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Radziwonik-Fraczyk W, Elert-Dobkowska E, Karpinski M, Pilch J, Ziora-Jakutowicz K, Kubalska J, Szczesniak D, Stepniak I, Zaremba J, Sulek A. Next generation sequencing panel as an effective approach to genetic testing in patients with a highly variable phenotype of neuromuscular disorders. Neurogenetics 2024; 25:233-247. [PMID: 38758368 PMCID: PMC11249508 DOI: 10.1007/s10048-024-00762-y] [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: 03/19/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
Neuromuscular disorders (NMDs) include a wide range of diseases affecting the peripheral nervous system. The genetic diagnoses are increasingly obtained with using the next generation sequencing (NGS). We applied the custom-design targeted NGS panel including 89 genes, together with genotyping and multiplex ligation-dependent probe amplification (MLPA) to identify a genetic spectrum of NMDs in 52 Polish patients. As a result, the genetic diagnosis was determined by NGS panel in 29 patients so its diagnostic utility is estimated at 55.8%. The most pathogenic variants were found in CLCN1, followed by CAPN3, SCN4A, and SGCA genes. Genotyping of myotonic dystrophy type 1 and 2 (DM1 and DM2) as a secondary approach has been performed. The co-occurrence of CAPN3 and CNBP mutations in one patient as well as DYSF and CNBP mutations in another suggests possibly more complex inheritance as well as expression of a phenotype. In 7 individuals with single nucleotide variant found in NGS testing, the MLPA of the CAPN3 gene was performed detecting the deletion encompassing exons 2-8 in the CAPN3 gene in one patient, confirming recessive limb-girdle muscular dystrophy type 1 (LGMDR1). Thirty patients obtained a genetic diagnosis (57.7%) after using NGS testing, genotyping and MLPA analysis. The study allowed for the identification of 27 known and 4 novel pathogenic/likely pathogenic variants and variants of uncertain significance (VUS) associated with NMDs.In conclusion, the diagnostic approach with diverse molecular techniques enables to broaden the mutational spectrum and maximizes the diagnostic yield. Furthermore, the co-occurrence of DM2 and LGMD has been detected in 2 individuals.
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Affiliation(s)
| | | | | | - Jacek Pilch
- Department of Pediatric Neurology, Medical University of Silesia, Katowice, Poland
| | | | - Jolanta Kubalska
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Dominika Szczesniak
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Iwona Stepniak
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Jacek Zaremba
- Department of Genetics, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Anna Sulek
- Faculty of Medicine, Lazarski University, Warsaw, Poland.
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2
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Kernohan KD, Boycott KM. The expanding diagnostic toolbox for rare genetic diseases. Nat Rev Genet 2024; 25:401-415. [PMID: 38238519 DOI: 10.1038/s41576-023-00683-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2023] [Indexed: 05/23/2024]
Abstract
Genomic technologies, such as targeted, exome and short-read genome sequencing approaches, have revolutionized the care of patients with rare genetic diseases. However, more than half of patients remain without a diagnosis. Emerging approaches from research-based settings such as long-read genome sequencing and optical genome mapping hold promise for improving the identification of disease-causal genetic variants. In addition, new omic technologies that measure the transcriptome, epigenome, proteome or metabolome are showing great potential for variant interpretation. As genetic testing options rapidly expand, the clinical community needs to be mindful of their individual strengths and limitations, as well as remaining challenges, to select the appropriate diagnostic test, correctly interpret results and drive innovation to address insufficiencies. If used effectively - through truly integrative multi-omics approaches and data sharing - the resulting large quantities of data from these established and emerging technologies will greatly improve the interpretative power of genetic and genomic diagnostics for rare diseases.
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Affiliation(s)
- Kristin D Kernohan
- CHEO Research Institute, University of Ottawa, Ottawa, ON, Canada
- Newborn Screening Ontario, CHEO, Ottawa, ON, Canada
| | - Kym M Boycott
- CHEO Research Institute, University of Ottawa, Ottawa, ON, Canada.
- Department of Genetics, CHEO, Ottawa, ON, Canada.
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3
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Krenn M, Wagner M, Zulehner G, Weng R, Jäger F, Keritam O, Sener M, Brücke C, Milenkovic I, Langer A, Buchinger D, Habersam R, Mayerhanser K, Brugger M, Brunet T, Jacob M, Graf E, Berutti R, Cetin H, Hoefele J, Winkelmann J, Zimprich F, Rath J. Next-generation sequencing and comprehensive data reassessment in 263 adult patients with neuromuscular disorders: insights into the gray zone of molecular diagnoses. J Neurol 2024; 271:1937-1946. [PMID: 38127101 PMCID: PMC10972933 DOI: 10.1007/s00415-023-12101-6] [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: 09/20/2023] [Revised: 11/03/2023] [Accepted: 11/04/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Neuromuscular disorders (NMDs) are heterogeneous conditions with a considerable fraction attributed to monogenic defects. Despite the advancements in genomic medicine, many patients remain without a diagnosis. Here, we investigate whether a comprehensive reassessment strategy improves the diagnostic outcomes. METHODS We analyzed 263 patients with NMD phenotypes that underwent diagnostic exome or genome sequencing at our tertiary referral center between 2015 and 2023. We applied a comprehensive reassessment encompassing variant reclassification, re-phenotyping and NGS data reanalysis. Multivariable logistic regression was performed to identify predictive factors associated with a molecular diagnosis. RESULTS Initially, a molecular diagnosis was identified in 53 cases (20%), while an additional 23 (9%) had findings of uncertain significance. Following comprehensive reassessment, the diagnostic yield increased to 23%, revealing 44 distinct monogenic etiologies. Reasons for newly obtained molecular diagnoses were variant reclassifications in 7 and NGS data reanalysis in 3 cases including one recently described disease-gene association (DNAJB4). Male sex reduced the odds of receiving a molecular diagnosis (OR 0.42; 95%CI 0.21-0.82), while a positive family history (OR 5.46; 95%CI 2.60-11.76) and a myopathy phenotype (OR 2.72; 95%CI 1.11-7.14) increased the likelihood. 7% were resolved through targeted genetic testing or classified as acquired etiologies. CONCLUSION Our findings reinforce the use of NGS in NMDs of suspected monogenic origin. We show that a comprehensive reassessment enhances diagnostic accuracy. However, one needs to be aware that genetic diagnoses are often made with uncertainty and can even be downgraded based on new evidence.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Gudrun Zulehner
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Rosa Weng
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Fiona Jäger
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Omar Keritam
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Merve Sener
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Christof Brücke
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Ivan Milenkovic
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Agnes Langer
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Dominic Buchinger
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Richard Habersam
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Katharina Mayerhanser
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Melanie Brugger
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Theresa Brunet
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- Department of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Dr. Von Hauner's Children's Hospital, University of Munich, Munich, Germany
| | - Maureen Jacob
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Elisabeth Graf
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Riccardo Berutti
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Hakan Cetin
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Julia Hoefele
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Juliane Winkelmann
- Institute of Human Genetics, Klinikum Rechts Der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Jakob Rath
- Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria.
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4
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Piñeros-Fernández MC, Morte B, García-Giménez JL. Utility of exome sequencing for the diagnosis of pediatric-onset neuromuscular diseases beyond diagnostic yield: a narrative review. Neurol Sci 2024; 45:1455-1464. [PMID: 37989827 PMCID: PMC10942921 DOI: 10.1007/s10072-023-07210-z] [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: 09/26/2023] [Accepted: 11/15/2023] [Indexed: 11/23/2023]
Abstract
Diagnosis of neuromuscular diseases (NMD) can be challenging because of the heterogeneity of this group of diseases. This review aimed to describe the diagnostic yield of whole exome sequencing (WES) for pediatric-onset neuromuscular disease diagnosis, as well as other benefits of this approach in patient management since WES can contribute to appropriate treatment selection in NMD patients. WES increases the possibility of reaching a conclusive genetic diagnosis when other technologies have failed and even exploring new genes not previously associated with a specific NMD. Moreover, this strategy can be useful when a dual diagnosis is suspected in complex congenital anomalies and undiagnosed cases.
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Affiliation(s)
- Martha Cecilia Piñeros-Fernández
- Servicio de Neurología Pediátrica, Hospital Pediátrico, Fundación Cardio Infantil-LaCardio, Bogotá, Colombia
- Unidad Pediátrica, Los Cobos Medical Center, Bogotá, Colombia
- Consulta Externa Especializada, Virrey Solís IPS, Bogotá, Colombia
| | - Beatriz Morte
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - José Luis García-Giménez
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
- Instituto de Investigación Sanitaria INCLIVA, Valencia, Spain.
- Departamento de Fisiología, Facultad de Medicina y Odontología, Universitat de València, València, Spain.
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5
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Jolfayi AG, Kohansal E, Ghasemi S, Naderi N, Hesami M, MozafaryBazargany M, Moghadam MH, Fazelifar AF, Maleki M, Kalayinia S. Exploring TTN variants as genetic insights into cardiomyopathy pathogenesis and potential emerging clues to molecular mechanisms in cardiomyopathies. Sci Rep 2024; 14:5313. [PMID: 38438525 PMCID: PMC10912352 DOI: 10.1038/s41598-024-56154-7] [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: 11/22/2023] [Accepted: 03/01/2024] [Indexed: 03/06/2024] Open
Abstract
The giant protein titin (TTN) is a sarcomeric protein that forms the myofibrillar backbone for the components of the contractile machinery which plays a crucial role in muscle disorders and cardiomyopathies. Diagnosing TTN pathogenic variants has important implications for patient management and genetic counseling. Genetic testing for TTN variants can help identify individuals at risk for developing cardiomyopathies, allowing for early intervention and personalized treatment strategies. Furthermore, identifying TTN variants can inform prognosis and guide therapeutic decisions. Deciphering the intricate genotype-phenotype correlations between TTN variants and their pathologic traits in cardiomyopathies is imperative for gene-based diagnosis, risk assessment, and personalized clinical management. With the increasing use of next-generation sequencing (NGS), a high number of variants in the TTN gene have been detected in patients with cardiomyopathies. However, not all TTN variants detected in cardiomyopathy cohorts can be assumed to be disease-causing. The interpretation of TTN variants remains challenging due to high background population variation. This narrative review aimed to comprehensively summarize current evidence on TTN variants identified in published cardiomyopathy studies and determine which specific variants are likely pathogenic contributors to cardiomyopathy development.
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Affiliation(s)
- Amir Ghaffari Jolfayi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Erfan Kohansal
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Serwa Ghasemi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Niloofar Naderi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahshid Hesami
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Maryam Hosseini Moghadam
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Farjam Fazelifar
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Maleki
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
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6
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Rosenberg A, Tian C, He H, Ulm E, Collins Ruff K, B Nagaraj C. An evaluation of clinical presentation and genetic testing approaches for patients with neuromuscular disorders. Am J Med Genet A 2023; 191:2679-2692. [PMID: 37503964 DOI: 10.1002/ajmg.a.63356] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/20/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023]
Abstract
Inherited neuromuscular disorders (NMDs) are a large group of genetic conditions characterized by impaired peripheral nerve, motor neuron, neuromuscular junction, or skeletal muscle function. These conditions are also known to have clinical and genetic heterogeneity and variable ages of onset. Clinical evaluation for NMDs has increasingly incorporated molecular genetics. However, genetic testing is complicated by the variety of testing options and the ambiguity of NMD phenotypes. Examining test selection and yield may elucidate testing recommendations and improve the diagnostic journey for these patients. This retrospective chart review evaluated the clinical presentations, genetic testing approaches, and diagnostic outcomes of 155 patients with suspected NMDs at Cincinnati Children's Hospital Medical Center. A total of 262 individual tests were ordered, averaging 1.7 tests per patient. The clinic utilized 26 separate genetic tests, with test yields ranging from 0% to 66%. Overall, 21% of patients received a genetic diagnosis. Of all the clinical findings evaluated, elevated CPK levels with or without muscle weakness were the most informative symptoms correlated with a diagnostic result. This study highlights several genetic testing considerations for NMDs, including the variability of diagnostic outcomes. This knowledge is relevant to clinicians and patients, especially during the pretest counseling and consenting process.
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Affiliation(s)
- Amanda Rosenberg
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Cuixia Tian
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Hua He
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Elizabeth Ulm
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | | | - Chinmayee B Nagaraj
- Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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7
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Meyer AP, Ma J, Brock G, Hashimoto S, Cottrell CE, Mathew M, Hunter JM, Leung ML, Corsmeier D, Jayaraman V, Waldrop MA, Flanigan KM. Exome sequencing in the pediatric neuromuscular clinic leads to more frequent diagnosis of both neuromuscular and neurodevelopmental conditions. Muscle Nerve 2023; 68:833-840. [PMID: 37789688 DOI: 10.1002/mus.27976] [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: 01/06/2023] [Revised: 09/06/2023] [Accepted: 09/10/2023] [Indexed: 10/05/2023]
Abstract
INTRODUCTION/AIMS Exome sequencing (ES) has proven to be a valuable diagnostic tool for neuromuscular disorders, which often pose a diagnostic challenge. The aims of this study were to investigate the clinical outcomes associated with utilization of ES in the pediatric neuromuscular clinic and to determine if specific phenotypic features or abnormal neurodiagnostic tests were predictive of a diagnostic result. METHODS This was a retrospective medical record review of 76 pediatric neuromuscular clinic patients who underwent ES. Based upon clinical assessment prior to ES, patients were divided into two groups: affected by neuromuscular (n = 53) or non-neuromuscular (n = 23) syndromes. RESULTS A diagnosis was made in 28/76 (36.8%), with 29 unique disorders identified. In the neuromuscular group, a neuromuscular condition was confirmed in 78% of those receiving a genetic diagnosis. Early age of symptom onset was associated with a significantly higher diagnostic yield. The most common reason neuromuscular diagnoses were not detected on prior testing was due to causative genes not being present on disease-specific panels. Changes to medical care were made in 57% of individuals receiving a diagnosis on ES. DISCUSSION These data further support ES as a powerful diagnostic tool in the pediatric neuromuscular clinic and highlight the advantages of ES over gene panels, including the ability to identify diagnoses regardless of etiology, identify genes newly associated with disease, and identify multiple confounding diagnoses. Rapid and accurate diagnosis by ES can not only end the patient's diagnostic odyssey, but often impacts patients' medical management and genetic counseling of families.
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Affiliation(s)
- Alayne P Meyer
- Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Jianing Ma
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Guy Brock
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Sayaka Hashimoto
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Catherine E Cottrell
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Mariam Mathew
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Jesse M Hunter
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Marco L Leung
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pathology, The Ohio State University, Columbus, Ohio, USA
| | - Don Corsmeier
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Vijayakumar Jayaraman
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Megan A Waldrop
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- Department of Neurology, Nationwide Children's Hospital & The Ohio State University, Columbus, Ohio, USA
- Center for Gene Therapy, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Kevin M Flanigan
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- Department of Neurology, Nationwide Children's Hospital & The Ohio State University, Columbus, Ohio, USA
- Center for Gene Therapy, Nationwide Children's Hospital, Columbus, Ohio, USA
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8
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Krenn M, Sener M, Rath J, Zulehner G, Keritam O, Wagner M, Laccone F, Iglseder S, Marte S, Baumgartner M, Eisenkölbl A, Liechtenstein C, Rudnik S, Quasthoff S, Grinzinger S, Spenger J, Wortmann SB, Löscher WN, Zimprich F, Kellersmann A, Rappold M, Bernert G, Freilinger M, Cetin H. The clinical and molecular landscape of congenital myasthenic syndromes in Austria: a nationwide study. J Neurol 2023; 270:909-916. [PMID: 36308527 PMCID: PMC9886627 DOI: 10.1007/s00415-022-11440-0] [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: 08/31/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders caused by genetic defects resulting in impaired neuromuscular transmission. Although effective treatments are available, CMS is probably underdiagnosed, and systematic clinico-genetic investigations are warranted. METHODS We used a nationwide approach to collect Austrian patients with genetically confirmed CMS. We provide a clinical and molecular characterization of this cohort and aimed to ascertain the current frequency of CMS in Austria. RESULTS Twenty-eight cases with genetically confirmed CMS were identified, corresponding to an overall prevalence of 3.1 per million (95% CI 2.0-4.3) in Austria. The most frequent genetic etiology was CHRNE (n = 13), accounting for 46.4% of the cohort. Within this subgroup, the variant c.1327del, p.(Glu443Lysfs*64) was detected in nine individuals. Moreover, causative variants were found in DOK7 (n = 4), RAPSN (n = 3), COLQ (n = 2), GMPPB (n = 2), CHAT (n = 1), COL13A1 (n = 1), MUSK (n = 1) and AGRN (n = 1). Clinical onset within the first year of life was reported in one half of the patients. Across all subtypes, the most common symptoms were ptosis (85.7%), lower limb (67.9%), upper limb (60.7%) and facial weakness (60.7%). The majority of patients (96.4%) received specific treatment, including acetylcholinesterase inhibitors in 20, adrenergic agonists in 11 and 3,4-diaminopyridine in nine patients. CONCLUSIONS Our study presents the first systematic characterization of individuals with CMS in Austria, providing prevalence estimates and genotype-phenotype correlations that may help to improve the diagnostic approach and patient management.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Merve Sener
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Jakob Rath
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Gudrun Zulehner
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Omar Keritam
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University of Munich, Munich, Germany.,Institute for Neurogenomics, Helmholtz Center Munich, Munich, Germany
| | - Franco Laccone
- Institute of Medical Genetics, Medical University of Vienna, Vienna, Austria
| | - Stephan Iglseder
- Department of Neurology, Krankenhaus Barmherzige Brüder, Linz, Austria
| | | | - Manuela Baumgartner
- Department of Neuropaediatrics, Hospital Barmherzige Schwestern Linz, Linz, Austria
| | - Astrid Eisenkölbl
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Christian Liechtenstein
- Department of Paediatrics and Adolescent Medicine, Villach Regional Hospital, Villach, Austria
| | - Sabine Rudnik
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Stefan Quasthoff
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Susanne Grinzinger
- Department of Neurology, Salzburger Landeskliniken, Paracelsus Medical University, Salzburg, Austria
| | - Johannes Spenger
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Saskia B Wortmann
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria.,Amalia Children's Hospital, Radboudumc, Nijmegen, The Netherlands
| | - Wolfgang N Löscher
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | | | - Mika Rappold
- Department of Pediatrics, Klinik Favoriten, Vienna, Austria
| | | | - Michael Freilinger
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Hakan Cetin
- Department of Neurology, Medical University of Vienna, Vienna, Austria.
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9
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Ng KWP, Chin HL, Chin AXY, Goh DLM. Using gene panels in the diagnosis of neuromuscular disorders: A mini-review. Front Neurol 2022; 13:997551. [PMID: 36313509 PMCID: PMC9602396 DOI: 10.3389/fneur.2022.997551] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023] Open
Abstract
The diagnosis of inherited neuromuscular disorders is challenging due to their genetic and phenotypic variability. Traditionally, neurophysiology and histopathology were primarily used in the initial diagnostic approach to these conditions. Sanger sequencing for molecular diagnosis was less frequently utilized as its application was a time-consuming and cost-intensive process. The advent and accessibility of next-generation sequencing (NGS) has revolutionized the evaluation process of genetically heterogenous neuromuscular disorders. Current NGS diagnostic testing approaches include gene panels, whole exome sequencing (WES), and whole genome sequencing (WGS). Gene panels are often the most widely used, being more accessible due to availability and affordability. In this mini-review, we describe the benefits and risks of clinical genetic testing. We also discuss the utility, benefits, challenges, and limitations of using gene panels in the evaluation of neuromuscular disorders.
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Affiliation(s)
- Kay W. P. Ng
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Hui-Lin Chin
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Amanda X. Y. Chin
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Denise Li-Meng Goh
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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10
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Diagnostic Outcome of Genetic Testing for Neuromuscular Disorders in a Tertiary Center. J Clin Neuromuscul Dis 2022; 24:1-6. [PMID: 36005468 DOI: 10.1097/cnd.0000000000000389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ABSTRACT Genetic testing is an effective and reliable modality in clinical neuromuscular diagnosis. The recent developments in testing methods and increasing reliance on genetic testing in clinical practice require more studies to examine the benefits and advantages of such tests. We examined the results of single-gene sequencing/repeat analysis, panels, and whole-genome sequencing (WES) of 514 tests of 393 patients. All patients were suspected of a neuromuscular disorder and the samples were either WBC or muscle tissue. 28.60% (n.147) of the tests were positive while 23.74% (n.122) were VUS. In single-gene sequencing/repeat analysis, 43.08% were positive, in panels, 23.17% were positive, while 30.00% were positive in WES. Our results showed consistency with current studies and improvement of the utility of genetic testing. Although some obstacles are identified, providing statistical data can support more usage and popularity of genetic testing among physicians and patients.
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11
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Koczwara KE, Lake NJ, DeSimone AM, Lek M. Neuromuscular disorders: finding the missing genetic diagnoses. Trends Genet 2022; 38:956-971. [PMID: 35908999 DOI: 10.1016/j.tig.2022.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/24/2022]
Abstract
Neuromuscular disorders (NMDs) are a wide-ranging group of diseases that seriously affect the quality of life of affected individuals. The development of next-generation sequencing revolutionized the diagnosis of NMD, enabling the discovery of hundreds of NMD genes and many more pathogenic variants. However, the diagnostic yield of genetic testing in NMD cohorts remains incomplete, indicating a large number of genetic diagnoses are not identified through current methods. Fortunately, recent advancements in sequencing technologies, analytical tools, and high-throughput functional screening provide an opportunity to circumvent current challenges. Here, we discuss reasons for missing genetic diagnoses in NMD, how emerging technologies and tools can overcome these hurdles, and examine future approaches to improving diagnostic yields in NMD.
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Affiliation(s)
- Katherine E Koczwara
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Nicole J Lake
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Alec M DeSimone
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Monkol Lek
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
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12
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Krenn M, Jengojan S, Grisold W. Spinal muscular atrophy presenting with mild limb-girdle weakness in adulthood: Diagnostic pitfalls in the era of disease-modifying therapies. J Neurol Sci 2022; 440:120347. [PMID: 35908306 DOI: 10.1016/j.jns.2022.120347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/05/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022]
Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Suren Jengojan
- Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Grisold
- Ludwig Boltzmann Institute for Experimental und Clinical Traumatology, Vienna, Austria.
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13
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Elliott AM, Adam S, du Souich C, Lehman A, Nelson TN, van Karnebeek C, Alderman E, Armstrong L, Aubertin G, Blood K, Boelman C, Boerkoel C, Bretherick K, Brown L, Chijiwa C, Clarke L, Couse M, Creighton S, Watts-Dickens A, Gibson WT, Gill H, Tarailo-Graovac M, Hamilton S, Heran H, Horvath G, Huang L, Hulait GK, Koehn D, Lee HK, Lewis S, Lopez E, Louie K, Niederhoffer K, Matthews A, Meagher K, Peng JJ, Patel MS, Race S, Richmond P, Rupps R, Salvarinova R, Seath K, Selby K, Steinraths M, Stockler S, Tang K, Tyson C, van Allen M, Wasserman W, Mwenifumbo J, Friedman JM. Genome-wide sequencing and the clinical diagnosis of genetic disease: The CAUSES study. HGG ADVANCES 2022; 3:100108. [PMID: 35599849 PMCID: PMC9117924 DOI: 10.1016/j.xhgg.2022.100108] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 04/11/2022] [Indexed: 12/02/2022] Open
Abstract
Genome-wide sequencing (GWS) is a standard of care for diagnosis of suspected genetic disorders, but the proportion of patients found to have pathogenic or likely pathogenic variants ranges from less than 30% to more than 60% in reported studies. It has been suggested that the diagnostic rate can be improved by interpreting genomic variants in the context of each affected individual's full clinical picture and by regular follow-up and reinterpretation of GWS laboratory results. Trio exome sequencing was performed in 415 families and trio genome sequencing in 85 families in the CAUSES study. The variants observed were interpreted by a multidisciplinary team including laboratory geneticists, bioinformaticians, clinical geneticists, genetic counselors, pediatric subspecialists, and the referring physician, and independently by a clinical laboratory using standard American College of Medical Genetics and Genomics (ACMG) criteria. Individuals were followed for an average of 5.1 years after testing, with clinical reassessment and reinterpretation of the GWS results as necessary. The multidisciplinary team established a diagnosis of genetic disease in 43.0% of the families at the time of initial GWS interpretation, and longitudinal follow-up and reinterpretation of GWS results produced new diagnoses in 17.2% of families whose initial GWS interpretation was uninformative or uncertain. Reinterpretation also resulted in rescinding a diagnosis in four families (1.9%). Of the families studied, 33.6% had ACMG pathogenic or likely pathogenic variants related to the clinical indication. Close collaboration among clinical geneticists, genetic counselors, laboratory geneticists, bioinformaticians, and individuals' primary physicians, with ongoing follow-up, reanalysis, and reinterpretation over time, can improve the clinical value of GWS.
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Affiliation(s)
- Alison M. Elliott
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Women’s Health Research Institute, Vancouver, BC, Canada
| | - Shelin Adam
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Christèle du Souich
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Anna Lehman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Tanya N. Nelson
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Clara van Karnebeek
- Department of Pediatrics, Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
- Department of Pediatrics, Emma Children’s Hospital, Amsterdam, University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - Emily Alderman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Linlea Armstrong
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Gudrun Aubertin
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Katherine Blood
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Cyrus Boelman
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Division of Neurology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Cornelius Boerkoel
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Karla Bretherick
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Lindsay Brown
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Chieko Chijiwa
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Lorne Clarke
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Madeline Couse
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Susan Creighton
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Abby Watts-Dickens
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - William T. Gibson
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Harinder Gill
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | | | - Sara Hamilton
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Harindar Heran
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Gabriella Horvath
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Lijia Huang
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Gurdip K. Hulait
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - David Koehn
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Hyun Kyung Lee
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Suzanne Lewis
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Elena Lopez
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Kristal Louie
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Karen Niederhoffer
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Allison Matthews
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Kirsten Meagher
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Junran J. Peng
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Millan S. Patel
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Simone Race
- Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Phillip Richmond
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Rosemarie Rupps
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Ramona Salvarinova
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Kimberly Seath
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Kathryn Selby
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Division of Neurology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Michelle Steinraths
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sylvia Stockler
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Division of Biochemical Diseases, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Kaoru Tang
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Christine Tyson
- Division of Genome Diagnostics, Department of Pathology and Laboratory Medicine, BC Children’s and Women’s Hospitals, Vancouver, BC, Canada
| | - Margot van Allen
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Wyeth Wasserman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pediatrics, Center for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Jill Mwenifumbo
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Jan M. Friedman
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
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14
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Wortmann SB, Oud MM, Alders M, Coene KLM, van der Crabben SN, Feichtinger RG, Garanto A, Hoischen A, Langeveld M, Lefeber D, Mayr JA, Ockeloen CW, Prokisch H, Rodenburg R, Waterham HR, Wevers RA, van de Warrenburg BPC, Willemsen MAAP, Wolf NI, Vissers LELM, van Karnebeek CDM. How to proceed after "negative" exome: A review on genetic diagnostics, limitations, challenges, and emerging new multiomics techniques. J Inherit Metab Dis 2022; 45:663-681. [PMID: 35506430 PMCID: PMC9539960 DOI: 10.1002/jimd.12507] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/26/2022] [Accepted: 04/27/2022] [Indexed: 11/28/2022]
Abstract
Exome sequencing (ES) in the clinical setting of inborn metabolic diseases (IMDs) has created tremendous improvement in achieving an accurate and timely molecular diagnosis for a greater number of patients, but it still leaves the majority of patients without a diagnosis. In parallel, (personalized) treatment strategies are increasingly available, but this requires the availability of a molecular diagnosis. IMDs comprise an expanding field with the ongoing identification of novel disease genes and the recognition of multiple inheritance patterns, mosaicism, variable penetrance, and expressivity for known disease genes. The analysis of trio ES is preferred over singleton ES as information on the allelic origin (paternal, maternal, "de novo") reduces the number of variants that require interpretation. All ES data and interpretation strategies should be exploited including CNV and mitochondrial DNA analysis. The constant advancements in available techniques and knowledge necessitate the close exchange of clinicians and molecular geneticists about genotypes and phenotypes, as well as knowledge of the challenges and pitfalls of ES to initiate proper further diagnostic steps. Functional analyses (transcriptomics, proteomics, and metabolomics) can be applied to characterize and validate the impact of identified variants, or to guide the genomic search for a diagnosis in unsolved cases. Future diagnostic techniques (genome sequencing [GS], optical genome mapping, long-read sequencing, and epigenetic profiling) will further enhance the diagnostic yield. We provide an overview of the challenges and limitations inherent to ES followed by an outline of solutions and a clinical checklist, focused on establishing a diagnosis to eventually achieve (personalized) treatment.
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Affiliation(s)
- Saskia B. Wortmann
- Radboud Center for Mitochondrial and Metabolic Medicine, Department of PediatricsAmalia Children's Hospital, Radboud University Medical CenterNijmegenThe Netherlands
- University Children's Hospital, Paracelsus Medical UniversitySalzburgAustria
| | - Machteld M. Oud
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Department of Human GeneticsDonders Institute for Brain, Cognition and Behaviour, Radboud University Medical CenterNijmegenThe Netherlands
| | - Mariëlle Alders
- Department of Human GeneticsAmsterdam UMC, University of Amsterdam, Amsterdam Reproduction and Development Research InstituteAmsterdamThe Netherlands
| | - Karlien L. M. Coene
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - Saskia N. van der Crabben
- Department of Human GeneticsAmsterdam University Medical Centers, University of AmsterdamAmsterdamThe Netherlands
| | - René G. Feichtinger
- University Children's Hospital, Paracelsus Medical UniversitySalzburgAustria
| | - Alejandro Garanto
- Radboud Center for Mitochondrial and Metabolic Medicine, Department of PediatricsAmalia Children's Hospital, Radboud University Medical CenterNijmegenThe Netherlands
- Department of PediatricsAmalia Children's Hospital, Radboud Institute for Molecular LifesciencesNijmegenThe Netherlands
- Department of Human GeneticsRadboud Institute for Molecular LifesciencesNijmegenThe Netherlands
| | - Alex Hoischen
- Department of Human Genetics, Department of Internal Medicine and Radboud Center for Infectious DiseasesRadboud Institute of Medical Life Sciences, Radboud University Medical CenterNijmegenthe Netherlands
| | - Mirjam Langeveld
- Department of Endocrinology and MetabolismAmsterdam University Medical Centers, location AMC, University of AmsterdamAmsterdamThe Netherlands
| | - Dirk Lefeber
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
- Department of Neurology, Donders Institute for BrainCognition and Behaviour, Radboud University Medical CenterNijmegenThe Netherlands
| | - Johannes A. Mayr
- University Children's Hospital, Paracelsus Medical UniversitySalzburgAustria
| | - Charlotte W. Ockeloen
- Department of Human GeneticsRadboud Institute for Molecular LifesciencesNijmegenThe Netherlands
| | - Holger Prokisch
- School of MedicineInstitute of Human Genetics, Technical University Munich and Institute of NeurogenomicsNeuherbergGermany
| | - Richard Rodenburg
- Radboud Center for Mitochondrial and Metabolic MedicineTranslational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical CenterNijmegenThe Netherlands
| | - Hans R. Waterham
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Clinical ChemistryAmsterdam University Medical Centers, location AMC, University of AmsterdamAmsterdamThe Netherlands
| | - Ron A. Wevers
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - Bart P. C. van de Warrenburg
- Department of Neurology, Donders Institute for BrainCognition and Behaviour, Radboud University Medical CenterNijmegenThe Netherlands
| | - Michel A. A. P. Willemsen
- Departments of Pediatric Neurology and PediatricsAmalia Children's Hospital, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical CenterNijmegenThe Netherlands
| | - Nicole I. Wolf
- Amsterdam Leukodystrophy Center, Department of Child NeurologyEmma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Lisenka E. L. M. Vissers
- Department of Human GeneticsDonders Institute for Brain, Cognition and Behaviour, Radboud University Medical CenterNijmegenThe Netherlands
| | - Clara D. M. van Karnebeek
- Radboud Center for Mitochondrial and Metabolic Medicine, Department of PediatricsAmalia Children's Hospital, Radboud University Medical CenterNijmegenThe Netherlands
- United for Metabolic DiseasesAmsterdamThe Netherlands
- Department of Human GeneticsAmsterdam UMC, University of Amsterdam, Amsterdam Reproduction and Development Research InstituteAmsterdamThe Netherlands
- Department of Pediatrics, Emma Center for Personalized MedicineAmsterdam University Medical Centers, Amsterdam, Amsterdam Genetics Endocrinology Metabolism Research Institute, University of AmsterdamAmsterdamThe Netherlands
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15
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Doleckova K, Roth J, Stellmachova J, Gescheidt T, Sigut V, Houska P, Jech R, Zech M, Vyhnalek M, Vyhnalkova E, Seeman P, Meszarosova AU. SPG11: clinical and genetic features of seven Czech patients and literature review. Neurol Res 2022; 44:379-389. [DOI: 10.1080/01616412.2021.1975224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kristyna Doleckova
- Department of Neurology and Center of Clinical Neuroscience First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague
| | - Jan Roth
- Department of Neurology and Center of Clinical Neuroscience First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague
| | - Julia Stellmachova
- Department of Medical Genetics, University Hospital Olomouc, Olomouc, Czechia
| | - Tomas Gescheidt
- Department of Neurology, St. Anne´s University Hospital, Brno, Czechia
| | | | - Pavel Houska
- Department of Neurology, Strakonice Hospital, Strakonice, Czechia
| | - Robert Jech
- Department of Neurology and Center of Clinical Neuroscience First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Martin Vyhnalek
- Department of Neurology, Second Faculty of Medicine, Charles University and University Hospital Motol, Prague
| | - Emilie Vyhnalkova
- Department of Biology and Medical Genetics, Second Faculty of Medicine, Charles University and University Hospital Motol, Prague
| | - Pavel Seeman
- Department of Paediatric Neurology, Neurogenetic Laboratory, Second Faculty of Medicine, Charles University and University Hospital Motol, Prague
| | - Anna Uhrova Meszarosova
- Department of Paediatric Neurology, Neurogenetic Laboratory, Second Faculty of Medicine, Charles University and University Hospital Motol, Prague
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16
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Krenn M, Tomschik M, Wagner M, Zulehner G, Weng R, Rath J, Klotz S, Gelpi E, Bsteh G, Keritam O, Colonna I, Paternostro C, Jäger F, Lindeck-Pozza E, Iglseder S, Grinzinger S, Schönfelder M, Hohenwarter C, Freimüller M, Embacher N, Wanschitz J, Topakian R, Töpf A, Straub V, Quasthoff S, Zimprich F, Löscher WN, Cetin H. Clinico-genetic spectrum of limb-girdle muscular weakness in Austria: a multi-centre cohort study. Eur J Neurol 2022; 29:1815-1824. [PMID: 35239206 PMCID: PMC9314602 DOI: 10.1111/ene.15306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 11/26/2022]
Abstract
Background and purpose Hereditary myopathies with limb‐girdle muscular weakness (LGW) are a genetically heterogeneous group of disorders, in which molecular diagnosis remains challenging. Our aim was to present a detailed clinical and genetic characterization of a large cohort of patients with LGW. Methods This nationwide cohort study included patients with LGW suspected to be associated with hereditary myopathies. Parameters associated with specific genetic aetiologies were evaluated, and we further assessed how they predicted the detection of causative variants by conducting genetic analyses. Results Molecular diagnoses were identified in 62.0% (75/121) of the cohort, with a higher proportion of patients diagnosed by next‐generation sequencing (NGS) than by single‐gene testing (77.3% vs. 22.7% of solved cases). The median (interquartile range) time from onset to genetic diagnosis was 8.9 (3.7–19.9) and 17.8 (7.9–27.8) years for single‐gene testing and NGS, respectively. The most common diagnoses were myopathies associated with variants in CAPN3 (n = 9), FKRP (n = 9), ANO5 (n = 8), DYSF (n = 8) and SGCA (n = 5), which together accounted for 32.2% of the cohort. Younger age at disease onset (p = 0.043), >10× elevated creatine kinase activity levels (p = 0.024) and myopathic electromyography findings (p = 0.007) were significantly associated with the detection of causative variants. Conclusions Our findings suggest that an earlier use of NGS in patients with LGW is needed to avoid long diagnostic delays. We further present parameters predictive of a molecular diagnosis that may help to select patients for genetic analyses, especially in centres with limited access to sequencing.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matthias Tomschik
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Matias Wagner
- Institute of Human Genetics, Technical University Munich, Munich, Germany.,Institute for Neurogenomics, Helmholtz Center Munich, Neuherberg, Germany.,LMU University Hospital, Department of Pediatrics, Dr. von Hauner Children's Hospital, Division of Pediatric Neurology, LMU Center for Development and Children with Medical Complexity, Ludwig-Maximilians-University, Munich, Germany
| | - Gudrun Zulehner
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Rosa Weng
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Jakob Rath
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sigrid Klotz
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Ellen Gelpi
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Gabriel Bsteh
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Omar Keritam
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Isabella Colonna
- Department of Neurology, Medical University of Graz, Graz, Austria
| | | | - Fiona Jäger
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | | | - Stephan Iglseder
- Department of Neurology, KH der Barmherzigen Brüder, Linz, Austria
| | - Susanne Grinzinger
- Department of Neurology, Paracelsus Medical University of Salzburg, Salzburg, Austria
| | - Martina Schönfelder
- Department of Neurology, Klinikum Klagenfurt am Wörthersee, Klagenfurt, Austria
| | | | | | - Norbert Embacher
- Department of Neurology, University Hospital St, Pölten, St. Pölten, Austria
| | - Julia Wanschitz
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Raffi Topakian
- Department of Neurology, Klinikum Wels-Grieskirchen, Wels, Austria
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Stefan Quasthoff
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang N Löscher
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Hakan Cetin
- Department of Neurology, Medical University of Vienna, Vienna, Austria
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17
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Mensch A, Nägel S, Zierz S, Kraya T, Stoevesandt D. Bildgebung der Muskulatur bei Neuromuskulären Erkrankungen
– von der Initialdiagnostik bis zur Verlaufsbeurteilung. KLIN NEUROPHYSIOL 2022. [DOI: 10.1055/a-1738-5356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
ZusammenfassungDie bildgebende Diagnostik hat sich zu einem integralen Element der Betreuung von
PatientInnen mit neuromuskulären Erkrankungen entwickelt. Als
wesentliches Diagnostikum ist hierbei die Magnetresonanztomografie als breit
verfügbares und vergleichsweise standardisiertes Untersuchungsverfahren
etabliert, wobei die Sonografie der Muskulatur bei hinreichend erfahrenem
Untersucher ebenfalls geeignet ist, wertvolle diagnostische Informationen zu
liefern. Das CT hingegen spielt eine untergeordnete Rolle und sollte nur bei
Kontraindikationen für eine MRT in Erwägung gezogen werden.
Zunächst wurde die Bildgebung bei Muskelerkrankungen primär in
der Initialdiagnostik unter vielfältigen Fragestellungen eingesetzt. Das
Aufkommen innovativer Therapiekonzepte bei verschiedenen neuromuskulären
Erkrankungen machen neben einer möglichst frühzeitigen
Diagnosestellung insbesondere auch eine multimodale Verlaufsbeurteilung zur
Evaluation des Therapieansprechens notwendig. Auch hier wird die Bildgebung der
Muskulatur als objektiver Parameter des Therapieerfolges intensiv diskutiert und
in Forschung wie Praxis zunehmend verwendet.
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Affiliation(s)
- Alexander Mensch
- Universitätsklinik und Poliklinik für Neurologie,
Martin-Luther-Universität Halle-Wittenberg und
Universitätsklinikum Halle, Halle (Saale)
| | - Steffen Nägel
- Universitätsklinik und Poliklinik für Neurologie,
Martin-Luther-Universität Halle-Wittenberg und
Universitätsklinikum Halle, Halle (Saale)
| | - Stephan Zierz
- Universitätsklinik und Poliklinik für Neurologie,
Martin-Luther-Universität Halle-Wittenberg und
Universitätsklinikum Halle, Halle (Saale)
| | - Torsten Kraya
- Universitätsklinik und Poliklinik für Neurologie,
Martin-Luther-Universität Halle-Wittenberg und
Universitätsklinikum Halle, Halle (Saale)
- Klinik für Neurologie, Klinikum St. Georg,
Leipzig
| | - Dietrich Stoevesandt
- Universitätsklinik und Poliklinik für Radiologie,
Martin-Luther-Universität Halle-Wittenberg und
Universitätsklinikum Halle, Halle (Saale)
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18
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Retrospective analysis and reclassification of DYSF variants in a large French series of dysferlinopathy patients. Genet Med 2021; 23:1574-1577. [PMID: 33927379 DOI: 10.1038/s41436-021-01164-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/07/2021] [Accepted: 03/22/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Recent evolution of sequencing technologies and the development of international standards in variant interpretation have profoundly changed the diagnostic approaches in clinical genetics. As a consequence, many variants that were initially claimed to be disease-causing can be now reclassified as benign or uncertain in light of the new data available. Unfortunately, the misclassified variants are still present in the scientific literature and variant databases, greatly interfering with interpretation of diagnostic sequencing results. Despite the urgent need, large-scale efforts to update the classifications of these variants are still not sufficient. METHODS We retrospectively analyzed 176 DYSF gene variants that were identified in dysferlinopathy patients referred to the Marseille Medical Genetics Department for diagnostic sequencing since 2001. RESULTS We reclassified all variants into five-tier American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) pathogenicity classes, revealing changed pathogenicity for 17 variants. We then updated the information for the variants that have been previously published in the variant database and submitted 46 additional DYSF variants. CONCLUSION Besides direct benefit for dysferlinopathy diagnostics, our study contributes to the much needed effort to reanalyze variants from previously published cohorts and to work with curators of variant databases to update the entries for erroneously classified variants.
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19
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Deschauer M, Hengel H, Rupprich K, Kreiß M, Schlotter-Weigel B, Grimmel M, Admard J, Schneider I, Alhaddad B, Gazou A, Sturm M, Vorgerd M, Balousha G, Balousha O, Falna M, Kirschke JS, Kornblum C, Jordan B, Kraya T, Strom TM, Weis J, Schöls L, Schara U, Zierz S, Riess O, Meitinger T, Haack TB. Bi-allelic truncating mutations in VWA1 cause neuromyopathy. Brain 2021; 144:574-583. [PMID: 33459760 DOI: 10.1093/brain/awaa418] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/01/2020] [Accepted: 09/23/2020] [Indexed: 11/15/2022] Open
Abstract
The von Willebrand Factor A domain containing 1 protein, encoded by VWA1, is an extracellular matrix protein expressed in muscle and peripheral nerve. It interacts with collagen VI and perlecan, two proteins that are affected in hereditary neuromuscular disorders. Lack of VWA1 is known to compromise peripheral nerves in a Vwa1 knock-out mouse model. Exome sequencing led us to identify bi-allelic loss of function variants in VWA1 as the molecular cause underlying a so far genetically undefined neuromuscular disorder. We detected six different truncating variants in 15 affected individuals from six families of German, Arabic, and Roma descent. Disease manifested in childhood or adulthood with proximal and distal muscle weakness predominantly of the lower limbs. Myopathological and neurophysiological findings were indicative of combined neurogenic and myopathic pathology. Early childhood foot deformity was frequent, but no sensory signs were observed. Our findings establish VWA1 as a new disease gene confidently implicated in this autosomal recessive neuromyopathic condition presenting with child-/adult-onset muscle weakness as a key clinical feature.
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Affiliation(s)
- Marcus Deschauer
- Department of Neurology, Technical University of Munich, School of Medicine, 81675 Munich, Germany
| | - Holger Hengel
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Katrin Rupprich
- Department of Neuropediatrics, University Hospital Essen, 45147 Germany
| | - Martina Kreiß
- Institute of Human Genetics, University of Bonn, 53127 Bonn, Germany
| | | | - Mona Grimmel
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Jakob Admard
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Ilka Schneider
- Department of Neurology, University of Halle-Wittenberg, 06097 Halle, Germany
| | - Bader Alhaddad
- Institute of Human Genetics, Technical University of Munich, School of Medicine, 81675 Munich, Germany
| | - Anastasia Gazou
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Matthias Vorgerd
- Department of Neurology, University Hospital Bergmannsheil, Heimer Institute for Muscle Research, 44789 Bochum, Germany
| | - Ghassan Balousha
- Department of Pathology and Histology, Al-Quds University, Eastern Jerusalem, Palestinian Authority
| | - Osama Balousha
- Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestinian Authority
| | - Mohammed Falna
- Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestinian Authority
| | - Jan S Kirschke
- Department of Diagnostic and Interventional Neuroradiology, Technical University of Munich, School of Medicine, 81675 Munich, Germany
| | - Cornelia Kornblum
- Department of Neurology, University Hospital Bonn, 53127 Bonn, Germany
| | - Berit Jordan
- Department of Neurology, University of Halle-Wittenberg, 06097 Halle, Germany.,Department of Neurology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Torsten Kraya
- Department of Neurology, University of Halle-Wittenberg, 06097 Halle, Germany
| | - Tim M Strom
- Institute of Human Genetics, Technical University of Munich, School of Medicine, 81675 Munich, Germany
| | - Joachim Weis
- Institute for Neuropathology, Medical Faculty, RWTH Aachen University, 52074 Aachen, Germany
| | - Ludger Schöls
- Department of Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany.,German Center of Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Ulrike Schara
- Department of Neuropediatrics, University Hospital Essen, 45147 Germany
| | - Stephan Zierz
- Department of Neurology, University of Halle-Wittenberg, 06097 Halle, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,Center for Rare Diseases, University of Tübingen, 72076 Tübingen, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technical University of Munich, School of Medicine, 81675 Munich, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany.,Institute of Human Genetics, Technical University of Munich, School of Medicine, 81675 Munich, Germany.,Center for Rare Diseases, University of Tübingen, 72076 Tübingen, Germany
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20
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Krenn M, Schloegl M, Pataraia E, Gelpi E, Schröder S, Rauscher C, Mayr JA, Kotzot D, Zimprich F, Meitinger T, Wagner M. Delineation of epileptic and neurodevelopmental phenotypes associated with variants in STX1B. Seizure 2021; 87:25-29. [PMID: 33677401 DOI: 10.1016/j.seizure.2021.02.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/04/2021] [Accepted: 02/18/2021] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVE To further delineate the clinical and genetic spectrum of epileptic and neurodevelopmental conditions associated with variants in STX1B. METHODS We screened our diagnostic in-house database (comprising >20,000 exome sequencing datasets) for pathogenic and likely pathogenic variants inSTX1B. The detected cases were phenotyped in detail, and the findings were compared to previously published case reports. RESULTS We identified four unrelated individuals with pathogenic or likely pathogenic variants in STX1B (one missense and three loss-of-function variants). All patients displayed epileptic phenotypes, including epileptiform discharges on electroencephalography (without apparent seizures), developmental and epileptic encephalopathy and focal epilepsy. Three of the four patients had developmental delay. Febrile seizures occurred in two individuals. One patient with focal epilepsy underwent epilepsy surgery without lasting improvement. The neuropathological workup of brain tissue revealed a mild malformation of cortical development without alterations of cortical lamination or dysplastic neurons. CONCLUSIONS Our findings confirm the wide clinical range ofSTX1B-related epileptic conditions and highlight the necessity of genetic testing prior to epilepsy surgery in cases with monogenic epilepsy. The identification of loss-of-function variants in very differently affected individuals suggests that no clear genotype-phenotype correlation can be established.
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Affiliation(s)
- Martin Krenn
- Department of Neurology, Medical University of Vienna, Vienna, Austria; Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Monika Schloegl
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | | | - Ellen Gelpi
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sebastian Schröder
- Department of Paediatric Neurology and Developmental Medicine, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Christian Rauscher
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University, Salzburg, Austria
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University, Salzburg, Austria
| | - Dieter Kotzot
- Unit of Clinical Genetics, University Hospital of the Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Thomas Meitinger
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Matias Wagner
- Institute of Human Genetics, Technical University Munich, Munich, Germany; Institute for Neurogenomics, Helmholtz Center Munich, Neuherberg, Germany.
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