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Vaché C, Faugère V, Baux D, Mansard L, Van Goethem C, Dhaenens CM, Grunewald O, Audo I, Zeitz C, Meunier I, Bocquet B, Cossée M, Bergougnoux A, Kalatzis V, Roux AF. Validation of Nanopore long-read sequencing to resolve RPGR ORF15 genotypes in individuals with X-linked retinitis pigmentosa. Eur J Hum Genet 2024:10.1038/s41431-024-01649-0. [PMID: 38969740 DOI: 10.1038/s41431-024-01649-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/15/2024] [Accepted: 06/11/2024] [Indexed: 07/07/2024] Open
Abstract
X-linked retinitis pigmentosa (XLRP) is characterized by progressive vision loss leading to legal blindness in males and a broad severity spectrum in carrier females. Pathogenic alterations of the retinitis pigmentosa GTPase regulator gene (RPGR) are responsible for over 70% of XLRP cases. In the retina, the RPGRORF15 transcript includes a terminal exon, called ORF15, that is altered in the large majority of RPGR-XLRP cases. Unfortunately, due to its highly repetitive sequence, ORF15 represents a considerable challenge in terms of sequencing for molecular diagnostic laboratories. However, in a recent preliminary work Yahya et al. reported a long-read sequencing approach seeming promising. Here, the aim of the study was to validate and integrate this new sequencing strategy in a routine screening workflow. For that purpose, we performed a masked test on 52 genomic DNA samples from male and female individuals carrying 32 different pathogenic ORF15 variations including 20 located in the highly repetitive region of the exon. For the latter, we have obtained a detection rate of 80-85% in males and 60-80% in females after bioinformatic analyses. These numbers raised to 100% for both status after adding a complementary visual inspection of ORF15 long-reads. In accordance with these results, and considering the frequency of ORF15 pathogenic variations in XLRP, we suggest that a long-read screening of ORF15 should be systematically considered before any other sequencing approach in subjects with a diagnosis compatible with XLRP.
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Affiliation(s)
- Christel Vaché
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France.
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France.
| | - Valérie Faugère
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
| | - David Baux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- Montpellier BioInformatique pour le Diagnostic Clinique (MOBIDIC), CHU Montpellier, Montpellier, France
| | - Luke Mansard
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
| | - Charles Van Goethem
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Montpellier BioInformatique pour le Diagnostic Clinique (MOBIDIC), CHU Montpellier, Montpellier, France
| | - Claire-Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Olivier Grunewald
- Univ. Lille, Inserm, CHU Lille, U1172-LilNCog-Lille Neuroscience and Cognition, Lille, France
| | - Isabelle Audo
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, Centre de Référence Maladies Rares REFERET, Inserm-DGOS CIC1423, Paris, France
| | - Christina Zeitz
- Sorbonne Université, Inserm, CNRS, Institut de la Vision, Paris, France
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Béatrice Bocquet
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Mireille Cossée
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- PhyMedExp, Univ Montpellier, Inserm, CNRS, Montpellier, France
| | - Anne Bergougnoux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- PhyMedExp, Univ Montpellier, Inserm, CNRS, Montpellier, France
| | - Vasiliki Kalatzis
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- National Reference Center for Inherited Sensory Diseases, Univ Montpellier, CHU, Montpellier, France
| | - Anne-Françoise Roux
- Molecular Genetics Laboratory, Univ Montpellier, CHU Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier (INM), Univ Montpellier, Inserm, Montpellier, France
- GCS AURAGEN, Lyon, France
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2
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German RJ, Vuocolo B, Vossaert L, Owen N, Lewis RA, Saba L, Wangler MF, Nagamani S. Novel hemizygous single-nucleotide duplication in RPGR in a patient with retinal dystrophy and sensorineural hearing loss. Mol Genet Genomic Med 2024; 12:e2404. [PMID: 38404254 PMCID: PMC10895382 DOI: 10.1002/mgg3.2404] [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: 06/30/2023] [Revised: 02/02/2024] [Accepted: 02/06/2024] [Indexed: 02/27/2024] Open
Abstract
BACKGROUND The RPGR gene has been associated with X-linked cone-rod dystrophy. This report describes a variant in RPGR detected with exome sequencing (ES). Genes like RPGR have not always been included in panel-based testing and thus genome-wide tests such as ES may be required for accurate diagnosis. METHODS The Texome Project is studying the impact of ES in medically underserved patients who are in need of genomic testing to guide diagnosis and medical management. The hypothesis is that ES could uncover diagnoses not made by standard medical care. RESULTS A 58-year-old male presented with retinitis pigmentosa, sensorineural hearing loss, and a family history of retinal diseases. A previous targeted gene panel for retinal disorders had not identified a molecular cause. ES through the Texome Project identified a novel, hemizygous variant in RPGR (NM_000328.3: c.1302dup, p.L435Sfs*18) that explained the ocular phenotype. CONCLUSIONS Continued genetics evaluation can help to end diagnostic odysseys of patients. Careful consideration of genes represented when utilizing gene panels is crucial to ensure an accurate diagnosis. Medically underserved populations are less likely to receive comprehensive genetic testing in their diagnostic workup. Our report is an example of the medical impact of genomic medicine implementation.
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Affiliation(s)
- Ryan J. German
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
| | - Blake Vuocolo
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
| | - Liesbeth Vossaert
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Baylor Genetics LaboratoriesHoustonTexasUSA
| | - Nichole Owen
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Baylor Genetics LaboratoriesHoustonTexasUSA
| | - Richard A. Lewis
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Department of MedicineBaylor College of MedicineHoustonTexasUSA
- Department of OphthalmologyBaylor College of MedicineHoustonTexasUSA
| | - Lisa Saba
- Department of PathologyTexas Children's HospitalHoustonTexasUSA
| | | | - Michael F. Wangler
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Jan and Dan Duncan Neurological Research InstituteTexas Children's HospitalHoustonTexasUSA
- Texas Children's HospitalHoustonTexasUSA
| | - Sandesh Nagamani
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTexasUSA
- Department of MedicineBaylor College of MedicineHoustonTexasUSA
- Texas Children's HospitalHoustonTexasUSA
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3
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Bonetti G, Cozza W, Bernini A, Kaftalli J, Mareso C, Cristofoli F, Medori MC, Colombo L, Martella S, Staurenghi G, Salvetti AP, Falsini B, Placidi G, Attanasio M, Pertile G, Bengala M, Bosello F, Petracca A, D’Esposito F, Toschi B, Lanzetta P, Ricci F, Viola F, Marceddu G, Bertelli M. Towards a Long-Read Sequencing Approach for the Molecular Diagnosis of RPGR ORF15 Genetic Variants. Int J Mol Sci 2023; 24:16881. [PMID: 38069202 PMCID: PMC10706286 DOI: 10.3390/ijms242316881] [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: 10/17/2023] [Revised: 11/17/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023] Open
Abstract
Sequencing of the low-complexity ORF15 exon of RPGR, a gene correlated with retinitis pigmentosa and cone dystrophy, is difficult to achieve with NGS and Sanger sequencing. False results could lead to the inaccurate annotation of genetic variants in dbSNP and ClinVar databases, tools on which HGMD and Ensembl rely, finally resulting in incorrect genetic variants interpretation. This paper aims to propose PacBio sequencing as a feasible method to correctly detect genetic variants in low-complexity regions, such as the ORF15 exon of RPGR, and interpret their pathogenicity by structural studies. Biological samples from 75 patients affected by retinitis pigmentosa or cone dystrophy were analyzed with NGS and repeated with PacBio. The results showed that NGS has a low coverage of the ORF15 region, while PacBio was able to sequence the region of interest and detect eight genetic variants, of which four are likely pathogenic. Furthermore, molecular modeling and dynamics of the RPGR Glu-Gly repeats binding to TTLL5 allowed for the structural evaluation of the variants, providing a way to predict their pathogenicity. Therefore, we propose PacBio sequencing as a standard procedure in diagnostic research for sequencing low-complexity regions such as RPGRORF15, aiding in the correct annotation of genetic variants in online databases.
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Affiliation(s)
- Gabriele Bonetti
- MAGI’s LAB, 38068 Rovereto, Italy; (M.C.M.); (M.B.)
- Department of Pharmaceutical Sciences, University of Perugia, 06123 Perugia, Italy
| | - William Cozza
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Andrea Bernini
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, 53100 Siena, Italy;
| | - Jurgen Kaftalli
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Chiara Mareso
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | | | | | - Leonardo Colombo
- Department of Ophthalmology, ASST Santi Paolo e Carlo Hospital, University of Milan, 20142 Milan, Italy; (L.C.); (S.M.)
| | - Salvatore Martella
- Department of Ophthalmology, ASST Santi Paolo e Carlo Hospital, University of Milan, 20142 Milan, Italy; (L.C.); (S.M.)
| | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, 20157 Milan, Italy; (G.S.); (A.P.S.)
| | - Anna Paola Salvetti
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, 20157 Milan, Italy; (G.S.); (A.P.S.)
| | - Benedetto Falsini
- UOC Oculistica, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Largo Gemelli 8, 00168 Rome, Italy (G.P.)
- Istituto di Oftalmologia, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Giorgio Placidi
- UOC Oculistica, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Largo Gemelli 8, 00168 Rome, Italy (G.P.)
| | - Marcella Attanasio
- Ospedale Sacrocuore Don Calabria, Viale Luigi Rizzardi, 4, 37024 Negrar di Valpolicella, Italy; (M.A.); (G.P.)
| | - Grazia Pertile
- Ospedale Sacrocuore Don Calabria, Viale Luigi Rizzardi, 4, 37024 Negrar di Valpolicella, Italy; (M.A.); (G.P.)
| | - Mario Bengala
- Medical Genetics Unit, Department of Oncohematology, Policlinico Tor Vergata, 00133 Rome, Italy;
| | - Francesca Bosello
- Department of Surgical Sciences, Dentistry, Paediatrics and Gynaecology, Section of Ophthalmology, University of Verona, 37134 Verona, Italy;
| | - Antonio Petracca
- Division of Medical Genetics, Fondazione IRCCS-Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Fabiana D’Esposito
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
- Imperial College Ophthalmic Research Group (ICORG) Unit, Imperial College, London NW1 5QH, UK
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, 80138 Naples, Italy
| | - Benedetta Toschi
- Section of Medical Genetics, Department of Medical and Oncological Area, University Hospital of Pisa, 56126 Pisa, Italy;
| | - Paolo Lanzetta
- Department of Medicine-Ophthalmology, University of Udine, 33100 Udine, Italy;
- Istituto Europeo di Microchirurgia Oculare (IEMO), 33100 Udine, Italy
| | - Federico Ricci
- Department of Experimental Medicine, Tor Vergata University of Rome, Viale Oxford, 00133 Rome, Italy;
| | - Francesco Viola
- Department of Ophthalmology, Fondazione IRCCS Cà Granda, Clinica Regina Elena, 20122 Milan, Italy;
| | - Giuseppe Marceddu
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
| | - Matteo Bertelli
- MAGI’s LAB, 38068 Rovereto, Italy; (M.C.M.); (M.B.)
- MAGI Euregio, 39100 Bolzano, Italy; (W.C.); (J.K.); (C.M.); (F.D.); (G.M.)
- MAGISNAT, Atlanta Tech Park, 107 Technology Parkway, Peachtree Corners, GA 30092, USA
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Koller S, Beltraminelli T, Maggi J, Wlodarczyk A, Feil S, Baehr L, Gerth-Kahlert C, Menghini M, Berger W. Functional Analysis of a Novel, Non-Canonical RPGR Splice Variant Causing X-Linked Retinitis Pigmentosa. Genes (Basel) 2023; 14:genes14040934. [PMID: 37107692 PMCID: PMC10137330 DOI: 10.3390/genes14040934] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
X-linked retinitis pigmentosa (XLRP) caused by mutations in the RPGR gene is one of the most severe forms of RP due to its early onset and intractable progression. Most cases have been associated with genetic variants within the purine-rich exon ORF15 region of this gene. RPGR retinal gene therapy is currently being investigated in several clinical trials. Therefore, it is crucial to report and functionally characterize (all novel) potentially pathogenic DNA sequence variants. Whole-exome sequencing (WES) was performed for the index patient. The splicing effects of a non-canonical splice variant were tested on cDNA from whole blood and a minigene assay. WES revealed a rare, non-canonical splice site variant predicted to disrupt the wildtype splice acceptor and create a novel acceptor site 8 nucleotides upstream of RPGR exon 12. Reverse-transcription PCR analyses confirmed the disruption of the correct splicing pattern, leading to the insertion of eight additional nucleotides in the variant transcript. Transcript analyses with minigene assays and cDNA from peripheral blood are useful tools for the characterization of splicing defects due to variants in the RPGR and may increase the diagnostic yield in RP. The functional analysis of non-canonical splice variants is required to classify those variants as pathogenic according to the ACMG's criteria.
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Affiliation(s)
- Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Tim Beltraminelli
- Department of Ophthalmology, Institute of Clinical Neurosciences of Southern Switzerland, Ente Ospedaliero Cantonale (EOC), 6962 Lugano, Switzerland
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Agnès Wlodarczyk
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Luzy Baehr
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
| | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital, University of Zurich, 8091 Zurich, Switzerland
| | - Moreno Menghini
- Department of Ophthalmology, Institute of Clinical Neurosciences of Southern Switzerland, Ente Ospedaliero Cantonale (EOC), 6962 Lugano, Switzerland
- Department of Ophthalmology, University Hospital, University of Zurich, 8091 Zurich, Switzerland
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8057 Zurich, Switzerland
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5
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Challenges and Opportunities in the Genetic Analysis of Inherited Retinal Dystrophies in Africa, a Literature Review. J Pers Med 2023; 13:jpm13020239. [PMID: 36836473 PMCID: PMC9964248 DOI: 10.3390/jpm13020239] [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: 12/26/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 01/31/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are a global problem that is largely unaddressed, especially in Africa. Black indigenous Africans are rarely represented in research that develops genetic tests and genetic therapies for IRDs, yet their genomes are more diverse. The aim of this literature review is to synthesize information on the IRD genetic research conducted among indigenous black Africans to identify challenges and opportunities for progress. PubMed was searched to identify empirical publications reporting the genetic analysis of IRDs among indigenous Africans. A total of 11 articles were selected for the review. Based on the information in the articles, the main genetic testing methods in use include next-generation, whole exome, and Sanger sequencing. The main IRDs characterized by the genetic tests include retinitis pigmentosa, Leber Congenital Amaurosis, Stagardt disease, and cone dystrophy. Examples of implicated genes include MERTK, GUCY2D, ABCA4, and KCNV2 for the four IRDs, respectively. Research activities on the genetics of IRDs are generally scanty in Africa. Even in South Africa and North Africa where some research activities were noted, only a few indigenous black Africans were included in the study cohorts. There is an urgent need for genetic research on IRDs, especially in East, Central, and West Africa.
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6
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Fadaie Z, Whelan L, Ben-Yosef T, Dockery A, Corradi Z, Gilissen C, Haer-Wigman L, Corominas J, Astuti GDN, de Rooij L, van den Born LI, Klaver CCW, Hoyng CB, Wynne N, Duignan ES, Kenna PF, Cremers FPM, Farrar GJ, Roosing S. Whole genome sequencing and in vitro splice assays reveal genetic causes for inherited retinal diseases. NPJ Genom Med 2021; 6:97. [PMID: 34795310 PMCID: PMC8602293 DOI: 10.1038/s41525-021-00261-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 10/21/2021] [Indexed: 01/08/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a major cause of visual impairment. These clinically heterogeneous disorders are caused by pathogenic variants in more than 270 genes. As 30-40% of cases remain genetically unexplained following conventional genetic testing, we aimed to obtain a genetic diagnosis in an IRD cohort in which the genetic cause was not found using whole-exome sequencing or targeted capture sequencing. We performed whole-genome sequencing (WGS) to identify causative variants in 100 unresolved cases. After initial prioritization, we performed an in-depth interrogation of all noncoding and structural variants in genes when one candidate variant was detected. In addition, functional analysis of putative splice-altering variants was performed using in vitro splice assays. We identified the genetic cause of the disease in 24 patients. Causative coding variants were observed in genes such as ATXN7, CEP78, EYS, FAM161A, and HGSNAT. Gene disrupting structural variants were also detected in ATXN7, PRPF31, and RPGRIP1. In 14 monoallelic cases, we prioritized candidate noncanonical splice sites or deep-intronic variants that were predicted to disrupt the splicing process based on in silico analyses. Of these, seven cases were resolved as they carried pathogenic splice defects. WGS is a powerful tool to identify causative variants residing outside coding regions or heterozygous structural variants. This approach was most efficient in cases with a distinct clinical diagnosis. In addition, in vitro splice assays provide important evidence of the pathogenicity of rare variants.
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Affiliation(s)
- Zeinab Fadaie
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Whelan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Adrian Dockery
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Zelia Corradi
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Galuh D N Astuti
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Division of Human Genetics, Center for Biomedical Research (CEBIOR), Faculty of Medicine, Diponegoro University, Semarang, Indonesia
| | - Laura de Rooij
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Caroline C W Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Niamh Wynne
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Emma S Duignan
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Paul F Kenna
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Department of Ophthalmology, Royal Victoria Eye and Ear Hospital, Dublin, Ireland
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - G Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.
- Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands.
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7
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Next-Generation Sequencing Applications for Inherited Retinal Diseases. Int J Mol Sci 2021; 22:ijms22115684. [PMID: 34073611 PMCID: PMC8198572 DOI: 10.3390/ijms22115684] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal diseases (IRDs) represent a collection of phenotypically and genetically diverse conditions. IRDs phenotype(s) can be isolated to the eye or can involve multiple tissues. These conditions are associated with diverse forms of inheritance, and variants within the same gene often can be associated with multiple distinct phenotypes. Such aspects of the IRDs highlight the difficulty met when establishing a genetic diagnosis in patients. Here we provide an overview of cutting-edge next-generation sequencing techniques and strategies currently in use to maximise the effectivity of IRD gene screening. These techniques have helped researchers globally to find elusive causes of IRDs, including copy number variants, structural variants, new IRD genes and deep intronic variants, among others. Resolving a genetic diagnosis with thorough testing enables a more accurate diagnosis and more informed prognosis and should also provide information on inheritance patterns which may be of particular interest to patients of a child-bearing age. Given that IRDs are heritable conditions, genetic counselling may be offered to help inform family planning, carrier testing and prenatal screening. Additionally, a verified genetic diagnosis may enable access to appropriate clinical trials or approved medications that may be available for the condition.
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8
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Maggi J, Koller S, Bähr L, Feil S, Kivrak Pfiffner F, Hanson JVM, Maspoli A, Gerth-Kahlert C, Berger W. Long-Range PCR-Based NGS Applications to Diagnose Mendelian Retinal Diseases. Int J Mol Sci 2021; 22:ijms22041508. [PMID: 33546218 PMCID: PMC7913364 DOI: 10.3390/ijms22041508] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/27/2022] Open
Abstract
The purpose of this study was to develop a flexible, cost-efficient, next-generation sequencing (NGS) protocol for genetic testing. Long-range polymerase chain reaction (PCR) amplicons of up to 20 kb in size were designed to amplify entire genomic regions for a panel (n = 35) of inherited retinal disease (IRD)-associated loci. Amplicons were pooled and sequenced by NGS. The analysis was applied to 227 probands diagnosed with IRD: (A) 108 previously molecularly diagnosed, (B) 94 without previous genetic testing, and (C) 25 undiagnosed after whole-exome sequencing (WES). The method was validated with 100% sensitivity on cohort A. Long-range PCR-based sequencing revealed likely causative variant(s) in 51% and 24% of proband from cohorts B and C, respectively. Breakpoints of 3 copy number variants (CNVs) could be characterized. Long-range PCR libraries spike-in extended coverage of WES. Read phasing confirmed compound heterozygosity in 5 probands. The proposed sequencing protocol provided deep coverage of the entire gene, including intronic and promoter regions. Our method can be used (i) as a first-tier assay to reduce genetic testing costs, (ii) to elucidate missing heritability cases, (iii) to characterize breakpoints of CNVs at nucleotide resolution, (iv) to extend WES data to non-coding regions by spiking-in long-range PCR libraries, and (v) to help with phasing of candidate variants.
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Affiliation(s)
- Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Samuel Koller
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Luzy Bähr
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Silke Feil
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Fatma Kivrak Pfiffner
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - James V. M. Hanson
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, 8091 Zurich, Switzerland; (J.V.M.H.); (C.G.-K.)
| | - Alessandro Maspoli
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
| | - Christina Gerth-Kahlert
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, 8091 Zurich, Switzerland; (J.V.M.H.); (C.G.-K.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.); (L.B.); (S.F.); (F.K.P.); (A.M.)
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8057 Zurich, Switzerland
- Correspondence: ; Tel.: +41-44-556-33-50
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