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Fernandes M, Mario de Andrade E, Reis da Silva SG, Romagnoli VDS, Ortega JM, Antônio de Oliveira Mendes T. Geneapp: A web application for visualizing alternative splicing for biomedicine. Comput Biol Med 2024; 178:108789. [PMID: 38936077 DOI: 10.1016/j.compbiomed.2024.108789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 06/17/2024] [Accepted: 06/18/2024] [Indexed: 06/29/2024]
Abstract
Alternative Splicing (AS) is an essential mechanism for eukaryotes. However, the consequences of deleting a single exon can be dramatic for the organism and can lead to cancer in humans. Additionally, alternative 5' and 3' splice sites, which define the boundaries of exons, also play key roles to human disorders. Therefore, Investigating AS events is crucial for understanding the molecular basis of human diseases and developing therapeutic strategies. Workflow for AS event analysis can be sampling followed by data analysis with bioinformatics to identify the different AS events in the control and case samples, data visualization for curation, and selection of relevant targets for experimental validation. The raw output of the analysis software does not favor the inspection of events by bioinformaticians requiring custom scripts for data visualization. In this work, we propose the Geneapp application with three modules: GeneappScript, GeneappServer, and GeneappExplorer. GeneappScript is a wrapper that assists in identifying AS in samples compared in two different approaches, while GeneappServer integrates data from AS analysis already performed by the user. In GeneappExplorer, the user visualizes the previous dataset by exploring AS events in genes with functional annotation. This targeted screens that Geneapp allows to perform helps in the identification of targets for experimental validation to confirm the hypotheses under study. The Geneapp is freely available for non-commercial use at https://geneapp.net to advance research on AS for bioinformatics.
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Affiliation(s)
- Miquéias Fernandes
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil.
| | - Edson Mario de Andrade
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - Saymon Gazolla Reis da Silva
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - Vinícius Dos Santos Romagnoli
- Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil
| | - José Miguel Ortega
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Tiago Antônio de Oliveira Mendes
- Postgraduation Program in Bioinformatics, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil; Institute of Applied Biotechnology to Agriculture (BIOAGRO), Universidade Federal de Viçosa, Minas Gerais, Brazil.
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Li JD, Taipale M, Blencowe BJ. Efficient, specific, and combinatorial control of endogenous exon splicing with dCasRx-RBM25. Mol Cell 2024:S1097-2765(24)00475-1. [PMID: 38917795 DOI: 10.1016/j.molcel.2024.05.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 04/24/2024] [Accepted: 05/30/2024] [Indexed: 06/27/2024]
Abstract
Efficient targeted control of splicing is a major goal of functional genomics and therapeutic applications. Guide (g)RNA-directed, deactivated (d)Cas CRISPR enzymes fused to splicing effectors represent a promising strategy due to the flexibility of these systems. However, efficient, specific, and generalizable activation of endogenous exons using this approach has not been previously reported. By screening over 300 dCasRx-splicing factor fusion proteins tethered to splicing reporters, we identify dCasRx-RBM25 as a potent activator of exons. Moreover, dCasRx-RBM25 efficiently activates the splicing of ∼90% of targeted endogenous alternative exons and displays high on-target specificity. Using gRNA arrays for combinatorial targeting, we demonstrate that dCasRx-RBM25 enables multiplexed activation and repression of exons. Using this feature, the targeting of neural-regulated exons in Ptpb1 and Puf60 in embryonic stem cells reveals combinatorial effects on downstream alternative splicing events controlled by these factors. Collectively, our results enable versatile, combinatorial exon-resolution functional assays and splicing-directed therapeutic applications.
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Affiliation(s)
- Jack Daiyang Li
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Mikko Taipale
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
| | - Benjamin J Blencowe
- Donnelly Centre, University of Toronto, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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3
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Graham JH, Schlachetzki JCM, Yang X, Breuss MW. Genomic Mosaicism of the Brain: Origin, Impact, and Utility. Neurosci Bull 2024; 40:759-776. [PMID: 37898991 PMCID: PMC11178748 DOI: 10.1007/s12264-023-01124-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/16/2023] [Indexed: 10/31/2023] Open
Abstract
Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic mutations. Traditionally, research focused on the impact of genomic mosaicism on clinical phenotype-motivated by its involvement in cancers and overgrowth syndromes. More recently, we increasingly shifted towards the plethora of neutral mosaic variants that can act as recorders of cellular lineage and environmental exposures. Here, we summarize the current state of the field of genomic mosaicism research with a special emphasis on our current understanding of this phenomenon in brain development and homeostasis. Although the field of genomic mosaicism has a rich history, technological advances in the last decade have changed our approaches and greatly improved our knowledge. We will provide current definitions and an overview of contemporary detection approaches for genomic mosaicism. Finally, we will discuss the impact and utility of genomic mosaicism.
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Affiliation(s)
- Jared H Graham
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, 80045-2581, CO, USA
| | - Johannes C M Schlachetzki
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, 92093-0021, San Diego, CA, USA
| | - Xiaoxu Yang
- Department of Neurosciences, University of California San Diego, La Jolla, 92093-0021, San Diego, CA, USA
- Rady Children's Institute for Genomic Medicine, San Diego, 92123, CA, USA
| | - Martin W Breuss
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado School of Medicine, Aurora, 80045-2581, CO, USA.
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4
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Grosz BR, Parmar JM, Ellis M, Bryen S, Simons C, Reis ALM, Stevanovski I, Deveson IW, Nicholson G, Laing N, Wallis M, Ravenscroft G, Kumar KR, Vucic S, Kennerson ML. A deep intronic variant in MME causes autosomal recessive Charcot-Marie-Tooth neuropathy through aberrant splicing. J Peripher Nerv Syst 2024; 29:262-274. [PMID: 38860315 DOI: 10.1111/jns.12637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/26/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024]
Abstract
BACKGROUND Loss-of-function variants in MME (membrane metalloendopeptidase) are a known cause of recessive Charcot-Marie-Tooth Neuropathy (CMT). A deep intronic variant, MME c.1188+428A>G (NM_000902.5), was identified through whole genome sequencing (WGS) of two Australian families with recessive inheritance of axonal CMT using the seqr platform. MME c.1188+428A>G was detected in a homozygous state in Family 1, and in a compound heterozygous state with a known pathogenic MME variant (c.467del; p.Pro156Leufs*14) in Family 2. AIMS We aimed to determine the pathogenicity of the MME c.1188+428A>G variant through segregation and splicing analysis. METHODS The splicing impact of the deep intronic MME variant c.1188+428A>G was assessed using an in vitro exon-trapping assay. RESULTS The exon-trapping assay demonstrated that the MME c.1188+428A>G variant created a novel splice donor site resulting in the inclusion of an 83 bp pseudoexon between MME exons 12 and 13. The incorporation of the pseudoexon into MME transcript is predicted to lead to a coding frameshift and premature termination codon (PTC) in MME exon 14 (p.Ala397ProfsTer47). This PTC is likely to result in nonsense mediated decay (NMD) of MME transcript leading to a pathogenic loss-of-function. INTERPRETATION To our knowledge, this is the first report of a pathogenic deep intronic MME variant causing CMT. This is of significance as deep intronic variants are missed using whole exome sequencing screening methods. Individuals with CMT should be reassessed for deep intronic variants, with splicing impacts being considered in relation to the potential pathogenicity of variants.
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Affiliation(s)
- Bianca R Grosz
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, New South Wales, Australia
- The University of Sydney, Camperdown, New South Wales, Australia
| | - Jevin M Parmar
- Rare Disease Genetics and Functional Genomics Research Group, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Melina Ellis
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, New South Wales, Australia
- The University of Sydney, Camperdown, New South Wales, Australia
| | - Samantha Bryen
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Cas Simons
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Centre for Population Genomics, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Andre L M Reis
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Genomics and Inherited Disease Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Igor Stevanovski
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Genomics and Inherited Disease Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Ira W Deveson
- Centre for Population Genomics, Garvan Institute of Medical Research, and UNSW Sydney, Sydney, New South Wales, Australia
- Genomics and Inherited Disease Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Garth Nicholson
- The University of Sydney, Camperdown, New South Wales, Australia
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Concord, New South Wales, Australia
| | - Nigel Laing
- Rare Disease Genetics and Functional Genomics Research Group, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Mathew Wallis
- Tasmanian Clinical Genetics Service, Tasmanian Health Service, Hobart, Australia
- School of Medicine and Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Gianina Ravenscroft
- Rare Disease Genetics and Functional Genomics Research Group, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Kishore R Kumar
- The University of Sydney, Camperdown, New South Wales, Australia
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Concord, New South Wales, Australia
- Translational Neurogenomics Group, Genomic and Inherited Disease Program, The Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
- St Vincent's Healthcare Campus, Faculty of Medicine, UNSW Sydney, Darlinghurst, New South Wales, Australia
| | - Steve Vucic
- The University of Sydney, Camperdown, New South Wales, Australia
- Brain and Nerve Research Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Marina L Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Sydney, New South Wales, Australia
- The University of Sydney, Camperdown, New South Wales, Australia
- Molecular Medicine Laboratory and Neurology Department, Concord Repatriation General Hospital, Concord, New South Wales, Australia
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Trajkova S, Kerkhof J, Rossi Sebastiano M, Pavinato L, Ferrero E, Giovenino C, Carli D, Di Gregorio E, Marinoni R, Mandrile G, Palermo F, Carestiato S, Cardaropoli S, Pullano V, Rinninella A, Giorgio E, Pippucci T, Dimartino P, Rzasa J, Rooney K, McConkey H, Petlichkovski A, Pasini B, Sukarova-Angelovska E, Campbell CM, Metcalfe K, Jenkinson S, Banka S, Mussa A, Ferrero GB, Sadikovic B, Brusco A. DNA methylation analysis in patients with neurodevelopmental disorders improves variant interpretation and reveals complexity. HGG ADVANCES 2024; 5:100309. [PMID: 38751117 PMCID: PMC11216013 DOI: 10.1016/j.xhgg.2024.100309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 05/09/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024] Open
Abstract
Analysis of genomic DNA methylation by generating epigenetic signature profiles (episignatures) is increasingly being implemented in genetic diagnosis. Here we report our experience using episignature analysis to resolve both uncomplicated and complex cases of neurodevelopmental disorders (NDDs). We analyzed 97 NDDs divided into (1) a validation cohort of 59 patients with likely pathogenic/pathogenic variants characterized by a known episignature and (2) a test cohort of 38 patients harboring variants of unknown significance or unidentified variants. The expected episignature was obtained in most cases with likely pathogenic/pathogenic variants (53/59 [90%]), a revealing exception being the overlapping profile of two SMARCB1 pathogenic variants with ARID1A/B:c.6200, confirmed by the overlapping clinical features. In the test cohort, five cases showed the expected episignature, including (1) novel pathogenic variants in ARID1B and BRWD3; (2) a deletion in ATRX causing MRXFH1 X-linked mental retardation; and (3) confirmed the clinical diagnosis of Cornelia de Lange (CdL) syndrome in mutation-negative CdL patients. Episignatures analysis of the in BAF complex components revealed novel functional protein interactions and common episignatures affecting homologous residues in highly conserved paralogous proteins (SMARCA2 M856V and SMARCA4 M866V). Finally, we also found sex-dependent episignatures in X-linked disorders. Implementation of episignature profiling is still in its early days, but with increasing utilization comes increasing awareness of the capacity of this methodology to help resolve the complex challenges of genetic diagnoses.
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Affiliation(s)
- Slavica Trajkova
- Department of Neurosciences Rita Levi-Montalcini, University of Turin, Turin 10126, Italy
| | - Jennifer Kerkhof
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON N6A5W9, Canada
| | - Matteo Rossi Sebastiano
- Molecular Biotechnology Center "Guido Tarone" University of Turin, 10126 Turin, Italy; Department of Molecular Biotechnology and Health Sciences, University of Turin, CASSMedChem, 10126 Turin, Italy
| | - Lisa Pavinato
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Enza Ferrero
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Chiara Giovenino
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Diana Carli
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy
| | - Eleonora Di Gregorio
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, 10126 Turin, Italy
| | - Roberta Marinoni
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, 10126 Turin, Italy
| | - Giorgia Mandrile
- Medical Genetics Unit and Thalassemia Center, San Luigi University Hospital, Orbassano, TO 10049, Italy
| | - Flavia Palermo
- Medical Genetics Unit and Thalassemia Center, San Luigi University Hospital, Orbassano, TO 10049, Italy
| | - Silvia Carestiato
- Department of Neurosciences Rita Levi-Montalcini, University of Turin, Turin 10126, Italy
| | - Simona Cardaropoli
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy
| | - Verdiana Pullano
- Department of Neurosciences Rita Levi-Montalcini, University of Turin, Turin 10126, Italy
| | - Antonina Rinninella
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, 10126 Turin, Italy; Department of Biomedical and Biotechnological Sciences, Medical Genetics, University of Catania, 94124 Catania, Italy
| | - Elisa Giorgio
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy; Neurogenetics Research Center, IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Tommaso Pippucci
- IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, Italy
| | - Paola Dimartino
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
| | - Jessica Rzasa
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON N6A5W9, Canada
| | - Kathleen Rooney
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON N6A5W9, Canada; Department of Pathology and Laboratory Medicine, Western University, London, ON N6A3K7, Canada
| | - Haley McConkey
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON N6A5W9, Canada; Department of Pathology and Laboratory Medicine, Western University, London, ON N6A3K7, Canada
| | - Aleksandar Petlichkovski
- Department of Immunology and Human Genetics, Faculty of Medicine, University "Sv. Kiril I Metodij", Skopje 1000, Republic of Macedonia
| | - Barbara Pasini
- Department of Medical Sciences, University of Turin, 10126 Turin, Italy; Medical Genetics Unit, Città della Salute e della Scienza University Hospital, 10126 Turin, Italy
| | - Elena Sukarova-Angelovska
- Department of Endocrinology and Genetics, Faculty of Medicine, University "Sv. Kiril I Metodij", Skopje 1000, Republic of Macedonia
| | - Christopher M Campbell
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK
| | - Kay Metcalfe
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK
| | - Sarah Jenkinson
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, St. Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK; Division of Evolution, Infection & Genomics, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9WL, UK
| | - Alessandro Mussa
- Department of Public Health and Pediatric Sciences, University of Turin, 10126 Turin, Italy; Pediatric Clinical Genetics Unit, Regina Margherita Childrens' Hospital, 10126 Turin, Italy
| | | | - Bekim Sadikovic
- Verspeeten Clinical Genome Centre, London Health Sciences Centre, London, ON N6A5W9, Canada; Department of Pathology and Laboratory Medicine, Western University, London, ON N6A3K7, Canada
| | - Alfredo Brusco
- Medical Genetics Unit, Città della Salute e della Scienza University Hospital, 10126 Turin, Italy; Department of Neurosciences Rita Levi-Montalcini, University of Turin, Turin 10126, Italy.
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Kuznetsova KG, Vašíček J, Skiadopoulou D, Molnes J, Udler M, Johansson S, Njølstad PR, Manning A, Vaudel M. Bioinformatics pipeline for the systematic mining genomic and proteomic variation linked to rare diseases: The example of monogenic diabetes. PLoS One 2024; 19:e0300350. [PMID: 38635808 PMCID: PMC11025945 DOI: 10.1371/journal.pone.0300350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/23/2024] [Indexed: 04/20/2024] Open
Abstract
Monogenic diabetes is characterized as a group of diseases caused by rare variants in single genes. Like for other rare diseases, multiple genes have been linked to monogenic diabetes with different measures of pathogenicity, but the information on the genes and variants is not unified among different resources, making it challenging to process them informatically. We have developed an automated pipeline for collecting and harmonizing data on genetic variants linked to monogenic diabetes. Furthermore, we have translated variant genetic sequences into protein sequences accounting for all protein isoforms and their variants. This allows researchers to consolidate information on variant genes and proteins linked to monogenic diabetes and facilitates their study using proteomics or structural biology. Our open and flexible implementation using Jupyter notebooks enables tailoring and modifying the pipeline and its application to other rare diseases.
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Affiliation(s)
- Ksenia G. Kuznetsova
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Jakub Vašíček
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Dafni Skiadopoulou
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
| | - Janne Molnes
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Miriam Udler
- Department of Medicine, Massachusetts General Hospital, Boston, MA, United States of America
- Metabolism Program, Broad Institute of MIT and Harvard, Cambridge, MA, United States of America
- Department of Medicine, Harvard Medical School, Boston, MA, United States of America
| | - Stefan Johansson
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Pål Rasmus Njølstad
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Children and Youth Clinic, Haukeland University Hospital, Bergen, Norway
| | - Alisa Manning
- Department of Medicine, Massachusetts General Hospital, Boston, MA, United States of America
- Metabolism Program, Broad Institute of MIT and Harvard, Cambridge, MA, United States of America
- Department of Medicine, Harvard Medical School, Boston, MA, United States of America
| | - Marc Vaudel
- Mohn Center for Diabetes Precision Medicine, Department of Clinical Science, University of Bergen, Bergen, Norway
- Computational Biology Unit, Department of Informatics, University of Bergen, Bergen, Norway
- Department of Genetics and Bioinformatics, Norwegian Institute of Public Health, Oslo, Norway
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7
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Badia-Bringué G, Lavín JL, Casais R, Alonso-Hearn M. Alternative splicing of pre-mRNA modulates the immune response in Holstein cattle naturally infected with Mycobacterium avium subsp. paratuberculosis. Front Immunol 2024; 15:1354500. [PMID: 38495873 PMCID: PMC10940349 DOI: 10.3389/fimmu.2024.1354500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/09/2024] [Indexed: 03/19/2024] Open
Abstract
Little is known about the role of alternative splicing (AS) in regulating gene expression in Mycobacteria-infected individuals in distinct stages of infection. Pre-mRNA AS consists of the removal of introns and the assembly of exons contained in eukaryotic genes. AS events can influence transcript stability or structure with important physiological consequences. Using RNA-Seq data from peripheral blood (PB) and ileocecal valve (ICV) samples collected from Holstein cattle with focal and diffuse paratuberculosis (PTB)-associated histopathological lesions in gut tissues and without lesions (controls), we detected differential AS profiles between the infected and control groups. Four of the identified AS events were experimentally validated by reverse transcription-digital droplet PCR (RT-ddPCR). AS events in several genes correlated with changes in gene expression. In the ICV of animals with diffuse lesions, for instance, alternatively spliced genes correlated with changes in the expression of genes involved in endocytosis, antigen processing and presentation, complement activation, and several inflammatory and autoimmune diseases in humans. Taken together, our results identified common mechanisms of AS involvement in the pathogenesis of PTB and human diseases and shed light on novel diagnostic and therapeutic interventions to control these diseases.
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Affiliation(s)
- Gerard Badia-Bringué
- Department of Animal Health, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, Spain
- Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Leioa, Bizkaia, Spain
| | - José Luis Lavín
- Department of Applied Mathematics, NEIKER- Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, Spain
| | - Rosa Casais
- Center of Animal Biotechnology, Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Deva, Spain
| | - Marta Alonso-Hearn
- Department of Animal Health, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Bizkaia, Spain
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Wu H, Lin JH, Tang XY, Marenne G, Zou WB, Schutz S, Masson E, Génin E, Fichou Y, Le Gac G, Férec C, Liao Z, Chen JM. Combining full-length gene assay and SpliceAI to interpret the splicing impact of all possible SPINK1 coding variants. Hum Genomics 2024; 18:21. [PMID: 38414044 PMCID: PMC10898081 DOI: 10.1186/s40246-024-00586-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND Single-nucleotide variants (SNVs) within gene coding sequences can significantly impact pre-mRNA splicing, bearing profound implications for pathogenic mechanisms and precision medicine. In this study, we aim to harness the well-established full-length gene splicing assay (FLGSA) in conjunction with SpliceAI to prospectively interpret the splicing effects of all potential coding SNVs within the four-exon SPINK1 gene, a gene associated with chronic pancreatitis. RESULTS Our study began with a retrospective analysis of 27 SPINK1 coding SNVs previously assessed using FLGSA, proceeded with a prospective analysis of 35 new FLGSA-tested SPINK1 coding SNVs, followed by data extrapolation, and ended with further validation. In total, we analyzed 67 SPINK1 coding SNVs, which account for 9.3% of the 720 possible coding SNVs. Among these 67 FLGSA-analyzed SNVs, 12 were found to impact splicing. Through detailed comparison of FLGSA results and SpliceAI predictions, we inferred that the remaining 653 untested coding SNVs in the SPINK1 gene are unlikely to significantly affect splicing. Of the 12 splice-altering events, nine produced both normally spliced and aberrantly spliced transcripts, while the remaining three only generated aberrantly spliced transcripts. These splice-impacting SNVs were found solely in exons 1 and 2, notably at the first and/or last coding nucleotides of these exons. Among the 12 splice-altering events, 11 were missense variants (2.17% of 506 potential missense variants), and one was synonymous (0.61% of 164 potential synonymous variants). Notably, adjusting the SpliceAI cut-off to 0.30 instead of the conventional 0.20 would improve specificity without reducing sensitivity. CONCLUSIONS By integrating FLGSA with SpliceAI, we have determined that less than 2% (1.67%) of all possible coding SNVs in SPINK1 significantly influence splicing outcomes. Our findings emphasize the critical importance of conducting splicing analysis within the broader genomic sequence context of the study gene and highlight the inherent uncertainties associated with intermediate SpliceAI scores (0.20 to 0.80). This study contributes to the field by being the first to prospectively interpret all potential coding SNVs in a disease-associated gene with a high degree of accuracy, representing a meaningful attempt at shifting from retrospective to prospective variant analysis in the era of exome and genome sequencing.
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Affiliation(s)
- Hao Wu
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, 168 Changhai Road, Shanghai, 200433, China
- Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Jin-Huan Lin
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, 168 Changhai Road, Shanghai, 200433, China
- Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Xin-Ying Tang
- Shanghai Institute of Pancreatic Diseases, Shanghai, China
- Department of Prevention and Health Care, Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China
| | - Gaëlle Marenne
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Wen-Bin Zou
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, 168 Changhai Road, Shanghai, 200433, China
- Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Sacha Schutz
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
- Service de Génétique Médicale et de Biologie de La Reproduction, CHRU Brest, Brest, France
| | - Emmanuelle Masson
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
- Service de Génétique Médicale et de Biologie de La Reproduction, CHRU Brest, Brest, France
| | | | - Yann Fichou
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Gerald Le Gac
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
- Service de Génétique Médicale et de Biologie de La Reproduction, CHRU Brest, Brest, France
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Zhuan Liao
- Department of Gastroenterology, Changhai Hospital, Naval Medical University, 168 Changhai Road, Shanghai, 200433, China.
- Shanghai Institute of Pancreatic Diseases, Shanghai, China.
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France.
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9
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Bagger FO, Borgwardt L, Jespersen AS, Hansen AR, Bertelsen B, Kodama M, Nielsen FC. Whole genome sequencing in clinical practice. BMC Med Genomics 2024; 17:39. [PMID: 38287327 PMCID: PMC10823711 DOI: 10.1186/s12920-024-01795-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/01/2024] [Indexed: 01/31/2024] Open
Abstract
Whole genome sequencing (WGS) is becoming the preferred method for molecular genetic diagnosis of rare and unknown diseases and for identification of actionable cancer drivers. Compared to other molecular genetic methods, WGS captures most genomic variation and eliminates the need for sequential genetic testing. Whereas, the laboratory requirements are similar to conventional molecular genetics, the amount of data is large and WGS requires a comprehensive computational and storage infrastructure in order to facilitate data processing within a clinically relevant timeframe. The output of a single WGS analyses is roughly 5 MIO variants and data interpretation involves specialized staff collaborating with the clinical specialists in order to provide standard of care reports. Although the field is continuously refining the standards for variant classification, there are still unresolved issues associated with the clinical application. The review provides an overview of WGS in clinical practice - describing the technology and current applications as well as challenges connected with data processing, interpretation and clinical reporting.
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Affiliation(s)
- Frederik Otzen Bagger
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Line Borgwardt
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Sand Jespersen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Anna Reimer Hansen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Bertelsen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Miyako Kodama
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Finn Cilius Nielsen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
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10
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Lord J, Oquendo CJ, Wai HA, Douglas AGL, Bunyan DJ, Wang Y, Hu Z, Zeng Z, Danis D, Katsonis P, Williams A, Lichtarge O, Chang Y, Bagnall RD, Mount SM, Matthiasardottir B, Lin C, Hansen TVO, Leman R, Martins A, Houdayer C, Krieger S, Bakolitsa C, Peng Y, Kamandula A, Radivojac P, Baralle D. Predicting the impact of rare variants on RNA splicing in CAGI6. Hum Genet 2024:10.1007/s00439-023-02624-3. [PMID: 38170232 DOI: 10.1007/s00439-023-02624-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/18/2023] [Indexed: 01/05/2024]
Abstract
Variants which disrupt splicing are a frequent cause of rare disease that have been under-ascertained clinically. Accurate and efficient methods to predict a variant's impact on splicing are needed to interpret the growing number of variants of unknown significance (VUS) identified by exome and genome sequencing. Here, we present the results of the CAGI6 Splicing VUS challenge, which invited predictions of the splicing impact of 56 variants ascertained clinically and functionally validated to determine splicing impact. The performance of 12 prediction methods, along with SpliceAI and CADD, was compared on the 56 functionally validated variants. The maximum accuracy achieved was 82% from two different approaches, one weighting SpliceAI scores by minor allele frequency, and one applying the recently published Splicing Prediction Pipeline (SPiP). SPiP performed optimally in terms of sensitivity, while an ensemble method combining multiple prediction tools and information from databases exceeded all others for specificity. Several challenge methods equalled or exceeded the performance of SpliceAI, with ultimate choice of prediction method likely to depend on experimental or clinical aims. One quarter of the variants were incorrectly predicted by at least 50% of the methods, highlighting the need for further improvements to splicing prediction methods for successful clinical application.
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Affiliation(s)
- Jenny Lord
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | | | - Htoo A Wai
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Andrew G L Douglas
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - David J Bunyan
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK
| | - Yaqiong Wang
- Center for Molecular Medicine, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, 201102, China
| | - Zhiqiang Hu
- University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Zishuo Zeng
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08873, USA
| | - Daniel Danis
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Drive, Farmington, CT, 06032, USA
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Amanda Williams
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yuchen Chang
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology at Centenary Institute, University of Sydney, Sydney, Australia
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Stephen M Mount
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Brynja Matthiasardottir
- Graduate Program in Biological Sciences and Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Inflammatory Disease Section, National Human Genome Research Institute, Bethesda, MD, USA
| | | | - Thomas van Overeem Hansen
- Department of Clinical Genetics, University Hospital of Copenhagen, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Raphael Leman
- Laboratoire de Biologie et Génétique du Cancer, Centre François Baclesse, Caen, France
- Inserm U1245, Cancer Brain and Genomics, Normandie Université, UNICAEN, FHU G4 génomique, Rouen, France
| | - Alexandra Martins
- Inserm U1245, Cancer Brain and Genomics, Normandie Université, UNIROUEN, FHU G4 génomique, Rouen, France
| | - Claude Houdayer
- Inserm U1245, Cancer Brain and Genomics, Normandie Université, UNIROUEN, FHU G4 génomique, Rouen, France
- Department of Genetics, Univ Rouen Normandie, INSERM U1245, FHU-G4 Génomique and CHU Rouen, 76000, Rouen, France
| | - Sophie Krieger
- Laboratoire de Biologie et Génétique du Cancer, Centre François Baclesse, Caen, France
- Inserm U1245, Cancer Brain and Genomics, Normandie Université, UNICAEN, FHU G4 génomique, Rouen, France
| | | | - Yisu Peng
- Khoury College of Computer Sciences, Northeastern University, Boston, MA, 02115, USA
| | - Akash Kamandula
- Khoury College of Computer Sciences, Northeastern University, Boston, MA, 02115, USA
| | - Predrag Radivojac
- Khoury College of Computer Sciences, Northeastern University, Boston, MA, 02115, USA
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
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11
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Li K, Xiao J, Ling Z, Luo T, Xiong J, Chen Q, Dong L, Wang Y, Wang X, Jiang Z, Xia L, Yu Z, Hua R, Guo R, Tang D, Lv M, Lian A, Li B, Zhao G, He X, Xia K, Cao Y, Li J. Prioritizing de novo potential non-canonical splicing variants in neurodevelopmental disorders. EBioMedicine 2024; 99:104928. [PMID: 38113761 PMCID: PMC10767160 DOI: 10.1016/j.ebiom.2023.104928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 11/30/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Genomic variants outside of the canonical splicing site (±2) may generate abnormal mRNA splicing, which are defined as non-canonical splicing variants (NCSVs). However, the clinical interpretation of NCSVs in neurodevelopmental disorders (NDDs) is largely unknown. METHODS We investigated the contribution of NCSVs to NDDs from 345,787 de novo variants (DNVs) in 47,574 patients with NDDs. We performed functional enrichment and protein-protein interaction analysis to assess the association between genes carrying prioritised NCSVs and NDDs. Minigene was used to validate the impact of NCSVs on mRNA splicing. FINDINGS We observed significantly more NCSVs (p = 0.02, odds ratio [OR] = 2.05) among patients with NDD than in controls. Both canonical splicing variants (CSVs) and NCSVs contributed to an equal proportion of patients with NDD (0.76% vs. 0.82%). The candidate genes carrying NCSVs were associated with glutamatergic synapse and chromatin remodelling. Minigene successfully validated 59 of 79 (74.68%) NCSVs that led to abnormal splicing in 40 candidate genes, and 9 of the genes (ARID1B, KAT6B, TCF4, SMARCA2, SHANK3, PDHA1, WDR45, SCN2A, SYNGAP1) harboured recurrent NCSVs with the same variant present in more than two unrelated patients with NDD. Moreover, 36 of 59 (61.02%) NCSVs are novel clinically relevant variants, including 34 unreported and 2 clinically conflicting interpretations or of uncertain significance NCSVs in the ClinVar database. INTERPRETATION This study highlights the common pathology and clinical importance of NCSVs in unsolved patients with NDD. FUNDING The present study was funded by grants from the National Natural Science Foundation of China, China Postdoctoral Science Foundation, the Hunan Youth Science and Technology Innovation Talent Project, the Provincial Natural Science Foundation of Hunan, The Scientific Research Program of FuRong laboratory, and the Natural Science Project of the University of Anhui Province.
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Affiliation(s)
- Kuokuo Li
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Jifang Xiao
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Zhengbao Ling
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Tengfei Luo
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Jingyu Xiong
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Qian Chen
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Lijie Dong
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Yijing Wang
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Xiaomeng Wang
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Zhaowei Jiang
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Lu Xia
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Zhen Yu
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Rong Hua
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Rui Guo
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Dongdong Tang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Mingrong Lv
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China
| | - Aojie Lian
- National Health Commission Key Laboratory of Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan, China
| | - Bin Li
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - GuiHu Zhao
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China
| | - Xiaojin He
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China; Anhui Provincial Human Sperm Bank, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China.
| | - Kun Xia
- Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China.
| | - Yunxia Cao
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), No 81 Meishan Road, Hefei, 230032, Anhui, China; Key Laboratory of Population Health Across Life Cycle (Anhui Medical University), Ministry of Education of the People's Republic of China, No 81 Meishan Road, Hefei, 230032, Anhui, China.
| | - Jinchen Li
- Bioinformatics Center, National Clinical Research Centre for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan, China; Centre for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China; Bioinformatics Center, Furong Laboratory, Central South University, Changsha, Hunan, China.
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12
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Ferese R, Scala S, Suppa A, Campopiano R, Asci F, Zampogna A, Chiaravalloti MA, Griguoli A, Storto M, Pardo AD, Giardina E, Zampatti S, Fornai F, Novelli G, Fanelli M, Zecca C, Logroscino G, Centonze D, Gambardella S. Cohort analysis of novel SPAST variants in SPG4 patients and implementation of in vitro and in vivo studies to identify the pathogenic mechanism caused by splicing mutations. Front Neurol 2023; 14:1296924. [PMID: 38145127 PMCID: PMC10748595 DOI: 10.3389/fneur.2023.1296924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Introduction Pure hereditary spastic paraplegia (SPG) type 4 (SPG4) is caused by mutations of SPAST gene. This study aimed to analyze SPAST variants in SPG4 patients to highlight the occurrence of splicing mutations and combine functional studies to assess the relevance of these variants in the molecular mechanisms of the disease. Methods We performed an NGS panel in 105 patients, in silico analysis for splicing mutations, and in vitro minigene assay. Results and discussion The NGS panel was applied to screen 105 patients carrying a clinical phenotype corresponding to upper motor neuron syndrome (UMNS), selectively affecting motor control of lower limbs. Pathogenic mutations in SPAST were identified in 12 patients (11.42%), 5 missense, 3 frameshift, and 4 splicing variants. Then, we focused on the patients carrying splicing variants using a combined approach of in silico and in vitro analysis through minigene assay and RNA, if available. For two splicing variants (i.e., c.1245+1G>A and c.1414-2A>T), functional assays confirm the types of molecular alterations suggested by the in silico analysis (loss of exon 9 and exon 12). In contrast, the splicing variant c.1005-1delG differed from what was predicted (skipping exon 7), and the functional study indicates the loss of frame and formation of a premature stop codon. The present study evidenced the high splice variants in SPG4 patients and indicated the relevance of functional assays added to in silico analysis to decipher the pathogenic mechanism.
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Affiliation(s)
| | | | - Antonio Suppa
- IRCCS Neuromed, Pozzilli, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | | | | | | | | | | | | | | | - Emiliano Giardina
- Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Stefania Zampatti
- Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Giuseppe Novelli
- IRCCS Neuromed, Pozzilli, Italy
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Mirco Fanelli
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
| | - Chiara Zecca
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology of the University of Bari “Aldo Moro” at “Pia Fondazione Card G. Panico” Hospital Tricase, Lecce, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology of the University of Bari “Aldo Moro” at “Pia Fondazione Card G. Panico” Hospital Tricase, Lecce, Italy
| | - Diego Centonze
- IRCCS Neuromed, Pozzilli, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Stefano Gambardella
- IRCCS Neuromed, Pozzilli, Italy
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
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13
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Chear CT, Ismail IH, Chan KC, Noh LM, Kassim A, Latiff AHA, Gill SS, Ramly NH, Tan KK, Sundaraj C, Choo CM, Mohamed SAS, Baharin MF, Zamri AS, Yahya SNHS, Mohamad SB, Ripen AM. Clinical features and mutational analysis of X-linked agammaglobulinemia patients in Malaysia. Front Immunol 2023; 14:1252765. [PMID: 37809070 PMCID: PMC10560089 DOI: 10.3389/fimmu.2023.1252765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Background Bruton's tyrosine kinase (BTK) is a cytoplasmic protein involved in the B cell development. X-linked agammaglobulinemia (XLA) is caused by mutation in the BTK gene, which results in very low or absent B cells. Affected males have markedly reduced immunoglobulin levels, which render them susceptible to recurrent and severe bacterial infections. Methods: Patients suspected with X-linked agammaglobulinemia were enrolled during the period of 2010-2018. Clinical summary, and immunological profiles of these patients were recorded. Peripheral blood samples were collected for monocyte BTK protein expression detection and BTK genetic analysis. The medical records between January 2020 and June 2023 were reviewed to investigate COVID-19 in XLA. Results Twenty-two patients (from 16 unrelated families) were molecularly diagnosed as XLA. Genetic testing revealed fifteen distinct mutations, including four splicing mutations, four missense mutations, three nonsense mutations, three short deletions, and one large indel mutation. These mutations scattered throughout the BTK gene and mostly affected the kinase domain. All mutations including five novel mutations were predicted to be pathogenic or deleterious by in silico prediction tools. Genetic testing confirmed that eleven mothers and seven sisters were carriers for the disease, while three mutations were de novo. Flow cytometric analysis showed that thirteen patients had minimal BTK expression (0-15%) while eight patients had reduced BTK expression (16-64%). One patient was not tested for monocyte BTK expression due to insufficient sample. Pneumonia (n=13) was the most common manifestation, while Pseudomonas aeruginosa was the most frequently isolated pathogen from the patients (n=4). Mild or asymptomatic COVID-19 was reported in four patients. Conclusion This report provides the first overview of demographic, clinical, immunological and genetic data of XLA in Malaysia. The combination of flow cytometric assessment and BTK genetic analysis provides a definitive diagnosis for XLA patients, especially with atypical clinical presentation. In addition, it may also allow carrier detection and assist in genetic counselling and prenatal diagnosis.
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Affiliation(s)
- Chai Teng Chear
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Shah Alam, Selangor, Malaysia
| | - Intan Hakimah Ismail
- Clinical Immunology Unit, Department of Paediatrics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Kwai Cheng Chan
- Pediatric Department, Penang General Hospital, Ministry of Health, George Town, Penang, Malaysia
| | - Lokman Mohd Noh
- Pediatric Department, Tunku Azizah Hospital (Women and Children Hospital Kuala Lumpur), Ministry of Health, Kuala Lumpur, Malaysia
| | - Asiah Kassim
- Pediatric Department, Tunku Azizah Hospital (Women and Children Hospital Kuala Lumpur), Ministry of Health, Kuala Lumpur, Malaysia
| | | | - Sandeep Singh Gill
- Pediatric Department, Hospital Wanita Dan Kanak-Kanak Sabah, Ministry of Health, Kota Kinabalu, Sabah, Malaysia
| | - Nazatul Haslina Ramly
- Pediatric Department, Tunku Azizah Hospital (Women and Children Hospital Kuala Lumpur), Ministry of Health, Kuala Lumpur, Malaysia
| | - Kah Kee Tan
- Pediatric Department, Perdana University and Royal College of Surgeons in Ireland (PURCSI), School of Medicine, Perdana University, Kuala Lumpur, Malaysia
| | - Charlotte Sundaraj
- Pediatric Department, Hospital Putrajaya, Ministry of Health, Putrajaya, Malaysia
| | - Chong Ming Choo
- Pediatric Department, Hospital Sultan Abdul Halim, Ministry of Health, Sungai Petani, Kedah, Malaysia
| | | | - Mohd Farid Baharin
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Shah Alam, Selangor, Malaysia
| | - Amelia Suhana Zamri
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Shah Alam, Selangor, Malaysia
| | - Sharifah Nurul Husna Syed Yahya
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Shah Alam, Selangor, Malaysia
| | - Saharuddin Bin Mohamad
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, Malaysia
- Centre of Research in Systems Biology, Structural Bioinformatics and Human Digital Imaging (CRYSTAL), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Adiratna Mat Ripen
- Primary Immunodeficiency Unit, Allergy and Immunology Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Shah Alam, Selangor, Malaysia
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14
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Michaud V, Sequeira A, Mercier E, Lasseaux E, Plaisant C, Hadj-Rabia S, Whalen S, Bonneau D, Dieux-Coeslier A, Morice-Picard F, Coursimault J, Arveiler B, Javerzat S. Unsuspected consequences of synonymous and missense variants in OCA2 can be detected in blood cell RNA samples of patients with albinism. Pigment Cell Melanoma Res 2023. [PMID: 37650133 DOI: 10.1111/pcmr.13123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/18/2023] [Indexed: 09/01/2023]
Abstract
Oculocutaneous albinism type 2 (OCA2) is the second most frequent form of albinism and represents about 30% of OCA worldwide. As with all types of OCA, patients present with hypopigmentation of hair and skin, as well as severe visual abnormalities. We focused on a subgroup of 29 patients for whom genetic diagnosis was pending because at least one of their identified variants in or around exon 10 of OCA2 is of uncertain significance (VUS). By minigene assay, we investigated the effect of these VUS on exon 10 skipping and showed that not only intronic but also some synonymous variants can result in enhanced exon skipping. We further found that excessive skipping of exon 10 could be detected directly on blood samples of patients and of their one parent with the causal variant, avoiding invasive skin biopsies. Moreover, we show that variants, which result in lack of detectable OCA2 mRNA can be identified from blood samples as well, as shown for the most common OCA2 pathogenic missense variant c.1327G>A/p.(Val443Ile). In conclusion, blood cell RNA analysis allows testing the potential effect of any OCA2 VUS on transcription products. This should help to elucidate yet unsolved OCA2 patients and improve genetic counseling.
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Affiliation(s)
- Vincent Michaud
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, Bordeaux, France
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Angèle Sequeira
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, Bordeaux, France
| | - Elina Mercier
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, Bordeaux, France
| | - Eulalie Lasseaux
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Claudio Plaisant
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Smail Hadj-Rabia
- Department of Dermatology, Reference Center for Genodermatoses and Rare Skin Diseases (MAGEC), INSERM U1163, University of Paris, Imagine Institute, AP-HP5, Necker-Enfants Malades Hospital, Paris, France
| | - Sandra Whalen
- Clinical Genetics, Centre de Référence Maladies Rares Anomalies du développement et syndromes malformatifs, APHP, Sorbonne University, Hospital Armand Trousseau, Paris, France
| | | | - Anne Dieux-Coeslier
- Clinical Genetics Department, Reference Center for Developmental Anomalies, CHU Lille, Lille, France
| | - Fanny Morice-Picard
- Pediatric Dermatology Unit, National Center for Rare Skin Disorders, University Hospital of Bordeaux, Bordeaux, France
| | - Juliette Coursimault
- Department of Genetics and Reference Center for Developmental Disorders, Normandie Univ, UNIROUEN, CHU Rouen, Inserm U1245, Rouen, France
| | - Benoît Arveiler
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, Bordeaux, France
- Department of Medical Genetics, University Hospital of Bordeaux, Bordeaux, France
| | - Sophie Javerzat
- Rare Diseases Genetics and Metabolism, INSERM U1211, SBM Department, University of Bordeaux, Bordeaux, France
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15
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Wojcik MH, Reuter CM, Marwaha S, Mahmoud M, Duyzend MH, Barseghyan H, Yuan B, Boone PM, Groopman EE, Délot EC, Jain D, Sanchis-Juan A, Starita LM, Talkowski M, Montgomery SB, Bamshad MJ, Chong JX, Wheeler MT, Berger SI, O'Donnell-Luria A, Sedlazeck FJ, Miller DE. Beyond the exome: What's next in diagnostic testing for Mendelian conditions. Am J Hum Genet 2023; 110:1229-1248. [PMID: 37541186 PMCID: PMC10432150 DOI: 10.1016/j.ajhg.2023.06.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 08/06/2023] Open
Abstract
Despite advances in clinical genetic testing, including the introduction of exome sequencing (ES), more than 50% of individuals with a suspected Mendelian condition lack a precise molecular diagnosis. Clinical evaluation is increasingly undertaken by specialists outside of clinical genetics, often occurring in a tiered fashion and typically ending after ES. The current diagnostic rate reflects multiple factors, including technical limitations, incomplete understanding of variant pathogenicity, missing genotype-phenotype associations, complex gene-environment interactions, and reporting differences between clinical labs. Maintaining a clear understanding of the rapidly evolving landscape of diagnostic tests beyond ES, and their limitations, presents a challenge for non-genetics professionals. Newer tests, such as short-read genome or RNA sequencing, can be challenging to order, and emerging technologies, such as optical genome mapping and long-read DNA sequencing, are not available clinically. Furthermore, there is no clear guidance on the next best steps after inconclusive evaluation. Here, we review why a clinical genetic evaluation may be negative, discuss questions to be asked in this setting, and provide a framework for further investigation, including the advantages and disadvantages of new approaches that are nascent in the clinical sphere. We present a guide for the next best steps after inconclusive molecular testing based upon phenotype and prior evaluation, including when to consider referral to research consortia focused on elucidating the underlying cause of rare unsolved genetic disorders.
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Affiliation(s)
- Monica H Wojcik
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Chloe M Reuter
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Shruti Marwaha
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Medhat Mahmoud
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Michael H Duyzend
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Hayk Barseghyan
- Center for Genetics Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037, USA
| | - Bo Yuan
- Department of Molecular and Human Genetics and Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Philip M Boone
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Emily E Groopman
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Emmanuèle C Délot
- Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037, USA; Center for Genetics Medicine Research, Children's National Research and Innovation Campus, Washington, DC, USA; Department of Pediatrics, George Washington University, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037, USA
| | - Deepti Jain
- Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA 98195, USA
| | - Alba Sanchis-Juan
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lea M Starita
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Michael Talkowski
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Stephen B Montgomery
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael J Bamshad
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA; Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jessica X Chong
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA
| | - Matthew T Wheeler
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Seth I Berger
- Center for Genetics Medicine Research and Rare Disease Institute, Children's National Hospital, Washington, DC 20010, USA
| | - Anne O'Donnell-Luria
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fritz J Sedlazeck
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Computer Science, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Danny E Miller
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA.
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16
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Kavousi S, Pourahmadiyan A, Soleymani F, Noruzinia M. Identification of a Novel de novo Splicing Mutation in Duchenne Muscular Dystrophy Gene in an Iranian Family. Mol Syndromol 2023; 14:331-340. [PMID: 37766830 PMCID: PMC10521217 DOI: 10.1159/000528035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 11/05/2022] [Indexed: 09/29/2023] Open
Abstract
Introduction Duchenne muscular dystrophy (DMD) (NM_004006.3) is one of the most notable neuromuscular disorders of early years. The majority of DMD cases are caused by deletions or duplications in dystrophin, while point mutations are less prevalent in dystrophin abnormalities. It is a common knowledge that the severity of the disease depends on the effect of the mutation on the translational reading frame of the dystrophin mRNA. Case Report We studied an 8-year-old boy with relevant clinical presentations for DMD. Deletion/duplication screening was performed by using multiplex ligation-dependent probe amplification, and whole-exome sequencing was conducted in order to identify potential variants. A novel de novo splice site variant was identified in the DMD gene (DMD: c.8548-2A>G). To explore the effect of a novel variant in DMD, various in silico analyses were carried out to investigate the pathogenicity of the causative variant. To study the structure of a DMD protein and information on how the genetic variant impacts splicing site in models of wild-type and mutated DMD, we carried out different computational studies. Sanger sequencing was performed for the purpose of variant confirmation and familial segregation analysis. Discussion This novel de novo variant was predicted to have an effect on splicing, which leads to DMD due to its significant impacts on dystrophin functionality. The novel mutation would be expected to disrupt the protein structure.
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Affiliation(s)
- Saeideh Kavousi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | | | | | - Mehrdad Noruzinia
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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17
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Masson E, Zou WB, Pu N, Rebours V, Génin E, Wu H, Lin JH, Wang YC, Li ZS, Cooper DN, Férec C, Liao Z, Chen JM. Classification of PRSS1 variants responsible for chronic pancreatitis: An expert perspective from the Franco-Chinese GREPAN study group. Pancreatology 2023; 23:491-506. [PMID: 37581535 DOI: 10.1016/j.pan.2023.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 08/16/2023]
Abstract
BACKGROUND PRSS1 was the first reported chronic pancreatitis (CP) gene. The existence of both gain-of-function (GoF) and gain-of-proteotoxicity (GoP) pathological PRSS1 variants, together with the fact that PRSS1 variants have been identified in CP subtypes spanning the range from monogenic to multifactorial, has made the classification of PRSS1 variants very challenging. METHODS All currently reported PRSS1 variants (derived primarily from two databases) were manually reviewed with respect to their clinical genetics, functional analysis and population allele frequency. They were classified by variant type and pathological mechanism within the framework of our recently proposed ACMG/AMP guidelines-based seven-category system. RESULTS The total number of distinct germline PRSS1 variants included for analysis was 100, comprising 3 copy number variants (CNVs), 12 5' and 3' variants, 19 intronic variants, 5 nonsense variants, 1 frameshift deletion variant, 6 synonymous variants, 1 in-frame duplication, 3 gene conversions and 50 missense variants. Based upon a combination of clinical genetic and functional analysis, population data and in silico analysis, we classified 26 variants (all 3 CNVs, the in-frame duplication, all 3 gene conversions and 19 missense) as "pathogenic", 3 variants (missense) as "likely pathogenic", 5 variants (four missense and one promoter) as "predisposing", 13 variants (all missense) as "unknown significance", 2 variants (missense) as "likely benign", and all remaining 51 variants as "benign". CONCLUSIONS We describe an expert classification of the 100 PRSS1 variants reported to date. The results have immediate implications for reclassifying many ClinVar-registered PRSS1 variants as well as providing optimal guidelines/standards for reporting PRSS1 variants.
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Affiliation(s)
- Emmanuelle Masson
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | - Wen-Bin Zou
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Na Pu
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Department of Critical Care Medicine, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Vinciane Rebours
- Pancreatology and Digestive Oncology Department, Beaujon Hospital, APHP - Clichy, Université Paris Cité, Paris, France
| | - Emmanuelle Génin
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | - Hao Wu
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Jin-Huan Lin
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Yuan-Chen Wang
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Zhao-Shen Li
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Zhuan Liao
- Department of Gastroenterology, Changhai Hospital, The Secondary Military Medical University, Shanghai, China; Shanghai Institute of Pancreatic Diseases, Shanghai, China.
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France.
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18
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Qiu Y, Wang H, Fan M, Pan H, Guan J, Jiang Y, Jia Z, Wu K, Zhou H, Zhuang Q, Lei Z, Ding X, Cai H, Dong Y, Yan L, Lin A, Fu Y, Zhang D, Yan Q, Wang Q. Impaired AIF-CHCHD4 interaction and mitochondrial calcium overload contribute to auditory neuropathy spectrum disorder in patient-iPSC-derived neurons with AIFM1 variant. Cell Death Dis 2023; 14:375. [PMID: 37365177 DOI: 10.1038/s41419-023-05899-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/08/2023] [Accepted: 06/16/2023] [Indexed: 06/28/2023]
Abstract
Auditory neuropathy spectrum disorder (ANSD) is a hearing impairment caused by dysfunction of inner hair cells, ribbon synapses, spiral ganglion neurons and/or the auditory nerve itself. Approximately 1/7000 newborns have abnormal auditory nerve function, accounting for 10%-14% of cases of permanent hearing loss in children. Although we previously identified the AIFM1 c.1265 G > A variant to be associated with ANSD, the mechanism by which ANSD is associated with AIFM1 is poorly understood. We generated induced pluripotent stem cells (iPSCs) from peripheral blood mononuclear cells (PBMCs) via nucleofection with episomal plasmids. The patient-specific iPSCs were edited via CRISPR/Cas9 technology to generate gene-corrected isogenic iPSCs. These iPSCs were further differentiated into neurons via neural stem cells (NSCs). The pathogenic mechanism was explored in these neurons. In patient cells (PBMCs, iPSCs, and neurons), the AIFM1 c.1265 G > A variant caused a novel splicing variant (c.1267-1305del), resulting in AIF p.R422Q and p.423-435del proteins, which impaired AIF dimerization. Such impaired AIF dimerization then weakened the interaction between AIF and coiled-coil-helix-coiled-coil-helix domain-containing protein 4 (CHCHD4). On the one hand, the mitochondrial import of ETC complex subunits was inhibited, subsequently leading to an increased ADP/ATP ratio and elevated ROS levels. On the other hand, MICU1-MICU2 heterodimerization was impaired, leading to mCa2+ overload. Calpain was activated by mCa2+ and subsequently cleaved AIF for its translocation into the nucleus, ultimately resulting in caspase-independent apoptosis. Interestingly, correction of the AIFM1 variant significantly restored the structure and function of AIF, further improving the physiological state of patient-specific iPSC-derived neurons. This study demonstrates that the AIFM1 variant is one of the molecular bases of ANSD. Mitochondrial dysfunction, especially mCa2+ overload, plays a prominent role in ANSD associated with AIFM1. Our findings help elucidate the mechanism of ANSD and may lead to the provision of novel therapies.
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Affiliation(s)
- Yue Qiu
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Hongyang Wang
- Senior Department of Otolaryngology, Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Mingjie Fan
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
- Department of Pediatrics, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, China
| | - Huaye Pan
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Jing Guan
- Senior Department of Otolaryngology, Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Yangwei Jiang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Zexiao Jia
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Kaiwen Wu
- Senior Department of Otolaryngology, Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Hui Zhou
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Qianqian Zhuang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Zhaoying Lei
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Xue Ding
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Huajian Cai
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yufei Dong
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Lei Yan
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Aifu Lin
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yong Fu
- The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310052, China
| | - Dong Zhang
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Qingfeng Yan
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
- Department of Pediatrics, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, China.
- Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou, Zhejiang, 310058, China.
| | - Qiuju Wang
- Senior Department of Otolaryngology, Head and Neck Surgery, Chinese PLA Institute of Otolaryngology, Chinese PLA General Hospital, Beijing, 100853, China.
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19
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Asaad M, Mahfood M, Al Mutery A, Tlili A. Loss-of-function mutations in MYO15A and OTOF cause non-syndromic hearing loss in two Yemeni families. Hum Genomics 2023; 17:42. [PMID: 37189200 DOI: 10.1186/s40246-023-00489-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 05/06/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Hearing loss is a rare hereditary deficit that is rather common among consanguineous populations. Autosomal recessive non-syndromic hearing loss is the predominant form of hearing loss worldwide. Although prevalent, hearing loss is extremely heterogeneous and poses a pitfall in terms of diagnosis and screening. Using next-generation sequencing has enabled a rapid increase in the identification rate of genes and variants in heterogeneous conditions, including hearing loss. We aimed to identify the causative variants in two consanguineous Yemeni families affected with hearing loss using targeted next-generation sequencing (clinical exome sequencing). The proband of each family was presented with sensorineural hearing loss as indicated by pure-tone audiometry results. RESULTS We explored variants obtained from both families, and our analyses collectively revealed the presence and segregation of two novel loss-of-function variants: a frameshift variant, c.6347delA in MYO15A in Family I, and a splice site variant, c.5292-2A > C, in OTOF in Family II. Sanger sequencing and PCR-RFLP of DNA samples from 130 deaf and 50 control individuals confirmed that neither variant was present in our in-house database. In silico analyses predicted that each variant has a pathogenic effect on the corresponding protein. CONCLUSIONS We describe two novel loss-of-function variants in MYO15A and OTOF that cause autosomal recessive non-syndromic hearing loss in Yemeni families. Our findings are consistent with previously reported pathogenic variants in the MYO15A and OTOF genes in Middle Eastern individuals and suggest their implication in hearing loss.
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Affiliation(s)
- Maria Asaad
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
| | - Mona Mahfood
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
| | - Abdullah Al Mutery
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE
- Human Genetics and Stem Cells Research Group, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, UAE
| | - Abdelaziz Tlili
- Department of Applied Biology, College of Sciences, University of Sharjah, Building W8 - Room 107, P.O. Box 27272, Sharjah, UAE.
- Human Genetics and Stem Cells Research Group, Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, UAE.
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20
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Aguilera C, Padró-Miquel A, Esteve-Garcia A, Cerdà P, Torres-Iglesias R, Llecha N, Riera-Mestre A. Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience. Genes (Basel) 2023; 14:genes14030772. [PMID: 36981042 PMCID: PMC10048779 DOI: 10.3390/genes14030772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/14/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
BACKGROUND Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in more than 90% of the patients undergoing molecular testing. The identification of variants of unknown significance is often seen as a challenge in clinical practice that makes family screening and genetic counseling difficult. Here, we show that the implementation of cDNA analysis to assess the effect of splice site variants on mRNA splicing is a powerful tool. METHODS Gene panel sequencing of genes associated with HHT and other arteriovenous malformation-related syndromes was performed. To evaluate the effect of the splice site variants, cDNA analysis of ENG and ACVRL1 genes was carried out. RESULTS three novel splice site variants were identified in ENG (c.68-2A > T and c.1311+4_1311+8del) and ACVLR1 (c.526-6C > G) genes correspondingly in three individuals with HHT that met ≥ 3 Curaçao criteria. All three variants led to an aberrant splicing inducing exon skipping (ENG:c.68-2A > T and ACVRL1:c.526-6C > G) or intron retention (ENG:c.1311+4_1311+8del) allowing the confirmation of the predicted effect on splicing and the reclassification from unknown significance to pathogenic/likely pathogenic of two of them. CONCLUSIONS RNA analysis should be performed to assess and/or confirm the impact of variants on splicing. The molecular diagnosis of HHT patients is crucial to allow family screening and accurate genetic counseling. A multidisciplinary approach including clinicians and geneticists is crucial when dealing with patients with rare diseases.
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Affiliation(s)
- Cinthia Aguilera
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Genetics Laboratory, Laboratori Clínic Territorial Metropolitana Sud, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Ariadna Padró-Miquel
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Genetics Laboratory, Laboratori Clínic Territorial Metropolitana Sud, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Anna Esteve-Garcia
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Clinical Genetics Unit, Laboratori Clínic Territorial Metropolitana Sud, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Pau Cerdà
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Internal Medicine Department, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Raquel Torres-Iglesias
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Internal Medicine Department, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Núria Llecha
- Genetics Laboratory, Laboratori Clínic Territorial Metropolitana Sud, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Clinical Genetics Unit, Laboratori Clínic Territorial Metropolitana Sud, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
| | - Antoni Riera-Mestre
- Hereditary Hemorrhagic Telangiectasia Unit, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Internal Medicine Department, Hospital Universitari de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), 08907 L'Hospitalet de Llobregat, Spain
- Faculty of Medicine and Health Sciences, Universitat de Barcelona, 08907 L'Hospitalet de Llobregat, Spain
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21
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Núñez-Moreno G, Tamayo A, Ruiz-Sánchez C, Cortón M, Mínguez P. VIsoQLR: an interactive tool for the detection, quantification and fine-tuning of isoforms in selected genes using long-read sequencing. Hum Genet 2023; 142:495-506. [PMID: 36881176 DOI: 10.1007/s00439-023-02539-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/23/2023] [Indexed: 03/08/2023]
Abstract
DNA variants altering the pre-mRNA splicing process represent an underestimated cause of human genetic diseases. Their association with disease traits should be confirmed using functional assays from patient cell lines or alternative models to detect aberrant mRNAs. Long-read sequencing is a suitable technique to identify and quantify mRNA isoforms. Available isoform detection and/or quantification tools are generally designed for the whole transcriptome analysis. However experiments focusing on genes of interest need more precise data fine-tuning and visualization tools.Here we describe VIsoQLR, an interactive analyzer, viewer and editor for the semi-automated identification and quantification of known and novel isoforms using long-read sequencing data. VIsoQLR is tailored to thoroughly analyze mRNA expression in splicing assays of selected genes. Our tool takes sequences aligned to a reference, and for each gene, it defines consensus splice sites and quantifies isoforms. VIsoQLR introduces features to edit the splice sites through dynamic and interactive graphics and tables, allowing accurate manual curation. Known isoforms detected by other methods can also be imported as references for comparison. A benchmark against two other popular transcriptome-based tools shows VIsoQLR accurate performance on both detection and quantification of isoforms. Here, we present VIsoQLR principles and features and its applicability in a case study example using nanopore-based long-read sequencing. VIsoQLR is available at https://github.com/TBLabFJD/VIsoQLR .
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Affiliation(s)
- Gonzalo Núñez-Moreno
- Department of Genetics and Genomics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.
- Bioinformatics Unit, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
| | - Alejandra Tamayo
- Department of Genetics and Genomics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871, Alcalá de Henares, Spain
| | - Carolina Ruiz-Sánchez
- Department of Genetics and Genomics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Marta Cortón
- Department of Genetics and Genomics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Pablo Mínguez
- Department of Genetics and Genomics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Bioinformatics Unit, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
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22
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Wojcik MH, Reuter CM, Marwaha S, Mahmoud M, Duyzend MH, Barseghyan H, Yuan B, Boone PM, Groopman EE, Délot EC, Jain D, Sanchis-Juan A, Starita LM, Talkowski M, Montgomery SB, Bamshad MJ, Chong JX, Wheeler MT, Berger SI, O’Donnell-Luria A, Sedlazeck FJ, Miller DE. Beyond the exome: what's next in diagnostic testing for Mendelian conditions. ARXIV 2023:arXiv:2301.07363v1. [PMID: 36713248 PMCID: PMC9882576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Despite advances in clinical genetic testing, including the introduction of exome sequencing (ES), more than 50% of individuals with a suspected Mendelian condition lack a precise molecular diagnosis. Clinical evaluation is increasingly undertaken by specialists outside of clinical genetics, often occurring in a tiered fashion and typically ending after ES. The current diagnostic rate reflects multiple factors, including technical limitations, incomplete understanding of variant pathogenicity, missing genotype-phenotype associations, complex gene-environment interactions, and reporting differences between clinical labs. Maintaining a clear understanding of the rapidly evolving landscape of diagnostic tests beyond ES, and their limitations, presents a challenge for non-genetics professionals. Newer tests, such as short-read genome or RNA sequencing, can be challenging to order and emerging technologies, such as optical genome mapping and long-read DNA or RNA sequencing, are not available clinically. Furthermore, there is no clear guidance on the next best steps after inconclusive evaluation. Here, we review why a clinical genetic evaluation may be negative, discuss questions to be asked in this setting, and provide a framework for further investigation, including the advantages and disadvantages of new approaches that are nascent in the clinical sphere. We present a guide for the next best steps after inconclusive molecular testing based upon phenotype and prior evaluation, including when to consider referral to a consortium such as GREGoR, which is focused on elucidating the underlying cause of rare unsolved genetic disorders.
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Affiliation(s)
- Monica H. Wojcik
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Division of Newborn Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Chloe M. Reuter
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Shruti Marwaha
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Medhat Mahmoud
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston TX 77030 USA
| | - Michael H. Duyzend
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Hayk Barseghyan
- Center for Genetics Medicine Research, Children’s National Research Institute, Children’s National Hospital, Washington, DC 20010 USA
- Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037 USA
| | - Bo Yuan
- Department of Molecular and Human Genetics and Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston TX 77030 USA
| | - Philip M. Boone
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Emily E. Groopman
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Emmanuèle C. Délot
- Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037 USA
- Center for Genetics Medicine Research, Children’s National Research and Innovation Campus, Washington, DC, USA
- Department of Pediatrics, George Washington University, School of Medicine and Health Sciences, George Washington University, Washington, DC 20037 USA
| | - Deepti Jain
- Department of Biostatistics, School of Public Health, University of Washington, Seattle WA 98195 USA
| | - Alba Sanchis-Juan
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
| | | | - Lea M. Starita
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195 USA
| | - Michael Talkowski
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114 USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Stephen B. Montgomery
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA 94305 USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305 USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Michael J. Bamshad
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195 USA
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195 USA
| | - Jessica X. Chong
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195 USA
| | - Matthew T. Wheeler
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Seth I. Berger
- Center for Genetics Medicine Research and Rare Disease Institute, Children’s National Hospital, Washington, DC 20010 USA
| | - Anne O’Donnell-Luria
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115 USA
- Center for Genomic Medicine, Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114 USA
| | - Fritz J. Sedlazeck
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston TX 77030 USA
- Department of Computer Science, Rice University, 6100 Main Street, Houston, TX, 77005 USA
| | - Danny E. Miller
- Brotman Baty Institute for Precision Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195 USA
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23
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Tamayo A, Núñez-Moreno G, Ruiz C, Plaisancie J, Damian A, Moya J, Chassaing N, Calvas P, Ayuso C, Minguez P, Corton M. Minigene Splicing Assays and Long-Read Sequencing to Unravel Pathogenic Deep-Intronic Variants in PAX6 in Congenital Aniridia. Int J Mol Sci 2023; 24:ijms24021562. [PMID: 36675087 PMCID: PMC9863980 DOI: 10.3390/ijms24021562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
PAX6 haploinsufficiency causes aniridia, a congenital eye disorder that involves the iris, and foveal hypoplasia. Comprehensive screening of the PAX6 locus, including the non-coding regions, by next-generation sequencing revealed four deep-intronic variants with potential effects on pre-RNA splicing. Nevertheless, without a functional analysis, their pathogenicity could not be established. We aimed to decipher their impact on the canonical PAX6 splicing using in vitro minigene splicing assays and nanopore-based long-read sequencing. Two multi-exonic PAX6 constructs were generated, and minigene assays were carried out. An aberrant splicing pattern was observed for two variants in intron 6, c.357+136G>A and c.357+334G>A. In both cases, several exonization events, such as pseudoexon inclusions and partial intronic retention, were observed due to the creation or activation of new/cryptic non-canonical splicing sites, including a shared intronic donor site. In contrast, two variants identified in intron 11, c.1032+170A>T and c.1033-275A>C, seemed not to affect splicing processes. We confirmed the high complexity of alternative splicing of PAX6 exon 6, which also involves unreported cryptic intronic sites. Our study highlights the importance of integrating functional studies into diagnostic algorithms to decipher the potential implication of non-coding variants, usually classified as variants of unknown significance, thus allowing variant reclassification to achieve a conclusive genetic diagnosis.
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Affiliation(s)
- Alejandra Tamayo
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Surgery, Medical and Social Sciences, Faculty of Medicine and Health Sciences, Science and Technology Campus, University of Alcalá, 28871 Alcalá de Henares, Spain
| | - Gonzalo Núñez-Moreno
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Carolina Ruiz
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Julie Plaisancie
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Alejandra Damian
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jennifer Moya
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
| | - Nicolas Chassaing
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Patrick Calvas
- Centre de Référence des Affections Rares en Génétique Ophtalmologique (CARGO), Hôpital Purpan, CHU Toulouse, 31000 Toulouse, France
- INSERM U1214, Université Toulouse III, 31000 Toulouse, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28240 Madrid, Spain
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
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24
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Barbosa P, Savisaar R, Carmo-Fonseca M, Fonseca A. Computational prediction of human deep intronic variation. Gigascience 2022; 12:giad085. [PMID: 37878682 PMCID: PMC10599398 DOI: 10.1093/gigascience/giad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 06/07/2023] [Accepted: 09/20/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND The adoption of whole-genome sequencing in genetic screens has facilitated the detection of genetic variation in the intronic regions of genes, far from annotated splice sites. However, selecting an appropriate computational tool to discriminate functionally relevant genetic variants from those with no effect is challenging, particularly for deep intronic regions where independent benchmarks are scarce. RESULTS In this study, we have provided an overview of the computational methods available and the extent to which they can be used to analyze deep intronic variation. We leveraged diverse datasets to extensively evaluate tool performance across different intronic regions, distinguishing between variants that are expected to disrupt splicing through different molecular mechanisms. Notably, we compared the performance of SpliceAI, a widely used sequence-based deep learning model, with that of more recent methods that extend its original implementation. We observed considerable differences in tool performance depending on the region considered, with variants generating cryptic splice sites being better predicted than those that potentially affect splicing regulatory elements. Finally, we devised a novel quantitative assessment of tool interpretability and found that tools providing mechanistic explanations of their predictions are often correct with respect to the ground - information, but the use of these tools results in decreased predictive power when compared to black box methods. CONCLUSIONS Our findings translate into practical recommendations for tool usage and provide a reference framework for applying prediction tools in deep intronic regions, enabling more informed decision-making by practitioners.
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Affiliation(s)
- Pedro Barbosa
- LASIGE, Departamento de Informática, Faculdade de Ciências, Universidade de Lisboa, 1749-016,, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | | | - Maria Carmo-Fonseca
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | - Alcides Fonseca
- LASIGE, Departamento de Informática, Faculdade de Ciências, Universidade de Lisboa, 1749-016,, Lisboa, Portugal
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25
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Te Paske IBAW, Mensenkamp AR, Neveling K, Hoogerbrugge N, Ligtenberg MJL, De Voer RM. Noncoding Aberrations in Mismatch Repair Genes Underlie a Substantial Part of the Missing Heritability in Lynch Syndrome. Gastroenterology 2022; 163:1691-1694.e7. [PMID: 36037994 DOI: 10.1053/j.gastro.2022.08.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 08/15/2022] [Accepted: 08/22/2022] [Indexed: 12/02/2022]
Affiliation(s)
- Iris B A W Te Paske
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Arjen R Mensenkamp
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | | | - Nicoline Hoogerbrugge
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Marjolijn J L Ligtenberg
- Department of Human Genetics, Department of Pathology, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands
| | - Richarda M De Voer
- Department of Human Genetics, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, the Netherlands.
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26
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García-Ruiz S, Gustavsson EK, Zhang D, Reynolds RH, Chen Z, Fairbrother-Browne A, Gil-Martínez AL, Botia JA, Collado-Torres L, Ryten M. IntroVerse: a comprehensive database of introns across human tissues. Nucleic Acids Res 2022; 51:D167-D178. [PMID: 36399497 PMCID: PMC9825543 DOI: 10.1093/nar/gkac1056] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/21/2022] [Accepted: 10/30/2022] [Indexed: 11/19/2022] Open
Abstract
Dysregulation of RNA splicing contributes to both rare and complex diseases. RNA-sequencing data from human tissues has shown that this process can be inaccurate, resulting in the presence of novel introns detected at low frequency across samples and within an individual. To enable the full spectrum of intron use to be explored, we have developed IntroVerse, which offers an extensive catalogue on the splicing of 332,571 annotated introns and a linked set of 4,679,474 novel junctions covering 32,669 different genes. This dataset has been generated through the analysis of 17,510 human control RNA samples from 54 tissues provided by the Genotype-Tissue Expression Consortium. IntroVerse has two unique features: (i) it provides a complete catalogue of novel junctions and (ii) each novel junction has been assigned to a specific annotated intron. This unique, hierarchical structure offers multiple uses, including the identification of novel transcripts from known genes and their tissue-specific usage, and the assessment of background splicing noise for introns thought to be mis-spliced in disease states. IntroVerse provides a user-friendly web interface and is freely available at https://rytenlab.com/browser/app/introverse.
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Affiliation(s)
- Sonia García-Ruiz
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Emil K Gustavsson
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - David Zhang
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Regina H Reynolds
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Zhongbo Chen
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK
| | - Aine Fairbrother-Browne
- Department of Genetics and Genomic Medicine Research & Teaching, UCL GOS Institute of Child Health, London, WC1N 1EH, UK,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK,Department of Medical and Molecular Genetics, School of Basic and Medical Biosciences, King's College London, London, WC2R 2LS, UK
| | - Ana Luisa Gil-Martínez
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, UCL, London WC1N 3BG, UK,Department of Information and Communications Engineering Faculty of Informatics, Espinardo Campus, University of Murcia, Murcia, 30100, Spain
| | - Juan A Botia
- Department of Information and Communications Engineering Faculty of Informatics, Espinardo Campus, University of Murcia, Murcia, 30100, Spain
| | | | - Mina Ryten
- To whom correspondence should be addressed. Tel: +44 2081387617;
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27
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Coll M, Fernandez-Falgueras A, Iglesias A, del Olmo B, Nogue-Navarro L, Simon A, Perez Serra A, Puigmule M, Lopez L, Pico F, Corona M, Vallverdu-Prats M, Tiron C, Campuzano O, Castella J, Brugada R, Alcalde M. Unpredicted Aberrant Splicing Products Identified in Postmortem Sudden Cardiac Death Samples. Int J Mol Sci 2022; 23:ijms232012640. [PMID: 36293497 PMCID: PMC9604081 DOI: 10.3390/ijms232012640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/21/2022] Open
Abstract
Molecular screening for pathogenic mutations in sudden cardiac death (SCD)-related genes is common practice for SCD cases. However, test results may lead to uncertainty because of the identification of variants of unknown significance (VUS) occurring in up to 70% of total identified variants due to a lack of experimental studies. Genetic variants affecting potential splice site variants are among the most difficult to interpret. The aim of this study was to examine rare intronic variants identified in the exonic flanking sequence to meet two main objectives: first, to validate that canonical intronic variants produce aberrant splicing; second, to determine whether rare intronic variants predicted as VUS may affect the splicing product. To achieve these objectives, 28 heart samples of cases of SCD carrying rare intronic variants were studied. Samples were analyzed using 85 SCD genes in custom panel sequencing. Our results showed that rare intronic variants affecting the most canonical splice sites displayed in 100% of cases that they would affect the splicing product, possibly causing aberrant isoforms. However, 25% of these cases (1/4) showed normal splicing, contradicting the in silico results. On the contrary, in silico results predicted an effect in 0% of cases, and experimental results showed >20% (3/14) unpredicted aberrant splicing. Thus, deep intron variants are likely predicted to not have an effect, which, based on our results, might be an underestimation of their effect and, therefore, of their pathogenicity classification and family members’ follow-up.
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Affiliation(s)
- Monica Coll
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | | | - Anna Iglesias
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Bernat del Olmo
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Laia Nogue-Navarro
- Faculty of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), Can Baumann, 08500 Vic, Spain
| | - Adria Simon
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Alexandra Perez Serra
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Marta Puigmule
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
| | - Laura Lopez
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Ferran Pico
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Monica Corona
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Marta Vallverdu-Prats
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
| | - Coloma Tiron
- Cardiology Service, Hospital Dr. Josep Trueta, University of Girona, 17007 Girona, Spain
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
| | - Oscar Campuzano
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Medical Science Department, School of Medicine, University of Girona, 17004 Girona, Spain
| | - Josep Castella
- Forensic Pathology Service, Institut de Medicina Legal i Ciències Forenses de Catalunya (IMLCFC), 08075 Barcelona, Spain
| | - Ramon Brugada
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
- Cardiology Service, Hospital Dr. Josep Trueta, University of Girona, 17007 Girona, Spain
- Centro Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029 Madrid, Spain
- Medical Science Department, School of Medicine, University of Girona, 17004 Girona, Spain
- Correspondence: (R.B.); (M.A.)
| | - Mireia Alcalde
- Cardiovascular Genetics Center, Institut d’Investigació Biomèdica de Girona (IdIBGi), 17190 Salt, Spain
- Correspondence: (R.B.); (M.A.)
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28
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Unni P, Friend J, Weinberg J, Okur V, Hochscherf J, Dominguez I. Predictive functional, statistical and structural analysis of CSNK2A1 and CSNK2B variants linked to neurodevelopmental diseases. Front Mol Biosci 2022; 9:851547. [PMID: 36310603 PMCID: PMC9608649 DOI: 10.3389/fmolb.2022.851547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 06/29/2022] [Indexed: 12/02/2022] Open
Abstract
Okur-Chung Neurodevelopmental Syndrome (OCNDS) and Poirier-Bienvenu Neurodevelopmental Syndrome (POBINDS) were recently identified as rare neurodevelopmental disorders. OCNDS and POBINDS are associated with heterozygous mutations in the CSNK2A1 and CSNK2B genes which encode CK2α, a serine/threonine protein kinase, and CK2β, a regulatory protein, respectively, which together can form a tetrameric enzyme called protein kinase CK2. A challenge in OCNDS and POBINDS is to understand the genetic basis of these diseases and the effect of the various CK2⍺ and CK2β mutations. In this study we have collected all variants available to date in CSNK2A1 and CSNK2B, and identified hotspots. We have investigated CK2⍺ and CK2β missense mutations through prediction programs which consider the evolutionary conservation, functionality and structure or these two proteins, compared these results with published experimental data on CK2α and CK2β mutants, and suggested prediction programs that could help predict changes in functionality of CK2α mutants. We also investigated the potential effect of CK2α and CK2β mutations on the 3D structure of the proteins and in their binding to each other. These results indicate that there are functional and structural consequences of mutation of CK2α and CK2β, and provide a rationale for further study of OCNDS and POBINDS-associated mutations. These data contribute to understanding the genetic and functional basis of these diseases, which is needed to identify their underlying mechanisms.
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Affiliation(s)
- Prasida Unni
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston University, Boston, MA, United States
| | - Jack Friend
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston University, Boston, MA, United States
| | - Janice Weinberg
- Department of Biostatistics, Boston University School of Public Health, Boston University, Boston, MA, United States
| | - Volkan Okur
- New York Genome Center, New York, NY, United States
| | - Jennifer Hochscherf
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Isabel Dominguez
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston University, Boston, MA, United States
- *Correspondence: Isabel Dominguez,
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29
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Mendoza-Alvarez A, Tosco-Herrera E, Muñoz-Barrera A, Rubio-Rodríguez LA, Alonso-Gonzalez A, Corrales A, Iñigo-Campos A, Almeida-Quintana L, Martin-Fernandez E, Martinez-Beltran D, Perez-Rodriguez E, Callero A, Garcia-Robaina JC, González-Montelongo R, Marcelino-Rodriguez I, Lorenzo-Salazar JM, Flores C. A catalog of the genetic causes of hereditary angioedema in the Canary Islands (Spain). Front Immunol 2022; 13:997148. [PMID: 36203598 PMCID: PMC9531158 DOI: 10.3389/fimmu.2022.997148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Hereditary angioedema (HAE) is a rare disease where known causes involve C1 inhibitor dysfunction or dysregulation of the kinin cascade. The updated HAE management guidelines recommend performing genetic tests to reach a precise diagnosis. Unfortunately, genetic tests are still uncommon in the diagnosis routine. Here, we characterized for the first time the genetic causes of HAE in affected families from the Canary Islands (Spain). Whole-exome sequencing data was obtained from 41 affected patients and unaffected relatives from 29 unrelated families identified in the archipelago. The Hereditary Angioedema Database Annotation (HADA) tool was used for pathogenicity classification and causal variant prioritization among the genes known to cause HAE. Manual reclassification of prioritized variants was used in those families lacking known causal variants. We detected a total of eight different variants causing HAE in this patient series, affecting essentially SERPING1 and F12 genes, one of them being a novel SERPING1 variant (c.686-12A>G) with a predicted splicing effect which was reclassified as likely pathogenic in one family. Altogether, the diagnostic yield by assessing previously reported causal genes and considering variant reclassifications according to the American College of Medical Genetics guidelines reached 66.7% (95% Confidence Interval [CI]: 30.1-91.0) in families with more than one affected member and 10.0% (95% CI: 1.8-33.1) among cases without family information for the disease. Despite the genetic causes of many patients remain to be identified, our results reinforce the need of genetic tests as first-tier diagnostic tool in this disease, as recommended by the international WAO/EAACI guidelines for the management of HAE.
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Affiliation(s)
| | - Eva Tosco-Herrera
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Adrian Muñoz-Barrera
- Genomics Division, Instituto Tecnológico y de Energías Renovables, Santa Cruz de Tenerife, Spain
| | - Luis A. Rubio-Rodríguez
- Genomics Division, Instituto Tecnológico y de Energías Renovables, Santa Cruz de Tenerife, Spain
| | - Aitana Alonso-Gonzalez
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Almudena Corrales
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio Iñigo-Campos
- Genomics Division, Instituto Tecnológico y de Energías Renovables, Santa Cruz de Tenerife, Spain
| | - Lourdes Almeida-Quintana
- Allergy Service, Hospital Universitario de Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Spain
| | - Elena Martin-Fernandez
- Allergy Service, Hospital Universitario Dr. Molina Orosa, Las Palmas de Gran Canaria, Spain
| | - Dara Martinez-Beltran
- Allergy Service, Hospital Universitario Insular-Materno Infantil, Las Palmas de Gran Canaria, Spain
| | - Eva Perez-Rodriguez
- Allergy Service, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Ariel Callero
- Allergy Service, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | - Jose C. Garcia-Robaina
- Allergy Service, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
| | | | - Itahisa Marcelino-Rodriguez
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Public Health and Preventive Medicine Area, Universidad de La Laguna, Santa Cruz de Tenerife, Spain
| | - Jose M. Lorenzo-Salazar
- Genomics Division, Instituto Tecnológico y de Energías Renovables, Santa Cruz de Tenerife, Spain
| | - Carlos Flores
- Research Unit, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain
- Genomics Division, Instituto Tecnológico y de Energías Renovables, Santa Cruz de Tenerife, Spain
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
- Facultad de Ciencias de la Salud, Universidad Fernando Pessoa Canarias, Las Palmas de Gran Canaria, Spain
- *Correspondence: Carlos Flores,
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30
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Wai HA, Constable M, Drewes C, Davies IC, Svobodova E, Dempsey E, Saggar A, Homfray T, Mansour S, Douzgou S, Barr K, Mercer C, Hunt D, Douglas AGL, Baralle D. Short amplicon reverse transcription-polymerase chain reaction detects aberrant splicing in genes with low expression in blood missed by ribonucleic acid sequencing analysis for clinical diagnosis. Hum Mutat 2022; 43:963-970. [PMID: 35476365 PMCID: PMC9325405 DOI: 10.1002/humu.24378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 12/03/2022]
Abstract
Use of blood RNA sequencing (RNA-seq) as a splicing analysis tool for clinical interpretation of variants of uncertain significance (VUSs) found via whole-genome and exome sequencing can be difficult for genes that have low expression in the blood due to insufficient read count coverage aligned to specific genes of interest. Here, we present a short amplicon reverse transcription-polymerase chain reaction(RT-PCR) for the detection of genes with low blood expression. Short amplicon RT-PCR, is designed to span three exons where an exon harboring a variant is flanked by one upstream and one downstream exon. We tested short amplicon RT-PCRs for genes that have median transcripts per million (TPM) values less than one according to the genotype-tissue expression database. Median TPM values of genes analyzed in this study are SYN1 = 0.8549, COL1A1 = 0.6275, TCF4 = 0.4009, DSP = .2894, TTN = 0.2851, COL5A2 = 0.1036, TERT = 0.04452, NTRK2 = 0.0344, ABCA4 = 0.00744, PRPH = 0, and WT1 = 0. All these genes show insufficient exon-spanning read coverage in our RNA-seq data to allow splicing analysis. We successfully detected all genes tested except PRPH and WT1. Aberrant splicing was detected in SYN1, TCF4, NTRK2, TTN, and TERT VUSs. Therefore, our results show short amplicon RT-PCR is a useful alternative for the analysis of splicing events in genes with low TPM in blood RNA for clinical diagnostics.
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Affiliation(s)
- Htoo A. Wai
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Matthew Constable
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Cosima Drewes
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Ian C. Davies
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Eliska Svobodova
- Department of Experimental Biology, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
| | - Esther Dempsey
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Anand Saggar
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Tessa Homfray
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Sahar Mansour
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Sofia Douzgou
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation TrustHealth Innovation ManchesterManchesterUK,Division of Evolution and Genomic Sciences, Faculty of Biology, Medicine and Health, School of Biological SciencesUniversity of ManchesterManchesterUK
| | - Kate Barr
- Bristol Regional Clinical Genetics ServiceSt Michael's HospitalBristolUK
| | - Catherine Mercer
- Department of Experimental Biology, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
| | - David Hunt
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - Andrew G. L. Douglas
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
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31
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New Developments and Possibilities in Reanalysis and Reinterpretation of Whole Exome Sequencing Datasets for Unsolved Rare Diseases Using Machine Learning Approaches. Int J Mol Sci 2022; 23:ijms23126792. [PMID: 35743235 PMCID: PMC9224427 DOI: 10.3390/ijms23126792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 11/21/2022] Open
Abstract
Rare diseases impact the lives of 300 million people in the world. Rapid advances in bioinformatics and genomic technologies have enabled the discovery of causes of 20–30% of rare diseases. However, most rare diseases have remained as unsolved enigmas to date. Newer tools and availability of high throughput sequencing data have enabled the reanalysis of previously undiagnosed patients. In this review, we have systematically compiled the latest developments in the discovery of the genetic causes of rare diseases using machine learning methods. Importantly, we have detailed methods available to reanalyze existing whole exome sequencing data of unsolved rare diseases. We have identified different reanalysis methodologies to solve problems associated with sequence alterations/mutations, variation re-annotation, protein stability, splice isoform malfunctions and oligogenic analysis. In addition, we give an overview of new developments in the field of rare disease research using whole genome sequencing data and other omics.
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32
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Targeted RNAseq Improves Clinical Diagnosis of Very Early-Onset Pediatric Immune Dysregulation. J Pers Med 2022; 12:jpm12060919. [PMID: 35743704 PMCID: PMC9224647 DOI: 10.3390/jpm12060919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 02/05/2023] Open
Abstract
Despite increased use of whole exome sequencing (WES) for the clinical analysis of rare disease, overall diagnostic yield for most disorders hovers around 30%. Previous studies of mRNA have succeeded in increasing diagnoses for clearly defined disorders of monogenic inheritance. We asked if targeted RNA sequencing could provide similar benefits for primary immunodeficiencies (PIDs) and very early-onset inflammatory bowel disease (VEOIBD), both of which are difficult to diagnose due to high heterogeneity and variable severity. We performed targeted RNA sequencing of a panel of 260 immune-related genes for a cohort of 13 patients (seven suspected PID cases and six VEOIBD) and analyzed variants, splicing, and exon usage. Exonic variants were identified in seven cases, some of which had been previously prioritized by exome sequencing. For four cases, allele specific expression or lack thereof provided additional insights into possible disease mechanisms. In addition, we identified five instances of aberrant splicing associated with four variants. Three of these variants had been previously classified as benign in ClinVar based on population frequency. Digenic or oligogenic inheritance is suggested for at least two patients. In addition to validating the use of targeted RNA sequencing, our results show that rare disease research will benefit from incorporating contributing genetic factors into the diagnostic approach.
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33
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Tsybulskyi V, Meyer IM. ShapeSorter: a fully probabilistic method for detecting conserved RNA structure features supported by SHAPE evidence. Nucleic Acids Res 2022; 50:e85. [PMID: 35641016 PMCID: PMC9410897 DOI: 10.1093/nar/gkac405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/09/2022] [Indexed: 12/20/2022] Open
Abstract
There is an increased interest in the determination of RNA structures in vivo as it is now possible to probe them in a high-throughput manner, e.g. using SHAPE protocols. By now, there exist a range of computational methods that integrate experimental SHAPE-probing evidence into computational RNA secondary structure prediction. The state-of-the-art in this field is currently provided by computational methods that employ the minimum-free energy strategy for prediction RNA secondary structures with SHAPE-probing evidence. These methods, however, rely on the assumption that transcripts in vivo fold into the thermodynamically most stable configuration and ignore evolutionary evidence for conserved RNA structure features. We here present a new computational method, ShapeSorter, that predicts RNA structure features without employing the thermodynamic strategy. Instead, ShapeSorter employs a fully probabilistic framework to identify RNA structure features that are supported by evolutionary and SHAPE-probing evidence. Our method can capture RNA structure heterogeneity, pseudo-knotted RNA structures as well as transient and mutually exclusive RNA structure features. Moreover, it estimates P-values for the predicted RNA structure features which allows for easy filtering and ranking. We investigate the merits of our method in a comprehensive performance benchmarking and conclude that ShapeSorter has a significantly superior performance for predicting base-pairs than the existing state-of-the-art methods.
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Affiliation(s)
- Volodymyr Tsybulskyi
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115 Berlin, Germany.,Freie Universität Berlin, Department of Mathematics and Computer Science, Institute of Computer Science, Takustraße 9, 14195 Berlin, Germany
| | - Irmtraud M Meyer
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115 Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Thielallee 63, 14195 Berlin, Germany.,Freie Universität Berlin, Department of Mathematics and Computer Science, Institute of Computer Science, Takustraße 9, 14195 Berlin, Germany
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34
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Montgomery SB, Bernstein JA, Wheeler MT. Toward transcriptomics as a primary tool for rare disease investigation. Cold Spring Harb Mol Case Stud 2022; 8:a006198. [PMID: 35217565 PMCID: PMC8958920 DOI: 10.1101/mcs.a006198] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In the past 5 years transcriptome or RNA-sequencing (RNA-seq) has steadily emerged as a complementary assay for rare disease diagnosis and discovery. In this perspective, we summarize several recent developments and challenges in the use of RNA-seq for rare disease investigation. Using an accessible patient sample, such as blood, skin, or muscle, RNA-seq enables the assay of expressed RNA transcripts. Analysis of RNA-seq allows the identification of aberrant or outlier gene expression and alternative splicing as functional evidence to support rare disease study and diagnosis. Further, many types of variant effects can be profiled beyond coding variants, as the consequences of noncoding variants that impact gene expression and splicing can be directly observed. This is particularly apparent for structural variants that disproportionately underlie outlier gene expression and for splicing variants in which RNA-seq can both measure aberrant canonical splicing and detect deep intronic effects. However, a major potential limitation of RNA-seq in rare disease investigation is the developmental and cell type specificity of gene expression as a pathogenic variant's effect may be limited to a specific spatiotemporal context and access to a patient's tissue sample from the relevant tissue and timing of disease expression may not be possible. We speculate that as advances in computational methods and emerging experimental techniques overcome both developmental and cell type specificity, there will be broadening use of RNA sequencing and multiomics in rare disease diagnosis and delivery of precision health.
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Affiliation(s)
- Stephen B Montgomery
- Departments of Genetics and Pathology, Stanford University, California 94305, USA
| | - Jonathan A Bernstein
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Matthew T Wheeler
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, California 94304, USA
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35
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Conboy JG. A Deep Exon Cryptic Splice Site Promotes Aberrant Intron Retention in a Von Willebrand Disease Patient. Int J Mol Sci 2021; 22:13248. [PMID: 34948044 PMCID: PMC8706089 DOI: 10.3390/ijms222413248] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 12/13/2022] Open
Abstract
A translationally silent single nucleotide mutation in exon 44 (E44) of the von Willebrand factor (VWF) gene is associated with inefficient removal of intron 44 in a von Willebrand disease (VWD) patient. This intron retention (IR) event was previously attributed to reordered E44 secondary structure that sequesters the normal splice donor site. We propose an alternative mechanism: the mutation introduces a cryptic splice donor site that interferes with the function of the annotated site to favor IR. We evaluated both models using minigene splicing reporters engineered to vary in secondary structure and/or cryptic splice site content. Analysis of splicing efficiency in transfected K562 cells suggested that the mutation-generated cryptic splice site in E44 was sufficient to induce substantial IR. Mutations predicted to vary secondary structure at the annotated site also had modest effects on IR and shifted the balance of residual splicing between the cryptic site and annotated site, supporting competition among the sites. Further studies demonstrated that introduction of cryptic splice donor motifs at other positions in E44 did not promote IR, indicating that interference with the annotated site is context dependent. We conclude that mutant deep exon splice sites can interfere with proper splicing by inducing IR.
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Affiliation(s)
- John G Conboy
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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36
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Antisense-Mediated Down-Regulation of Factor V-Short Splicing in a Liver Cell Line Model. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11209621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coagulation factor V (FV) is a liver-derived protein encoded by the F5 gene. Alternative splicing of F5 exon 13 produces a low-abundance splicing isoform, known as FV-short, which binds the anticoagulant protein tissue factor pathway inhibitor (TFPIα) with high affinity, stabilising it in the circulation and potently enhancing its anticoagulant activity. Accordingly, rare F5 gene mutations that up-regulate FV-short splicing are associated with bleeding. In this study we have explored the possibility of decreasing FV-short splicing by antisense-based splicing modulation. To this end, we have designed morpholino antisense oligonucleotides (MAOs) targeting the FV-short-specific donor and acceptor splice sites and tested their efficacy in a liver cell line (HepG2) that naturally expresses full-length FV and FV-short. Cells were treated with 0–20 µM MAO, and full-length FV and FV-short mRNA expression was analysed by RT-(q)PCR. Both MAOs, alone or in combination, decreased the FV-short/full-length FV mRNA ratio down to ~50% of its original value in a specific and dose-dependent manner. This pilot study provides proof-of-principle for the possibility to decrease FV-short expression by antisense-mediated splicing modulation. In turn, this may form the basis for novel therapeutic approaches to bleeding disorders caused by FV-short over-expression and/or elevated TFPIα (activity) levels.
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