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Galli F, Bragg L, Rossi M, Proietti D, Perani L, Bagicaluppi M, Tonlorenzi R, Sibanda T, Caffarini M, Talapatra A, Santoleri S, Meregalli M, Bano-Otalora B, Bigot A, Bozzoni I, Bonini C, Mouly V, Torrente Y, Cossu G. Cell-mediated exon skipping normalizes dystrophin expression and muscle function in a new mouse model of Duchenne Muscular Dystrophy. EMBO Mol Med 2024; 16:927-944. [PMID: 38438561 PMCID: PMC11018779 DOI: 10.1038/s44321-024-00031-3] [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: 02/27/2023] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 03/06/2024] Open
Abstract
Cell therapy for muscular dystrophy has met with limited success, mainly due to the poor engraftment of donor cells, especially in fibrotic muscle at an advanced stage of the disease. We developed a cell-mediated exon skipping that exploits the multinucleated nature of myofibers to achieve cross-correction of resident, dystrophic nuclei by the U7 small nuclear RNA engineered to skip exon 51 of the dystrophin gene. We observed that co-culture of genetically corrected human DMD myogenic cells (but not of WT cells) with their dystrophic counterparts at a ratio of either 1:10 or 1:30 leads to dystrophin production at a level several folds higher than what predicted by simple dilution. This is due to diffusion of U7 snRNA to neighbouring dystrophic resident nuclei. When transplanted into NSG-mdx-Δ51mice carrying a mutation of exon 51, genetically corrected human myogenic cells produce dystrophin at much higher level than WT cells, well in the therapeutic range, and lead to force recovery even with an engraftment of only 3-5%. This level of dystrophin production is an important step towards clinical efficacy for cell therapy.
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Affiliation(s)
- Francesco Galli
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
| | - Laricia Bragg
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Maira Rossi
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Daisy Proietti
- Institue of Experimental Neurology, Division of Neurosciences. Ospedale San Raffaele Milan, Milan, Italy
| | - Laura Perani
- Institue of Experimental Neurology, Division of Neurosciences. Ospedale San Raffaele Milan, Milan, Italy
| | - Marco Bagicaluppi
- Institue of Experimental Neurology, Division of Neurosciences. Ospedale San Raffaele Milan, Milan, Italy
| | - Rossana Tonlorenzi
- Institue of Experimental Neurology, Division of Neurosciences. Ospedale San Raffaele Milan, Milan, Italy
| | - Tendai Sibanda
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Miriam Caffarini
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Avraneel Talapatra
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Sabrina Santoleri
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Mirella Meregalli
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Centro Dino Ferrari, 20122, Milan, Italy
| | - Beatriz Bano-Otalora
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Anne Bigot
- Institut de Myologie, Université Pierre et Marie Curie, Paris 6 UM76, Univ. Paris 6/U974, UMR7215, CNRS, Pitié-Salpétrière-INSERM, UMRS 974, Paris, France
| | - Irene Bozzoni
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, 00161, Rome, Italy
- Center for Life Nano- & Neuro-Science@Sapienza of Istituto Italiano di Tecnologia (IIT), 00161, Rome, Italy
| | - Chiara Bonini
- Experimental Hematology Unit, Vita-Salute San Raffaele University, Milan, Italy
- IRCCS Ospedale San Raffaele Scientific Institute, 20133, Milan, Italy
| | - Vincent Mouly
- Institut de Myologie, Université Pierre et Marie Curie, Paris 6 UM76, Univ. Paris 6/U974, UMR7215, CNRS, Pitié-Salpétrière-INSERM, UMRS 974, Paris, France
| | - Yvan Torrente
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Centro Dino Ferrari, 20122, Milan, Italy
| | - Giulio Cossu
- Division of Cell Matrix Biology & Regenerative Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
- Institue of Experimental Neurology, Division of Neurosciences. Ospedale San Raffaele Milan, Milan, Italy.
- Experimental and Clinical Research Center. Charité Medical Faculty and Max Delbrück Center 13125 Berlin, Berlin, Germany.
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Mackels L, Servais L. The Importance of Early Treatment of Inherited Neuromuscular Conditions. J Neuromuscul Dis 2024; 11:253-274. [PMID: 38306060 DOI: 10.3233/jnd-230189] [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: 02/03/2024]
Abstract
There has been tremendous progress in treatment of neuromuscular diseases over the last 20 years, which has transformed the natural history of these severely debilitating conditions. Although the factors that determine the response to therapy are many and in some instance remain to be fully elucidated, early treatment clearly has a major impact on patient outcomes across a number of inherited neuromuscular conditions. To improve patient care and outcomes, clinicians should be aware of neuromuscular conditions that require prompt treatment initiation. This review describes data that underscore the importance of early treatment of children with inherited neuromuscular conditions with an emphasis on data resulting from newborn screening efforts.
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Affiliation(s)
- Laurane Mackels
- MDUK Oxford Neuromuscular Centre, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- Adult Neurology Department, Citadelle Hospital, Liège, Belgium
| | - Laurent Servais
- Neuromuscular Centre, Division of Paediatrics, University and University Hospital of Liège, Liège, Belgium
- MDUK Oxford Neuromuscular Centre, Department of Paediatrics, University of Oxford & NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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3
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Poulos J, Samuels M, Palace J, Beeson D, Robb S, Ramdas S, Chan S, Munot P. Congenital myasthenic syndromes: a retrospective natural history study of respiratory outcomes in a single centre. Brain Commun 2023; 5:fcad299. [PMID: 38035366 PMCID: PMC10684295 DOI: 10.1093/braincomms/fcad299] [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: 09/30/2022] [Revised: 06/05/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
Respiratory problems are a major cause of morbidity and mortality in patients with congenital myasthenic syndromes, a rare heterogeneous group of neuromuscular disorders caused by genetic defects impacting the structure and function of the neuromuscular junction. Recurrent, life-threatening episodic apnoea in early infancy and childhood and progressive respiratory failure requiring ventilation are features of certain genotypes of congenital myasthenic syndromes. Robb et al. published empirical guidance on respiratory management of the congenital myasthenic syndromes, but other than this workshop report, there are little published longitudinal natural history data on respiratory outcomes of these disorders. We report a retrospective, single-centre study on respiratory outcomes in a cohort of 40 well characterized genetically confirmed cases of congenital myasthenic syndromes, including 10 distinct subtypes (DOK7, COLQ, RAPSN, CHAT, CHRNA1, CHRNG, COL13A1, CHRNE, CHRNE fast channel syndrome and CHRNA1 slow channel syndrome), with many followed up over 20 years in our centre. A quantitative and longitudinal analysis of key spirometry and sleep study parameters, as well as a description of historical hospital admissions for respiratory decompensation, provides a snapshot of the respiratory trajectory of congenital myasthenic syndrome patients based on genotype.
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Affiliation(s)
- Jordan Poulos
- Paediatrics, University College London Medical School, London WC1E 6BT, UK
| | - Martin Samuels
- Respiratory Medicine, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Jacqueline Palace
- University of Oxford and Department of Neurology, Oxford Radcliffe Hospitals, Oxford OX3 9DU, UK
| | - David Beeson
- Neurology, Nuffield Department of Clinical Neurosciences, Oxford OX3 7BN, UK
| | - Stephanie Robb
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Sithara Ramdas
- Neurology, MDUK Neuromuscular Centre, Oxford University Hospitals, Oxford OX3 9DU, UK
| | - Samantha Chan
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
- Neurosciences, University College London and Institute of Child Health, London WC1N 1EH, UK
| | - Pinki Munot
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London WC1N 3JH, UK
- Neurosciences, University College London and Institute of Child Health, London WC1N 1EH, UK
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Orriëns LB, Eker D, Braakman HMH, Merkus PJFM, Erasmus CE. Recognising symptoms of congenital myasthenic syndromes in children: A guide for paediatricians. Acta Paediatr 2023; 112:2434-2439. [PMID: 37551152 DOI: 10.1111/apa.16945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/09/2023]
Abstract
AIM Congenital myasthenic syndromes (CMS) are a rare and diverse group of treatable neuromuscular transmission disorders. Diagnosis is often substantially delayed. This study aimed to identify common symptoms of CMS in children and their manifestation to aid diagnosis and early intervention. METHODS We performed a retrospective cohort study, including 18 children (median age 13 years, range 9 years 5 months-18 years 0 month) with CMS. Data on CMS symptoms and their manifestation were extracted from patients' charts and supplemented with parental telephone interviews. Descriptive analyses were used to identify common symptoms. RESULTS A median diagnostic delay of 4 years and 7 months (interquartile range: 51 months) was observed. Proximal muscle weakness (100%), ptosis (89%), clumsy gait (82%), difficulty eating solid foods (78%) and recurrent respiratory tract infections (72%) were most common in these patients. Symptoms mostly co-occurred and frequently had a fluctuating character, aggravated by infections or fatigue. CONCLUSION Early referral to diagnose CMS is crucial to enable timely initiation of treatment. Heightened attention to a combination of symptoms related to muscle weakness, rather than individual symptoms, should support paediatricians in flagging these neuromuscular disorders. Medical history taking should be tailored to parents' perceptions, asking questions about recognisable symptoms of muscle weakness.
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Affiliation(s)
- Lynn B Orriëns
- Division of Paediatrics, Department of Paediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Dilan Eker
- Division of Paediatrics, Department of Paediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Hilde M H Braakman
- Division of Paediatrics, Department of Paediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Peter J F M Merkus
- Division of Paediatrics, Department of Paediatric Pulmonology, Radboud University Medical Centre, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Corrie E Erasmus
- Division of Paediatrics, Department of Paediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Amalia Children's Hospital, Nijmegen, The Netherlands
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5
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Kaya O, Kirik S. Can Scoliosis Help the Early Diagnosis of Congenital Myasthenic Syndrome? Cureus 2023; 15:e45875. [PMID: 37766777 PMCID: PMC10520996 DOI: 10.7759/cureus.45875] [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] [Accepted: 09/24/2023] [Indexed: 09/29/2023] Open
Abstract
Background Congenital myasthenic syndromes (CMS) are a group of hereditary diseases of the neuromuscular junction. CMS are extremely rare diseases that cause hypotonia; however, scoliosis may theoretically be helpful in early diagnosis of CMS. The objective of this study was to emphasize the clinical features of the patients we followed up with the diagnosis of CMS and demonstrate that scoliosis is an important finding in the diagnosis of CMS in the presence of hypotonia/weakness. Materials and methods In this retrospective study, data were retrieved by examining the digital files of the patients who presented to Aydın Maternity and Children's Hospital and Elazığ Fethi Sekin City Hospital Pediatric Neurology Clinics between 2018 and 2023. The diagnosis of CMS was strongly supported by a combination of clinical characteristics, neurophysiological studies, genetic tests, AChR antibodies, and serum creatine kinase measurement. The presence of scoliosis was evaluated by an orthopedics and traumatology specialist. Results Eleven CMS patients with accompanying scoliosis were included in the study. The mean age of the patients was 69.4±39.28 months. The age of the patients at the time of diagnosis was 42.7±35.19 months. Among the patients, eight were males (72.7%), and three were females (27.2%). Seven patients (63.6%) had COLQ mutations. Electromyography was conducted on eight patients, with one of them showing no pathological findings, while seven exhibited decremental responses. All patients had ptosis, while six (54.5%) had bulbar signs. Ten patients (90.9%) had weakness. Nine patients (81.8%) experienced frequent recurrent lower respiratory tract infections. Both the patient with CHAT mutation and RAPSN mutation had arthrogryposis. Conclusion In this study, CMS stands out as an essential consideration in the differential diagnosis, particularly when scoliosis accompanies early-onset muscle weakness.
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Affiliation(s)
- Oğuz Kaya
- Orthopaedics and Traumatology, Elazığ Fethi Sekin City Hospital, Elazığ, TUR
| | - Serkan Kirik
- Pediatric Neurology, Fırat University School of Medicine, Elazığ, TUR
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Yin Y, Cao J, Fan Y, Xu Y. COLQ-mutation congenital myasthenic syndrome in late adolescence: Case report and review of the literature. Heliyon 2023; 9:e19980. [PMID: 37809778 PMCID: PMC10559664 DOI: 10.1016/j.heliyon.2023.e19980] [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: 11/30/2022] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 10/10/2023] Open
Abstract
Congenital myasthenia syndromes (CMS) are a heterogeneous group of hereditary disorders of the neuromuscular junction. The symptoms include fatigue, muscle weakness, ptosis, mastication or swallowing problem, respiratory distress. We present a 42-year-old male patient who was admitted with complaints of paroxysmal limb weakness for 25 years and got repeated apnea crisis due to using AchE inhibitors. We considered this patient to be COLQ-related CMS because of two types characteristics. One is the symptom will deteriorate or non-responsive after giving AchE inhibitors and the other is repeated compound action potentials may appear after one current stimulation. At last we confirmed the diagnosis by genetic testing. It is a rare CMS case caused by homozygous mutation in the COLQ gene which occurred at late adolescence. Our case demonstrates that for those serum-negative MG patients, CMS gene mutation screening should be considered, especially if the patient has an symptom onset of childhood and adolescence.
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Affiliation(s)
- Yatao Yin
- Department of Rehabilitation Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Cao
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Yuanteng Fan
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Yan Xu
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
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7
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Horibe T, Shimomura H, Tokunaga S, Taniguchi N, Lee T, Kimura S, Takeshima Y. A Pediatric Case of COLQ-Related Congenital Myasthenic Syndrome with Marked Fatigue. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10050769. [PMID: 37238317 DOI: 10.3390/children10050769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023]
Abstract
Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous inherited disorder that is treatable. Although the disease usually develops at birth or during infancy, some patients develop the disease in the second to third decades of life. Collagen-like tail subunit of asymmetric acetylcholinesterase (COLQ)-related CMS is CMS with mutations in the COLQ, which results in end-plate acetylcholinesterase deficiency. Diagnostic delay is common in patients with later-onset CMS due to slow progression and fluctuating symptoms. Understanding CMS with atypical and unusual presentations is important to treat this condition effectively. Here, we report a case of COLQ-related CMS. A 10-year-old girl presented with only marked fatigue, which was provoked by exercise but improved after 30-60 min of rest. While motor nerve conduction velocity was normal, a compound muscle action potential (CMAP) with four peaks was recorded. Repetitive stimulation of the accessory nerve exhibited a decrease in CMAP amplitude. Genetic tests revealed compound heterozygous mutations in COLQ (c.1196-1_1197delinsTG and c.1354C>T). Treatment with salbutamol improved fatigue but not the electrophysiological markers. Thus, significant fatigue is a hallmark of COLQ-related CMS; early diagnosis is essential for ensuring appropriate treatment.
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Affiliation(s)
- Takuya Horibe
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Hideki Shimomura
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Sachi Tokunaga
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Naoko Taniguchi
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Tomoko Lee
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
| | - Shigemi Kimura
- Children's Rehabilitation, Sleep and Development Medical Center, Hyogo Prefectural Rehabilitation Central Hospital, Kobe 651-2134, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo Medical University School of Medicine, Nishinomiya 663-8501, Japan
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Arruti N, Munot P, Bowman R. Demographics and ocular findings in children with myasthenia. Eye (Lond) 2023; 37:700-704. [PMID: 35338356 PMCID: PMC9998382 DOI: 10.1038/s41433-022-02030-5] [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: 04/08/2021] [Revised: 02/15/2022] [Accepted: 03/11/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To report the demographics and ocular features of myasthenia gravis in the paediatric population. METHODS Retrospective revision of the medical records of all patients younger than 18 years of age with myasthenia who were examined at Great Ormond Street Hospital between the 1st of January 2016 and 1st of January 2020. RESULTS A total of 49 children were assessed during the 4-year period. There was a female predominance, with only 12 males (24.5%). 26 children (53.1%) had juvenile myasthenia gravis (JMG) while 18 (36.7%) had congenital myasthenic syndrome (CMS). 4 patients (8.2%) were diagnosed with probable CMS while 1 (2.0%) was classified as probable JMG. The mean age at diagnosis was 5.3 years old (SD 3.9) whereas the mean age at onset was 3.7 years old (SD 3.9). Almost half of the children (49%) had ocular involvement, present in 19 patients in the JMG group (70.4%) and in 5 children (22.7%) in the CMS cohort. Ptosis was the most common sign at presentation, seen in 32 patients (65.3%). Nine patients (18.4%) presented with a squint and another 7 (14.3%) developed it later on. Anti-acetylcholine receptor antibodies were positive in 18 of the 26 JMG patients (69.2%) whereas identifiable mutations were found in the 18 CMS patients (100%). Pyridostigmine was the drug of choice in our series, used by thirty-three patients (67.3%). The majority of the patients (73.5%) improved after treatment. CONCLUSIONS JMG was the most common type of paediatric MG, specifically the ocular form. Ptosis was the most common sign at presentation. The majority of the patients improved after medical treatment.
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Affiliation(s)
- Natalia Arruti
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, Great Ormond Street, London, WC1N 3JH, UK.
| | - Pinki Munot
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Richard Bowman
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, Great Ormond Street, London, WC1N 3JH, UK
- Ulverscroft Vision Research Group, UCL Great Ormond Street Institute for Child Health, 30 Guilford Street, London, WC1N 1EH, UK
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Ohno K, Ohkawara B, Shen XM, Selcen D, Engel AG. Clinical and Pathologic Features of Congenital Myasthenic Syndromes Caused by 35 Genes-A Comprehensive Review. Int J Mol Sci 2023; 24:ijms24043730. [PMID: 36835142 PMCID: PMC9961056 DOI: 10.3390/ijms24043730] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders characterized by impaired neuromuscular signal transmission due to germline pathogenic variants in genes expressed at the neuromuscular junction (NMJ). A total of 35 genes have been reported in CMS (AGRN, ALG14, ALG2, CHAT, CHD8, CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, COL13A1, COLQ, DOK7, DPAGT1, GFPT1, GMPPB, LAMA5, LAMB2, LRP4, MUSK, MYO9A, PLEC, PREPL, PURA, RAPSN, RPH3A, SCN4A, SLC18A3, SLC25A1, SLC5A7, SNAP25, SYT2, TOR1AIP1, UNC13A, VAMP1). The 35 genes can be classified into 14 groups according to the pathomechanical, clinical, and therapeutic features of CMS patients. Measurement of compound muscle action potentials elicited by repetitive nerve stimulation is required to diagnose CMS. Clinical and electrophysiological features are not sufficient to identify a defective molecule, and genetic studies are always required for accurate diagnosis. From a pharmacological point of view, cholinesterase inhibitors are effective in most groups of CMS, but are contraindicated in some groups of CMS. Similarly, ephedrine, salbutamol (albuterol), amifampridine are effective in most but not all groups of CMS. This review extensively covers pathomechanical and clinical features of CMS by citing 442 relevant articles.
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Affiliation(s)
- Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Correspondence: (K.O.); (A.G.E.)
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Xin-Ming Shen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Duygu Selcen
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
| | - Andrew G. Engel
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA
- Correspondence: (K.O.); (A.G.E.)
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Tan KA, Chew HB, Yacob Y, Khoo TB. A Common CHAT Gene Mutation of Congenital Myasthenic Syndrome Found in Kadazandusun Children. J Pediatr Genet 2022. [DOI: 10.1055/s-0042-1750747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
AbstractCongenital myasthenic syndrome (CMS) is an uncommon inherited neuromuscular junction disease. The clinical presentation of this disorder is diverse. Typically patients with this disorder present with early-onset swallowing difficulty and apnea in infancy, fluctuating ocular palsies and fatigable proximal muscle weakness during childhood, and late-onset form involving progressive weakness in adulthood. Difficulty in performing neurophysiology studies in children and the absence of a pathognomonic investigation marker increase the challenges in diagnosis of this disorder. The emergence of next-generation sequencing technology has circumvented these challenges somewhat, and has contributed to the discovery of novel mutations. We present here diagnostic odyssey of three CMS patients from two unrelated Kadazandusun kinships and their follow-up treatment. A rare homozygous mutation c.916G > C (p.Val306Leu) in CHAT gene was found in two siblings born of a consanguineous marriage. Third patient had compound heterozygous mutations c.406G > A (p.Val136Met) and c.916G > C (p.Val306Leu) in CHAT gene. We postulate that p.Val306Leu may be a founder mutation in the Kadazandusuns, an indigenous ethnic minority of Borneo Island.
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Affiliation(s)
- Khian Aun Tan
- Pediatric Neurology Unit, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
| | - Hui Bein Chew
- Genetic Department, Hospital Kuala Lumpur, Kuala Lumpur, Malaysia
| | - Yusnita Yacob
- Molecular Diagnostics Unit, Institute for Medical Research, National Institutes of Health, Selangor, Malaysia
| | - Teik Beng Khoo
- Pediatric Neurology Unit, Hospital Tunku Azizah, Kuala Lumpur, Malaysia
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11
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Lotta S, Lisa B. Congenital or Early Developing Neuromuscular Diseases Affecting Feeding, Swallowing and Speech – A Review of the Literature from January 1998 to August 2021. J Neuromuscul Dis 2022; 9:581-596. [PMID: 35848032 PMCID: PMC9535595 DOI: 10.3233/jnd-210772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background: The knowledge about the impact of oral motor impairment in neuromuscular diseases (NMDs) is limited but increasing. Objective: The aim of this review was to collect and compile knowledge on how muscle weakness in congenital or early developing NMDs directly or indirectly affects feeding, swallowing, speech and saliva control. Methods: A literature search was performed in PubMed from January 1, 1998, to August 31, 2021. The keywords “feeding”, “dysphagia”, “swallowing”, “dysarthria”, “speech”, “drooling” and “sialorrhea” were used in combination with “paediatric neuromuscular disease” or specific diagnoses. Results: Sixty-five studies were selected for the review, 33 focused on feeding and swallowing, 11 on speech, four on a combination of feeding, swallowing, saliva control or speech and 17 general descriptions. Most of the studies reported on patients with a disorder affecting muscles. These studies show that muscle weakness and impaired motility affecting the muscles innervated by the cranial nerves may influence feeding, swallowing, and speech, and that respiratory function, general health and neurodevelopmental delay also influence these functions. Feeding impairment and breathing difficulties are common in NMDs. Lifesaving interventions such as tube feeding and ventilatory support are common in severe cases. Conclusions: Feeding impairment, dysphagia and dysarthria are prevalent in NMDs with congenital or early age of onset. Feeding and swallowing has been studied more than speech and saliva control. More children with NMD survive thanks to new treatment options and it is therefore urgent to follow up how these therapies may impact the development of feeding, swallowing, and speech.
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Affiliation(s)
- Sjögreen Lotta
- Mun-H-Center, Orofacial Resource Centre for Rare Diseases, Public Dental Service, Medicinaregatan, Gothenburg, Sweden
| | - Bengtsson Lisa
- Mun-H-Center, Orofacial Resource Centre for Rare Diseases, Public Dental Service, Medicinaregatan, Gothenburg, Sweden
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12
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Arikawa-Hirasawa E. Impact of the Heparan Sulfate Proteoglycan Perlecan on Human Disease and Health. Am J Physiol Cell Physiol 2022; 322:C1117-C1122. [PMID: 35417267 DOI: 10.1152/ajpcell.00113.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Perlecan, a basement membrane-type heparan sulfate proteoglycan, is an important molecule in the functional diversity of organisms because of the diversity of its glycan chains and the multifunctionality of its core proteins. Human diseases associated with perlecan have been identified using gene-deficient mice. Two human diseases related to perlecan have been reported. One is Silverman-Handmaker type Dyssegmental Dysplasia, resulting from complete loss of function of the HSPG2 gene which encods perlecan core protein which maps to chromosome 1p36. The other is Schwartz-Jampel syndrome from partial loss of function of the HSPG2 gene. Subsequent in vivo and in vitrostudies have revealed the organ-specific functions of perlecan, suggesting its involvement in the pathogenesis of various human diseases. In this review, we discuss the role of perlecan in human diseases and summarize our knowledge about perlecan as a future therapeutic target to treat the related diseases and for healthy longevity.
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Affiliation(s)
- Eri Arikawa-Hirasawa
- Research Institute for Diseases of OldAge Juntendo University Graduate School of Medicine, Tokyo, Japan
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13
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Saito M, Ogasawara M, Inaba Y, Osawa Y, Nishioka M, Yamauchi S, Atsumi K, Takeuchi S, Imai K, Motobayashi M, Misawa Y, Iida A, Nishino I. Successful treatment of congenital myasthenic syndrome caused by a novel compound heterozygous variant in RAPSN. Brain Dev 2022; 44:50-55. [PMID: 34565654 DOI: 10.1016/j.braindev.2021.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/29/2021] [Accepted: 09/05/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous neuromuscular disorder characterized by muscle weakness and caused by mutations in more than 35 different genes. This condition should not be overlooked as a subset of patients with CMS are treatable. However, the diagnosis of CMS is often difficult due to the broad variability in disease severity and course. CASE REPORT A five-year-old boy without remarkable family history was born with marked general muscle hypotonia and weakness, respiratory insufficiency, anomalies, and multiple joint contractures. Congenital myopathy was suspected based upon type 1 fiber predominance on muscle biopsy. However, he was diagnosed with CMS at age 4 years when his ptosis and ophthalmoplegia were found to be improved by edrophonium chloride and repetitive nerve stimulation showed attenuation of compound muscle action potentials. An exome sequencing identified a compound heterozygous missense variant of c.737C > T (p.A246V) and a novel intronic insertion c.1166 + 4_1166 + 5insAAGCCCACCAC in RAPSN. RT-PCR analysis which showed the skipping of exon 7 in a skeletal muscle sample confirmed that the intronic insertion was pathogenic. His myasthenic symptoms were remarkably improved by pyridostigmine. CONCLUSION The patient's diagnosis of CMS was confirmed by exome sequencing, and RT-PCR revealed that the skipping of exon 7 in RAPSN was caused by a novel intronic insertion. The genetic information uncovered in this case should therefore be added to the collection of tools for diagnosing and treating CMS.
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Affiliation(s)
- Maki Saito
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Masashi Ogasawara
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan; Medical Genome Center, NCNP, Kodaira, Tokyo, Japan
| | - Yuji Inaba
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan.
| | - Yoshihiro Osawa
- Department of Pediatrics, Iida Municipal Hospital, Iida, Japan
| | - Makoto Nishioka
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan
| | - Shoko Yamauchi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Kana Atsumi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Shihoko Takeuchi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Ken Imai
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan
| | - Mitsuo Motobayashi
- Division of Neuropediatrics, Nagano Children's Hospital, Azumino, Japan; Life Science Research Center, Nagano Children's Hospital, Azumino, Japan
| | - Yuka Misawa
- Division of Rehabilitation, Nagano Children's Hospital, Azumino, Japan
| | | | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan; Medical Genome Center, NCNP, Kodaira, Tokyo, Japan
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14
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Lorenzoni PJ, Ducci RDP, Arndt RC, Hrysay NMC, Fustes OJH, Töpf A, Lochmüller H, Werneck LC, Kay CSK, Scola RH. Congenital myasthenic syndrome in a cohort of patients with 'double' seronegative myasthenia gravis. ARQUIVOS DE NEURO-PSIQUIATRIA 2021; 80:69-74. [PMID: 34932651 PMCID: PMC9651496 DOI: 10.1590/0004-282x-anp-2020-0575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/27/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) have some phenotypic overlap with seronegative myasthenia gravis (SNMG). OBJECTIVE The aim of this single center study was to assess the minimum occurrence of CMS misdiagnosed as double SNMG in a Brazilian cohort. METHODS The genetic analysis of the most common mutations in CHRNE, RAPSN, and DOK7 genes was used as the main screening tool. RESULTS We performed genetic analysis in 22 patients with a previous diagnosis of 'double' SNMG. In this study, one CMS patient was confirmed due to the presence of compound heterozygous variants in the CHRNE gene (c.130insG/p.Cys210Phe). CONCLUSIONS This study confirmed that CMS due to CHNRE mutations can be mistaken for SNMG. In addition, our study estimated the prevalence of misdiagnosed CMS to be 4.5% in 'double' SNMG patients of our center. Based on our findings, genetic screening could be helpful in the diagnostic workup of patients with 'double' SNMG in whom differential diagnosis is recommended.
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Affiliation(s)
- Paulo José Lorenzoni
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Renata Dal-Pra Ducci
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Raquel Cristina Arndt
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Nyvia Milicio Coblinski Hrysay
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Otto Jesus Hernandez Fustes
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Ana Töpf
- Newcastle University, Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, Newcastle upon Tyne, UK
| | - Hanns Lochmüller
- University of Ottawa, Children's Hospital of Eastern Ontario Research Institute, Department of Medicine, Division of Neurology, Ottawa, Canada.,University of Ottawa, The Ottawa Hospital, Brain and Mind Research Institute, Ottawa, Canada
| | - Lineu Cesar Werneck
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Cláudia Suemi Kamoi Kay
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
| | - Rosana Herminia Scola
- Universidade Federal do Paraná, Hospital de Clínicas, Departamento de Clínica Médica, Serviço de Doenças Neuromusculares, Curitiba PR, Brazil
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15
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Banerjee A, Senguttuvan G, Reddy C, Saini AG. Fluctuating Weakness in an 18-Month-Boy: Congenital Myasthenia. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0040-1718771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractIn this article, we reported a case of an 18-month-old male child patient who presented with motor predominant delay in attaining developmental milestones and early onset fatiguable weakness with ptosis and ophthalmoparesis. This ptosis and ophthalmoparesis typically worsened with progression of the day. Examination showed proximal weakness with preserved muscle stretch reflexes. Electrophysiology showed characteristic decrement on repetitive nerve stimulation test that localized to disorders of the neuromuscular junction. Next-generation sequencing showed a pathogenic variant of CHRNE that was responsible for congenital myasthenic syndrome. Such variants show increased improvement with salbutamol in addition to anticholinesterase inhibitors. Hence, the patient was started on pyridostigmine, and the plan was to add on salbutamol on follow-up if optimal improvement does not occur.
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Affiliation(s)
- Arundhati Banerjee
- Department of Pediatrics, Pediatric Neurology Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Gananamani Senguttuvan
- Department of Pediatrics, Pediatric Neurology Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Chaitanya Reddy
- Department of Pediatrics, Pediatric Neurology Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Arushi Gahlot Saini
- Department of Pediatrics, Pediatric Neurology Unit, Advanced Pediatrics Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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16
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Hoei-Hansen CE, Tygesen MLB, Dunø M, Vissing J, Ballegaard M, Born AP. Combined Muscle Biopsy and Comprehensive Electrophysiology in General Anesthesia is Valuable in Diagnosis of Neuromuscular Disease in Children. Neuropediatrics 2021; 52:462-468. [PMID: 33706403 DOI: 10.1055/s-0041-1726120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AIM The diagnostic workup in patients with delayed motor milestones suspected of having either myopathy or a congenital myasthenic syndrome is complex. Our hypothesis was that performance of a muscle biopsy and neurophysiology including stimulated single-fiber electromyography during an anesthetic procedure, combined with genetic testing has a high diagnostic quality. MATERIALS AND METHODS Clinical and paraclinical data were retrospectively collected from 24 patients aged from 1 month to 10 years (median: 5.2 years). RESULTS Neurophysiology examination was performed in all patients and was abnormal in 11 of 24. No patients had findings suggestive of a myasthenic syndrome. Muscle biopsy was performed in 21 of 24 and was normal in 16. Diagnostic findings included nemaline rods, inclusion bodies, fiber size variability, and type-II fiber atrophy. Genetic testing with either a gene panel or exome sequencing was performed in 18 of 24 patients, with pathogenic variants detected in ACTA1, NEB, SELENON, GRIN2B, SCN8A, and COMP genes. CONCLUSION Results supporting a neuromuscular abnormality were found in 15 of 24. In six patients (25%), we confirmed a genetic diagnosis and 12 had a clinical neuromuscular diagnosis. The study suggests that combined use of neurophysiology and muscle biopsy in cases where genetic testing does not provide a diagnosis can be useful in children with delayed motor milestones and clinical evidence of a neuromuscular disease.
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Affiliation(s)
- Christina E Hoei-Hansen
- Department of Paediatrics, Copenhagen University Hospital, Rigshospitalet, Denmark.,Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Marie L B Tygesen
- Department of Paediatrics, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Morten Dunø
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - John Vissing
- Department of Neurology, Copenhagen University Hospital, Rigshospitalet, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Martin Ballegaard
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Copenhagen University Hospital, Rigshospitalet, Denmark
| | - Alfred P Born
- Department of Paediatrics, Copenhagen University Hospital, Rigshospitalet, Denmark
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17
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Novel pathogenic ALG2 mutation causing congenital myasthenic syndrome: A case report. Neuromuscul Disord 2021; 32:80-83. [PMID: 34980536 DOI: 10.1016/j.nmd.2021.11.012] [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: 04/04/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/23/2022]
Abstract
ALG2 mutations are extremely rare causes of congenital myasthenic syndromes (CMS). The clinical phenotype and treatment response is therefore not well described. We present the case of a baby who immediately after birth presented with pronounced truncal hypotonia, proximal muscle weakness and feeding difficulties. Single fibre electromyography showed neuromuscular transmission failure and salbutamol and ephedrine treatment improved both muscle weakness and neuromuscular transmission. Genetic analysis revealed a likely pathogenic variant c.1040del, p.(Gly347Valfs*27) in exon 2 and a variant of uncertain significance, c.239G>A, p.(Gly80Asp) in exon 1 of the ALG2 gene. Western blot in whole cell lysates of HEK293 cells transfected with p.Gly80Asp, or p.Gly347Valfs*27 expression constructs indicated that p.Gly347Valfs*27 is likely a null allele and p.Gly80Asp is pathogenic through marked reduction of ALG2 expression. This case highlights the utility of functional studies in clarifying variants of unknown significance, in suspected cases of CMS.
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18
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Qin Z, Xiang K, Su DF, Sun Y, Liu X. Activation of the Cholinergic Anti-Inflammatory Pathway as a Novel Therapeutic Strategy for COVID-19. Front Immunol 2021; 11:595342. [PMID: 33633726 PMCID: PMC7901247 DOI: 10.3389/fimmu.2020.595342] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/29/2020] [Indexed: 12/13/2022] Open
Abstract
The outbreak of coronavirus disease 2019 (COVID-19) underlined the urgent need for alleviating cytokine storm. We propose here that activating the cholinergic anti-inflammatory pathway (CAP) is a potential therapeutic strategy. However, there is currently no approved drugs targeting the regulatory pathway. It is evident that nicotine, anisodamine and some herb medicine, activate the CAP and exert anti-inflammation action in vitro and in vivo. As the vagus nerve affects both inflammation and specific immune response, we propose that vagus nerve stimulation by invasive or non-invasive devices and acupuncture at ST36, PC6, or GV20, are also feasible approaches to activate the CAP and control COVID-19. It is worth to investigate the efficacy and safety of the strategy in patients with COVID-19.
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Affiliation(s)
- Zhen Qin
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China.,Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Yantai University, Yantai, China
| | - Kefa Xiang
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Ding-Feng Su
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yang Sun
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Xia Liu
- Department of Clinical Pharmacy, School of Pharmacy, Second Military Medical University, Shanghai, China
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19
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Liu Y, Wu W, Huang Q. Endoscopic management of pediatric extubation failure in the intensive care unit. Int J Pediatr Otorhinolaryngol 2020; 139:110465. [PMID: 33120102 DOI: 10.1016/j.ijporl.2020.110465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES This study investigated the endoscopic findings associated with pediatric extubation failure (EF) and evaluated the prognosis of endoscopic procedures. METHODS We retrospectively reviewed the data of children with EF in the intensive care unit from January 1, 2013 to December 31, 2019. Fifty-one children receiving endoscopic examination were enrolled in this study. EF was defined as the need for reintubation within 72 h of the first attempted extubation. RESULTS Thirty-three children (65%) were successfully extubated after endoscopic procedures, and 18 children (35%) failed in extubation. There was a higher percentage of children transferred from other hospitals with intubation in the failure group (56% vs 12%, p = 0.002). Subglottic stenosis (SGS) (35%) and laryngeal and tracheal granulation (33%) were two of the most common findings. Fourteen patients (82%) with granulation were successfully extubated. Two children in the failure group were diagnosed with mitochondrial myopathies (chrM:3243) and congenital myasthenic syndrome (CHAT). The success rate in cases of SGS reached 83% (15/18). Five patients diagnosed with laryngomalacia and another 3 patients with tracheomalacia failed extubation after supraglottoplasty and needed a temporary tracheostomy. CONCLUSION Granulation and subglottic stenosis were the leading causes of extubation failure. Patients transferred with intubation might have a poor prognosis after endoscopic procedures. Neuromuscular and metabolic disorders could be a hidden reason for extubation failure.
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Affiliation(s)
- Yupeng Liu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Ear Institute, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, 1665 Kongjiang Road, Shanghai, 200092, China.
| | - Wenjin Wu
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Ear Institute, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, 1665 Kongjiang Road, Shanghai, 200092, China.
| | - Qi Huang
- Department of Otolaryngology Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Ear Institute, Shanghai Jiaotong University School of Medicine, 1665 Kongjiang Road, Shanghai, 200092, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, 1665 Kongjiang Road, Shanghai, 200092, China.
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20
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Abstract
Congenital myasthenic syndromes comprise a rare heterogeneous group of diseases that impair neuromuscular transmission and are characterized by muscle fatigability and transient or permanent weakness. Symptoms are often present from birth or early childhood. These syndromes have a wide range of phenotypes and severity. Caused by genetic mutations in any of the numerous genes encoding for components of the neuromuscular junction. They are classified by where in the neuromuscular junction the mutated component is located: presynaptic, synaptic, or postsynaptic. Mutations in about 30 genes have been implicated. Diagnosis can be difficult. Treatment options vary depending on the specific genetic type.
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21
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Lawal TA, Todd JJ, Witherspoon JW, Bönnemann CG, Dowling JJ, Hamilton SL, Meilleur KG, Dirksen RT. Ryanodine receptor 1-related disorders: an historical perspective and proposal for a unified nomenclature. Skelet Muscle 2020; 10:32. [PMID: 33190635 PMCID: PMC7667763 DOI: 10.1186/s13395-020-00243-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
The RYR1 gene, which encodes the sarcoplasmic reticulum calcium release channel or type 1 ryanodine receptor (RyR1) of skeletal muscle, was sequenced in 1988 and RYR1 variations that impair calcium homeostasis and increase susceptibility to malignant hyperthermia were first identified in 1991. Since then, RYR1-related myopathies (RYR1-RM) have been described as rare, histopathologically and clinically heterogeneous, and slowly progressive neuromuscular disorders. RYR1 variants can lead to dysfunctional RyR1-mediated calcium release, malignant hyperthermia susceptibility, elevated oxidative stress, deleterious post-translational modifications, and decreased RyR1 expression. RYR1-RM-affected individuals can present with delayed motor milestones, contractures, scoliosis, ophthalmoplegia, and respiratory insufficiency. Historically, RYR1-RM-affected individuals were diagnosed based on morphologic features observed in muscle biopsies including central cores, cores and rods, central nuclei, fiber type disproportion, and multi-minicores. However, these histopathologic features are not always specific to RYR1-RM and often change over time. As additional phenotypes were associated with RYR1 variations (including King-Denborough syndrome, exercise-induced rhabdomyolysis, lethal multiple pterygium syndrome, adult-onset distal myopathy, atypical periodic paralysis with or without myalgia, mild calf-predominant myopathy, and dusty core disease) the overlap among diagnostic categories is ever increasing. With the continuing emergence of new clinical subtypes along the RYR1 disease spectrum and reports of adult-onset phenotypes, nuanced nomenclatures have been reported (RYR1- [related, related congenital, congenital] myopathies). In this narrative review, we provide historical highlights of RYR1 research, accounts of the main diagnostic disease subtypes and propose RYR1-related disorders (RYR1-RD) as a unified nomenclature to describe this complex and evolving disease spectrum.
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Affiliation(s)
- Tokunbor A Lawal
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA.
| | - Joshua J Todd
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Jessica W Witherspoon
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Carsten G Bönnemann
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - James J Dowling
- Departments of Paediatrics and Molecular Genetics, Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Susan L Hamilton
- Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Katherine G Meilleur
- Tissue Injury Branch, National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, USA
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
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22
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Gan S, Yang H, Xiao T, Pan Z, Wu L. AGRN Gene Mutation Leads to Congenital Myasthenia Syndromes: A Pediatric Case Report and Literature Review. Neuropediatrics 2020; 51:364-367. [PMID: 32221959 DOI: 10.1055/s-0040-1708534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The congenital myasthenia syndromes (CMS) are a group of autosomal recessive or autosomal dominant diseases that affect neuromuscular junctions. CMS caused by AGRN mutations is very uncommon typically characterized by ptosis, mild weakness, and proximal limb weakness. We report the case of an 8-year-old female who exhibited the onset of motor development retardation from infancy and slow progression to proximal muscle weakness. Repeated nerve stimulation at 3 Hz showed a clear decrement with 17%. Whole exon sequencing showed an AGRN gene compound heterozygous mutation (c.5009C >T and c.5078T > C). She was treated with salbutamol but without improvement. Then pseudoephedrine was adapted as a treatment choice and obtained remarkable curative effect. We have summarized and analyzed 12 patients who have been reported in the literature. An early age of onset and muscle weakness in the lower limbs are the main feature of an early AGRN gene mutation. Both types of AGRN-related CMS respond favorably to ephedrine. This is the first report showing that pseudoephedrine is effective as a choice for the treatment of AGRN-related CMS.
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Affiliation(s)
- Siyi Gan
- Department of Pediatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Haiyan Yang
- Department of Pediatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Ting Xiao
- Department of Pediatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Zou Pan
- Department of Pediatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
| | - Liwen Wu
- Department of Pediatric Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, PR China
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23
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Wang A, Xiao Y, Huang P, Liu L, Xiong J, Li J, Mao D, Liu L. Novel NtA and LG1 Mutations in Agrin in a Single Patient Causes Congenital Myasthenic Syndrome. Front Neurol 2020; 11:239. [PMID: 32328026 PMCID: PMC7160337 DOI: 10.3389/fneur.2020.00239] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/12/2020] [Indexed: 12/27/2022] Open
Abstract
Congenital myasthenic syndrome (CMS) is a group of genetic disorders of neuromuscular transmission that is characterized by muscle weakness. A mutation in the gene encoding agrin (AGRN) is a rare cause of CMS, and only a few families or isolated cases have been reported. We reported a pediatric proband exhibiting muscle weakness in the trunk and limbs with skeletal malformation and intellectual disability and performed whole-exome sequencing (WES) of the proband parent-offspring trio. Results revealed a new compound heterozygous mutation in AGRN: c.125A>C (p.Glu42Ala) in the N-terminal agrin domain (NtA) and c.4516G>A (p.Ala1506Thr) in the laminin G1 domain (LG1). Bioinformatic analysis predicted the mutation as possibly pathogenic. The new compound heterozygous mutation in AGRN may disrupt agrin's known function of bridging laminin and α-dystroglycan and undermine the formation and maintenance of the neuromuscular junction (NMJ) via both muscular and neural agrin pathways. It may also induce secondary peripheral neuropathy and skeletal malformation.
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Affiliation(s)
- Aiping Wang
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yangyang Xiao
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Peng Huang
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Lingjuan Liu
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jie Xiong
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jian Li
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ding'an Mao
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liqun Liu
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Pediatrics Neurology, Children's Medical Center, The Second Xiangya Hospital, Central South University, Changsha, China
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Lorenzoni PJ, Kay CSK, Arndt RC, Hrysay NMC, Ducci RDP, Fustes OHJ, Töpf A, Lochmüller H, Werneck LC, Scola RH. Congenital myasthenic syndrome due to DOK7 mutation in a cohort of patients with 'unexplained' limb-girdle muscular weakness. J Clin Neurosci 2020; 75:195-198. [PMID: 32238315 DOI: 10.1016/j.jocn.2020.01.080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/27/2020] [Indexed: 10/24/2022]
Abstract
Congenital myasthenic syndromes (CMS) associated with pathogenic variants in the DOK7 gene (DOK7-CMS) have phenotypic overlap with other neuromuscular disorders associated with limb-girdle muscular weakness (LGMW). Genetic analysis of the most common mutation (c.1124_1127dupTGCC) in DOK7 was performed in 34 patients with "unexplained" LGMW associated with non-specific changes in muscle biopsy. Of the 34 patients, one patient showed the DOK7 c.1124_1127dupTGCC variant in homozygousity. Our study estimates the minimum prevalence of undiagnosed DOK7-CMS to be 2.9% in southern Brazilian patients from our centre. Our data confirm that clinicians should look for DOK7-CMS patients when the clinical manifestation is an 'unexplained' LGMW, mainly if associated with non-specific changes in muscle biopsy.
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Affiliation(s)
- Paulo José Lorenzoni
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Cláudia Suemi Kamoi Kay
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Raquel Cristina Arndt
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Nyvia Milicio Coblinski Hrysay
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Renata Dal-Pra Ducci
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Otto H Jesus Fustes
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Lineu Cesar Werneck
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil
| | - Rosana Herminia Scola
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba, Brazil.
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Stratton AT, Roberts Iii RO, Kupfer O, Carry T, Parsons J, Apkon S. Pediatric neuromuscular disorders: Care considerations during the COVID-19 pandemic. J Pediatr Rehabil Med 2020; 13:405-414. [PMID: 33185615 DOI: 10.3233/prm-200768] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
COVID-19, the respiratory and frequently systemic disease caused by the novel SARS-COV-2 virus, was first recognized in December 2019 and quickly spread to become a pandemic and world-wide public health emergency over the subsequent 3-4 months. While COVID-19 has a very low morbidity rate across approximately 80% of the population, it has a high morbidity and mortality rate in the remaining 20% of the population.1 These numbers have put a significant strain on medical systems around the world. Patients with neuromuscular diseases such as those with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), tend to be more medically fragile and have higher health care needs than the general population. Respiratory insufficiency, cardiac disease, obesity, and immunocompromised status due to chronic steroid treatments in certain patient populations with neuromuscular conditions are specific risk factors for severe COVID-19 disease. In general, the pediatric population has shown to be less severely impacted with lower infection rates and lower morbidity and mortality rates than the adult population, however, as expected, children with underlying medical conditions are at higher risk of morbidity from COVID-19 than their peers.2 Many patients with neuromuscular disease also rely heavily on caregiver support through their lifetime and thus maintaining the health of their primary caregivers is also a significant consideration in the health and well-being of the patients. This paper will address routine and emergency medical care, rehabilitation services, and other considerations for the pediatric patient with a neuromuscular condition during the COVID-19 pandemic.
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Affiliation(s)
- Anne Troike Stratton
- Department of Physical Medicine and Rehabilitation, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Richard Ogden Roberts Iii
- Department of Pediatrics, Section of Diabetes and Endocrinology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX, USA
| | - Oren Kupfer
- Department of Pediatrics, Section of Pulmonary Medicine, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Terri Carry
- Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Julie Parsons
- Department of Pediatrics, Section of Neurology, Haberfeld Family Endowed Chair in Pediatric Neuromuscular Disorders, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Susan Apkon
- Department of Physical Medicine and Rehabilitation, Fischahs Chair in Pediatric Rehabilitation, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
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Gonzalez Garcia A, Tutmaher MS, Upadhyayula SR, Sanchez Russo R, Verma S. Novel PLEC gene variants causing congenital myasthenic syndrome. Muscle Nerve 2019; 60:E40-E43. [PMID: 31509265 DOI: 10.1002/mus.26703] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/05/2019] [Accepted: 09/08/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Aixa Gonzalez Garcia
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia
| | - Michelle S Tutmaher
- Department of Pediatrics and Neurology, Emory University School of Medicine, Atlanta, Georgia
| | - Saila R Upadhyayula
- Department of Pediatrics and Neurology, Emory University School of Medicine, Atlanta, Georgia
| | | | - Sumit Verma
- Department of Pediatrics and Neurology, Emory University School of Medicine, Atlanta, Georgia
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Stålberg E, van Dijk H, Falck B, Kimura J, Neuwirth C, Pitt M, Podnar S, Rubin DI, Rutkove S, Sanders DB, Sonoo M, Tankisi H, Zwarts M. Standards for quantification of EMG and neurography. Clin Neurophysiol 2019; 130:1688-1729. [DOI: 10.1016/j.clinph.2019.05.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/07/2019] [Accepted: 05/09/2019] [Indexed: 12/11/2022]
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Abstract
Congenital myopathies (CM) are a genetically heterogeneous group of neuromuscular disorders most commonly presenting with neonatal/childhood-onset hypotonia and muscle weakness, a relatively static or slowly progressive disease course, and originally classified into subcategories based on characteristic histopathologic findings in muscle biopsies. This enduring concept of disease definition and classification based on the clinicopathologic phenotype was pioneered in the premolecular era. Advances in molecular genetics have brought into focus the increased blurring of the original seemingly "watertight" categories through broadening of the clinical phenotypes in existing genes, and continuous identification of novel genetic backgrounds. This review summarizes the histopathologic landscape of the 4 "classical" subtypes of CM-nemaline myopathies, core myopathies, centronuclear myopathies, and congenital fiber type disproportion and some of the emerging and novel genetic diseases with a CM presentation.
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Affiliation(s)
- Rahul Phadke
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children and Division of Neuropathology, National Hospital for Neurology and Neurosurgery, London, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.
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Italian recommendations for diagnosis and management of congenital myasthenic syndromes. Neurol Sci 2018; 40:457-468. [PMID: 30554356 DOI: 10.1007/s10072-018-3682-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/10/2018] [Indexed: 12/11/2022]
Abstract
Congenital myasthenic syndromes (CMS) are genetic disorders due to mutations in genes encoding proteins involved in the neuromuscular junction structure and function. CMS usually present in young children, but perinatal and adult onset has been reported. Clinical presentation is highly heterogeneous, ranging from mild symptoms to severe manifestations, sometimes with life-threatening respiratory episodes, especially in the first decade of life. Although considered rare, CMS are probably underestimated due to diagnostic difficulties. Because of the several therapeutic opportunities, CMS should be always considered in the differential diagnosis of neuromuscular disorders. The Italian Network on CMS proposes here recommendations for proper CMS diagnosis and management, aiming to guide clinicians in their practical approach to CMS patients.
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Kao JC, Milone M, Selcen D, Shen XM, Engel AG, Liewluck T. Congenital myasthenic syndromes in adult neurology clinic: A long road to diagnosis and therapy. Neurology 2018; 91:e1770-e1777. [PMID: 30291185 PMCID: PMC6251603 DOI: 10.1212/wnl.0000000000006478] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/27/2018] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVE To investigate the diagnostic challenges of congenital myasthenic syndromes (CMS) in adult neuromuscular practice. METHODS We searched the Mayo Clinic database for patients with CMS diagnosed in adulthood in the neuromuscular clinic between 2000 and 2016. Clinical, laboratory, and electrodiagnostic data were reviewed. RESULTS We identified 34 patients with CMS, 30 of whom had a molecular diagnosis (14 DOK7, 6 RAPSN, 2 LRP4, 2 COLQ, 2 slow-channel syndrome, 1 primary acetylcholine receptor deficiency, 1 AGRN, 1 GFPT1, and 1 SCN4A). Ophthalmoparesis was often mild and present in 13 patients. Predominant limb-girdle weakness occurred in 19 patients. Two patients had only ptosis. Age at onset ranged from birth to 39 years (median 5 years). The median time from onset to diagnosis was 26 years (range 4-56 years). Thirteen patients had affected family members. Fatigable weakness was present when examined. Creatine kinase was elevated in 4 of 23 patients (range 1.2-4.2 times the upper limit of normal). Repetitive nerve stimulation revealed a decrement in 30 patients. Thirty-two patients were previously misdiagnosed with seronegative myasthenia gravis (n = 16), muscle diseases (n = 15), weakness of undetermined cause (n = 8), and others (n = 4). Fifteen patients received immunotherapy or thymectomy without benefits. Fourteen of the 25 patients receiving pyridostigmine did not improve or worsen. CONCLUSION Misdiagnosis occurred in 94% of the adult patients with CMS and causes a median diagnostic delay of nearly 3 decades from symptom onset. Seronegative myasthenia gravis and muscle diseases were the 2 most common misdiagnoses, which led to treatment delay and unnecessary exposure to immunotherapy, thymectomy, or muscle biopsy.
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Affiliation(s)
- Justin C Kao
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand
| | - Margherita Milone
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand
| | - Duygu Selcen
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand
| | - Xin-Ming Shen
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand
| | - Andrew G Engel
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand
| | - Teerin Liewluck
- From the Department of Neurology (J.C.K., M.M., D.S., X.-M.S., A.G.E., T.L.), Mayo Clinic, Rochester, MN; and Department of Neurology (J.C.K.), Auckland City Hospital, New Zealand.
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Yang K, Cheng H, Yuan F, Meng L, Yin R, Zhang Y, Wang S, Wang C, Lu Y, Xi J, Lu Q, Chen Y. CHRNE compound heterozygous mutations in congenital myasthenic syndrome: A case report. Medicine (Baltimore) 2018; 97:e0347. [PMID: 29702980 PMCID: PMC5944527 DOI: 10.1097/md.0000000000010347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
RATIONALE Congenital myasthenic syndrome (CMSs) are a group of rare genetic disorders of the neurological junction, which can result in structural or functional weakness. Here, we characterized a case of CMS in order to clarify the diagnosis and expand the understanding of it. The molecular diagnosis had implications for choice of treatment and genetic counseling. PATIENT CONCERNS A 3-year-old male patient with CMS had ptosis and limb weakness for 2 months after birth. Clinical course and electrophysiological, imaging, and genetic findings were assessed. Protein structure/function was predicted. A novel mutation of c.295C>T (exon 4) and another known mutation of c.442T>A (exon 5) were found in CHRNE. Both mutations localized in conserved sequences. The c.442T>A (p.C148S) missense mutation in CHRNE was predicted to be damaging/deleterious. The iterative threading assembly refinement (I-TASSER) server generated vastly different 3-dimensional (3D) atomic models based on protein sequences from wide-type and novel nonsense mutation of c.295C>T (p.R99X) in CHRNE. DIAGNOSES The diagnosis of CMS with CHRNE mutations in Han Chinese was confirmed. INTERVENTIONS The patient was given prednisone (10 mg, once daily, taken orally) and pyridostigmine (15 mg, three times a day, taken orally). OUTCOMES The patient had a moderate response to prednisone and pyridostigmine. LESSONS We expanded the genotype and phenotype of CMS with CHRNE mutations in Han Chinese and provided new insights into the molecular mechanism of CMS and help to the diagnosis and treatment of CMS.
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Affiliation(s)
| | | | | | - Linyi Meng
- Department of Pharmacy, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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Dowling JJ, D. Gonorazky H, Cohn RD, Campbell C. Treating pediatric neuromuscular disorders: The future is now. Am J Med Genet A 2018; 176:804-841. [PMID: 28889642 PMCID: PMC5900978 DOI: 10.1002/ajmg.a.38418] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 12/12/2022]
Abstract
Pediatric neuromuscular diseases encompass all disorders with onset in childhood and where the primary area of pathology is in the peripheral nervous system. These conditions are largely genetic in etiology, and only those with a genetic underpinning will be presented in this review. This includes disorders of the anterior horn cell (e.g., spinal muscular atrophy), peripheral nerve (e.g., Charcot-Marie-Tooth disease), the neuromuscular junction (e.g., congenital myasthenic syndrome), and the muscle (myopathies and muscular dystrophies). Historically, pediatric neuromuscular disorders have uniformly been considered to be without treatment possibilities and to have dire prognoses. This perception has gradually changed, starting in part with the discovery and widespread application of corticosteroids for Duchenne muscular dystrophy. At present, several exciting therapeutic avenues are under investigation for a range of conditions, offering the potential for significant improvements in patient morbidities and mortality and, in some cases, curative intervention. In this review, we will present the current state of treatment for the most common pediatric neuromuscular conditions, and detail the treatment strategies with the greatest potential for helping with these devastating diseases.
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Affiliation(s)
- James J. Dowling
- Division of NeurologyHospital for Sick ChildrenTorontoOntarioCanada
- Program for Genetics and Genome BiologyHospital for Sick ChildrenTorontoOntarioCanada
- Departments of Paediatrics and Molecular GeneticsUniversity of TorontoTorontoOntarioCanada
| | | | - Ronald D. Cohn
- Program for Genetics and Genome BiologyHospital for Sick ChildrenTorontoOntarioCanada
- Departments of Paediatrics and Molecular GeneticsUniversity of TorontoTorontoOntarioCanada
| | - Craig Campbell
- Department of PediatricsClinical Neurological SciencesEpidemiologyWestern UniversityLondonOntarioCanada
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Neurophysiological Assessment of Abnormalities of the Neuromuscular Junction in Children. Int J Mol Sci 2018; 19:ijms19020624. [PMID: 29470437 PMCID: PMC5855846 DOI: 10.3390/ijms19020624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 11/16/2022] Open
Abstract
The function of the neuromuscular junction in children is amenable to electrophysiological testing. Of the two tests available, repetitive nerve stimulation is uncomfortable and has a reduced sensitivity compared with single-fibre methodology. The latter is the method of choice, recording the variability in neuromuscular transmission as a value called jitter. It can be performed by voluntary activation of the muscle being examined, which is not suitable in children, or by stimulation techniques. A modification of these techniques, called Stimulated Potential Analysis with Concentric needle Electrodes (SPACE), is well tolerated and can be performed while the child is awake. It has a high sensitivity (84%) for the diagnosis of neuromuscular transmission disorders, the majority of which are myasthenic syndromes, and a moderate specificity (70%). The latter can be improved by the exclusion of neurogenic causes and the determination of the degree of jitter abnormality. Minor jitter abnormalities, under 115% of the upper limit of normal, are usually caused by myopathies with an associated neuromuscular transmission disorder, whereas levels higher than this value are usually associated with one of the myasthenic conditions.
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Congenital myopathies: disorders of excitation-contraction coupling and muscle contraction. Nat Rev Neurol 2018; 14:151-167. [PMID: 29391587 DOI: 10.1038/nrneurol.2017.191] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories. However, these entities seem to belong to a much wider phenotypic spectrum. To date, congenital myopathies have been attributed to mutations in over 20 genes, which encode proteins implicated in skeletal muscle Ca2+ homeostasis, excitation-contraction coupling, thin-thick filament assembly and interactions, and other mechanisms. RYR1 mutations are the most frequent genetic cause, and CCD and MmD are the most common subgroups. Next-generation sequencing has vastly improved mutation detection and has enabled the identification of novel genetic backgrounds. At present, management of congenital myopathies is largely supportive, although new therapeutic approaches are reaching the clinical trial stage.
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Abstract
Prevalence studies have shown heterogeneous use of home mechanical ventilation in different conditions, with a marked increase in uptake especially in users of noninvasive ventilation. Although randomized controlled trials have examined noninvasive ventilation in acute exacerbations of chronic obstructive pulmonary disease, for weaning from invasive ventilation and for postextubation respiratory failure, the evidence base for long-term noninvasive ventilation and comparisons with invasive ventilation are less well developed. The combination of noninvasive ventilation and cough-assist devices has reduced the indications for tracheotomy ventilation in some situations (e.g., Duchenne muscular dystrophy, spinal muscular atrophy, myopathies, and amyotrophic lateral sclerosis) and has also prolonged survival. Several excellent overviews have been written on the history of home mechanical ventilation and its evolution from negative pressure to positive pressure techniques, including a systematic review of outcomes. This review, instead, will cover recent trials, trends in the field, outcomes, and safety. Because the greatest growth has been in home noninvasive ventilation, this will be the main focus of this article.
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Feng H, Zhou H. New compound heterozygous variants of the cholinergic receptor nicotinic delta subunit gene in a Chinese male with congenital myasthenic syndrome: A case report. Medicine (Baltimore) 2017; 96:e8981. [PMID: 29390429 PMCID: PMC5758131 DOI: 10.1097/md.0000000000008981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
INTRODUCTION Congenital myasthenic syndromes (CMS) are a group of genetic disorders that stem mostly from molecular defects in nicotinic acetylcholine receptors (AChRs). Defects in the cholinergic receptor nicotinic delta subunit (CHRND) gene can cause a series of myasthenic syndromes. Here, we report 2 new compound heterozygous variants of the CHRND gene in a Chinese male with CMS. CASE PRESENTATION A 43-year-old Chinese male presented with progressive muscle weakness, difficulty chewing, and an inability to lift his head from the time he was 8 years old. He was treated with pyridostigmine, which was partially effective. Two weeks prior, he was hospitalized for dyspnea. Upon examination, he was unable to drum his cheeks and exhibited fatigable muscle weakness and facial muscle atrophy. Sequencing of his exome revealed 2 previously unreported mutations in CHRND, c.59G>A (exon2) and c.423G>C (exon5). CONCLUSIONS We identified a new mutational site that contributes to the onset of CMS.
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Caggiano S, Khirani S, Verrillo E, Barnerias C, Amaddeo A, Gitiaux C, Thierry B, Desguerre I, Cutrera R, Fauroux B. Sleep in infants with congenital myasthenic syndromes. Eur J Paediatr Neurol 2017; 21:842-851. [PMID: 28755803 DOI: 10.1016/j.ejpn.2017.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 05/11/2017] [Accepted: 07/15/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVES Infants with congenital myasthenic syndrome (CMS) are at risk of brief resolved unexplained event (BRUE) and sleep-disordered breathing. The aim of the study was to explore sleep in infants with CMS with a particular focus on heart rate (HR) variability. METHODS Overnight polygraphy was performed and HR variations associated with respiratory events were analysed. Bradycardia and tachycardia were defined as a variation of HR of ±10 bpm from baseline and analysed as events/hour. RESULTS The data of 5 infants with CMS were analysed. Two patients had known mutations (COLQ and RAPSN). One patient had a tracheostomy. The apnoea-hypopnoea index (AHI) was abnormal in all the patients (range 2.8-47.7 events/h), with the highest AHI being observed in the 3 youngest infants. Nocturnal transcutaneous gas exchange was normal in all patients except the tracheostomised patient. Mean HR was 114 ± 23 bpm with a mean HR index of 4.5 ± 4.3 events/h. The amplitudes of HR variations (bradycardia or tachycardia) were around 15-20 bpm, regardless of the type of respiratory event, and comparable between patients. No correlations were found between HR indexes or variations and the type and mean duration of respiratory events. Ventilatory support was initiated in 3 infants immediately after the sleep study because of a high AHI and/or nocturnal hypoventilation. CONCLUSIONS All 5 infants had an abnormal AHI with younger infants having the highest AHI. Three infants required ventilatory support after the polygraphy, underlining its clinical usefulness. No significant abnormalities of HR were observed during the sleep studies.
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Affiliation(s)
- Serena Caggiano
- Respiratory Unit, Academic Pediatric Department, Bambino Gesù Children's Hospital, Rome, Italy; AP-HP, Hôpital Necker-Enfants Malades, Pediatric Noninvasive Ventilation and Sleep Unit, Paris, France
| | - Sonia Khirani
- AP-HP, Hôpital Necker-Enfants Malades, Pediatric Noninvasive Ventilation and Sleep Unit, Paris, France; ASV Santé, Gennevilliers, France
| | - Elisabetta Verrillo
- Respiratory Unit, Academic Pediatric Department, Bambino Gesù Children's Hospital, Rome, Italy
| | - Christine Barnerias
- AP-HP, Hôpital Necker-Enfants Malades, Referral Center for Neuromuscular Diseases, Paris, France
| | - Alessandro Amaddeo
- AP-HP, Hôpital Necker-Enfants Malades, Pediatric Noninvasive Ventilation and Sleep Unit, Paris, France; INSERM U955, Equipe 13, Créteil, France; Paris Descartes University, Paris, France
| | - Cyril Gitiaux
- AP-HP, Hôpital Necker-Enfants Malades, Referral Center for Neuromuscular Diseases, Paris, France; Paris Descartes University, Paris, France
| | - Briac Thierry
- AP-HP, Hôpital Necker-Enfants Malades, Pediatric Head and Neck Surgery, Paris, France
| | - Isabelle Desguerre
- AP-HP, Hôpital Necker-Enfants Malades, Referral Center for Neuromuscular Diseases, Paris, France; Paris Descartes University, Paris, France
| | - Renato Cutrera
- Respiratory Unit, Academic Pediatric Department, Bambino Gesù Children's Hospital, Rome, Italy
| | - Brigitte Fauroux
- AP-HP, Hôpital Necker-Enfants Malades, Pediatric Noninvasive Ventilation and Sleep Unit, Paris, France; INSERM U955, Equipe 13, Créteil, France; Paris Descartes University, Paris, France.
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Pitt MC. Use of stimulated electromyography in the analysis of the neuromuscular junction in children. Muscle Nerve 2017; 56:841-847. [DOI: 10.1002/mus.25685] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 04/18/2017] [Accepted: 05/01/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew C. Pitt
- Department of Clinical NeurophysiologyGreat Ormond Street Hospital for Children NHS Foundation TrustGreat Ormond Street, LondonWC1N 3JH United Kingdom
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Abstract
Myasthenia gravis is a disorder of neuromuscular transmission that leads to fatigue of skeletal muscles and fluctuating weakness. Myasthenia that affects children can be classified into the following 3 forms: transient neonatal myasthenia, congenital myasthenic syndromes, and juvenile myasthenia gravis (JMG). JMG is an autoimmune disorder that has a tendency to affect the extraocular muscles, but can also affect all skeletal muscles leading to generalized weakness and fatigability. Respiratory muscles may be involved leading to respiratory failure requiring ventilator support. Diagnosis should be suspected clinically, and confirmatory diagnostic testing be performed, including serum acetylcholine receptor antibodies, repetitive nerve stimulation, and electromyography. Treatment for JMG includes acetylcholinesterase inhibitors, immunosuppressive medications, plasma exchange, intravenous immunoglobulins, and thymectomy. Children with myasthenia gravis require monitoring by a pediatric ophthalmologist for the development of amblyopia from ptosis or strabismus.
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Kichula EA. Inherited Neuromuscular Disorders: Presentation, Diagnosis, and Advances in Treatment. CURRENT PEDIATRICS REPORTS 2017. [DOI: 10.1007/s40124-017-0118-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Pitt MC, Mchugh JC, Deeb J, Smith RA. Assessing neuromuscular junction stability from stimulated EMG in children. Clin Neurophysiol 2016; 128:290-296. [PMID: 28042994 DOI: 10.1016/j.clinph.2016.11.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/28/2016] [Accepted: 11/16/2016] [Indexed: 11/27/2022]
Abstract
OBJECTIVE We present our 9-year experience of stimulated EMG potential analysis using concentric electrodes (SPACE) to evaluate neuromuscular junction (NMJ) disorders in awake children. The technique uses high frequency filtration of stimulated motor unit potentials and applies peak detection software to estimate mean consecutive difference (MCD). METHODS SPACE was carried out in orbicularis oculi of 878 children (377 girls; median age 47months) between 2007 and 2015, stimulating the facial nerve with a monopolar cathode. Mean MCD-index (MCD-I) was expressed as a ratio of the measured MCD to the upper normal limit. Diagnostic accuracy was calculated for primary NMJ disorders based on the 660 cases with clinical follow-up data. RESULTS Primary NMJ disorders were present in 106 children, including 46 with genetically confirmed congenital myasthenic syndrome (CMS). Mean MCD-I was two times higher in children with primary NMJ disorders compared to others (205±108μs vs 94±38μs, p<0.005). After excluding children with neuronopathies, an MCD-I >100% had 84% sensitivity and 74% specificity for the primary NMJ disorders. Receiver operating characteristics (ROC) curve identified an MCD-I >115% as providing best diagnostic accuracy with sensitivity of 77% and specificity of 84%. CONCLUSION SPACE is practicable and safe in unsedated children. SIGNIFICANCE In combination with routine EMG, it has high diagnostic accuracy and can facilitate recognition of paediatric NMJ transmission disorders.
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Affiliation(s)
- Matthew C Pitt
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, United Kingdom.
| | - John C Mchugh
- Department of Clinical Neurophysiology, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland
| | - Jacquie Deeb
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, United Kingdom; Department of Clinical Neurophysiology, Queen's Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust, London, United Kingdom
| | - Ralph A Smith
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, United Kingdom
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Aharoni S, Sadeh M, Shapira Y, Edvardson S, Daana M, Dor-Wollman T, Mimouni-Bloch A, Halevy A, Cohen R, Sagie L, Argov Z, Rabie M, Spiegel R, Chervinsky I, Orenstein N, Engel AG, Nevo Y. Congenital myasthenic syndrome in Israel: Genetic and clinical characterization. Neuromuscul Disord 2016; 27:136-140. [PMID: 28024842 DOI: 10.1016/j.nmd.2016.11.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/20/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
Abstract
The objective of the study was to evaluate the epidemiology of patients with congenital myasthenic syndrome (CMS) in Israel. Targeted mutation analysis was performed based on the clinical symptoms and electrophysiological findings for known CMS. Additional specific tests were performed in patients of Iranian and/or Iraqi Jewish origin. All medical records were reviewed and clinical data, genetic mutations and outcomes were recorded. Forty-five patients with genetic mutations in known CMS genes from 35 families were identified. Mutations in RAPSN were identified in 13 kinships in Israel. The most common mutation was c.-38A>G detected in 8 patients of Iranian and/or Iraqi Jewish origin. Four different recessive mutations in COLQ were identified in 11 kinships, 10 of which were of Muslim-Arab descent. Mutations in CHRNE were identified in 7 kinships. Less commonly detected mutations were in CHRND, CHAT, GFPT1 and DOK7. In conclusion, mutations in RAPSN and COLQ are the most common causes of CMS in our cohort. Specific mutations in COLQ, RAPSN, and CHRNE occur in specific ethnic populations and should be taken into account when the diagnosis of a CMS is suspected.
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Affiliation(s)
- Sharon Aharoni
- Institute of Child Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Menachem Sadeh
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Neurology, Wolfson Medical Center, Holon, Israel
| | - Yehuda Shapira
- Neuropediatric Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Simon Edvardson
- Neuropediatric Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Muhannad Daana
- Neuropediatric Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Talia Dor-Wollman
- Neuropediatric Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Aviva Mimouni-Bloch
- Pediatric Neurology and Developmental Unit, Loewenstein Rehabilitation Hospital, Raanana, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ayelet Halevy
- Institute of Child Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Rony Cohen
- Institute of Child Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liora Sagie
- Pediatric Neurology Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Zohar Argov
- Department of Neurology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Malcolm Rabie
- Institute of Child Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ronen Spiegel
- Genetic Institute, Emek Medical Center, Afula, Israel
| | | | - Naama Orenstein
- Genetics Unit, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Andrew G Engel
- Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN, USA
| | - Yoram Nevo
- Institute of Child Neurology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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43
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Pitt MC, Jabre JF. Determining jitter values in the very young by use of the e‐norms methodology. Muscle Nerve 2016; 55:51-54. [DOI: 10.1002/mus.25191] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 04/25/2016] [Accepted: 05/13/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Matthew C. Pitt
- Department of Clinical NeurophysiologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonWC1N 3JH UK
| | - Joe F. Jabre
- Department of Neurology, David Geffen School of MedicineUniversity of California Los AngelesLos Angeles California USA
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Nonlethal CHRNA1-Related Congenital Myasthenic Syndrome with a Homozygous Null Mutation. Can J Neurol Sci 2016; 44:125-127. [PMID: 27748205 DOI: 10.1017/cjn.2016.322] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Nishikawa A, Mitsuhashi S, Miyata N, Nishino I. Targeted massively parallel sequencing and histological assessment of skeletal muscles for the molecular diagnosis of inherited muscle disorders. J Med Genet 2016; 54:104-110. [DOI: 10.1136/jmedgenet-2016-104073] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/28/2016] [Accepted: 08/08/2016] [Indexed: 01/04/2023]
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Liewluck T, Milone M, Tian X, Engel AG, Staff NP, Wong LJ. Adult-onset respiratory insufficiency, scoliosis, and distal joint hyperlaxity in patients with multiminicore disease due to novel Megf10
mutations. Muscle Nerve 2016; 53:984-8. [DOI: 10.1002/mus.25054] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2016] [Indexed: 01/29/2023]
Affiliation(s)
- Teerin Liewluck
- Department of Neurology; University of Colorado School of Medicine, Anschutz Medical Campus; Aurora Colorado USA
- Department of Neurology; Mayo Clinic; Rochester Minnesota USA
| | | | - Xia Tian
- Department of Molecular and Human Genetics; Baylor College of Medicine, One Baylor Plaza, NAB 2015; Houston Texas 77030 USA
| | - Andrew G. Engel
- Department of Neurology; Mayo Clinic; Rochester Minnesota USA
| | - Nathan P. Staff
- Department of Neurology; Mayo Clinic; Rochester Minnesota USA
| | - Lee-Jun Wong
- Department of Molecular and Human Genetics; Baylor College of Medicine, One Baylor Plaza, NAB 2015; Houston Texas 77030 USA
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47
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Tan JS, Ambang T, Ahmad-Annuar A, Rajahram GS, Wong KT, Goh KJ. Congenital myasthenic syndrome due to novel CHAT
mutations in an ethnic kadazandusun family. Muscle Nerve 2016; 53:822-6. [DOI: 10.1002/mus.25037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Joo-San Tan
- Division of Neurology, Department of Medicine, Faculty of Medicine; University of Malaya; Kuala Lumpur Malaysia
| | - Tomica Ambang
- Division of Neurology, Department of Medicine, Faculty of Medicine; University of Malaya; Kuala Lumpur Malaysia
| | - Azlina Ahmad-Annuar
- Department of Biomedical Science, Faculty of Medicine; University of Malaya; Kuala Lumpur Malaysia
| | - Giri Shan Rajahram
- Department of Medicine; Hospital Queen Elizabeth; Kota Kinabalu Sabah Malaysia
| | - Kum Thong Wong
- Department of Pathology, Faculty of Medicine; University of Malaya; Kuala Lumpur Malaysia
| | - Khean Jin Goh
- Division of Neurology, Department of Medicine, Faculty of Medicine; University of Malaya; Kuala Lumpur Malaysia
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Abstract
Stridor is a variably pitched respiratory sound, caused by abnormal air passage during breathing and often is the most prominent sign of upper airway obstruction. It is usually heard on inspiration (typically resulting from supraglottic or glottic obstruction) but also can occur on expiration (originating from obstruction at or below glottic level and/or severe upper airway obstruction). Stridor due to congenital anomalies may exist from birth or may develop within days, weeks or months. Various congenital and acquired disorders prevail in neonates, infants, children, and adolescents, and have to be distinguished. History, age of the child and physical examination together often allow a presumptive diagnosis. Further investigations may be necessary to establish a definite diagnosis, and flexible airway endoscopy is the diagnostic procedure of choice in most circumstances ("stridor is visible").
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Affiliation(s)
- Andreas Pfleger
- Division of Paediatric Pulmonology and Allergology, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Austria
| | - Ernst Eber
- Division of Paediatric Pulmonology and Allergology, Department of Paediatrics and Adolescent Medicine, Medical University of Graz, Austria.
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Finlayson S, Morrow JM, Rodriguez Cruz PM, Sinclair CDJ, Fischmann A, Thornton JS, Knight S, Norbury R, White M, Al-Hajjar M, Carboni N, Jayawant S, Robb SA, Yousry TA, Beeson D, Palace J. Muscle magnetic resonance imaging in congenital myasthenic syndromes. Muscle Nerve 2016; 54:211-9. [PMID: 26789134 PMCID: PMC4982021 DOI: 10.1002/mus.25035] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 12/27/2015] [Accepted: 01/06/2016] [Indexed: 11/26/2022]
Abstract
Introduction In this study we investigated muscle magnetic resonance imaging in congenital myasthenic syndromes (CMS). Methods Twenty‐six patients with 9 CMS subtypes and 10 controls were imaged. T1‐weighted (T1w) and short‐tau inversion recovery (STIR) 3‐Tesla MRI images obtained at thigh and calf levels were scored for severity. Results Overall mean the T1w score was increased in GFPT1 and DPAGT1 CMS. T1w scans of the AChR‐deficiency, COLQ, and CHAT subjects were indistinguishable from controls. STIR images from CMS patients did not differ significantly from those of controls. Mean T1w score correlated with age in the CMS cohort. Conclusions MRI appearances ranged from normal to marked abnormality. T1w images seem to be especially abnormal in some CMS caused by mutations of proteins involved in the glycosylation pathway. A non‐selective pattern of fat infiltration or a normal‐appearing scan in the setting of significant clinical weakness should suggest CMS as a potential diagnosis. Muscle MRI could play a role in differentiating CMS subtypes. Muscle Nerve54: 211–219, 2016
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Affiliation(s)
- Sarah Finlayson
- Nuffield Department of Clinical Neurosciences, University of Oxford and Oxford Radcliffe Hospitals NHS Trust, Oxford, UK
| | - Jasper M Morrow
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - Pedro M Rodriguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford and Oxford Radcliffe Hospitals NHS Trust, Oxford, UK
| | | | - Arne Fischmann
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - John S Thornton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - Steve Knight
- University of Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, Oxford, UK
| | - Ray Norbury
- University of Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, Oxford, UK
| | - Mel White
- Department of Paediatrics, University of Oxford and Children's Hospital, Oxford, UK
| | - Michal Al-Hajjar
- Nuffield Department of Clinical Neurosciences, University of Oxford and Oxford Radcliffe Hospitals NHS Trust, Oxford, UK
| | - Nicola Carboni
- Neurology Department, Hospital San Francesco of Nuoro, Sardinia, Italy
| | - Sandeep Jayawant
- Department of Paediatrics, University of Oxford and Children's Hospital, Oxford, UK
| | - Stephanie A Robb
- Dubowitz Neuromuscular Centre, Institute of Child Health and Great Ormond Street Hospital, London, UK
| | - Tarek A Yousry
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, UK
| | - David Beeson
- Neurosciences Group, Weatherall Institute of Molecular Medicine, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford and Oxford Radcliffe Hospitals NHS Trust, Oxford, UK
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50
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Watne L, Yang ML. Clinical course of growth in patients with congenital neuromuscular disease in a single multidisciplinary neuromuscular clinic. J Pediatr Rehabil Med 2016; 9:13-21. [PMID: 26966796 DOI: 10.3233/prm-160357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To assess the effect of nutritional interventions on growth and on respiratory status in patients with congenital myopathy (CM), congenital muscular dystrophy (CMD), and congenital myasthenic syndrome (CMS). METHODS Retrospective cohort study based on case-note review of 18 patients affected by CM, CMD, and CMS, followed at a single pediatric neuromuscular center, between 2006 and 2014. RESULTS Seventy-two percent of patients required placement of a gastrostomy tube for bulbar weakness or for growth failure. Of those patients, 10 had 1 year follow up anthropometric data and 6 had 2 year follow up anthropometric data. Height percentiles and z-scores were significantly improved in patients after 1 year, while weight and BMI percentiles and z-scores were not. Weight and height percentiles and z-scores were significantly improved in patients at 2 year follow up, while BMI percentiles and z-scores were not. The number of respiratory illnesses was not significantly different before or after placement of the feeding tube. Of the patients who did not have placement of a gastrostomy tube, 4 had 1 year follow up anthropometric data and 3 had 2 year follow up anthropometric data. Gastrostomy tube fed patients had significantly higher mean weight percentiles and z-scores compared to orally fed patients. There was no significant difference in height or BMI between the gastrostomy fed and orally fed groups. Individual growth curves highlight the effect of intervention on weight and height. CONCLUSIONS This is a single multidisciplinary center experience describing the effect of nutritional interventions on growth in patients with congenital neuromuscular disorders. While the number of patients and their data in this report are limited, it highlights that the growth in this group of patients is unique but that the low weight and short stature respond to nutritional interventions with changes typically seen after 2 years of intervention.
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Affiliation(s)
- Laura Watne
- Children's Hospital Colorado, Aurora, CO, USA
| | - Michele L Yang
- Department of Pediatrics, University of Colorado Denver School of Medicine, Aurora, CO, USA
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