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 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: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:Two families with monozygotic twins discordant for schizophrenia NimbleGen Human DNA Methylation 3x720k CpG Island Plus RefSeq Promoter Microarray
Project description:We examined six pairs of monozygotic twins discordant (MZD) for schizophrenia and identified copy number variation (CNV) and single nucleotide polymorphism (SNP) differences between affected and unaffected co-twins using the Affymetrix Genome Wide SNP 6.0.
Project description:Schizophrenia affects approximately 1% of the world population. Genetics, epigenetics, and environmental factors are known to play a role in this psychiatric disorder. While there is a high concordance in monozygotic twins, about half of twin pairs are discordant for schizophrenia. To address the question of how and when concordance in monozygotic twins occur, we have obtained fibroblasts from two pairs of schizophrenia discordant twins (one sibling with schizophrenia while the second one is unaffected by schizophrenia) and three pairs of healthy twins (both of the siblings are healthy). We have prepared iPSC models for these 3 groups of patients with schizophrenia, unaffected co-twins, and the healthy twins. When the study started the co-twins were considered healthy and unaffected but both the co-twins were later diagnosed with a depressive disorder. The reprogrammed iPSCs were differentiated into hippocampal neurons to measure the neurophysiological abnormalities in the patients. We found that the neurons derived from the schizophrenia patients were less arborized, were hypoexcitable with immature spike features, and exhibited a significant reduction in synaptic activity with dysregulation in synapse-related genes. Interestingly, the neurons derived from the co-twin siblings who did not have schizophrenia formed another distinct group that was different from the neurons in the group of the affected twin siblings but also different from the neurons in the group of the control twins. Importantly, their synaptic activity was not affected. Our measurements that were obtained from schizophrenia patients and their monozygotic twin and compared also to control healthy twins point to hippocampal synaptic deficits as a central mechanism in schizophrenia
Project description:We examined six pairs of monozygotic twins discordant (MZD) for schizophrenia and identified copy number variation (CNV) and single nucleotide polymorphism (SNP) differences between affected and unaffected co-twins using the Affymetrix Genome Wide SNP 6.0. Affymetrix SNP arrays were performed according to the manufacurer's protocol on DNA extracted from whole blood CNV analysis was done using Affymetrix Genotyping Console 4.0 and Partek Genotyping Suite
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.
