DNA methylome profiling of blood to identify individuals in a pair of monozygotic twins
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ABSTRACT: Short tandem repeat (STR) markers cannot be used to distinguish between genetically identical monozygotic (MZ) twins, causing problems in a case with an MZ twin as a suspect. Many studies have shown that in older MZ twins, there are significant differences in overall content and genomic distribution of methylation
Project description:Using the Infinium HM450 platform, we have performed a longitudinal study of DNA methylation at birth and age 18 months in DNA from buccal swabs from 10 monozygotic (MZ) and 5 dizygotic (DZ) twin pairs from the Peri/postnatal Epigenetic Twins Study (PETS) cohort.
Project description:Objective:; To identify genes involved in idiopathic absence epilepsies by analysing gene expression using a monozygotic (MZ) twin design. Methods:; Genome-wide gene expression in lymphoblastoid cell lines was determined using microarrays derived from five discordant and four concordant MZ twin pairs with idiopathic absence epilepsies and five unaffected MZ twin pairs. Gene expression was analysed using three strategies: discordant MZ twins were compared as matched pairs, MZ twins concordant for epilepsy were compared to control MZ twins, and a singleton design of affected versus unaffected MZ twin individuals was used irrespective of twin pairing. An overlapping gene list was generated from these analyses. Dysregulation of genes recognised from the microarray experiment were validated using quantitative real time PCR (qRT-PCR) in the twin sample and in an independent sample of 18 sporadic absence cases and 24 healthy controls. Results:; Sixty-five probe sets were identified from the microarray analysis strategies. Sixteen genes were chosen for validation and nine of these genes confirmed by qRT-PCR in the twin sample. Differential expression of the immediate early gene EGR1 and RCN2, coding for the calcium-binding protein Reticulocalbin 2, was re-confirmed by qRT-PCR in the independent sample. Interpretation:; Using a unique sample of discordant MZ twins, our study identified genes with altered expression, which suggest novel mechanisms in idiopathic absence epilepsy. Dysregulation of EGR1 and RCN2 might represent common transcriptional alterations in idiopathic absence epilepsy. Experiment Overall Design: Genome-wide gene expression in lymphoblastoid cell lines was determined using microarrays derived from five discordant and four concordant MZ twin pairs with idiopathic absence epilepsies and five unaffected MZ twin pairs.
Project description:Objective: To identify genes involved in idiopathic absence epilepsies by analysing gene expression using a monozygotic (MZ) twin design. Methods: Genome-wide gene expression in lymphoblastoid cell lines was determined using microarrays derived from five discordant and four concordant MZ twin pairs with idiopathic absence epilepsies and five unaffected MZ twin pairs. Gene expression was analysed using three strategies: discordant MZ twins were compared as matched pairs, MZ twins concordant for epilepsy were compared to control MZ twins, and a singleton design of affected versus unaffected MZ twin individuals was used irrespective of twin pairing. An overlapping gene list was generated from these analyses. Dysregulation of genes recognised from the microarray experiment were validated using quantitative real time PCR (qRT-PCR) in the twin sample and in an independent sample of 18 sporadic absence cases and 24 healthy controls. Results: Sixty-five probe sets were identified from the microarray analysis strategies. Sixteen genes were chosen for validation and nine of these genes confirmed by qRT-PCR in the twin sample. Differential expression of the immediate early gene EGR1 and RCN2, coding for the calcium-binding protein Reticulocalbin 2, was re-confirmed by qRT-PCR in the independent sample. Interpretation: Using a unique sample of discordant MZ twins, our study identified genes with altered expression, which suggest novel mechanisms in idiopathic absence epilepsy. Dysregulation of EGR1 and RCN2 might represent common transcriptional alterations in idiopathic absence epilepsy. Keywords: Childhood Absence Epilepsy, Juvenile Absence Epilepsy, Idiopathic Generalised Epilepsy, gene expression, twin study, monozygotic twins
Project description:DNA methylation appears to play an essential mechanistic role in the pathogenesis of ALL, thereby potentiate its use as a biomarker for diagnosis and prognosis (Milani, Lundmark et al. 2010; Geng, Brennan et al. 2012; Sandoval, Heyn et al. 2013), and even a potential target of novel therapeutic approaches in ALL. In present study, we collected blood specimens for 4 pairs of monozygotic twins (MZ) and 1 pair of dizygotic twin (DZ) that are discordant for ALL. We sought to comprehensively assess the magnitude of genetic and epigenetic differences between ALL-affected and unaffected twins. we conducted whole genome and whole methylome sequencing on these five pairs of ALL-discordant twins. We also examined both the MZ and DZ twins using whole-genome bisulfite sequencing (WGBS). At first, the methylation differences across the genome were addressed globally by Circos software. And then tried to characterize the co-twin methylation divergence in specific genomic regions between ALL-discordant twin pairs. These patterns of dynamic co-twin methylation changes in these discordant ALL samples were generally consistent among MZ and DZ twins, indicating similarities of methylation abnormalities. As a result, 780, 566, 309, 293 and 2110 DMRs were identified, with a similar distribution pattern across different genomic elements among the five twin pairs.Then we annotate whether these DMRs were located in regulatory elements and identification of genes with recurring methylation alterations in a cohort of ALL patients. We collected blood specimens from 4 pairs of MZ twins and 1 pair of DZ twin that are discordant for ALL. At first, the methylation differences across the genome were addressed globally by Circos software. And then tried to characterize the co-twin methylation divergence in specific genomic regions and differentially methylated gene regions (DMRs) were identified between ALL-discordant twin pairs. Then we annotate whether these DMRs were located in regulatory elements and identification of genes with recurring methylation alterations in a cohort of ALL patients.
Project description:We aim to investigate circulating genome-wide microRNA (miRome) profiles in Moyamoya disease (MMD)-discordant monozygotic (MZ) twins with the RNF213 founder mutation (rs112735431).A disease discordant monozygotic twin-based study design may unmask potential confounders from previously published circulating microRNA signature in MMD. Circulating genome-wide microRNA (miRNome) profiling was performed in MMD-discordant monozygotic twins, non-twin-MMD patients, and non-MMD healthy volunteers by microarray followed by qPCRvalidation, using blood samples. Differential plasma-microRNAs were further quantified in endothelial cells differentiated from iPS cell lines (iPSECs) derived from another independent non-twin cohort. Lastly, their target gene expression in the iPSECs was analyzed. Microarray detected 309 plasma-microRNAs in MMD-discordant monozygotic twins that were also detected in the non-twin cohort. Principal component analysis of the plasma-microRNA expression level demonstrated distinct 2 groups separated by MMD and healthy control in the twin- and non-twin cohorts. Of these, differential up-regulations of hsa-miR-6722-3p/-328-3p were validated in the plasma of MMD (Imposed threshold: absolute log2 expression fold change (logFC) > 0.26 for the twin cohort; absolute logFC > 0.26, p < 0.05, and q < 0.15 for the non-twin cohort). In MMD derived iPSECs, hsa-miR-6722-3p/-328-3p showed a trend of up-regulation with a 3.0- or higher expression fold change. Bioinformatics analysis revealed that 41 target genes of miR- 6722-3p/-328-3p were significantly down-regulated in MMD derived iPSECs and were involved in STAT3, IGF-1-, and PTEN-signaling, suggesting a potential microRNA- gene expression interaction between circulating plasma and endothelial cells. In conclusion, our MMD-discordant monozygotic twin-based study confirmed a novel circulating microRNA signature in MMD as a potential diagnostic biomarker minimally confounded by genetic heterogeneity. The novel circulating microRNA signature can contribute for the future functional microRNA analysis to find new diagnostic and therapeutic target of MMD.
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:Peripheral blood from thirty-four monozygotic twin subjects from the general population (n = 17 twin pairs) was collected for epigenomic analysis via Illumina Infinium HumanMethylation450 Beadchip. All subjects were screened for DSM-IV based criteria for both current and lifetime psychiatric disorders. Out of 17 twin pairs, there were: 7 healthy twin pairs where none of the twins of a pair met criteria for any DSM-IV disorder; 6 discordant twin pairs where only one of the twins of each pair met diagnostic criteria; and 4 concordant twin pairs where both twins of a pair met clinical DSM-IV based criteria.
Project description:There is growing evidence that genomic DNA sequence changes occur in individual somatic cells during the lifetime of an individual and accumulation of these changes may influence aging and disease. In light of this, and contradicting reports regarding discordant copy number profiles between MZ twins(BARANZINI et al. 2010; BRUDER et al. 2008), we set out to identify de novo somatic copy number mutations in DNA from blood for MZ twin pairs of Mexican American descent who were participants of the San Antonio Family Heart Study (SAFHS) or San Antonio Family Diabetes/Gallbladder study (SAFDGS). By applying circular binary segmentation (CBS) to B-allele ratio differences we determined that the 3 MZ twin pairs in this study had concordant copy number profiles. We also detected 2 de novo germ-line CNVs in 2 MZ twin pairs from the SAFHS. This study includes data for 4 monozygotic (MZ) twin pairs, and both parents of 2 of these MZ twin pairs. The purpose of this study was to compare concordance of copy number profiles between MZ twins.
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:We established gene expression profiles of diagnostic bone marrow samples of monozygotic twins with acute lymphoblastic leukemia. We established technical duplicates for each twin.