Project description:Autism spectrum disorder(ASD) is a complex neurodevelopmental disorder. Aberrant DNA methylation has been observed in ASD but the mechanisms remain largely unknown. Here, we employed discordant monozygotic twins to investigate the contribution of DNA methylation to ASD etiology. Genome-wide DNA methylation analysis was performed using samples obtained from five pairs of ASD-discordant monozygotic twins, which revealed a total of 2397 differentially methylated genes. Further, such gene list was annotated with Kyoto Encyclopedia of Genes and Genomes and demonstrated predominant activation of neurotrophin signaling pathway in ASD-discordant monozygotic twins. The methylation of SH2B1 gene was further confirmed in the ASD-discordant, ASD-concordant monozygotic twins, and a set of 30 pairs of sporadic case-control by bisulfite-pyrosequencing. The results showed that there was a greater DNA methylation difference in ASD-discordant monozygotic twins than ASD-concordant monozygotic twins. Further, verification of the Chr.16:28856743 of SH2B1 showed significant differences in DNA methylation between case and control. These results suggest abnormal methylation of SH2B1 is associated with ASD etiology. Our data suggest that it might be worthwhile to further explore the functions of SH2B1 and related genes of neurotrophin signaling pathway in ASD.
Project description:Autism spectrum disorder(ASD) is a complex neurodevelopmental disorder. Aberrant DNA methylation has been observed in ASD but the mechanisms remain largely unknown. Here, we employed discordant monozygotic twins to investigate the contribution of DNA methylation to ASD etiology. Genome-wide DNA methylation analysis was performed using samples obtained from five pairs of ASD-discordant monozygotic twins, which revealed a total of 2397 differentially methylated genes. Further, such gene list was annotated with Kyoto Encyclopedia of Genes and Genomes and demonstrated predominant activation of neurotrophin signaling pathway in ASD-discordant monozygotic twins. The methylation of SH2B1 gene was further confirmed in the ASD-discordant, ASD-concordant monozygotic twins, and a set of 30 pairs of sporadic case-control by bisulfite-pyrosequencing. The results showed that there was a greater DNA methylation difference in ASD-discordant monozygotic twins than ASD-concordant monozygotic twins. Further, verification of the Chr.16:28856743 of SH2B1 showed significant differences in DNA methylation between case and control. These results suggest abnormal methylation of SH2B1 is associated with ASD etiology. Our data suggest that it might be worthwhile to further explore the functions of SH2B1 and related genes of neurotrophin signaling pathway in ASD.
Project description:The Nicotine Metabolic Ratio (NMR), the ratio of two stable metabolites of nicotine, cotinine and trans-3’hydroxycotinin, is a determinant of the number of cigarettes smoked per day (CPD), of smoking topography, responsiveness to treatment via transdermal nicotine for smoking cessation, and carcinogen activation and level. The predominant gene involved in nicotine metabolism is CYP2A6, a highly polymorphic locus located in a cluster of P450 cytochrome protein loci on chr19q13. A recent study comprehensively modeling CYP2A6 genetic variation at seven polymorphisms and a related Nicotine Metabolic Ratio, the cotinine: cotinine+nicotine ratio, explains 72% of NMRC/C+N variation. These results suggest that additional genes may be contributing to nicotine and cotinine metabolism directly or via interaction with CYP2A6 or other genes. To identify additional genes that may influence the NMR, we conducted a genome-wide gene expression analysis of lymphoblastoid cell line (LCL) gene expression in a sample of monozygotic twins discordant for the NMR.
Project description:This SuperSeries is composed of the following subset Series: GSE33476: Expression data from phenotypically discordant monozygotic twin lymphoblasts GSE33477: Analysis of genome-wide methylation of phenotypically discordant monozygotic twins Refer to individual Series
Project description:The exploration of copy number variation (CNV), notably of somatic cells, is an understudied aspect of genome biology. Any differences in the genetic make-up between twins derived from the same zygote represent an extreme example of somatic variation. We studied 19 pairs of monozygotic twins with either concordant or discordant phenotype using two platforms for genome-wide CNV analyses and show that CNVs exist within pairs in both groups. These findings impact our views of genotypic and phenotypic diversity in monozygotic twins, and suggest that CNV analysis in phenotypically discordant monozygotic twins may provide a powerful tool in identifying disease predisposition loci. Our results also imply that caution should be exercised with the interpretation of disease causality of de novo CNVs found in patients based on analysis of a single tissue in routine disease-related DNA diagnostics Keywords: copy number variation, concordant and discordant monozygotic twins
Project description:The aim of the current study is to establish the effect of excess body wiehgt and liver fat on plasma proteomic profile without interference from genetic variation. Label-free proteomics (HDMSE) was performed on plasma samples of young healthy monozygotic twins who were discordant for BMI. the twins were further subdivided into groups of liver fat discordant and liver fat concordant to see the efefct fo liver fat on plasma proteomic signature.
Project description:The exploration of copy number variation (CNV), notably of somatic cells, is an understudied aspect of genome biology. Any differences in the genetic make-up between twins derived from the same zygote represent an extreme example of somatic variation. We studied 19 pairs of monozygotic twins with either concordant or discordant phenotype using two platforms for genome-wide CNV analyses and show that CNVs exist within pairs in both groups. These findings impact our views of genotypic and phenotypic diversity in monozygotic twins, and suggest that CNV analysis in phenotypically discordant monozygotic twins may provide a powerful tool in identifying disease predisposition loci. Our results also imply that caution should be exercised with the interpretation of disease causality of de novo CNVs found in patients based on analysis of a single tissue in routine disease-related DNA diagnostics Analysis of copy number variability in concordant healthy monozygotic twin pairs as well as three monozygostic twin pairs discordant a Parkinsons disease (PD) phenotype using the Illumina HumanHap 300 dead chips. Keywords: SNP data