Project description:This is the first high-throughput analysis of DNA methylation in autoimmune diseases. We have used a cohort of MZ twins discordant for three diseases whose clinical signs often overlap: systemic lupus erythematosus (SLE), rheumatoid arthritis and dermatomyositis. Only MZ twins discordant for SLE featured widespread changes in the DNA methylation status of a significant number of genes. Individual analysis confirmed the existence of DNA methylation and expression changes in genes relevant to SLE pathogenesis. Our findings not only identify potentially relevant DNA methylation markers for the clinical characterization of SLE patients but also support the notion that epigenetic changes may be critical in the clinical manifestations of autoimmune disease. Total DNA isolated by standard procedures from 59 White Blood Cell (WBC) samples corresponding to monozygotic twins discordant for three different autoimmune diseases: systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and dermatomyositis (DM) and two additional controls for each MZ twin pair.
Project description:Gene expression profiling in peripheral blood cells from monozygotic twin pairs with various sytemic autoimmune diseases revealed 92 genes that could discriminate between MZ twin pairs and unrelated-matched controls. No genes were found that could discriminate between proband and unaffected twin pairs, or between the various disease phenotypes. RNA microarray analyses (Agilent Human 1A(V2) 20K oligo arrays) quantified differential gene expression in blood from 20 monozygotic (MZ) twin pairs, to minimize polymorphic gene effects, discordant for SAID (six with systemic lupus erythematosus (SLE), six rheumatoid arthritis (RA), eight idiopathic inflammatory myopathies (IIM)) and 40 unrelated - matched controls. Multiple statistical and pathway analyses were performed to assess differences in profiles of gene expression among the subject SAID groups and controls. ID's -xx-00 = Matched Control 1; xx-60 = second matched control; xx-01 = Affected MZ twin; xx-02 = unaffected MZ twin
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:Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly population worldwide. Recent studies have demonstrated strong genetic associations between AMD and single nucleotide polymorphisms (SNPs) within genes such as CFH and HTRA1. However, we found monozygotic twins had discordant AMD phenotypes (one with disease, the other without disease), suggesting that an epigenetic mechanism may control the pathogenesis of AMD. We obtained genomic DNA from the twins' peripheral blood mononuclear cells (PBMCs) and subjected it to DNA methylation-chip analysis (MeDIP-chip) that profiled genome-wide DNA methylation patterns on promoters of all genes and microRNAs. Our MeDIP-chip analysis identified 256 genes with hypo-methylated promoters only in the twins with AMD and 744 genes with hyper-methylated promoters only in the twins with AMD. Importantly, the promoter region of IL17RC was associated with hypo-methylated CpG sites only in the twins with AMD but not in the twins without AMD. Two pairs of twins with discordant AMD phenotypes. MeDIP-chip analysis of DNA methylation patterns in PBMCs.
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
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. Genotyping using the HumanHap300-duo bead chip from Illumina, GEO accession GPL5711
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 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.