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Shim Y, Koo YK, Shin S, Lee ST, Lee KA, Choi JR. Comparison of Optical Genome Mapping With Conventional Diagnostic Methods for Structural Variant Detection in Hematologic Malignancies. Ann Lab Med 2024; 44:324-334. [PMID: 38433573 PMCID: PMC10961627 DOI: 10.3343/alm.2023.0339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/21/2023] [Accepted: 02/13/2024] [Indexed: 03/05/2024] Open
Abstract
Background Structural variants (SVs) are currently analyzed using a combination of conventional methods; however, this approach has limitations. Optical genome mapping (OGM), an emerging technology for detecting SVs using a single-molecule strategy, has the potential to replace conventional methods. We compared OGM with conventional diagnostic methods for detecting SVs in various hematologic malignancies. Methods Residual bone marrow aspirates from 27 patients with hematologic malignancies in whom SVs were observed using conventional methods (chromosomal banding analysis, FISH, an RNA fusion panel, and reverse transcription PCR) were analyzed using OGM. The concordance between the OGM and conventional method results was evaluated. Results OGM showed concordance in 63% (17/27) and partial concordance in 37% (10/27) of samples. OGM detected 76% (52/68) of the total SVs correctly (concordance rate for each type of SVs: aneuploidies, 83% [15/18]; balanced translocation, 80% [12/15] unbalanced translocation, 54% [7/13] deletions, 81% [13/16]; duplications, 100% [2/2] inversion 100% [1/1]; insertion, 100% [1/1]; marker chromosome, 0% [0/1]; isochromosome, 100% [1/1]). Sixteen discordant results were attributed to the involvement of centromeric/telomeric regions, detection sensitivity, and a low mapping rate and coverage. OGM identified additional SVs, including submicroscopic SVs and novel fusions, in five cases. Conclusions OGM shows a high level of concordance with conventional diagnostic methods for the detection of SVs and can identify novel variants, suggesting its potential utility in enabling more comprehensive SV analysis in routine diagnostics of hematologic malignancies, although further studies and improvements are required.
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Affiliation(s)
- Yeeun Shim
- Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, Korea
- MDxK (Molecular Diagnostics Korea), Inc., Gwacheon, Korea
| | - Yu-Kyung Koo
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
- Dxome Co., Ltd., Seongnam, Korea
| | - Kyung-A Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea
- Dxome Co., Ltd., Seongnam, Korea
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Church AJ, Akkari Y, Deeb K, Kolhe R, Lin F, Spiteri E, Wolff DJ, Shao L. Section E6.7-6.12 of the American College of Medical Genetics and Genomics (ACMG) Technical Laboratory Standards: Cytogenomic studies of acquired chromosomal abnormalities in solid tumors. Genet Med 2024; 26:101070. [PMID: 38376505 DOI: 10.1016/j.gim.2024.101070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/21/2024] Open
Abstract
Clinical cytogenomic studies of solid tumor samples are critical to the diagnosis, prognostication, and treatment selection for cancer patients. An overview of current cytogenomic techniques for solid tumor analysis is provided, including standards for sample preparation, clinical and technical considerations, and documentation of results. With the evolving technologies and their application in solid tumor analysis, these standards now include sequencing technology and optical genome mapping, in addition to the conventional cytogenomic methods, such as G-banded chromosome analysis, fluorescence in situ hybridization, and chromosomal microarray analysis. This updated Section E6.7-6.12 supersedes the previous Section E6.5-6.8 in Section E: Clinical Cytogenetics of the American College of Medical Genetics and Genomics Standards for Clinical Genetics Laboratories.
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Affiliation(s)
- Alanna J Church
- Department of Pathology, Boston Children's Hospital, Boston, MA; Harvard Medical School, Boston, MA
| | - Yassmine Akkari
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH
| | - Kristin Deeb
- Department of Pathology, Emory University, Atlanta, GA
| | - Ravindra Kolhe
- Department of Pathology, Augusta University, Augusta, GA
| | - Fumin Lin
- Department of Pathology and Laboratory Medicine, University of California at Los Angeles, Los Angeles, CA
| | | | - Daynna J Wolff
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC
| | - Lina Shao
- Department of Pathology and Pediatrics, University of Michigan, Ann Arbor, MI
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Alesi V, Genovese S, Roberti MC, Sallicandro E, Di Tommaso S, Loddo S, Orlando V, Pompili D, Calacci C, Mei V, Pisaneschi E, Faggiano MV, Morgia A, Mammì C, Astrea G, Battini R, Priolo M, Dentici ML, Milone R, Novelli A. Structural rearrangements as a recurrent pathogenic mechanism for SETBP1 haploinsufficiency. Hum Genomics 2024; 18:29. [PMID: 38520002 PMCID: PMC10960460 DOI: 10.1186/s40246-024-00600-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 03/15/2024] [Indexed: 03/25/2024] Open
Abstract
Chromosomal structural rearrangements consist of anomalies in genomic architecture that may or may not be associated with genetic material gain and loss. Evaluating the precise breakpoint is crucial from a diagnostic point of view, highlighting possible gene disruption and addressing to appropriate genotype-phenotype association. Structural rearrangements can either occur randomly within the genome or present with a recurrence, mainly due to peculiar genomic features of the surrounding regions. We report about three non-related individuals, harboring chromosomal structural rearrangements interrupting SETBP1, leading to gene haploinsufficiency. Two out of them resulted negative to Chromosomal Microarray Analysis (CMA), being the rearrangement balanced at a microarray resolution. The third one, presenting with a complex three-chromosome rearrangement, had been previously diagnosed with SETBP1 haploinsufficiency due to a partial gene deletion at one of the chromosomal breakpoints. We thoroughly characterized the rearrangements by means of Optical Genome Mapping (OGM) and Whole Genome Sequencing (WGS), providing details about the involved sequences and the underlying mechanisms. We propose structural variants as a recurrent event in SETBP1 haploinsufficiency, which may be overlooked by laboratory routine genomic analyses (CMA and Whole Exome Sequencing) or only partially determined when associated with genomic losses at breakpoints. We finally introduce a possible role of SETBP1 in a Noonan-like phenotype.
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Affiliation(s)
- V Alesi
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - S Genovese
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy.
| | - M C Roberti
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - E Sallicandro
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - S Di Tommaso
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - S Loddo
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - V Orlando
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - D Pompili
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - C Calacci
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - V Mei
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - E Pisaneschi
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - M V Faggiano
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - A Morgia
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - C Mammì
- Operative Unit of Medical Genetics, Great Metropolitan Hospital of Reggio Calabria, 89100, Reggio Calabria, Italy
| | - G Astrea
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, 56125, Pisa, Italy
| | - R Battini
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, 56125, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, 56100, Pisa, Italy
| | - M Priolo
- Operative Unit of Medical Genetics, Great Metropolitan Hospital of Reggio Calabria, 89100, Reggio Calabria, Italy
| | - M L Dentici
- Medical Genetics Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
| | - R Milone
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, 56125, Pisa, Italy
| | - A Novelli
- Laboratory of Medical Genetics, Translational Cytogenomics Research Unit, Bambino Gesù Children Hospital, IRCCS, 00146, Rome, Italy
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Lestringant V, Guermouche-Flament H, Jimenez-Pocquet M, Gaillard JB, Penther D. Cytogenetics in the management of hematological malignancies: An overview of alternative technologies for cytogenetic characterization. Curr Res Transl Med 2024; 72:103440. [PMID: 38447270 DOI: 10.1016/j.retram.2024.103440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 12/22/2023] [Accepted: 01/11/2024] [Indexed: 03/08/2024]
Abstract
Genomic characterization is an essential part of the clinical management of hematological malignancies for diagnostic, prognostic and therapeutic purposes. Although CBA and FISH are still the gold standard in hematology for the detection of CNA and SV, some alternative technologies are intended to complement their deficiencies or even replace them in the more or less near future. In this article, we provide a technological overview of these alternatives. CMA is the historical and well established technique for the high-resolution detection of CNA. For SV detection, there are emerging techniques based on the study of chromatin conformation and more established ones such as RTMLPA for the detection of fusion transcripts and RNA-seq to reveal the molecular consequences of SV. Comprehensive techniques that detect both CNA and SV are the most interesting because they provide all the information in a single examination. Among these, OGM is a promising emerging higher-solution technique that offers a complete solution at a contained cost, at the expense of a relatively low throughput per machine. WGS remains the most adaptable solution, with long-read approaches enabling very high-resolution detection of CAs, but requiring a heavy bioinformatics installation and at a still high cost. However, the development of high-resolution genome-wide detection techniques for CAs allows for a much better description of chromoanagenesis. Therefore, we have included in this review an update on the various existing mechanisms and their consequences and implications, especially prognostic, in hematological malignancies.
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Affiliation(s)
| | | | | | - Jean-Baptiste Gaillard
- Unité de Génétique Chromosomique, Service de Génétique moléculaire et cytogénomique, CHU Montpellier, Montpellier, France
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Ferrer A, Stephens ZD, Kocher JPA. Experimental and Computational Approaches to Measure Telomere Length: Recent Advances and Future Directions. Curr Hematol Malig Rep 2023; 18:284-291. [PMID: 37947937 PMCID: PMC10709248 DOI: 10.1007/s11899-023-00717-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2023] [Indexed: 11/12/2023]
Abstract
PURPOSE OF REVIEW The length of telomeres, protective structures at the chromosome ends, is a well-established biomarker for pathological conditions including multisystemic syndromes called telomere biology disorders. Approaches to measure telomere length (TL) differ on whether they estimate average, distribution, or chromosome-specific TL, and each presents their own advantages and limitations. RECENT FINDINGS The development of long-read sequencing and publication of the telomere-to-telomere human genome reference has allowed for scalable and high-resolution TL estimation in pre-existing sequencing datasets but is still impractical as a dedicated TL test. As sequencing costs continue to fall and strategies for selectively enriching telomere regions prior to sequencing improve, these approaches may become a promising alternative to classic methods. Measurement methods rely on probe hybridization, qPCR or more recently, computational methods using sequencing data. Refinements of existing techniques and new approaches have been recently developed but a test that is accurate, simple, and scalable is still lacking.
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Affiliation(s)
- Alejandro Ferrer
- Division of Hematology, Mayo Clinic, Rochester, 200 First Street SW, Rochester, MN, USA.
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA.
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Goumy C, Guy Ouedraogo Z, Soler G, Eymard-Pierre E, Laurichesse H, Delabaere A, Gallot D, Bouchet P, Perthus I, Pebrel-Richard C, Gouas L, Salaun G, Salse J, Véronèse L, Tchirkov A. Optical genome mapping for prenatal diagnosis: A prospective study. Clin Chim Acta 2023; 551:117594. [PMID: 37832906 DOI: 10.1016/j.cca.2023.117594] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023]
Abstract
PURPOSE Cytogenetic analysis provides important information for prenatal decision-making and genetic counseling. Optical genome mapping (OGM) has demonstrated its performances in retrospective studies. In our prospective study, we assessed the quality of DNA obtained from cultures of amniotic fluid (AF) and chorionic villi (CV) and evaluated the ability of OGM to detect all clinically relevant aberrations identified by standard methods. METHODS A total of 37 prenatal samples from pregnancies with a fetal anomaly on ultrasound were analyzed prospectively by OGM between January 1, 2021 and June 31, 2022. OGM results were interpreted blindly and compared to the results obtained by standard techniques. RESULTS OGM results were interpretable in 92% of samples. We observed 100% concordance between OGM and karyotype and/or chromosomal microarray results. In addition, OGM identified a median of 30 small (<100 kb) structural variations per case with the involvement of 12 OMIM genes, of which 3 were OMIM morbid genes. CONCLUSION This prospective study showed OGM performed well in detecting genomic alterations in cell cultures from prenatal samples. The place of OGM in relation to CMA or exome sequencing remains to be defined in order to optimize the prenatal diagnostic procedure.
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Affiliation(s)
- Carole Goumy
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; INSERM U1240 Imagerie Moléculaire et Stratégies Théranostiques, Université Clermont Auvergne, Clermont Ferrand, France.
| | - Zangbéwendé Guy Ouedraogo
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; Service de Biochimie et Génétique Moléculaire, CHU Clermont-Ferrand, 63000 Clermont-Ferrand, France; Université Clermont Auvergne, CNRS, Inserm, GReD, 63001 Clermont-Ferrand, France
| | - Gwendoline Soler
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France
| | - Eleonore Eymard-Pierre
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; INSERM U1240 Imagerie Moléculaire et Stratégies Théranostiques, Université Clermont Auvergne, Clermont Ferrand, France
| | - Hélène Laurichesse
- Unité de Médecine Fœtale, CHU Clermont-Ferrand, CHU Estaing, F-63000, France
| | - Amélie Delabaere
- Unité de Médecine Fœtale, CHU Clermont-Ferrand, CHU Estaing, F-63000, France
| | - Denis Gallot
- Unité de Médecine Fœtale, CHU Clermont-Ferrand, CHU Estaing, F-63000, France; Université Clermont Auvergne, CNRS, Inserm, GReD, 63001 Clermont-Ferrand, France
| | - Pamela Bouchet
- Unité de Médecine Fœtale, CHU Clermont-Ferrand, CHU Estaing, F-63000, France
| | - Isabelle Perthus
- Service de Génétique Médicale, CHU Clermont-Ferrand, CHU Estaing, F-63000, France
| | - Céline Pebrel-Richard
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France
| | - Laetitia Gouas
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; INSERM U1240 Imagerie Moléculaire et Stratégies Théranostiques, Université Clermont Auvergne, Clermont Ferrand, France
| | - Gaëlle Salaun
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France
| | - Jérôme Salse
- UMR 1095 INRAE/UCA Génétique, Diversité et Ecophysiologie des Céréales (GDEC), Genotyping and Sequencing Plateform Gentyane, Clermont-Ferrand, France
| | - Lauren Véronèse
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; EA7453 CHELTER « Clonal Heterogeneity, Leukemic Environment, Therapy Resistance of Chronic Leukemias », Université Clermont Auvergne, Clermont-Ferrand, France
| | - Andrei Tchirkov
- Cytogénétique Médicale, Centre Hospitalier Universitaire de Clermont-Ferrand, Hôpital Estaing, Clermont-Ferrand, France; EA7453 CHELTER « Clonal Heterogeneity, Leukemic Environment, Therapy Resistance of Chronic Leukemias », Université Clermont Auvergne, Clermont-Ferrand, France
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de Boer E, Marcelis C, Neveling K, van Beusekom E, Hoischen A, Klein WM, de Leeuw N, Mantere T, Melo US, van Reeuwijk J, Smeets D, Spielmann M, Kleefstra T, van Bokhoven H, Vissers LE. A complex structural variant near SOX3 causes X-linked split-hand/foot malformation. HGG Adv 2023; 4:100200. [PMID: 37216008 PMCID: PMC10196709 DOI: 10.1016/j.xhgg.2023.100200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/13/2023] [Indexed: 05/24/2023] Open
Abstract
Split-hand/foot malformation (SHFM) is a congenital limb defect most typically presenting with median clefts in hands and/or feet, that can occur in a syndromic context as well as in isolated form. SHFM is caused by failure to maintain normal apical ectodermal ridge function during limb development. Although several genes and contiguous gene syndromes are implicated in the monogenic etiology of isolated SHFM, the disorder remains genetically unexplained for many families and associated genetic loci. We describe a family with isolated X-linked SHFM, for which the causative variant could be detected after a diagnostic journey of 20 years. We combined well-established approaches including microarray-based copy number variant analysis and fluorescence in situ hybridization coupled with optical genome mapping and whole genome sequencing. This strategy identified a complex structural variant (SV) comprising a 165-kb gain of 15q26.3 material ([GRCh37/hg19] chr15:99795320-99960362dup) inserted in inverted position at the site of a 38-kb deletion on Xq27.1 ([GRCh37/hg19] chrX:139481061-139518989del). In silico analysis suggested that the SV disrupts the regulatory framework on the X chromosome and may lead to SOX3 misexpression. We hypothesize that SOX3 dysregulation in the developing limb disturbed the fine balance between morphogens required for maintaining AER function, resulting in SHFM in this family.
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Affiliation(s)
- Elke de Boer
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Carlo Marcelis
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Ellen van Beusekom
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Willemijn M. Klein
- Department of Medical Imaging, Radiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nicole de Leeuw
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
| | - Tuomo Mantere
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Laboratory of Cancer Genetics and Tumor Biology, Cancer and Translational Medicine Research Unit and Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Uirá S. Melo
- Max Planck Institute for Molecular Genetics, RG Development & Disease, Berlin, Germany
- Institute for Medical and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jeroen van Reeuwijk
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
| | - Dominique Smeets
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
| | - Malte Spielmann
- Max Planck Institute for Molecular Genetics, RG Development & Disease, Berlin, Germany
- Institute of Human Genetics, University Hospitals Schleswig-Holstein, University of Lübeck and Kiel University, 23562 Lübeck, Kiel, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Lübeck/Kiel, Lübeck, Germany
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- Center of Excellence for Neuropsychiatry, Vincent van Gogh Institute for Psychiatry, Venray, the Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- Department of Cognitive Neuroscience, Radboudumc, Nijmegen, the Netherlands
| | - Lisenka E.L.M. Vissers
- Department of Human Genetics, Radboudumc University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
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Lloveras E, Pérez C, Mendez B, Martin S, Alves C, Reis-Lima M. Tandem Triplication 11p15.5-ICR1 (H19/IGF2) Detected by Microarray and Optical Genome Mapping in a Prenatal Beckwith-Wiedemann Case. Cytogenet Genome Res 2023; 163:32-35. [PMID: 37369188 DOI: 10.1159/000531703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 06/20/2023] [Indexed: 06/29/2023] Open
Abstract
Optical genome mapping (OGM) appears as a new tool for matching standard cytogenetic methods (karyotype and microarray) into a single assay. The chromosomal region 11p15.5 harbours two differentially methylated regions, the imprinting centre regions 1 and 2 (ICR1, ICR2). Disturbances in both regions alter human growth and are associated with two imprinting disorders, Beckwith-Wiedemann (BWS) and Silver-Russell syndromes. Herein, we present a prenatal case with a triplication in 11p15.5, including the H19/IGF2 imprinted region, detected by microarray and OGM. A 30-year-old pregnant woman of 17 weeks of gestation was referred for prenatal karyotype and microarray study because of increased nuchal translucency, short femur, megabladder, hyperechogenic bowel, and renal ectasia. Microarray, OGM, and MS-MLPA were performed, and a tandem cis-triplication in 11p15.5 and hypermethylation of the ICR1 region, compatible with BWS was detected. OGM, with its power to detect all classes of structural variants, including copy number variants, at a higher resolution than traditional cytogenetic methods can play a significant role in prenatal care and management as a next-generation cytogenomic tool. This study further supports the hypotheses that the amplification/duplication-triplication of the H19/IGF2 region could be related to BWS if it is of paternal origin.
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Affiliation(s)
- Elisabet Lloveras
- Departamento de Genética, Laboratorio Central Barcelona, SYNLAB International Group, Barcelona, Spain
| | - Cristina Pérez
- Departamento de Genética, Laboratorio Central Barcelona, SYNLAB International Group, Barcelona, Spain
| | - Begoña Mendez
- Departamento de Genética, Laboratorio Central Barcelona, SYNLAB International Group, Barcelona, Spain
| | - Susana Martin
- Departamento de Genética, Laboratorio Central Barcelona, SYNLAB International Group, Barcelona, Spain
| | - Claudia Alves
- Laboratório de Genética Médica, SYNLAB International Group, Porto, Portugal
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Ogiwara Y, Hattori A, Ikegawa K, Hasegawa Y, Kuroki Y, Miyado M, Fukami M. Optical Genome Mapping for a Patient with a Congenital Disorder and Chromosomal Translocation. Cytogenet Genome Res 2023; 162:617-624. [PMID: 37231804 DOI: 10.1159/000531103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
We performed optical genome mapping (OGM), a newly developed cytogenetic technique, for a patient with a disorder of sex development (DSD) and a 46,XX,t(9;11)(p22;p13) karyotype. The results of OGM were validated using other methods. OGM detected a 9;11 reciprocal translocation and successfully mapped its breakpoints to small regions of 0.9-12.3 kb. OGM identified 46 additional small structural variants, only three of which were detected by array-based comparative genomic hybridization. OGM suggested the presence of complex rearrangements on chromosome 10; however, these variants appeared to be artifacts. The 9;11 translocation was unlikely to be associated with DSD, while the pathogenicity of the other structural variants remained unknown. These results indicate that OGM is a powerful tool for detecting and characterizing chromosomal structural variations, although the current methods of OGM data analyses need to be improved.
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Affiliation(s)
- Yasuko Ogiwara
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
- Department of Advanced Pediatric Medicine, Tohoku University School of Medicine, Tokyo, Japan
| | - Atsushi Hattori
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kento Ikegawa
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Yukihiro Hasegawa
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan
| | - Yoko Kuroki
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
- Department of Genome Medicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Mami Miyado
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Maki Fukami
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, Tokyo, Japan
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10
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Shi S, Huang P, Yan R, Li R. Identification of complex and cryptic chromosomal rearrangements by optical genome mapping. Mol Cytogenet 2023; 16:5. [PMID: 37101225 PMCID: PMC10134526 DOI: 10.1186/s13039-023-00636-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 04/12/2023] [Indexed: 04/28/2023] Open
Abstract
BACKGROUND Optical genome mapping (OGM) has developed into a highly promising method for detecting structural variants (SVs) in human genomes. Complex chromosomal rearrangements (CCRs) and cryptic translocations are rare events that are considered difficult to detect by routine cytogenetic methods. In this study, OGM was applied to delineate the precise chromosomal rearrangements in three cases with uncertain or unconfirmed CCRs detected by conventional karyotyping and one case with a cryptic translocation suggested by fetal chromosomal microarray analysis (CMA). RESULTS In the three cases with CCRs, OGM not only confirmed or revised the original karyotyping results but also refined the precise chromosomal structures. In the case with a suspected translocation not detected by karyotyping, OGM efficiently identified the cryptic translocation and defined the genomic breakpoints with relatively high accuracy. CONCLUSIONS Our study confirmed OGM as a robust alternative approach to karyotyping for the detection of chromosomal structural rearrangements, including CCRs and cryptic translocations.
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Affiliation(s)
- Shanshan Shi
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Jinan University, No. 613 Huangpu West Road, Guangzhou, 510630, People's Republic of China
| | - Peizhi Huang
- Prenatal Diagnosis Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Ruiling Yan
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Jinan University, No. 613 Huangpu West Road, Guangzhou, 510630, People's Republic of China.
| | - Ruiman Li
- Fetal Medicine Center, Department of Obstetrics and Gynecology, The First Affiliated Hospital, Jinan University, No. 613 Huangpu West Road, Guangzhou, 510630, People's Republic of China.
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11
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de Bruijn SE, Rodenburg K, Corominas J, Ben-Yosef T, Reurink J, Kremer H, Whelan L, Plomp AS, Berger W, Farrar GJ, Ferenc Kovács Á, Fajardy I, Hitti-Malin RJ, Weisschuh N, Weener ME, Sharon D, Pennings RJE, Haer-Wigman L, Hoyng CB, Nelen MR, Vissers LELM, van den Born LI, Gilissen C, Cremers FPM, Hoischen A, Neveling K, Roosing S. Optical genome mapping and revisiting short-read genome sequencing data reveal previously overlooked structural variants disrupting retinal disease-associated genes. Genet Med 2023; 25:100345. [PMID: 36524988 DOI: 10.1016/j.gim.2022.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Structural variants (SVs) play an important role in inherited retinal diseases (IRD). Although the identification of SVs significantly improved upon the availability of genome sequencing, it is expected that involvement of SVs in IRDs is higher than anticipated. We revisited short-read genome sequencing data to enhance the identification of gene-disruptive SVs. METHODS Optical genome mapping was performed to improve SV detection in short-read genome sequencing-negative cases. In addition, reanalysis of short-read genome sequencing data was performed to improve the interpretation of SVs and to re-establish SV prioritization criteria. RESULTS In a monoallelic USH2A case, optical genome mapping identified a pericentric inversion (173 megabase), with 1 breakpoint disrupting USH2A. Retrospectively, the variant could be observed in genome sequencing data but was previously deemed false positive. Reanalysis of short-read genome sequencing data (427 IRD cases) was performed which yielded 30 pathogenic SVs affecting, among other genes, USH2A (n = 15), PRPF31 (n = 3), and EYS (n = 2). Eight of these (>25%) were overlooked during previous analyses. CONCLUSION Critical evaluation of our findings allowed us to re-establish and improve our SV prioritization and interpretation guidelines, which will prevent missing pathogenic events in future analyses. Our data suggest that more attention should be paid to SV interpretation and the current contribution of SVs in IRDs is still underestimated.
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Affiliation(s)
- Suzanne E de Bruijn
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Kim Rodenburg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tamar Ben-Yosef
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Janine Reurink
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hannie Kremer
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Hearing and Genes, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Whelan
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, Schlieren, Switzerland; Neuroscience Center Zurich (ZNZ), University and ETH Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - G Jane Farrar
- The School of Genetics and Microbiology, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Árpád Ferenc Kovács
- 2nd Department of Paediatrics, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Isabelle Fajardy
- Division of Maternal Malnutrition, Department of Perinatal Environment and Health, Lille University, Lille, France; Division Biochemistry and Molecular Biology, Biology and Pathology Center, Lille, France
| | - Rebekkah J Hitti-Malin
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nicole Weisschuh
- Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Dror Sharon
- Division of Ophthalmology, Hadassah University Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ronald J E Pennings
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Hearing and Genes, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Carel B Hoyng
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marcel R Nelen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisenka E L M Vissers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, 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
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alexander Hoischen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Radboud Institute of Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, The Netherlands
| | - Kornelia Neveling
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands; Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
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12
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Shim Y, Lee J, Seo J, Park CK, Shin S, Han H, Lee ST, Choi JR, Chung BH, Choi YD. Optical genome mapping identifies clinically relevant genomic rearrangements in prostate cancer biopsy sample. Cancer Cell Int 2022; 22:306. [PMID: 36209207 PMCID: PMC9548106 DOI: 10.1186/s12935-022-02728-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 09/27/2022] [Indexed: 11/20/2022] Open
Abstract
Background Prostate cancer (PCa) is characterized by complex genomic rearrangements such as the ETS oncogene family fusions, yet the clinical relevance is not well established. While paneled genetic tests of DNA repair genes are recommended in advanced PCa, conventional genomic or cytogenetic tools are not ideal for genome-wide screening of structural variations (SVs) such as balanced translocation due to cost and/or resolution issues. Methods In this study, we tested the feasibility of whole-genome optical genomic mapping (OGM), a newly developed platform for genome-wide SV analysis to detect complex genomic rearrangements in consecutive unselected PCa samples from MRI/US-fusion targeted biopsy. Results We tested ten samples, and nine (90%) passed quality check. Average mapping rate and coverage depth were 58.1 ± 23.7% and 157.3 ± 97.7×, respectively (mean ± SD). OGM detected copy number alterations such as chr6q13 loss and chr8q12-24 gain. Two adjacent tumor samples were distinguished by inter/intra-chromosomal translocations, revealing that they’re from the same ancestor. Furthermore, OGM detected large deletion of chr13q13.1 accompanied by inter-chromosomal translocation t(13;20)(q13.1;p13) occurring within BRCA2 gene, suggesting complete loss of function. Conclusion In conclusion, clinically relevant genomic SVs were successfully detected in PCa samples by OGM. We suggest that OGM can complement panel sequencing of DNA repair genes BRCA1/2 or ATM in high-risk PCa. Supplementary Information The online version contains supplementary material available at 10.1186/s12935-022-02728-2.
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Affiliation(s)
- Yeeun Shim
- Department of Laboratory Medicine, Graduate School of Medical Science, Brain Korea 21 project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jongsoo Lee
- Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jieun Seo
- Department of Genetics, School of Medicine, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Cheol Keun Park
- Department of Pathology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Pathology Center, Seegene Medical Foundation, Seoul, Republic of Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Hyunho Han
- Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,, Dxome Seongnam-daero 331 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,, Dxome Seongnam-daero 331 beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of Korea
| | - Byung Ha Chung
- Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Young Deuk Choi
- Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
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13
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Yang Y, Hao W. Identification of a familial complex chromosomal rearrangement by optical genome mapping. Mol Cytogenet 2022; 15:41. [PMID: 36127686 PMCID: PMC9490972 DOI: 10.1186/s13039-022-00619-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Complex chromosomal rearrangements (CCRs) are rare chromosomal structural variations, containing a variety of rearrangements such as translocation, inversion and/or insertion. With the development of cytogenetic and molecular genetic techniques, some chromosomal rearrangements that were initially considered to be simple reciprocal translocations in the past might eventually involve more complex chromosomal rearrangements. CASE PRESENTATION In this case, a pregnant woman, who had a spontaneous abortion last year, had abnormal prenatal test results again in the second pregnancy. Applying a combination of genetic methods including karyotype analysis, chromosomal microarray analysis, fluorescence in situ hybridization and optical genome mapping confirmed that the pregnant woman was a carrier of a CCR involving three chromosomes and four breakpoints, and the CCR was paternal-origin. Her first and second pregnancy abnormalities were caused by chromosomal microdeletions and microduplications due to the malsegregations of the derivative chromosomes. CONCLUSIONS We presented a rare familial CCR involving three chromosomes and four breakpoints. This study provided precise and detailed information for the subsequent reproductive decision-making and genetic counselling of the patient.
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Affiliation(s)
- Yang Yang
- Prenatal Diagnosis Center, Hangzhou Maternity and Child Care Hospital, #369 Kunpeng Road, Shangcheng District, Hangzhou, 310008, Zhejiang, China
| | - Wang Hao
- Prenatal Diagnosis Center, Hangzhou Maternity and Child Care Hospital, #369 Kunpeng Road, Shangcheng District, Hangzhou, 310008, Zhejiang, China. .,Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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14
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Ghorbani F, de Boer-Bergsma J, Verschuuren-Bemelmans CC, Pennings M, de Boer EN, Kremer B, Vanhoutte EK, de Vries JJ, van de Berg R, Kamsteeg EJ, van Diemen CC, Westers H, van de Warrenburg BP, Verbeek DS. Prevalence of intronic repeat expansions in RFC1 in Dutch patients with CANVAS and adult-onset ataxia. J Neurol 2022. [PMID: 35864213 DOI: 10.1007/s00415-022-11275-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/07/2022] [Accepted: 07/07/2022] [Indexed: 11/16/2022]
Abstract
Recently, an intronic biallelic (AAGGG)n repeat expansion in RFC1 was shown to be a cause of CANVAS and adult-onset ataxia in multiple populations. As the prevalence of the RFC1 repeat expansion in Dutch cases was unknown, we retrospectively tested 9 putative CANVAS cases and two independent cohorts (A and B) of 395 and 222 adult-onset ataxia cases, respectively, using the previously published protocol and, for the first time optical genome mapping to determine the size of the expanded RFC1 repeat. We identified the biallelic (AAGGG)n repeat expansion in 5/9 (55%) putative CANVAS patients and in 10/617 (1.6%; cohorts A + B) adult-onset ataxia patients. In addition to the AAGGG repeat motif, we observed a putative GAAGG repeat motif in the repeat expansion with unknown significance in two adult-onset ataxia patients. All the expanded (AAGGG)n repeats identified were in the range of 800–1299 repeat units. The intronic biallelic RFC1 repeat expansion thus explains a number of the Dutch adult-onset ataxia cases that display the main clinical features of CANVAS, and particularly when ataxia is combined with neuropathy. The yield of screening for RFC1 expansions in unselected cohorts is relatively low. To increase the current diagnostic yield in ataxia patients, we suggest adding RFC1 screening to the genetic diagnostic workflow by using advanced techniques that attain long fragments.
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15
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Bhattacharya S, Barseghyan H, Délot EC, Vilain E. nanotatoR: a tool for enhanced annotation of genomic structural variants. BMC Genomics 2021; 22:10. [PMID: 33407088 PMCID: PMC7789800 DOI: 10.1186/s12864-020-07182-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/22/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Whole genome sequencing is effective at identification of small variants, but because it is based on short reads, assessment of structural variants (SVs) is limited. The advent of Optical Genome Mapping (OGM), which utilizes long fluorescently labeled DNA molecules for de novo genome assembly and SV calling, has allowed for increased sensitivity and specificity in SV detection. However, compared to small variant annotation tools, OGM-based SV annotation software has seen little development, and currently available SV annotation tools do not provide sufficient information for determination of variant pathogenicity. RESULTS We developed an R-based package, nanotatoR, which provides comprehensive annotation as a tool for SV classification. nanotatoR uses both external (DGV; DECIPHER; Bionano Genomics BNDB) and internal (user-defined) databases to estimate SV frequency. Human genome reference GRCh37/38-based BED files are used to annotate SVs with overlapping, upstream, and downstream genes. Overlap percentages and distances for nearest genes are calculated and can be used for filtration. A primary gene list is extracted from public databases based on the patient's phenotype and used to filter genes overlapping SVs, providing the analyst with an easy way to prioritize variants. If available, expression of overlapping or nearby genes of interest is extracted (e.g. from an RNA-Seq dataset, allowing the user to assess the effects of SVs on the transcriptome). Most quality-control filtration parameters are customizable by the user. The output is given in an Excel file format, subdivided into multiple sheets based on SV type and inheritance pattern (INDELs, inversions, translocations, de novo, etc.). nanotatoR passed all quality and run time criteria of Bioconductor, where it was accepted in the April 2019 release. We evaluated nanotatoR's annotation capabilities using publicly available reference datasets: the singleton sample NA12878, mapped with two types of enzyme labeling, and the NA24143 trio. nanotatoR was also able to accurately filter the known pathogenic variants in a cohort of patients with Duchenne Muscular Dystrophy for which we had previously demonstrated the diagnostic ability of OGM. CONCLUSIONS The extensive annotation enables users to rapidly identify potential pathogenic SVs, a critical step toward use of OGM in the clinical setting.
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Affiliation(s)
- Surajit Bhattacharya
- Center for Genetic Medicine Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Hayk Barseghyan
- Center for Genetic Medicine Research, Children's 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, 20052, USA.,Bionano Genomics Inc, San Diego, CA, 92121, USA
| | - Emmanuèle C Délot
- Center for Genetic Medicine Research, Children's 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, 20052, USA
| | - Eric Vilain
- Center for Genetic Medicine Research, Children's 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, 20052, USA.
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Abstract
The medical and psychosocial challenges faced by patients living with Disorders/Differences of Sex Development (DSD) and their families can be alleviated by a rapid and accurate diagnostic process. Clinical diagnosis of DSD is limited by a lack of standardization of anatomical and endocrine phenotyping and genetic testing, as well as poor genotype/phenotype correlation. Historically, DSD genes have been identified through positional cloning of disease-associated variants segregating in families and validation of candidates in animal and in vitro modeling of variant pathogenicity. Owing to the complexity of conditions grouped under DSD, genome-wide scanning methods are better suited for identifying disease causing gene variant(s) and providing a clinical diagnosis. Here, we review a number of established genomic tools (karyotyping, chromosomal microarrays and exome sequencing) used in clinic for DSD diagnosis, as well as emerging genomic technologies such as whole-genome (short-read) sequencing, long-read sequencing, and optical mapping used for novel DSD gene discovery. These, together with gene expression and epigenetic studies can potentiate the clinical diagnosis of DSD diagnostic rates and enhance the outcomes for patients and families.
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Affiliation(s)
- Abhinav Parivesh
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States
| | - Hayk Barseghyan
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States
| | - Emmanuèle Délot
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States.
| | - Eric Vilain
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, United States; Department of Genomics and Precision Medicine, The George Washington University, Washington, DC, United States.
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