scholarly journals Prenatal Diagnosis of Fetuses with Increased Nuchal Translucency by Genome Sequencing Analysis

2019 ◽  
Author(s):  
Kwong Wai Choy ◽  
Huilin Wang ◽  
Mengmeng Shi ◽  
Jingsi Chen ◽  
Zhenjun Yang ◽  
...  

AbstractBackgroundIncreased Nuchal Translucency (NT) is an important biomarker associated with increased risk of fetal structural anomalies. It is known to be contributed by a wide range of genetic etiologies from single nucleotide variants to those affecting millions of base-pairs. Currently, prenatal diagnosis is routinely performed by karyotyping and chromosomal microarray analysis (CMA), however, both of them have limited resolution. The diversity of the genetic etiologies warrants an integrated assay such as genome sequencing (GS) for comprehensive detection of genomic variants. Herein, we aim to evaluate the feasibility of applying GS in prenatal diagnosis for the fetuses with increased NT.MethodsWe retrospectively applied GS (>30-fold) for fetuses with increased NT (≥3.5-mm), who underwent routine prenatal diagnosis. Detection of single-nucleotide variants, copy-number variants and structural rearrangements was performed simultaneously and the results were integrated for interpretation in accordance with the guidelines of the American College of Medical Genetics and Genomics. Pathogenic or likely pathogenic (P/LP) variants were selected for validation and parental confirmation, when available.ResultsOverall, 50 fetuses were enrolled, including 34 cases with isolated increased NT and 16 cases with other fetal structural malformations. Routine CMA and karyotyping reported eight P/LP CNVs, yielding a diagnostic rate of 16.0% (8/50). In comparison, GS provided a 2-fold increase in diagnostic yield (32.0%, 16/50), including one mosaic turner syndrome, eight cases with microdeletions/microduplications and seven cases with P/LP point mutations. Moreover, GS identified two cryptic insertions and two inversions. Follow-up study further demonstrated the potential pathogenicity of an apparently balanced insertion which disrupted an OMIM autosomal dominant disease-causing gene at the inserted site.ConclusionsOur study demonstrates that applying GS in fetuses with increased NT can comprehensively detect and delineate the various genomic variants that are causative to the diseases. Importantly, prenatal diagnosis by GS doubled the diagnostic yield compared with routine protocols. Given a comparable turn-around-time and less DNA required, our study provides strong evidence to facilitate GS in prenatal diagnosis, particularly in fetuses with increased NT.

2019 ◽  
Vol 10 ◽  
Author(s):  
Kwong Wai Choy ◽  
Huilin Wang ◽  
Mengmeng Shi ◽  
Jingsi Chen ◽  
Zhenjun Yang ◽  
...  

2018 ◽  
Author(s):  
Maxime Garcia ◽  
Szilveszter Juhos ◽  
Malin Larsson ◽  
Pall I. Olason ◽  
Marcel Martin ◽  
...  

AbstractSummaryWhole-genome sequencing (WGS) is a cornerstone of precision medicine, but portable and reproducible open-source workflows for WGS analyses of germline and somatic variants are lacking. We present Sarek, a modular, comprehensive, and easy-to-install workflow, combining a range of software for the identification and annotation of single-nucleotide variants (SNVs), insertion and deletion variants (indels), structural variants, tumor sample heterogeneity, and karyotyping from germline or paired tumor/normal samples. Sarek is implemented in a bioinformatics workflow language (Nextflow) with Docker and Singularity compatible containers, ensuring easy deployment and full reproducibility at any Linux based compute cluster or cloud computing environment. Sarek supports the human reference genomes GRCh37 and GRCh38, and can readily be used both as a core production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups.AvailabilitySource code and instructions for local installation are available at GitHub (https://github.com/SciLifeLab/Sarek) under the MIT open-source license, and we invite the research community to contribute additional functionality as a collaborative open-source development project.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 63 ◽  
Author(s):  
Maxime Garcia ◽  
Szilveszter Juhos ◽  
Malin Larsson ◽  
Pall I. Olason ◽  
Marcel Martin ◽  
...  

Whole-genome sequencing (WGS) is a fundamental technology for research to advance precision medicine, but the limited availability of portable and user-friendly workflows for WGS analyses poses a major challenge for many research groups and hampers scientific progress. Here we present Sarek, an open-source workflow to detect germline variants and somatic mutations based on sequencing data from WGS, whole-exome sequencing (WES), or gene panels. Sarek features (i) easy installation, (ii) robust portability across different computer environments, (iii) comprehensive documentation, (iv) transparent and easy-to-read code, and (v) extensive quality metrics reporting. Sarek is implemented in the Nextflow workflow language and supports both Docker and Singularity containers as well as Conda environments, making it ideal for easy deployment on any POSIX-compatible computers and cloud compute environments. Sarek follows the GATK best-practice recommendations for read alignment and pre-processing, and includes a wide range of software for the identification and annotation of germline and somatic single-nucleotide variants, insertion and deletion variants, structural variants, tumour sample purity, and variations in ploidy and copy number. Sarek offers easy, efficient, and reproducible WGS analyses, and can readily be used both as a production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups. The Sarek source code, documentation and installation instructions are freely available at https://github.com/nf-core/sarek and at https://nf-co.re/sarek/.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 63 ◽  
Author(s):  
Maxime Garcia ◽  
Szilveszter Juhos ◽  
Malin Larsson ◽  
Pall I. Olason ◽  
Marcel Martin ◽  
...  

Whole-genome sequencing (WGS) is a fundamental technology for research to advance precision medicine, but the limited availability of portable and user-friendly workflows for WGS analyses poses a major challenge for many research groups and hampers scientific progress. Here we present Sarek, an open-source workflow to detect germline variants and somatic mutations based on sequencing data from WGS, whole-exome sequencing (WES), or gene panels. Sarek features (i) easy installation, (ii) robust portability across different computer environments, (iii) comprehensive documentation, (iv) transparent and easy-to-read code, and (v) extensive quality metrics reporting. Sarek is implemented in the Nextflow workflow language and supports both Docker and Singularity containers as well as Conda environments, making it ideal for easy deployment on any POSIX-compatible computers and cloud compute environments. Sarek follows the GATK best-practice recommendations for read alignment and pre-processing, and includes a wide range of software for the identification and annotation of germline and somatic single-nucleotide variants, insertion and deletion variants, structural variants, tumour sample purity, and variations in ploidy and copy number. Sarek offers easy, efficient, and reproducible WGS analyses, and can readily be used both as a production workflow at sequencing facilities and as a powerful stand-alone tool for individual research groups. The Sarek source code, documentation and installation instructions are freely available at https://github.com/nf-core/sarek and at https://nf-co.re/sarek/.


2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Yohsuke Ogawa ◽  
Kazumasa Shiraiwa ◽  
Yoshitoshi Ogura ◽  
Tadasuke Ooka ◽  
Sayaka Nishikawa ◽  
...  

ABSTRACTErysipelothrix rhusiopathiaecauses swine erysipelas, an important infectious disease in the swine industry. In Japan, the incidence of acute swine erysipelas due toE. rhusiopathiaeserovar 1a has recently increased markedly. To study the genetic relatedness of the strains from the recent cases, we analyzed 34E. rhusiopathiaeserovar 1a swine isolates collected between 1990 and 2011 and further investigated the possible association of the live Koganei 65-0.15 vaccine strain (serovar 1a) with the increase in cases. Pulsed-field gel electrophoresis analysis revealed no marked variation among the isolates; however, sequencing analysis of a hypervariable region in the surface-protective antigen A gene (spaA) revealed that the strains isolated after 2007 exhibited the samespaAgenotype and could be differentiated from older strains. Phylogenetic analysis based on genome-wide single-nucleotide polymorphisms (SNPs) revealed that the Japanese strains examined were closely related, showing a relatively small number of SNPs among them. The strains were classified into four major lineages, with Koganei 65-0.15 (lineage III) being phylogenetically separated from the other three lineages. The strains isolated after 2007 and the two older strains constituted one major lineage (lineage IV) with a specificspaAgenotype (M203/I257-SpaA), while the recent isolates were further divided into two geographic groups. The remaining older isolates belonged to either lineage I, with the I203/L257-SpaA type, or lineage II, with the I203/I257-SpaA type. These results indicate that the recent increased incidence of acute swine erysipelas in Japan is associated with two sublineages of lineage IV, which have independently evolved in two different geographic regions.IMPORTANCEUsing large-scale whole-genome sequence data fromErysipelothrix rhusiopathiaeisolates from a wide range of hosts and geographic origins, a recent study clarified the existence of three distinct clades (clades 1, 2, and 3) that are found across multiple continents and host species, representing both livestock and wildlife, and an “intermediate” clade between clade 2 and the dominant clade 3 within the species. In this study, we found that theE. rhusiopathiaeJapanese strains examined exhibited remarkably low levels of genetic diversity and confirmed that all of the Japanese and Chinese swine isolates examined in this study belong to clonal lineages within the intermediate clade. We report thatspaAgenotyping ofE. rhusiopathiaestrains is a practical alternative to whole-genome sequencing analysis of theE. rhusiopathiaeisolates from eastern Asian countries.


NAR Cancer ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Fengju Chen ◽  
Yiqun Zhang ◽  
Chad J Creighton

Abstract Whole-genome sequencing combined with transcriptomics can reveal impactful non-coding single nucleotide variants (SNVs) in cancer. Here, we developed an integrative analytical approach that, as a first step, identifies genes altered in expression or DNA methylation in association with nearby somatic SNVs, in contrast to alternative approaches that first identify mutational hotspots. Using genomic datasets from the Pan-Cancer Analysis of Whole Genomes (PCAWG) consortium and the Children's Brain Tumor Tissue Consortium (CBTTC), we identified hundreds of genes and associated CpG islands for which the nearby presence of a non-coding somatic SNV recurrently associated with altered expression or DNA methylation, respectively. Genomic regions upstream or downstream of genes, gene introns and gene untranslated regions were all involved. The PCAWG adult cancer cohort yielded different significant SNV-expression associations from the CBTTC pediatric brain tumor cohort. The SNV-expression associations involved a wide range of cancer types and histologies, as well as potential gain or loss of transcription factor binding sites. Notable genes with SNV-associated increased expression include TERT, COPS3, POLE2 and HDAC2—involving multiple cancer types—MYC, BCL2, PIM1 and IGLL5—involving lymphomas—and CYHR1—involving pediatric low-grade gliomas. Non-coding somatic SNVs show a major role in shaping the cancer transcriptome, not limited to mutational hotspots.


2019 ◽  
Vol 105 (4) ◽  
pp. 338-352 ◽  
Author(s):  
Maria Teresa Ricci ◽  
Sara Volorio ◽  
Stefano Signoroni ◽  
Paolo Mariani ◽  
Frederique Mariette ◽  
...  

Introduction: Recent advances in technology and research are rapidly changing the diagnostic approach to hereditary gastrointestinal cancer (HGIC) syndromes. Although the practice of clinical genetics is currently transitioning from targeted criteria-based testing to multigene panels, important challenges remain to be addressed. The aim of this study was to develop and technically validate the performance of a multigene panel for HGIC. Methods: CGT-colon-G14 is an amplicon-based panel designed to detect single nucleotide variants and small insertions/deletions in 14 well-established or presumed high-penetrance genes involved in HGIC. The assay parameters tested were sensitivity, specificity, accuracy, and inter-run and intra-run reproducibility. Performance and clinical impact were determined using 48 samples of patients with suspected HGIC/polyposis previously tested with the targeted approach. Results: The CGT-colon-G14 panel showed 99.99% accuracy and 100% inter- and intra-run reproducibility. Moreover, panel testing detected 1 actionable pathogenic variant and 16 variants with uncertain clinical impact that were missed by the conventional approach because they were located in genes not previously analyzed. Conclusion: Introduction of the CGT-colon-G14 panel into the clinic could provide a higher diagnostic yield than a step-wise approach; however, results may not always be straightforward without the implementation of new genetic counseling models.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Hye Kyung Lee ◽  
Harold E. Smith ◽  
Chengyu Liu ◽  
Michaela Willi ◽  
Lothar Hennighausen

AbstractDeaminase base editing has emerged as a tool to install or correct point mutations in the genomes of living cells in a wide range of organisms. However, the genome-wide off-target effects introduced by base editors in the mammalian genome have been examined in only one study. Here, we have investigated the fidelity of cytosine base editor 4 (BE4) and adenine base editors (ABE) in mouse embryos using unbiased whole-genome sequencing of a family-based trio cohort. The same sgRNA was used for BE4 and ABE. We demonstrate that BE4-edited mice carry an excess of single-nucleotide variants and deletions compared to ABE-edited mice and controls. Therefore, an optimization of cytosine base editors is required to improve its fidelity. While the remarkable fidelity of ABE has implications for a wide range of applications, the occurrence of rare aberrant C-to-T conversions at specific target sites needs to be addressed.


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