Project description:To assess the clinical impact of splice-altering noncoding mutations in autism spectrum disorder (ASD), we used a deep learning framework (SpliceAI) to predict the splice-altering potential of de novo mutations in 3,953 individuals with ASD from the Simons Simplex Collection. To validate these predictions, we selected 36 individuals that harbored predicted de-novo cryptic splice mutations; each individual represented the only case of autism within their immediate family. We obtained peripheral blood-derived lymphoblastoid cell lines (LCLs) and performed high-depth mRNA sequencing (approximately 350 million 150 bp single-end reads per sample). We used OLego to align the reads against a reference created from hg19 by substituting de novo variants of each individual with the corresponding alternate allele.
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:This SuperSeries is composed of the SubSeries listed below. DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Refer to individual Series
Project description:DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Whole-genome bisulfite sequencing for Dnmt1,3a,3b-triple-KO ES cells expressing DNMT3A2 or DNMT3B1 and for Dnmt1,3a,3b,Setd2-KO ES cells expressing DNMT3B1
Project description:DNA methylation is an epigenetic modification associated with transcriptional repression of promoters and is essential for mammalian development. Establishment of DNA methylation is mediated by the de novo DNA methyltransferases DNMT3A and DNMT3B, whereas DNMT1 ensures maintenance of methylation through replication. Absence of these enzymes is lethal, and somatic mutations in these genes have been associated with several human diseases. How genomic DNA methylation patterns are regulated remains poorly understood, as the mechanisms that guide recruitment and activity of DNMTs in vivo are largely unknown. To gain insights into this matter we determined chromosomal binding and site-specific activity of the mammalian de novo DNA methyltransferases DNMT3A and DNMT3B. We show that both enzymes localize to methylated, CpG dense regions in mouse stem cells, yet are excluded from active promoters and enhancers. By specifically measuring sites of de novo methylation, we observe that enzymatic activity reflects chromosomal binding. De novo methylation increases with CpG density, yet is excluded from nucleosomes. Notably, we observed selective binding of DNMT3B to the bodies of transcribed genes, which leads to their preferential methylation. This targeting to transcribed sequences requires SETD2-mediated methylation of lysine 36 on histone H3 and a functional PWWP domain of DNMT3B. Together these findings reveal how sequence and chromatin cues guide de novo methyltransferase activity to ensure methylome integrity. Genome-wide binding analysis for biotin-tagged DNMT3A2 and DNMT3B and variants in wild type ES, wild type neuroprogenitor cells, ES cells triple-KO for Dnmt1,3a,3b and ES cell mutant for Setd2
Project description:For decades, technical and cost hurdles have prevented the systematic investigation of non-coding sequences in complex human diseases, and thus our knowledge about autism spectrum disorders (ASD) has been primarily obtained from analysis of protein-coding sequences. We have combined the analysis of whole genome sequencing with global studies of regulatory sequences of human cortical neurons to reveal the regulatory architecture of ASD. Analysis of de novo mutations from whole genome sequencing of 261 autism families revealed the physical proximity of ASD de novo mutations specifically to the cortical expression quantitative loci (eQTLs) of synaptic genes. We performed ATAC-Seq, ChIP-Seq, RNA-Seq and Hi-C experiments on human cortical neurons, which for the first time provided a paranormal view of the regulatory landscape in these cells. We found that ASD de novo mutations preferentially affect regulatory elements, and the associated genes are shared targets of two ASD syndromic factors, CHD8 and PTEN. Analyzing 15 chromatin states across 127 human tissue/cell types revealed a significant enrichment of ASD de novo mutations in active transcription start sites and the perturbed genes implicated in neuron functions; this distribution enabled us to develop a machine-learning algorithm to assess potential ASD risk for a given individual. Taken together, our study for the first time revealed the regulatory landscape in human neurons, demonstrated the importance of the non-coding genome in ASD and provides a general framework for analyzing regulatory mutations for other complex human diseases.
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:Null mutations of tomato FRUITFULL-like genes FUL1, FUL2, MBP10, MBP20 caused delayed flowering and branched inflorescence, so we sequenced mRNA from vegetative meristems (VM), transition meristems (TM), floral meristems (FM), and FM of the first sympodial shoot of tomato mutant ful1/ful2/mbp10/mbp20 (slful) as well as the wild type Moneyberg (WT) to see genome-wide expression changes affected by the mutations.