Polymorphisms of BDNF Gene and Autism Spectrum Disorders: Family Based Association Study with Korean Trios

OBJECTIVE: Autism spectrum disorders (ASDs) are a group of early childhood-onset neurodevelopmental disorders characterized by deficits in social interaction and language skills, and repetitive behaviors. Brain-derived neurotrophic factor (BDNF) plays a critical role in the differentiation of normal neuronal cells during embryonic and postnatal neuronal development through its neurotrophic effects. METHODS: In this study, we performed a family-based association test (FBAT) between single nucleotide polymorphisms (SNPs; rs6265, rs11030101, rs7103411, and rs7103873) or haplotypes in the BDNF gene and affection status or several quantitative traits characterized by ADI-R with151 Korean trios, including a child diagnosed as ASDs. RESULTS: While no significant association was found between SNPs or haplotypes and the ASDs disease status, a quantitative transmission disequilibrium test (QTDT) by using quantitative traits identified associations of the SNPs (rs6265 and rs11030101) with a domain score for "Restricted, Repetitive and Stereotyped patterns of behavior" (C domain), especially at the subdomain scores for "encompassing preoccupation or circumscribed pattern of interest" (C1) (rs6265A allele, dominant model, p-value=0.019; rs11030101 A allele, additive model, p-value=0.015) and "preoccupations with part of objects or non-functional elements of material" (C4) (rs11030101 A allele, additive model, p-value=0.015) within the ADI-R diagnostic algorithm. In addition, significant associations were also identified between the haplotypes and these quantitative traits (C1, p-value=0.016; C4, p-value=0.012). CONCLUSION: We conclude that BDNF gene polymorphisms have a possible role in the pathogenesis of ASDs.

A family-based association study of the autism and PTEN genes polymorphisms in children / 中华实用儿科临床杂志

Objective To explore the correlation of single nucleotide polymorphism (SNP) with PTEN gene involving in mammalian target of rapamycin (mTOR) C1 signaling genes polymorphisms and autism in children.Methods A total of 97 cases with autism were enrolled from Mar.2011 to Dec.2012 in this study,who came from the child and adolescent out-patient department in Shanghai Mental Health Center of Shanghai Jiaotong University School of Medicine.Single SNP association and haplotype association analysis were performed using the family-based association test and Haploview software.Results 1.In a family-based association test,two SNPs showed significant association with autism(rs17107001 G:Z =2.982,P =0.003 ; rs2299941 G:Z =2.524,P =0.012).After the correction of false discovery rate,they all remained significant.2.Haplotype association analysis showed significant transmission disequilibrium in haplotype T-T-G and C-T-A generated from rs532678-rs17562384-rs2299941 (block2) in LD Block,and haplotype T-T-G was over transmitted to offspring(Z =-2.986,P =0.003) while haplotype C-T-A was the opposite (Z =-2.197,P =0.028).Conclusion The SNPs of PTEN genes might have a correlation with autism in children.

Association of the Catechol-o-Methyltransferase Gene Polymorphisms with Korean Autism Spectrum Disorders

This study evaluated the family-based genetic association between autism spectrum disorders (ASDs) and 5 single-nucleotide polymorphisms (SNPs) in the catechol-o-methyltransferase gene (COMT), which was found among 151 Korean ASDs family trios (dominant model Z = 2.598, P = 0.009, P(FDR) = 0.045). We found a statistically significant allele transmission or association in terms of the rs6269 SNP in the ASDs trios. Moreover, in the haplotype analysis, the haplotypes with rs6269 demonstrated significant evidence of an association with ASDs (additive model rs6269-rs4818-rs4680-rs769224 haplotype P = 0.004, P(FDR) = 0.040). Thus, an association may exist between the variants of the COMT gene and the occurrence of ASDs in Koreans.

The Serotonin Transporter Gene Polymorphism in Korean Attention-Deficit/Hyperactivity Disorder Children

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.