studies ; Checklist ; Child ; Child Behavior ; Diagnostic and Statistical Manual of Mental Disorders ; Endophenotypes ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Temperament

OBJECTIVES: The aim of the current study is to test for the association of DRD4 exon III VNTR polymorphism with attention-deficit hyperactivity disorder(ADHD) in Korean children population. METHODS: 113 Korean children with ADHD, 102 parents, and 133 control subjects participated with the current study. The distribution of genotypes and alleles of DRD4 exon III VNTR in children with ADHD was compared with that in control subjects. In addition, 69 children with ADHD and their parents were analyzed using the transmission disequilibrium test(TDT). RESULTS: We could not find any significant differences in the distribution of genotypes and alleles at DRD4 exon III VNTR polymorphism between children with ADHD and control subjects. In addition, there was no preferential transmission of long allele of DRD4 exon III VNTR polymorphism. CONCLUSION: These results suggest that DRD4 is not associated with ADHD in Korean children population.
Alleles ; Child* ; Exons* ; Genetic Association Studies ; Genotype ; Humans ; Parents