Project description:Intellectual disability is a common condition that carries lifelong severe medical and developmental consequences. The causes of intellectual disability (ID) remain unknown for the majority of patients due to the extensive clinical and genetic heterogeneity of this disorder. De novo mutations may play an important role in ID as most individuals with ID present as isolated cases without family history and/or clear syndromic indication. In addition, the involvement of such mutations have recently been demonstrated in a small number of individuals with ID. Here we evaluate the diagnostic potential and role of de novo mutations in a cohort of 100 patients with ID of unknown cause using family-based exome sequencing. Single end short-read (50 bp) SOLiD 4 sequencing data for 300 individuals, constituting 100 patient-parent trios. For more details please read; http://www.nejm.org/doi/full/10.1056/NEJMoa1206524. Dataset is created by RUNMC (Radboud University, Nijmegen Medical Center), partner of Geuvadis consortium (http://www.geuvadis.org).
Project description:An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift mutations and one de novo missense mutation in the CTCF gene in individuals with intellectual disability, microcephaly and growth retardation. Furthermore, a patient with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three patients with point mutations revealed deregulation of genes involved in signal transduction and emphasized the role of CTCF in enhancer-driven expression of genes. Our findings indicate that haploinsufficiency of CTCF affects genomic interaction of enhancers and their regulated gene promoters that drive developmental processes and cognition. ChIP-seq analysis of CTCF genomic binding sites in lymphocytes of a control individual (no replicates).
Project description:L061 family with idiopathic non-syndromic intellectual disability remained unsolved after targeted screening of ID-related genes, array-CGH and exome sequencing. In order to perform custom tandem repeat screening on the X chromosome by long read single molecule sequencing, X-linkage needed to be confirmed by SNP arrays.
Project description:An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift mutations and one de novo missense mutation in the CTCF gene in individuals with intellectual disability, microcephaly and growth retardation. Furthermore, a patient with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three patients with point mutations revealed deregulation of genes involved in signal transduction and emphasized the role of CTCF in enhancer-driven expression of genes. Our findings indicate that haploinsufficiency of CTCF affects genomic interaction of enhancers and their regulated gene promoters that drive developmental processes and cognition. Comparison of lymphocyte gene expression between 3 de novo CTCF mutation patients and 8 controls (4 technical replicates each, no biological replicates).
Project description:An X-chromosome exome sequencing analysis identified a mutation in O-GlcNAc transferase (OGT) (pL254F) in a family with X-linked intellectual disability (XLID). Affected patient lymohoblastoids exhibit decreased steady state OGT levels owing to an unstable protein compared to the unaffected, related male controls. Suprisingly, global O-GlcNAc levels remained remained unaltered. This prompted us to check the both protein and mRNA levels of the other cycling enzyme, O-GlcNAcase (OGA) which was also lowered. This implies that a compensation mechanism exists, however imperfect, owing to the disease state of the individuals. We performed glabal transcriptome analysis to assess any other changes in message between patients and controls. Our study highlights small differences in the global transcriptome of patient lymhoblastoids that have the L254F mutation in O-GlcNAc transferase when compared to familial controls using Illumina sequencing of total RNA
Project description:An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift mutations and one de novo missense mutation in the CTCF gene in individuals with intellectual disability, microcephaly and growth retardation. Furthermore, a patient with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three patients with point mutations revealed deregulation of genes involved in signal transduction and emphasized the role of CTCF in enhancer-driven expression of genes. Our findings indicate that haploinsufficiency of CTCF affects genomic interaction of enhancers and their regulated gene promoters that drive developmental processes and cognition.