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ObjectiveCommunication 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.MethodsForty-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.ResultsWe detected candidate single-nucleotide polymorphisms (SNPs) in chromosome 11, rs11212733 (p-value=9.76×10-6) and rs7125479 (p-value=1.48×10-4), as a marker of language delay in ASD using the transmission disequilibrium test and multifactor dimensionality reduction test.ConclusionAlthough 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.

BackgroundDysregulation of noradrenergic system may play important roles in pathophysiology of attention-deficit/hyperactivity disorder (ADHD). We examined the relationship between polymorphisms in the norepinephrine transporter SLC6A2 gene and attentional performance before and after medication in children with ADHD.MethodsFifty-three medication-naïve children with ADHD were genotyped and evaluated using the continuous performance test (CPT). After 8-weeks of methylphenidate treatment, these children were evaluated by CPT again. We compared the baseline CPT measures and the post-treatment changes in the CPT measures based on the G1287A and the A-3081T polymorphisms of SLC6A2.ResultsThere was no significant difference in the baseline CPT measures associated with the G1287A or A-3081T polymorphisms. After medication, however, ADHD subjects with the G/G genotype at the G1287A polymorphism showed a greater decrease in the mean omission error scores (p = 0.006) than subjects with the G/A or A/A genotypes, and subjects with the T allele at the A-3081T polymorphism (T/T or A/T) showed a greater decrease in the mean commission error scores (p = 0.003) than those with the A/A genotypes.ConclusionsOur results provide evidence for the possible role of the G1287A and A-3081T genotypes of SLC6A2 in methylphenidate-induced improvement in attentional performance and support the noradrenergic hypothesis for the pathophysiology of ADHD.

Objective：A significant proportion of children with autism spectrum disorders (ASD) have regression characterized by loss of previously acquired skills. The purpose of this study was to compare demographic, clinical characteristics and autism-related symptomatology of the children who have regression with children who don't have regression.Methods：The subjects with ASD and their unaffected siblings (SIB) were recruited from the Korean Autism Genetic Study Consortium. Typically developing children (TC) were volunteered from community. The subjects were administered the Korean version of Autism Diagnostic Interview-Revised (K-ADI-R) and the Korean version of Autism Diagnostic Observation Schedule (K-ADOS) to diagnose or exclude ASD. Regression was defined on the basis of K-ADI-R data. The Korean version of Vineland Adaptive Behavior Scale (K-VABS), Aberrant Behavior Checklist (K-ABC) and Social Responsiveness Scale (K-SRS) were obtained from their parents.Results：Regression occurred in 8.33% (n=14) of children with ASD (n=168). Any SIB (n=166) and TC (n=53) did not experience regression. Regression was associated with lower IQ and lower score of K-VABS. There was no difference in autism symptom severity and K-ABC, K-SRS scores, between children with ASD who experienced regression and who did not.Conclusion：Regression seems to be a distinctive feature of ASD. Regression is associated with cognitive and more general functions, rather than symptoms specific to autism. KEY WORDS：Autism Spectrum DisordersㆍRegressionㆍAutism Diagnostic Interview-Revised.

The authors examined the association between the MspI C/G and DraI C/T genotypes of the a 2A -adrenergic receptor gene and white-matter connectivity and attentional performance before and after medication in 53 children with attentiondeficit hyperactivity disorder. Subjects who carried the T allele at the DraI polymorphism showed fewer changes in the mean commission error scores after 8 weeks of medication and decreased fractional anisotropy (FA) values in the right middle frontal cortex than subjects without the T allele. Subjects with the C allele at the MspI polymorphism showed decreased FA values in the right postcentral gyrus than subjects without.(The Journal of Neuropsychiatry and Clinical Neurosciences 2013; 25:222-228) A ttention-deficit hyperactivity disorder (ADHD) is a disorder primarily characterized by inattention, impulsivity, and hyperactivity, with a prevalence of 5.3%.1 It has an estimated heritability of approximately 76% and is thought to be a complex, polygenic disorder.2