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Loret C, Pauset A, Faye PA, Prouzet-Mauleon V, Pyromali I, Nizou A, Miressi F, Sturtz F, Favreau F, Turcq B, Lia AS. CRISPR Base Editing to Create Potential Charcot-Marie-Tooth Disease Models with High Editing Efficiency: Human Induced Pluripotent Stem Cell Harboring SH3TC2 Variants. Biomedicines 2024; 12:1550. [PMID: 39062123 PMCID: PMC11274897 DOI: 10.3390/biomedicines12071550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/05/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
Human induced pluripotent stem cells (hiPSCs) represent a powerful tool to investigate neuropathological disorders in which the cells of interest are inaccessible, such as in the Charcot-Marie-Tooth disease (CMT), the most common inherited peripheral neuropathy. Developing appropriate cellular models becomes crucial in order to both study the disease's pathophysiology and test new therapeutic approaches. The generation of hiPS cellular models for disorders caused by a single nucleotide variation has been significantly improved following the development of CRISPR-based editing tools. In this study, we efficiently and quickly generated, by CRISPR editing, the two first hiPSCs cellular models carrying alterations involved in CMT4C, also called AR-CMTde-SH3TC2. This subtype of CMT is associated with alterations in the SH3TC2 gene and represents the most prevalent form of autosomal recessive demyelinating CMT. We aimed to develop models for two different SH3TC2 nonsense variants, c.211C>T, p.Gln71* and the most common AR-CMTde-SH3TC2 alteration, c.2860C>T, p.Arg954*. First, in order to determine the best CRISPR strategy to adopt on hiPSCs, we first tested a variety of sgRNAs combined with a selection of recent base editors using the conveniently cultivable and transfectable HEK-293T cell line. The chosen CRISPR base-editing strategy was then applied to hiPSCs derived from healthy individuals to generate isogenic CMT disease models with up to 93% editing efficiency. For point mutation generation, we first recommend to test your strategies on alternative cell line such as HEK-293T before hiPSCs to evaluate a variety of sgRNA-BE combinations, thus boosting the chance of achieving edited cellular clones with the hard-to-culture and to transfect hiPSCs.
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Affiliation(s)
- Camille Loret
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
| | - Amandine Pauset
- University of Bordeaux, CRISP'edit, TBMCore UAR CNRS 3427, US Inserm 005, F-33000 Bordeaux, France (V.P.-M.); (B.T.)
- University of Bordeaux, Modeling Transformation and Resistance in Leukemia, BRIC Inserm U1312, F-33000 Bordeaux, France
| | - Pierre-Antoine Faye
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
- CHU Limoges, Department of Biochemistry and Molecular Genetics, F-87000 Limoges, France
| | - Valérie Prouzet-Mauleon
- University of Bordeaux, CRISP'edit, TBMCore UAR CNRS 3427, US Inserm 005, F-33000 Bordeaux, France (V.P.-M.); (B.T.)
- University of Bordeaux, Modeling Transformation and Resistance in Leukemia, BRIC Inserm U1312, F-33000 Bordeaux, France
| | - Ioanna Pyromali
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
| | - Angélique Nizou
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
| | - Federica Miressi
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
| | - Franck Sturtz
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
- CHU Limoges, Department of Biochemistry and Molecular Genetics, F-87000 Limoges, France
| | - Frédéric Favreau
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
- CHU Limoges, Department of Biochemistry and Molecular Genetics, F-87000 Limoges, France
| | - Béatrice Turcq
- University of Bordeaux, CRISP'edit, TBMCore UAR CNRS 3427, US Inserm 005, F-33000 Bordeaux, France (V.P.-M.); (B.T.)
- University of Bordeaux, Modeling Transformation and Resistance in Leukemia, BRIC Inserm U1312, F-33000 Bordeaux, France
| | - Anne-Sophie Lia
- University of Limoges, NeurIT UR 20218, GEIST Institute, F-87000 Limoges, France; (P.-A.F.); (I.P.); (A.N.); (F.M.); (F.S.); (F.F.); (A.-S.L.)
- CHU Limoges, Department of Biochemistry and Molecular Genetics, F-87000 Limoges, France
- CHU Limoges, Department of Bioinformatics, F-87000 Limoges, France
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Shchagina O, Murtazina A, Chausova P, Orlova M, Dadali E, Kurbatov S, Kutsev S, Polyakov A. Genetic Landscape of SH3TC2 variants in Russian patients with Charcot-Marie-Tooth disease. Front Genet 2024; 15:1381915. [PMID: 38903759 PMCID: PMC11187259 DOI: 10.3389/fgene.2024.1381915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 05/13/2024] [Indexed: 06/22/2024] Open
Abstract
Introduction Charcot-Marie-Tooth disease type 4C (CMT4C) OMIM#601596 stands out as one of the most prevalent forms of recessive motor sensory neuropathy worldwide. This disorder results from biallelic pathogenic variants in the SH3TC2 gene. Methods Within a cohort comprising 700 unrelated Russian patients diagnosed with Charcot-Marie-Tooth disease, we conducted a gene panel analysis encompassing 21 genes associated with hereditary neuropathies. Among the cohort, 394 individuals exhibited demyelinating motor and sensory neuropathy. Results and discussion Notably, 10 cases of CMT4C were identified within this cohort. The prevalence of CMT4C among Russian demyelinating CMT patients lacking the PMP22 duplication is estimated at 2.5%, significantly differing from observations in European populations. In total, 4 novel and 9 previously reported variants in the SH3TC2 gene were identified. No accumulation of a major variant was detected. Three previously reported variants, c.2860C>T p. (Arg954*), p. (Arg658Cys) and c.279G>A p. (Lys93Lys), recurrently detected in unrelated families. Nucleotide alteration p. (Arg954*) is present in most of our patients (30%).
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Affiliation(s)
| | | | | | - Mariya Orlova
- Research Centre for Medical Genetics, Moscow, Russia
| | - Elena Dadali
- Research Centre for Medical Genetics, Moscow, Russia
| | - Sergei Kurbatov
- Research Institute of Experimental Biology and Medicine, Voronezh State Medical University named After N.N. Burdenko, Voronezh, Russia
- Saratov State Medical University, Saratov, Russia
| | - Sergey Kutsev
- Research Centre for Medical Genetics, Moscow, Russia
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Rehbein T, Wu TT, Treidler S, Pareyson D, Lewis R, Yum SW, McCray BA, Ramchandren S, Burns J, Li J, Finkel RS, Scherer SS, Zuchner S, Shy ME, Reilly MM, Herrmann DN. Neuropathy due to bi-allelic SH3TC2 variants: genotype-phenotype correlation and natural history. Brain 2023; 146:3826-3835. [PMID: 36947133 PMCID: PMC10473553 DOI: 10.1093/brain/awad095] [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: 10/05/2022] [Revised: 02/23/2023] [Accepted: 03/05/2023] [Indexed: 03/23/2023] Open
Abstract
Recessive SH3TC2 variants cause Charcot-Marie-Tooth disease type 4C (CMT4C). CMT4C is typically a sensorimotor demyelinating polyneuropathy, marked by early onset spinal deformities, but its clinical characteristics and severity are quite variable. Clear relationships between pathogenic variants and the spectrum of disease manifestations are to date lacking. Gene replacement therapy has been shown to ameliorate the phenotype in a mouse model of CMT4C, emphasizing the need for natural history studies to inform clinical trial readiness. Data, including both genetic information and clinical characteristics, were compiled from the longitudinal, prospective dataset of the Inherited Neuropathy Consortium, a member of the Rare Diseases Clinical Research Network (INC-RDCRN). The Charcot Marie Tooth Neuropathy Score (CMTNS), Examination Score (CMTES) and the Rasch-weighted CMTES (CMTES-R) were used to describe symptoms, neurological examinations and neurophysiological characteristics. Standardized response means were calculated at yearly intervals and a mixed model for repeated measures was used to estimate the change in CMTES and CMTES-R over time. Fifty-six individuals (59% female), median age 27 years (range 2-67 years) with homozygous or compound heterozygous variants in SH3TC2 were identified, including 34 unique variants, 14 of which have not previously been published. Twenty-eight participants had longitudinal data available. While there was no significant difference in the CMTES in those with protein truncating versus non-protein truncating variants, there were significant differences in the mean ulnar nerve compound muscle action potential amplitude, the mean radial sensory nerve action potential amplitude, and in the prevalence of scoliosis, suggesting the possibility of a milder phenotype in individuals with one or two non-protein-truncating variants. Overall, the mean value of the CMTES was 13, reflecting moderate clinical severity. There was a high rate of scoliosis (81%), scoliosis surgery (36%), and walking difficulty (94%) among study participants. The CMTES and CMTES-R appeared moderately responsive to change over extended follow-up, demonstrating a standardized response mean of 0.81 standard deviation units or 0.71 standard deviation units, respectively, over 3 years. Our analysis represents the largest cross-sectional and only longitudinal study to date, of the clinical phenotype of both adults and children with CMT4C. With the promise of upcoming genetic treatments, these data will further define the natural history of the disease and inform study design in preparation for clinical trials.
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Affiliation(s)
- Tyler Rehbein
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Tong Tong Wu
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY 14642, USA
| | - Simona Treidler
- Department of Neurology, Stony Brook University, Stony Brook, NY 11790, USA
| | - Davide Pareyson
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Richard Lewis
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Sabrina W Yum
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Brett A McCray
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Sindhu Ramchandren
- Clinical Development Department - Neuroscience, The Janssen Pharmaceutical Companies of Johnson & Johnson, Titusville, NJ 08560, USA
| | - Joshua Burns
- Faculty of Medicine and Health; Paediatric Gait Analysis Service of New South Wales, University of Sydney School of Health Sciences, Sydney Children’s Hospitals Network, Sydney 2031, Australia
| | - Jun Li
- Department of Neurology, Houston Methodist Hospital, Houston, TX 77030, USA
| | - Richard S Finkel
- Center for Experimental Neurotherapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Steven S Scherer
- Department of Neurology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephan Zuchner
- 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 33101, USA
| | - Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Mary M Reilly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - David N Herrmann
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
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Nagappa M, Sharma S, Govindaraj P, Chickabasaviah YT, Siram R, Shroti A, Seshagiri DV, Debnath M, Sinha S, Bindu PS, Taly AB. Characterisation of Patients with SH3TC2 Associated Neuropathy in an Indian Cohort. Neurol India 2023; 71:940-945. [PMID: 37929431 DOI: 10.4103/0028-3886.388101] [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] [Indexed: 11/07/2023]
Abstract
Background SH3TC2 variations lead to demyelinating recessive Charcot-Marie-Tooth (CMT) disease, which is commonly associated with early-onset scoliosis and cranial neuropathy. Data from Indian ethnicity is limited. Objective We aim to report the characteristics of patients with SH3TC2-associated neuropathy from an Indian cohort. Patients and Methods Data of five unrelated subjects with SH3TC2 variations were analyzed. Results Clinical features included female predominance (n = 4), early-onset neuropathy (n = 2), pes cavus and hammer toes (n = 4), kyphoscoliosis (n = 1), impaired vision and hearing (n = 1), facial muscle weakness (n = 1), impaired kinaesthetic sense (n = 3), tremor (n = 2), and ataxia (n = 1). Four patients had the "CMT" phenotype, while one patient had Roussy-Levy syndrome. All had demyelinating electrophysiology with conduction velocities being "very slow" in one, "slow" in one, "mildly slow" in two, and "intermediate" in one patient. Brain stem auditory evoked potentials were universally abnormal though only one patient had symptomatic deafness. Seven variants were identified in SH3TC2 [homozygous = 3 (c.1412del, c.69del, c.3152G>A), heterozygous = 4 (c.1105C>T, c.3511C>T, c.2028G>C, c.254A>T)]. Except for c.3511C>T variant, the rest were novel. Three patients had additional variations in genes having pathobiological relevance in other CMTs or amyotrophic lateral sclerosis. Conclusion We provide data on a cohort of patients of Indian origin with SH3TC2 variations and highlight differences from other cohorts. Though the majority were not symptomatic for hearing impairment, evoked potentials disclosed abnormalities in all. Further studies are required to establish the functional consequences of novel variants and their interacting molecular partners identified in the present study to strengthen their association with the phenotype.
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Affiliation(s)
- Madhu Nagappa
- Department of Neurology; Department of Neuromuscular Laboratory, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Shivani Sharma
- Department of Neurology; Department of Neuropathology; Department of Neuromuscular Laboratory, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | | | - Yasha T Chickabasaviah
- Department of Neuropathology; Department of Neuromuscular Laboratory, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Ramesh Siram
- Department of Neurology, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Akhilesh Shroti
- Department of Neurology, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Doniparthi V Seshagiri
- Department of Neurology, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Monojit Debnath
- Department of Human Genetics, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Sanjib Sinha
- Department of Neurology, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Parayil S Bindu
- Department of Neurology; Department of Neuromuscular Laboratory, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Arun B Taly
- Department of Neurology; Department of Neuromuscular Laboratory, Neurobiology Research Centre (NBRC), National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
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Shchagina O, Orlova M, Murtazina A, Filatova A, Skoblov M, Dadali E. Evaluation of Pathogenicity and Causativity of Variants in the MPZ and SH3TC2 Genes in a Family Case of Hereditary Peripheral Neuropathy. Int J Mol Sci 2023; 24:9786. [PMID: 37372933 DOI: 10.3390/ijms24129786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/31/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
The implementation of NGS methods into clinical practice allowed researchers effectively to establish the molecular cause of a disorder in cases of a genetically heterogeneous pathology. In cases of several potentially causative variants, we need additional analysis that can help in choosing a proper causative variant. In the current study, we described a family case of hereditary motor and sensory neuropathy (HMSN) type 1 (Charcot-Marie-Tooth disease). DNA analysis revealed two variants in the SH3TC2 gene (c.279G>A and c.1177+5G>A), as well as a previously described variant c.449-9C>T in the MPZ gene, in a heterozygous state. This family segregation study was incomplete because of the proband's father's unavailability. To evaluate the variants' pathogenicity, minigene splicing assay was carried out. This study showed no effect of the MPZ variant on splicing, but the c.1177+5G>A variant in the SH3TC2 gene leads to the retention of 122 nucleotides from intron 10 in the RNA sequence, causing a frameshift and an occurrence of a premature stop codon (NP_078853.2:p.Ala393GlyfsTer2).
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Affiliation(s)
- Olga Shchagina
- Research Centre for Medical Genetics, Moscow 115522, Russia
| | - Mariya Orlova
- Research Centre for Medical Genetics, Moscow 115522, Russia
| | | | | | | | - Elena Dadali
- Research Centre for Medical Genetics, Moscow 115522, Russia
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Pyromali I, Benslimane N, Favreau F, Goizet C, Lazaro L, Vitry M, Derouault P, Sturtz F, Magdelaine C, Lia AS. From Negative to Positive Diagnosis: Structural Variation Could Be the Second Mutation You Are Looking for in a Recessive Autosomal Gene. J Pers Med 2022; 12:jpm12020212. [PMID: 35207700 PMCID: PMC8878780 DOI: 10.3390/jpm12020212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 01/25/2022] [Accepted: 01/29/2022] [Indexed: 11/16/2022] Open
Abstract
Next-generation sequencing (NGS) allows the detection of plentiful mutations increasing the rate of patients getting a positive diagnosis. However, while single-nucleotide variants (SNVs) or small indels can be easily detected, structural variations (SVs) such as copy number variants (CNVs) are often not researched. In Charcot–Marie–Tooth disease (CMT), the most common hereditary peripheral neuropathy, the PMP22-duplication was the first variation detected. Since then, more than 90 other genes have been associated with CMT, with point mutations or small indels mostly described. Herein, we present a personalized approach we performed to obtain a positive diagnosis of a patient suffering from demyelinating CMT. His NGS data were aligned to the human reference sequence but also studied using the CovCopCan software, designed to detect large CNVs. This approach allowed the detection of only one mutation in SH3TC2, the frequent p.Arg954*, while SH3TC2 is known to be responsible for autosomal recessive demyelinating CMT forms. Interestingly, by modifying the standard CovCopCan use, we detected the second mutation of this patient corresponding to a 922 bp deletion in SH3TC2 (Chr5:148,390,609-Chr5:148,389,687), including only one exon (exon 14). This highlights that SVs, different from PMP22 duplication, can be responsible for peripheral neuropathy and should be searched systematically. This approach could also be employed to improve the diagnosis of all inherited diseases.
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Affiliation(s)
- Ioanna Pyromali
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
| | - Nesrine Benslimane
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
| | - Frédéric Favreau
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Biochimie et de Génétique Moléculaire, F-87000 Limoges, France;
| | - Cyril Goizet
- Centre Hospitalo-Universitaire (CHU) Bordeaux-GH Pellegrin Tripode, Service de Génétique Médicale, F-33076 Bordeaux, France;
| | - Leila Lazaro
- Centre Hospitalier (CH) de la Côte Basque, F-64100 Bayonne, France;
| | - Martine Vitry
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Biochimie et de Génétique Moléculaire, F-87000 Limoges, France;
| | - Paco Derouault
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Bioinformatique, F-87000 Limoges, France;
| | - Franck Sturtz
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Biochimie et de Génétique Moléculaire, F-87000 Limoges, France;
| | - Corinne Magdelaine
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Biochimie et de Génétique Moléculaire, F-87000 Limoges, France;
| | - Anne-Sophie Lia
- Faculty of Medicine, MMNP (Maintenance Myélinique et Neuropathies Périphériques), University of Limoges, EA6309, F-87000 Limoges, France; (I.P.); (N.B.); (F.F.); (F.S.); (C.M.)
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Biochimie et de Génétique Moléculaire, F-87000 Limoges, France;
- Centre Hospitalo-Universitaire (CHU) Limoges, Service de Bioinformatique, F-87000 Limoges, France;
- Correspondence: ; Tel.: +33-555-435-938
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Vaeth S, Andersen H, Christensen R, Jensen UB. A Search for Undiagnosed Charcot-Marie-Tooth Disease Among Patients Registered with Unspecified Polyneuropathy in the Danish National Patient Registry. Clin Epidemiol 2021; 13:113-120. [PMID: 33623438 PMCID: PMC7896779 DOI: 10.2147/clep.s292676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/09/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose In a recent study based on data from the Danish National Patients Registry (DNPR), we reported the prevalence of Charcot-Marie-Tooth disease (CMT) in Denmark to be 22.5 per 100.000. This prevalence is most likely a minimum estimate, as many cases of CMT may be misdiagnosed or remain undiagnosed due to the heterogeneous nature of the disorder. The aim of this study was to investigate the possible number of undiagnosed CMT cases among patients registered with unspecified polyneuropathy (UP) diagnoses in the DNPR. Patients and Methods From the DNPR we extracted data on all patients given an UP diagnosis in the period 1977 to 2012. We selected all patients diagnosed with a primary UP diagnosis before age 40 at a department of neurology, neurophysiology, clinical genetics or pediatrics, and excluded all patients with a specified polyneuropathy diagnosis or with diagnostic codes related to alcohol and diabetes mellitus. To assess the proportion of possible CMT patients, we performed medical record review in a random sample of patients diagnosed in the Central Denmark Region. To further investigate the possible overlap between UP and CMT in the DNPR, we performed a series of searches for ICD-8 and ICD-10 codes related to CMT. Results Between 1977 and 2012, 30.903 patients were diagnosed with UP without also being diagnosed with CMT. A total of 940 patients fulfilled the selection criteria. We found that 21.5% (95% CI 13.1%–32.2%) of the cases in the random sample fulfilled our criteria for CMT. This estimate increases the prevalence of CMT in Denmark with 3.6 per 100,000 (95% CI 2.4%–5.5%). Conclusion This study illustrates how hitherto undiagnosed CMT patients may be identified in the DNPR and further reports the number of possible CMT cases. Our results support the hypothesis that the true prevalence of CMT is higher than recently reported.
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Affiliation(s)
- Signe Vaeth
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus N, Denmark
| | - Henning Andersen
- Department of Neurology, Aarhus University Hospital, Aarhus C, Denmark
| | - Rikke Christensen
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus N, Denmark
| | - Uffe Birk Jensen
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus N, Denmark
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