Project description:We have performed comparative transcriptome profile from lymphoblastoid cell lines from four Williams-Beuren syndrome patients and two patients with partial deletions of the region. The goal was to find deregulated genes specifically in WBS versus atypical deletions, and to determine the biological pathways affected in WBS patients.
Project description:Williams-Beuren Syndrome (WBS) is a neurodevelopmental disorder caused by aa 1.5 Mb microdeletion on human chromosome 7. Although the molecular cause of the disorder is well-established, little is known about the global impact of the deletion on gene expression. Here we profiled the transcriptomes of fibroblast cell lines from 8 young girls with WBS, and 9 sex- and age-matched control individuals Keywords: disease state analysis, gene expression profiling
Project description:Copy number variants (CNVs) influence the expression of genes that map not only within the rearrangement, but also to its flanks. To assess the possible mechanism(s) underlying this “neighboring effect”, we compared intrachromosomal interactions and histone modifications in cell lines of patients affected by genomic disorders and control individuals. Using chromosome conformation capture (4C-seq), we observed that a set of genes flanking the Williams-Beuren Syndrome critical region (WBSCR) were often looping together, possibly forming an interacting cluster with each other and the WBSCR. Deletion of the WBSCR disrupts the expression of this group of flanking genes, as well as long-range interactions between them and the rearranged interval. We also pinpointed concomitant changes in histone modifications between samples.We conclude that large genomic rearrangements can lead to chromatin conformation changes that extend far away from the structural variant, thereby possibly modulating expression globally and modifying the phenotype. For example, we determined that the chromatin conformation, histone marks and relative expression levels of the flanking AUTS2 gene, mutations of which are associated with autism and intellectual disabilities, are modified in cell lines from Williams-Beuren syndrome patients. Examination of 4C-seq interaction profile of seven different genes (of which three in duplicate) in 2 different cell lines.
Project description:While psychiatric disorders (e.g., schizophrenia) and autism spectrum disorders (ASD) are typically associated with a deficit in social behavior, the opposite trait of hypersociability is exhibited by individuals with specific neurodevelopmental disorders, e.g., Angelman Syndrome (AS) and Williams-Beuren Syndrome (WBS). We have recently reported that the deletion of the miR379-410 cluster in mice led to hypersocial behavior. To study the roles of this miRNA cluster in the context of WBS, we sent for smallRNA sequencing RNA isolated from isogenic human iPSC-derived neurons harboring a deletion present in Williams-Beuren-Syndrome patients (7q11.23). Specifically, we found that members of the miR379-410 cluster were strikingly overrepresented among downregulated miRNAs in iNeurons harboring a deletion of the WBS critical region. Thus, we obtained the first evidence for the pathophysiological significance of the miR379-410 miRNA cluster in the context of WBS. We conclude that targeting this novel pathway could have therapeutic potential for WBS and other neurodevelopmental conditions characterized by social impairments.
Project description:Merm1/Wbscr22 is one of genes in chromosomal region deleted in Williams-Beuren syndrome, a multisystem developmental disorder. Wbscr22 contains a nuclear localization signal and an S-adenosyl-L-methionine-dependent methyltransferase fold, but its real function is completely unknown. In this study, to examine the function, we compared the gene expression profiles between control and Merm1/Wbscr22 knock-downed tumor cells.
