1
|
Henzi BC, Klein A. Important considerations for children with non-dystrophic myotonia. Lancet Neurol 2024; 23:953-955. [PMID: 39304247 DOI: 10.1016/s1474-4422(24)00367-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2024] [Revised: 08/27/2024] [Accepted: 08/27/2024] [Indexed: 09/22/2024]
Affiliation(s)
- Bettina C Henzi
- Division of Neuropediatrics, Development and Rehabilitation, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital Basel, University of Basel, Basel, Switzerland.
| | - Andrea Klein
- Division of Neuropediatrics, Development and Rehabilitation, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| |
Collapse
|
2
|
Vivekanandam V, Jayaseelan D, Hanna MG. Muscle channelopathies. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:521-532. [PMID: 37562884 DOI: 10.1016/b978-0-323-98818-6.00006-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Muscle channelopathies encompass a wide range of mainly episodic conditions that are characterized by muscle stiffness and weakness. The myotonic conditions, characterized predominantly by stiffness, include myotonia congenita, paramyotonia congenita, and sodium channel myotonia. The periodic paralysis conditions include hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and Andersen-Tawil syndrome. Clinical history is key, and diagnosis is confirmed by next-generation genetic sequencing of a panel of known genes but can also be supplemented by neurophysiology studies and MRI. As genetic testing expands, so have the spectrum of phenotypes seen including pediatric presentations and congenital myopathies. Management of these conditions requires a multidisciplinary approach with extra support needed when patients require anesthetics or when pregnant. Patients with Andersen-Tawil syndrome will also need cardiac input. Diagnosis is important as symptomatic treatment is available for all of these conditions but need to be tailored to the gene and variant of the patient.
Collapse
Affiliation(s)
- Vinojini Vivekanandam
- Centre for Neuromuscular Disorders, Queen Square UCL Institute of Neurology, London, United Kingdom
| | | | - Michael G Hanna
- Centre for Neuromuscular Disorders, Queen Square UCL Institute of Neurology, London, United Kingdom.
| |
Collapse
|
3
|
Stojkovic T, Masingue M, Turmel H, Hezode-Arzel M, Béhin A, Leonard-Louis S, Bassez G, Bauché S, Blondy P, Richard P, Sternberg D, Eymard B, Fournier E, Villar-Quiles RN. Diagnostic yield of a practical electrodiagnostic protocol discriminating between different congenital myasthenic syndromes. Neuromuscul Disord 2022; 32:870-878. [PMID: 36522822 DOI: 10.1016/j.nmd.2022.10.001] [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: 06/13/2022] [Revised: 09/28/2022] [Accepted: 10/02/2022] [Indexed: 11/07/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a group of heterogeneous diseases of the neuromuscular junction. We report electrodiagnostic testing (EDX) and genetic findings in a series of 120 CMS patients tested with a simple non-invasive EDX workup with surface recording of CMAPs and 3Hz repetitive nerve stimulation of accessory, radial and deep fibular nerves. Five ENMG phenotypes were retrieved based on the presence or not of R-CMAPs and the distribution pattern of decremental CMAP responses which significantly correlated with genetic findings (p <0.00001). R-CMAPs were found in all COLQ-mutated patients (CMS1A) and Slow Channel CMS (SCCMS) (CMS1B). CMS1A exhibited greater decrements in accessory nerve RNS than CMS1B. Patients without R-CMAPs were classified into CMS2A (DOK7-, MUSK-, GFPT1-, GMPPB-, TOR1AIP-mutated) when exhibiting predominant accessory nerve RNS decrements, CMS2B (CHRNE, CHRND, RAPSN) with predominant radial nerve RNS decrements, or CMS2C (AGRN) if there were predominant fibular decrements. Our algorithm may have a major impact on diagnostic and therapeutic monitoring in CMS patients, as well as for validation of the pathogenicity of genetic variants. It should also be part of the evaluation of unexplained muscle weakness or complex neuromuscular phenotypes.
Collapse
Affiliation(s)
- Tanya Stojkovic
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Marion Masingue
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Helène Turmel
- Department of Neurophysiology, APHP, Pitié Salpetrière hospital, Paris, France
| | | | - Anthony Béhin
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Sarah Leonard-Louis
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Guillaume Bassez
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Stéphanie Bauché
- Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| | - Patricia Blondy
- National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Pascale Richard
- Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Damien Sternberg
- National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Biochemistry Department, Center of Molecular and Cellular Genetics, APHP, Pitié Salpetrière hospital, Paris, France
| | - Bruno Eymard
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Emmanuel Fournier
- Department of Neurophysiology, APHP, Pitié Salpetrière hospital, Paris, France; National Reference Center for Muscle Channelopathies, APHP, Pitié Salpetrière hospital, Paris, France; Department of Physiology, Sorbonne University, Faculté de médecine Pitié-Salpêtrière, Paris, France
| | - Rocío Nur Villar-Quiles
- Reference Center for Neuromuscular Disorders (Nord/Est/Ile de France), Institute of Myology, Pitié-Salpêtrière Hospital, APHP, Pitié-Salpêtrière Hospital, Paris, France; Centre de Recherche en Myologie, Sorbonne Université-Inserm UMRS974, Paris, France
| |
Collapse
|
4
|
Villar-Quiles RN, Sternberg D, Tredez G, Beatriz Romero N, Evangelista T, Lafôret P, Cintas P, Sole G, Sacconi S, Bendahhou S, Franques J, Cances C, Noury JB, Delmont E, Blondy P, Perrin L, Hezode M, Fournier E, Fontaine B, Stojkovic T, Vicart S. Phenotypical variability and atypical presentations in a French cohort of Andersen-Tawil syndrome. Eur J Neurol 2022; 29:2398-2411. [PMID: 35460302 DOI: 10.1111/ene.15369] [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: 01/27/2022] [Revised: 03/31/2022] [Accepted: 04/18/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND PURPOSE Andersen-Tawil syndrome (ATS) is a skeletal muscle channelopathy caused by KCNJ2 mutations, characterized by a clinical triad of periodic paralysis, cardiac arrhythmias and dysmorphism. The muscle phenotype, particularly the atypical forms with prominent permanent weakness or predominantly painful symptoms, remains incompletely characterized. METHODS A retrospective clinical, histological, electroneuromyography (ENMG) and genetic analysis of molecularly confirmed ATS patients, diagnosed and followed up at neuromuscular reference centers in France, was conducted. RESULTS Thirty-five patients from 27 unrelated families carrying 17 different missense KCNJ2 mutations (four novel mutations) and a heterozygous KCNJ2 duplication are reported. The typical triad was observed in 42.9% of patients. Cardiac abnormalities were observed in 65.7%: 56.5% asymptomatic and 39.1% requiring antiarrhythmic drugs. 71.4% of patients exhibited dysmorphic features. Muscle symptoms were reported in 85.7%, amongst whom 13.3% had no cardiopathy and 33.3% no dysmorphic features. Periodic paralysis was present in 80% and was significantly more frequent in men. Common triggers were exercise, immobility and carbohydrate-rich diet. Ictal serum potassium concentrations were low in 53.6%. Of the 35 patients, 45.7% had permanent weakness affecting proximal muscles, which was mild and stable or slowly progressive over several decades. Four patients presented with exercise-induced pain and myalgia attacks. Diagnostic delay was 14.4 ± 9.5 years. ENMG long-exercise test performed in 25 patients (71.4%) showed in all a decremental response up to 40%. Muscle biopsy performed in 12 patients revealed tubular aggregates in six patients (associated in two of them with vacuolar lesions), dystrophic features in one patient and non-specific myopathic features in one patient; it was normal in four patients. DISCUSSION Recognition of atypical features (exercise-induced pain or myalgia and permanent weakness) along with any of the elements of the triad should arouse suspicion. The ENMG long-exercise test has a high diagnostic yield and should be performed. Early diagnosis is of utmost importance to improve disease prognosis.
Collapse
Affiliation(s)
- Rocio Nur Villar-Quiles
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.,Institute of Myology, Centre de Recherche en Myologie, UMRS974, Sorbonne Université - INSERM, Paris, France
| | - Damien Sternberg
- Reference Center for Muscle Channelopathies, Service de Biochimie et Centre de Génétique, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Grégoire Tredez
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Norma Beatriz Romero
- Institute of Myology, Centre de Recherche en Myologie, UMRS974, Sorbonne Université - INSERM, Paris, France.,Neuromuscular Morphology Unit, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Teresinha Evangelista
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.,Institute of Myology, Centre de Recherche en Myologie, UMRS974, Sorbonne Université - INSERM, Paris, France.,Neuromuscular Morphology Unit, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Pascal Lafôret
- Reference Center for Neuromuscular Disorders, APHP, Raymond-Poincaré Hospital, Paris, France
| | - Pascal Cintas
- Neurology Department, Pierre-Paul Riquet Hospital, CHU Toulouse, Toulouse, France
| | - Guilhem Sole
- Reference Centre for Neuromuscular Disorders, Pellegrin Hospital CHU Bordeaux, Bordeaux, France
| | - Sabrina Sacconi
- Neuromuscular Diseases and ALS Specialized Center, University of Nice-Sophia Antipolis, Nice, France
| | - Said Bendahhou
- UMR7370 CNRS, LP2M, Labex ICST, Faculty of Medicine, University of Nice-Sophia Antipolis, Nice, France
| | - Jérôme Franques
- Assistance Publique-Hôpitaux de Marseille, Department of Neurology and Neuromuscular Diseases, La Timone Hospital, Marseille, France
| | - Claude Cances
- AOC (Atlantique-Occitanie-Caraïbe) Reference Centre for Neuromuscular Disorders, Neuropediatric Department, Toulouse University Hospital, Toulouse, France
| | - J B Noury
- Neurology Department, Neuromuscular Center, CHRU Cavale Blanche, Brest, France
| | - Emilien Delmont
- Department of Neurology, University Hospital Timone, Marseille, France
| | - Patricia Blondy
- Reference Center for Muscle Channelopathies, Service de Biochimie et Centre de Génétique, APHP, Pitié-Salpêtrière Hospital, Paris, France
| | - Laurence Perrin
- Pediatrics Department, APHP, Robert-Débré Hospital, Paris, France
| | - Marianne Hezode
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Emmanuel Fournier
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Bertrand Fontaine
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.,Institute of Myology, Centre de Recherche en Myologie, UMRS974, Sorbonne Université - INSERM, Paris, France.,Reference Center for Muscle Channelopathies, APHP, Institut de Myologie, Pitié-Salpêtrière Hospital, Paris, France
| | - Tanya Stojkovic
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.,Institute of Myology, Centre de Recherche en Myologie, UMRS974, Sorbonne Université - INSERM, Paris, France
| | - Savine Vicart
- Reference Center for Neuromuscular Disorders, APHP, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.,Reference Center for Muscle Channelopathies, APHP, Institut de Myologie, Pitié-Salpêtrière Hospital, Paris, France
| |
Collapse
|
5
|
Altamura C, Ivanova EA, Imbrici P, Conte E, Camerino GM, Dadali EL, Polyakov AV, Kurbatov SA, Girolamo F, Carratù MR, Desaphy JF. Pathomechanisms of a CLCN1 Mutation Found in a Russian Family Suffering From Becker's Myotonia. Front Neurol 2020; 11:1019. [PMID: 33013670 PMCID: PMC7500137 DOI: 10.3389/fneur.2020.01019] [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: 12/16/2019] [Accepted: 08/04/2020] [Indexed: 11/13/2022] Open
Abstract
Objective: Myotonia congenita (MC) is a rare muscle disease characterized by sarcolemma over-excitability inducing skeletal muscle stiffness. It can be inherited either as an autosomal dominant (Thomsen's disease) or an autosomal recessive (Becker's disease) trait. Both types are caused by loss-of-function mutations in the CLCN1 gene, encoding for ClC-1 chloride channel. We found a ClC-1 mutation, p.G411C, identified in Russian patients who suffered from a severe form of Becker's disease. The purpose of this study was to provide a solid correlation between G411C dysfunction and clinical symptoms in the affected patient. Methods: We provide clinical and genetic information of the proband kindred. Functional studies include patch-clamp electrophysiology, biotinylation assay, western blot analysis, and confocal imaging of G411C and wild-type ClC-1 channels expressed in HEK293T cells. Results: The G411C mutation dramatically abolished chloride currents in transfected HEK cells. Biochemical experiments revealed that the majority of G411C mutant channels did not reach the plasma membrane but remained trapped in the cytoplasm. Treatment with the proteasome inhibitor MG132 reduced the degradation rate of G411C mutant channels, leading to their expression at the plasma membrane. However, despite an increase in cell surface expression, no significant chloride current was recorded in the G411C-transfected cell treated with MG132, suggesting that this mutation produces non-functional ClC-1 chloride channels. Conclusion: These results suggest that the molecular pathophysiology of G411C is linked to a reduced plasma membrane expression and biophysical dysfunction of mutant channels, likely due to a misfolding defect. Chloride current abolition confirms that the mutation is responsible for the clinical phenotype.
Collapse
Affiliation(s)
- Concetta Altamura
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, Bari, Italy
| | - Evgeniya A Ivanova
- N.P. Bochkov's Research Centre for Medical Genetics, Federal State Budgetary Scientific Institution, Moscow, Russia
| | - Paola Imbrici
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Elena Conte
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Giulia Maria Camerino
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Elena L Dadali
- N.P. Bochkov's Research Centre for Medical Genetics, Federal State Budgetary Scientific Institution, Moscow, Russia
| | - Alexander V Polyakov
- N.P. Bochkov's Research Centre for Medical Genetics, Federal State Budgetary Scientific Institution, Moscow, Russia
| | | | - Francesco Girolamo
- Unit of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience, and Sense Organs, School of Medicine, University of Bari Aldo Moro, Bari, Italy
| | - Maria Rosaria Carratù
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, Bari, Italy
| | - Jean-François Desaphy
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, Bari, Italy
| |
Collapse
|
6
|
Lv H, Qu Q, Liu H, Qian Q, Zheng X, Zhang Y. Clinical, neuroelectrophysiological and muscular pathological analysis of chronic progressive external ophthalmoplegia. Exp Ther Med 2020; 20:1770-1774. [PMID: 32742407 DOI: 10.3892/etm.2020.8822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 03/10/2020] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to explore the clinical, neuroelectrophysiological and muscular pathological characteristics of chronic progressive external ophthalmoplegia (CPEO) and to improve the understanding of CPEO. Clinical manifestations, neuroelectrophysiology and pathological features of muscle biopsies from 12 patients with CPEO were retrospectively analyzed. The average age of onset for the 12 patients (6 males and 6 females) was 17.2 years. All patients had different degrees of blepharoptosis. A total of 11 patients experienced ocular dyskinesia, but diplopia was rare. Electrophysiological testing in 12 patients revealed abnormal changes in 6 patients, including 4 patients with a myogenic lesion, 1 patient with a neurogenic lesion, and 1 patient with mixed myogenic/neurogenic lesions. Two patients had slow sensory nerve conduction velocity. Muscle biopsies in 12 patients demonstrated ragged-red, irregular and broken fibers in 11 patients through Gomori trichrome and hematoxylin and eosin (H&E) staining, increased lipid levels in some muscle fibers in 4 patients through Οil Ρed O staining and abnormal distribution of type I and II muscle fibers in 3 patients through ATPase staining. Electron microscopy in 5 patients showed an increased number of mitochondria and abnormal mitochondrial aggregation between submucosa and myofibrils in 4 patients. These findings suggest that the possibility of CPEO should be considered if patients present with obvious extraocular muscle paralysis without diplopia. Furthermore, the identification of ragged-red fibers by Gomori trichrome and H&E staining of muscle biopsies from patients is an important basis for the diagnosis of CPEO.
Collapse
Affiliation(s)
- Haidong Lv
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| | - Qianqian Qu
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| | - Haiyan Liu
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| | - Qi Qian
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| | - Xianzhao Zheng
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| | - Yan Zhang
- Department of Neurology, The People's Hospital of Jiaozuo City, Jiaozuo, Henan 454002, P.R. China
| |
Collapse
|
7
|
Altamura C, Desaphy JF, Conte D, De Luca A, Imbrici P. Skeletal muscle ClC-1 chloride channels in health and diseases. Pflugers Arch 2020; 472:961-975. [PMID: 32361781 DOI: 10.1007/s00424-020-02376-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/18/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022]
Abstract
In 1970, the study of the pathomechanisms underlying myotonia in muscle fibers isolated from myotonic goats highlighted the importance of chloride conductance for skeletal muscle function; 20 years later, the human ClC-1 chloride channel has been cloned; last year, the crystal structure of human protein has been solved. Over the years, the efforts of many researchers led to significant advances in acknowledging the role of ClC-1 in skeletal muscle physiology and the mechanisms through which ClC-1 dysfunctions lead to impaired muscle function. The wide spectrum of pathophysiological conditions associated with modification of ClC-1 activity, either as the primary cause, such as in myotonia congenita, or as a secondary adaptive mechanism in other neuromuscular diseases, supports the idea that ClC-1 is relevant to preserve not only for skeletal muscle excitability, but also for skeletal muscle adaptation to physiological or harmful events. Improving this understanding could open promising avenues toward the development of selective and safe drugs targeting ClC-1, with the aim to restore normal muscle function. This review summarizes the most relevant research on ClC-1 channel physiology, associated diseases, and pharmacology.
Collapse
Affiliation(s)
- Concetta Altamura
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari "Aldo Moro", Bari, Italy
| | - Jean-Francois Desaphy
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari "Aldo Moro", Bari, Italy
| | - Diana Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Annamaria De Luca
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy.
| |
Collapse
|
8
|
Shi J, Qu Q, Liu H, Cui W, Zhang Y, Lv H, Lu Z. SCN4A p.R675Q Mutation Leading to Normokalemic Periodic Paralysis: A Family Report and Literature Review. Front Neurol 2019; 10:1138. [PMID: 31708864 PMCID: PMC6824318 DOI: 10.3389/fneur.2019.01138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/10/2019] [Indexed: 11/22/2022] Open
Abstract
Objective: To investigate the clinical features, skeletal muscle imaging, and muscle pathological characteristics of normokalemic periodic paralysis (NormoKPP) caused by mutation of SCN4A gene p.R675Q. Methods: The clinical data, skeletal muscle imaging, pathological data, and gene test results of a family with NormoKPP were collected in detail in October 2018. The previous literature was reviewed and used for comparative analysis. Results: The proband was a 28-year-old male with paroxysmal weakness of both lower limbs for 14 years. Limb weakness was mainly manifested in the proximal extremities of both lower limbs, which occurred two to three times a year. The muscle weakness of each attack lasted for 1–2 weeks and gradually recovered. The blood potassium levels were normal. The abnormal signals of the posterior thigh muscle group and the medial calf muscle group could be seen on the magnetic resonance imaging (MRI) of the skeletal muscle, and the target-fiber could be seen in some muscle fibers in muscle pathology. The father of the proband and his brother had the same symptoms. In the same family, 10 people received genetic testing. The results showed that five had a mutation of SCN4A gene p.R675Q. The mutation gene came from the father of the proband. Conclusion: NormoKPP is a clinically rare form of sodium ion channel disease. The clinical manifestations, skeletal muscle imaging, and pathological changes are different from the common hypokalemic periodic paralysis. SCN4A gene detection is an important means for the diagnosis of NormoKPP.
Collapse
Affiliation(s)
- Jiejing Shi
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Qianqian Qu
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Haiyan Liu
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Wenhao Cui
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Yan Zhang
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Haidong Lv
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Jiaozuo, China
| | - Zuneng Lu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| |
Collapse
|