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Xu IRL, Danzi MC, Ruiz A, Raposo J, De Jesus YA, Reilly MM, Cortese A, Shy ME, Scherer SS, Hermann D, Fridman V, Baets J, Saporta M, Seyedsadjadi R, Stojkovic T, Claeys KG, Patel P, Feely S, Rebelo A, Dohrn MF, Züchner S. A study concept of expeditious clinical enrollment for genetic modifier studies in Charcot-Marie-Tooth neuropathy 1A. J Peripher Nerv Syst 2024; 29:202-212. [PMID: 38581130 PMCID: PMC11209807 DOI: 10.1111/jns.12621] [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: 01/24/2024] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 04/08/2024]
Abstract
BACKGROUND Caused by duplications of the gene encoding peripheral myelin protein 22 (PMP22), Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common hereditary neuropathy. Despite this shared genetic origin, there is considerable variability in clinical severity. It is hypothesized that genetic modifiers contribute to this heterogeneity, the identification of which may reveal novel therapeutic targets. In this study, we present a comprehensive analysis of clinical examination results from 1564 CMT1A patients sourced from a prospective natural history study conducted by the RDCRN-INC (Inherited Neuropathy Consortium). Our primary objective is to delineate extreme phenotype profiles (mild and severe) within this patient cohort, thereby enhancing our ability to detect genetic modifiers with large effects. METHODS We have conducted large-scale statistical analyses of the RDCRN-INC database to characterize CMT1A severity across multiple metrics. RESULTS We defined patients below the 10th (mild) and above the 90th (severe) percentiles of age-normalized disease severity based on the CMT Examination Score V2 and foot dorsiflexion strength (MRC scale). Based on extreme phenotype categories, we defined a statistically justified recruitment strategy, which we propose to use in future modifier studies. INTERPRETATION Leveraging whole genome sequencing with base pair resolution, a future genetic modifier evaluation will include single nucleotide association, gene burden tests, and structural variant analysis. The present work not only provides insight into the severity and course of CMT1A, but also elucidates the statistical foundation and practical considerations for a cost-efficient and straightforward patient enrollment strategy that we intend to conduct on additional patients recruited globally.
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Affiliation(s)
- Isaac R. L. Xu
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Matt C. Danzi
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Ariel Ruiz
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Jacquelyn Raposo
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Yeisha Arcia De Jesus
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Mary M Reilly
- Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square
| | - Andrea Cortese
- Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square
| | - Michael E Shy
- Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Steven S. Scherer
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, United States
| | - David Hermann
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 673, Rochester, New York, 14642, USA
| | - Vera Fridman
- Department of Neurology, University of Colorado Anschutz Medical Campus, 12631 E 17th Avenue, Mailstop B185, Room 5113C, Aurora, CO, 80045, USA
| | - Jonathan Baets
- Department of Neurology, Neuromuscular Reference Centre, Antwerp University Hospital, Antwerp, Belgium
- Faculty of Medicine and Health Sciences, Translational Neurosciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Mario Saporta
- Department of Neurology, University of Miami Miller School of Medicine, United States
| | - Reza Seyedsadjadi
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Tanya Stojkovic
- AP-HP, Centre de référence des maladies neuromusculaires Nord/Est/Ile de France, Hôpital Pitié-Salpêtrière, 47-83, boulevard de l’Hôpital, 75013 Paris, France
| | - Kristl G. Claeys
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Laboratory for Muscle Diseases and Neuropathies, KU Leuven, Leuven, Belgium
| | - Pooja Patel
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Shawna Feely
- Department of Neurology, University of Iowa, Iowa City, Iowa, USA
| | - Adriana Rebelo
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
| | | | - Maike F. Dohrn
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
- Department of Neurology, Medical Faculty of the RWTH Aachen University, Aachen, Germany
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation, Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami, Miller School of Medicine, Miami, FL, USA
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Mitrani-Rosenbaum S, Attali R, Argov Z. GNE myopathy: can homozygous asymptomatic subjects give a clue for the identification of protective factors? Neuromuscul Disord 2023; 33:762-768. [PMID: 37666692 DOI: 10.1016/j.nmd.2023.08.013] [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: 05/17/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/06/2023]
Abstract
GNE myopathy is caused by bi allelic recessive mutations in the GNE gene. The largest identified cohort of GNE myopathy patients carries a homozygous mutation- M743T (the "Middle Eastern" mutation). More than 160 such patients in 67 families have been identified by us. Mean onset in this cohort is 30 years (range 17-48) with variable disease severity. However, we have identified two asymptomatic females, homozygous for M743T in two different families, both with affected siblings. The first showed no myopathy when examined at age 76 years. The second has no sign of disease at age 60 years. Since both agreed only for testing of blood, we performed exome and RNA sequencing of their blood and that of their affected siblings. Various filtering layers resulted in 2723 variant loci between symptomatic and asymptomatic individuals, representing 1364 genes. Among those, 39 genes are known to be involved in neuromuscular diseases, and only in two of them the variant is located in the proper exon coding region, resulting in a missense change. Surprisingly, only 27 genes were significantly differentially expressed between the asymptomatic and the GNE myopathy affected individuals, with three overexpressed genes overlapping between exome and RNA sequencing. Although unable to unravel robust candidate genes, mostly because of the very low number of asymptomatic individuals analyzed, and because of the tissue analyzed (blood and not muscle), this study resulted in relatively restricted potential candidate protective genes, emphasizing the power of using polarized phenotypes (completely asymptomatic vs clearly affected individuals) with the same genotype to unmask those genes which could be used as targets for disease course modifiers.
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Affiliation(s)
- Stella Mitrani-Rosenbaum
- Goldyne Savad Institute of Gene Therapy, Hadassah Medical Center, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Ruben Attali
- Goldyne Savad Institute of Gene Therapy, Hadassah Medical Center, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Zohar Argov
- Department of Neurology, Hadassah Medical Center, The Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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3
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de Bruyn A, Montagnese F, Holm-Yildiz S, Scharff Poulsen N, Stojkovic T, Behin A, Palmio J, Jokela M, De Bleecker JL, de Visser M, van der Kooi AJ, Ten Dam L, Domínguez González C, Maggi L, Gallone A, Kostera-Pruszczyk A, Macias A, Łusakowska A, Nedkova V, Olive M, Álvarez-Velasco R, Wanschitz J, Paradas C, Mavillard F, Querin G, Fernández-Eulate G, Quinlivan R, Walter MC, Depuydt CE, Udd B, Vissing J, Schoser B, Claeys KG. Anoctamin-5 related muscle disease: clinical and genetic findings in a large European cohort. Brain 2023; 146:3800-3815. [PMID: 36913258 DOI: 10.1093/brain/awad088] [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: 11/26/2022] [Revised: 02/06/2023] [Accepted: 02/25/2023] [Indexed: 03/14/2023] Open
Abstract
Anoctamin-5 related muscle disease is caused by biallelic pathogenic variants in the anoctamin-5 gene (ANO5) and shows variable clinical phenotypes: limb-girdle muscular dystrophy type 12 (LGMD-R12), distal muscular dystrophy type 3 (MMD3), pseudometabolic myopathy or asymptomatic hyperCKaemia. In this retrospective, observational, multicentre study we gathered a large European cohort of patients with ANO5-related muscle disease to study the clinical and genetic spectrum and genotype-phenotype correlations. We included 234 patients from 212 different families, contributed by 15 centres from 11 European countries. The largest subgroup was LGMD-R12 (52.6%), followed by pseudometabolic myopathy (20.5%), asymptomatic hyperCKaemia (13.7%) and MMD3 (13.2%). In all subgroups, there was a male predominance, except for pseudometabolic myopathy. Median age at symptom onset of all patients was 33 years (range 23-45 years). The most frequent symptoms at onset were myalgia (35.3%) and exercise intolerance (34.1%), while at last clinical evaluation most frequent symptoms and signs were proximal lower limb weakness (56.9%) and atrophy (38.1%), myalgia (45.1%) and atrophy of the medial gastrocnemius muscle (38.4%). Most patients remained ambulatory (79.4%). At last evaluation, 45.9% of patients with LGMD-R12 additionally had distal weakness in the lower limbs and 48.4% of patients with MMD3 also showed proximal lower limb weakness. Age at symptom onset did not differ significantly between males and females. However, males had a higher risk of using walking aids earlier (P = 0.035). No significant association was identified between sportive versus non-sportive lifestyle before symptom onset and age at symptom onset nor any of the motor outcomes. Cardiac and respiratory involvement that would require treatment occurred very rarely. Ninety-nine different pathogenic variants were identified in ANO5 of which 25 were novel. The most frequent variants were c.191dupA (p.Asn64Lysfs*15) (57.7%) and c.2272C>T (p.Arg758Cys) (11.1%). Patients with two loss-of function variants used walking aids at a significantly earlier age (P = 0.037). Patients homozygous for the c.2272C>T variant showed a later use of walking aids compared to patients with other variants (P = 0.043). We conclude that there was no correlation of the clinical phenotype with the specific genetic variants, and that LGMD-R12 and MMD3 predominantly affect males who have a significantly worse motor outcome. Our study provides useful information for clinical follow up of the patients and for the design of clinical trials with novel therapeutic agents.
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Affiliation(s)
- Alexander de Bruyn
- Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Federica Montagnese
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Sonja Holm-Yildiz
- Copenhagen Neuromuscular Center (CNMC), Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Nanna Scharff Poulsen
- Copenhagen Neuromuscular Center (CNMC), Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Tanya Stojkovic
- Reference Center for Neuromuscular Disorders Nord/Est/Île-de-France, Sorbonne Université, AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Anthony Behin
- Reference Center for Neuromuscular Disorders Nord/Est/Île-de-France, Sorbonne Université, AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Johanna Palmio
- Neuromuscular Center, Department of Neurology, Tampere University Hospital, 33520 Tampere, Finland
| | - Manu Jokela
- Neuromuscular Center, Department of Neurology, Tampere University Hospital, 33520 Tampere, Finland
- Neurocenter, Department of Neurology, Clinical Neurosciences, Turku University Hospital and University of Turku, 20014 Turku, Finland
| | - Jan L De Bleecker
- Department of Neurology, University Hospital Gent, 9000 Gent, Belgium
| | - Marianne de Visser
- Department of Neurology, Amsterdam University Medical Centers, Location AMC, Neuroscience Institute, University of Amsterdam, 1107 AZ Amsterdam, The Netherlands
| | - Anneke J van der Kooi
- Department of Neurology, Amsterdam University Medical Centers, Location AMC, Neuroscience Institute, University of Amsterdam, 1107 AZ Amsterdam, The Netherlands
| | - Leroy Ten Dam
- Department of Neurology, Amsterdam University Medical Centers, Location AMC, Neuroscience Institute, University of Amsterdam, 1107 AZ Amsterdam, The Netherlands
| | - Cristina Domínguez González
- Reference Center for Rare Neuromuscular Disorders, imas12 Research Institute, Hospital Universitario 12 de Octubre, Biomedical Network Research Center on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28041 Madrid, Spain
| | - Lorenzo Maggi
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Annamaria Gallone
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | | | - Anna Macias
- Department of Neurology, Medical University of Warsaw, 02-091 Warsaw, Poland
| | - Anna Łusakowska
- Department of Neurology, Medical University of Warsaw, 02-091 Warsaw, Poland
| | - Velina Nedkova
- Department of Neurology, Bellvitge Hospital, 08041 Barcelona, Spain
| | - Montse Olive
- Neuromuscular Disorders Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau and Biomedical Research Institute Sant Pau (IIB Sat Pau), 08041 Barcelona, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28001 Madrid, Spain
| | - Rodrigo Álvarez-Velasco
- Neuromuscular Disorders Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau and Biomedical Research Institute Sant Pau (IIB Sat Pau), 08041 Barcelona, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28001 Madrid, Spain
| | - Julia Wanschitz
- Department of Neurology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Carmen Paradas
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
- Centro Investigacion Biomedica en Red Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, 41013 Sevilla, Spain
| | - Fabiola Mavillard
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
- Centro Investigacion Biomedica en Red Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, 41013 Sevilla, Spain
| | - Giorgia Querin
- Institut de Myologie, I-Motion Adult ClinicalTrials Platform, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Gorka Fernández-Eulate
- Reference Center for Neuromuscular Disorders Nord/Est/Île-de-France, Sorbonne Université, AP-HP, Hôpital Pitié-Salpêtrière, 75013 Paris, France
| | - Ros Quinlivan
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, WC1N 3BG London, UK
| | - Maggie C Walter
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Christophe E Depuydt
- Laboratory for Muscle Diseases and Neuropathies, Department of Neurosciences, KU Leuven, and Leuven Brain Institute (LBI), 3000 Leuven, Belgium
| | - Bjarne Udd
- Neuromuscular Center, Department of Neurology, Tampere University Hospital, 33520 Tampere, Finland
| | - John Vissing
- Copenhagen Neuromuscular Center (CNMC), Rigshospitalet, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Kristl G Claeys
- Department of Neurology, University Hospitals Leuven, 3000 Leuven, Belgium
- Laboratory for Muscle Diseases and Neuropathies, Department of Neurosciences, KU Leuven, and Leuven Brain Institute (LBI), 3000 Leuven, Belgium
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4
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Klann PJ, Wang X, Elfert A, Zhang W, Köhler C, Güttsches AK, Jacobsen F, Weyen U, Roos A, Ehrke-Schulz E, Ehrhardt A, Vorgerd M, Bayer W. Seroprevalence of Binding and Neutralizing Antibodies against 39 Human Adenovirus Types in Patients with Neuromuscular Disorders. Viruses 2022; 15:79. [PMID: 36680119 PMCID: PMC9866721 DOI: 10.3390/v15010079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
High pre-existing antibodies against viral vectors reduce their functionality and may lead to adverse complications. To circumvent this problem in future gene therapy approaches, we tested the seroprevalence of a large range of human adenovirus types in patients with neuromuscular disorders (NMDs) to find appropriate viral vector candidates for gene replacement therapy for NMDs. Binding and neutralizing antibodies against 39 human adenovirus types were tested in the sera of 133 patients with NMDs and 76 healthy controls aged 17-92 years. The influence of age, sex, and NMDs on antibody levels was analyzed. The seroprevalence of different adenoviruses in the cohort varied widely. The highest levels of binding antibodies were detected against HAdV-D27, -C1, -D24, -D70, -B14, -C6, -D13, -B34, and -E4, whereas the lowest reactivity was detected against HAdV-F41, -A31, -B11, -D75, -D8, -D65, -D26, -D80, and -D17. The highest neutralizing reactivity was observed against HAdV-B3, -C2, -E4, -C1, -G52, -C5, and -F41, whereas the lowest neutralizing reactivity was observed against HAdV-D74, -B34, -D73, -B37, -D48, -D13, -D75, -D8, -B35, and -B16. We detected no influence of sex and only minor differences between different age groups. Importantly, there were no significant differences between healthy controls and patients with NMDs. Our data show that patients with NMDs have very similar levels of binding and neutralizing antibodies against HAdV compared to healthy individuals, and we identified HAdV-A31, -B16, -B34, -B35, -D8, -D37, -D48, -D73, -D74, -D75, and -D80 as promising candidates for future vector development due to their low binding and neutralizing antibody prevalence.
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Affiliation(s)
- Patrick Julian Klann
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, 45122 Essen, Germany
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Xiaoyan Wang
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, 45122 Essen, Germany
| | - Anna Elfert
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Wenli Zhang
- Virology and Microbiology, Center for Medical Education and Research, Department of Human Medicine, Faculty of Health, Witten/Herdecke University, 58453 Witten, Germany
| | - Cornelia Köhler
- Clinics for Pediatrics and Adolescent Medicine, University Hospital Sankt Josef, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Anne-Katrin Güttsches
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Frank Jacobsen
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Ute Weyen
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Andreas Roos
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Eric Ehrke-Schulz
- Virology and Microbiology, Center for Medical Education and Research, Department of Human Medicine, Faculty of Health, Witten/Herdecke University, 58453 Witten, Germany
| | - Anja Ehrhardt
- Virology and Microbiology, Center for Medical Education and Research, Department of Human Medicine, Faculty of Health, Witten/Herdecke University, 58453 Witten, Germany
| | - Matthias Vorgerd
- Heimer Institute for Muscle Research, Department of Neurology, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Wibke Bayer
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, 45122 Essen, Germany
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Ionova SA, Murtazina AF, Tebieva IS, Getoeva ZK, Dadali EL, Chausova PA, Shchagina OA, Marakhonov AV, Kutsev SI, Zinchenko RA. The Presentation of Two Unrelated Clinical Cases from the Republic of North Ossetia-Alania with the Same Previously Undescribed Variant in the COL6A2 Gene. Int J Mol Sci 2022; 23:ijms232012127. [PMID: 36292982 PMCID: PMC9602836 DOI: 10.3390/ijms232012127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/01/2022] [Accepted: 10/08/2022] [Indexed: 11/16/2022] Open
Abstract
Here, we described three affected boys from two unrelated families of Ossetian-Digor origin from the Republic of North Ossetia-Alania who were admitted to the Research Centre for Medical Genetics with unspecified muscular dystrophy. High-throughput sequencing was performed and revealed two novel frameshift variants in the COL6A2 gene (NM_001849.3) in a heterozygous state each in both cases: c.508_535delinsCTGTGG and c.1659_1660del (case 1) and c.1689del and c.1659_1660del (case 2). In two cases, the same nucleotide variant in the COL6A2 gene (c.1659_1660del) was observed. We have suggested that the variant c.1659_1660del may be common in the Ossetian-Digor population because two analyzed families have the same ancestry from the same subethnic group of Ossetians). The screening for an asymptomatic carriage of the nucleotide variant c.1659_1660del in 54 healthy donors from Ossetian-Digor population revealed that the estimated carrier frequency is 0.0093 (CI: 0.0002–0.0505), which is high for healthy carriers of the pathogenic variant. Molecular genetic, anamnestic data and clinical examination results allowed us to diagnose Ullrich muscular dystrophy in those affected boys. Genetic heterogeneity and phenotypic diversity of muscular dystrophies complicate diagnosis. It is important to make a differential diagnosis of such conditions and use HTS methods to determine the most accurate diagnosis.
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Affiliation(s)
- Sofya A. Ionova
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
- Correspondence: ; Tel.: +7-999-926-73-82
| | - Aysylu F. Murtazina
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Inna S. Tebieva
- North Ossetian State Medical Academy of the Ministry of Health of the Russian Federation, Pushkinskaya str. 40, 362019 Vladikavkaz, Russia
- Republican Children’s Clinical Hospital, Barbashova str. 33, 362003 Vladikavkaz, Russia
| | - Zalina K. Getoeva
- Pravoberezhnaya Central District Clinical Hospital, Kominterna str. 12, 363020 Beslan, Russia
| | - Elena L. Dadali
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Polina A. Chausova
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Olga A. Shchagina
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Andrey V. Marakhonov
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Sergey I. Kutsev
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
| | - Rena A. Zinchenko
- Research Centre for Medical Genetics, Moskvorechie str. 1, 115522 Moscow, Russia
- N.A. Semashko National Research Institute of Public Health, Vorontsovo Pole str. 12-1, 105064 Moscow, Russia
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6
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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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