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Fan Q, Gwathmey K, Du X, Seth A, Corse A. Tubular aggregate myopathy causing progressive fatiguable weakness. Pract Neurol 2024; 24:137-140. [PMID: 37923376 DOI: 10.1136/pn-2023-003838] [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] [Accepted: 10/04/2023] [Indexed: 11/07/2023]
Abstract
Tubular aggregate myopathies comprise a rare group of disorders with characteristic pathological findings and heterogeneous phenotypes, including myasthenic syndrome. We describe a patient with tubular aggregate myopathy who presented with fatiguable weakness improving with pyridostigmine, respiratory involvement and possible cardiac manifestations. We highlight the utility of muscle biopsy in atypical myasthenic syndrome.
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Affiliation(s)
- Qihua Fan
- Neurology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Kelly Gwathmey
- Neurology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Xinli Du
- Neurology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Arjun Seth
- Neurology, Northwestern University, Evanston, Illinois, USA
| | - Andrea Corse
- Neurology, Johns Hopkins, Baltimore, Maryland, USA
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Özsoy Ö, Cinleti T, Günay Ç, Sarıkaya Uzan G, Giray Bozkaya Ö, Çağlayan AO, Hız Kurul S, Yiş U. Genetic, serological and clinical evaluation of childhood myasthenia syndromes- single center subgroup analysis experience in Turkey. Acta Neurol Belg 2023; 123:2325-2335. [PMID: 37656362 DOI: 10.1007/s13760-023-02370-3] [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: 04/04/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Congenital myasthenic syndrome is a disease that occurs due to several types such as mutations in different pre-synaptic, synaptic, post-synaptic proteins and, glycosylation defects associated with congenital myopathy. Juvenile myasthenia gravis is an autoimmune condition usually caused by antibodies targeting the acetylcholine receptor. AIMS Our objective is to conduct an analysis on the subgroup traits exhibited by patients who have been diagnosed with congenital myasthenic syndrome and juvenile myasthenia gravis, with a focus on their long-term monitoring and management. METHODS This study was conducted on children diagnosed with myasthenia gravis, who were under the care of Dokuz Eylul University's Department of Pediatric Neurology for a period of ten years. RESULTS A total of 22 (12 congenital myasthenic syndrome, 10 juvenile myasthenia gravis) patients were identified. Defects in the acetylcholine receptor (6/12) were the most common type in the congenital myasthenic syndrome group. Basal-lamina-related defects (5/12) were the second most prevalent. One patient had a GFPT1 gene mutation (1/12). Patients with ocular myasthenia gravis (n = 6) exhibited milder symptoms. In the generalized myasthenia gravis group (n = 4), specifically in postpubertal girls, a more severe clinical progression was observed, leading to the implementation of more aggressive treatment strategies. CONCLUSION This study highlights that clinical recognition of congenital myasthenic syndrome and knowledge of related genes will aid the rapid diagnosis and treatment of these rare neuromuscular disorders. Findings in the juvenile myasthenia gravis group demonstrate the impact of pubertal development and the need for timely and appropriate active therapy, including thymectomy, to improve prognosis.
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Affiliation(s)
- Özlem Özsoy
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey.
| | - Tayfun Cinleti
- Department of Pediatric Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Çağatay Günay
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Gamze Sarıkaya Uzan
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Özlem Giray Bozkaya
- Department of Pediatric Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
| | - Ahmet Okay Çağlayan
- Department of Medical Genetics, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
- Department of Molecular Medicine, Institute of Health Sciences, Dokuz Eylül University, İzmir, Turkey
| | - Semra Hız Kurul
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
- İzmir Biomedicine and Genome Center, Dokuz Eylül University Health Campus, İzmir, Turkey
- İzmir International Biomedicine and Genome Institute, Dokuz Eylül University, İzmir, Turkey
| | - Uluç Yiş
- Department of Pediatric Neurology, Faculty of Medicine, Dokuz Eylül University, İzmir, Turkey
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Williams EK, Shea C, Gonzalez-Perez P. Agenesis of Pectoralis Major Muscle in Late-Onset GFPT1-Related Congenital Myasthenic Syndrome: A Case Report. Neurol Genet 2023; 9:e200102. [PMID: 38235042 PMCID: PMC10523285 DOI: 10.1212/nxg.0000000000200102] [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] [Received: 05/17/2023] [Accepted: 08/22/2023] [Indexed: 01/19/2024]
Abstract
Objectives The objective of this study was to expand the phenotypic spectrum of glutamine-fructose-6-phosphate transaminase 1 (GFPT1)-related congenital myasthenia syndrome (CMS). Methods A 61-year-old man with agenesis of the left pectoralis major muscle presented with progressive muscle weakness for a decade that transiently improved after exertion. Results His examination revealed proximal and distal muscle weakness in upper extremities and proximal muscle weakness in lower extremities. Muscle enzymes were elevated. An electromyogram revealed a myopathic pattern; however, a muscle biopsy of deltoid muscle and genetic testing for limb-girdle muscular dystrophies were nondiagnostic. A 3-Hz repetitive nerve stimulation of the spinal accessory nerve recording from trapezius muscle demonstrated a >20% drop in amplitude of the 5th compound motor action potential relative to 1st at both baseline and after 45-second exercise. Acetylcholine receptor binding, lipoprotein-related protein 4, muscle-specific kinase, and voltage-gated calcium channel P/Q antibodies were negative. Genetic testing targeting CMS revealed 2 likely pathogenic variants within GFPT1: novel c.7+2T>G (intron 1) that was predicted to result in a null allele and known c*22 C>A (exon 19) associated with reduced GFPT1 expression. His muscle strength dramatically improved after pyridostigmine initiation. Discussion In addition to other reported neurodevelopmental abnormalities, pectoralis major muscle agenesis (or Poland syndrome) may be a clinical manifestation of GFPT1-related CMS.
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Affiliation(s)
- Erika K Williams
- From the Department of Neurology (E.K.W., C.S., P.G.-P.), Massachusetts General Hospital; and Department of Neurology (E.K.W., C.S.), Brigham Women's Hospital, Harvard Medical School, Boston, MA
| | - Cristina Shea
- From the Department of Neurology (E.K.W., C.S., P.G.-P.), Massachusetts General Hospital; and Department of Neurology (E.K.W., C.S.), Brigham Women's Hospital, Harvard Medical School, Boston, MA
| | - Paloma Gonzalez-Perez
- From the Department of Neurology (E.K.W., C.S., P.G.-P.), Massachusetts General Hospital; and Department of Neurology (E.K.W., C.S.), Brigham Women's Hospital, Harvard Medical School, Boston, MA
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Farshadyeganeh P, Nazim M, Zhang R, Ohkawara B, Nakajima K, Rahman MA, Nasrin F, Ito M, Takeda JI, Ohe K, Miyasaka Y, Ohno T, Masuda A, Ohno K. Splicing regulation of GFPT1 muscle-specific isoform and its roles in glucose metabolisms and neuromuscular junction. iScience 2023; 26:107746. [PMID: 37744035 PMCID: PMC10514471 DOI: 10.1016/j.isci.2023.107746] [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: 05/10/2023] [Revised: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/26/2023] Open
Abstract
Glutamine:fructose-6-phosphate transaminase 1 (GFPT1) is the rate-limiting enzyme of the hexosamine biosynthetic pathway (HBP). A 54-bp exon 9 of GFPT1 is specifically included in skeletal and cardiac muscles to generate a long isoform of GFPT1 (GFPT1-L). We showed that SRSF1 and Rbfox1/2 cooperatively enhance, and hnRNP H/F suppresses, the inclusion of human GFPT1 exon 9 by modulating recruitment of U1 snRNP. Knockout (KO) of GFPT1-L in skeletal muscle markedly increased the amounts of GFPT1 and UDP-HexNAc, which subsequently suppressed the glycolytic pathway. Aged KO mice showed impaired insulin-mediated glucose uptake, as well as muscle weakness and fatigue likely due to abnormal formation and maintenance of the neuromuscular junction. Taken together, GFPT1-L is likely to be acquired in evolution in mammalian striated muscles to attenuate the HBP for efficient glycolytic energy production, insulin-mediated glucose uptake, and the formation and maintenance of the neuromuscular junction.
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Affiliation(s)
- Paniz Farshadyeganeh
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Mohammad Nazim
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ruchen Zhang
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Bisei Ohkawara
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Kazuki Nakajima
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu 501-1193, Japan
| | - Mohammad Alinoor Rahman
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Department of Biochemistry and Molecular Biology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR 72205, USA
| | - Farhana Nasrin
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Department of Biochemistry and Molecular Biology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR 72205, USA
| | - Mikako Ito
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Jun-ichi Takeda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Kenji Ohe
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
- Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka 814-0180, Japan
| | - Yuki Miyasaka
- Division of Experimental Animals, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Tamio Ohno
- Division of Experimental Animals, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Akio Masuda
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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Paneque A, Fortus H, Zheng J, Werlen G, Jacinto E. The Hexosamine Biosynthesis Pathway: Regulation and Function. Genes (Basel) 2023; 14:genes14040933. [PMID: 37107691 PMCID: PMC10138107 DOI: 10.3390/genes14040933] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
The hexosamine biosynthesis pathway (HBP) produces uridine diphosphate-N-acetyl glucosamine, UDP-GlcNAc, which is a key metabolite that is used for N- or O-linked glycosylation, a co- or post-translational modification, respectively, that modulates protein activity and expression. The production of hexosamines can occur via de novo or salvage mechanisms that are catalyzed by metabolic enzymes. Nutrients including glutamine, glucose, acetyl-CoA, and UTP are utilized by the HBP. Together with availability of these nutrients, signaling molecules that respond to environmental signals, such as mTOR, AMPK, and stress-regulated transcription factors, modulate the HBP. This review discusses the regulation of GFAT, the key enzyme of the de novo HBP, as well as other metabolic enzymes that catalyze the reactions to produce UDP-GlcNAc. We also examine the contribution of the salvage mechanisms in the HBP and how dietary supplementation of the salvage metabolites glucosamine and N-acetylglucosamine could reprogram metabolism and have therapeutic potential. We elaborate on how UDP-GlcNAc is utilized for N-glycosylation of membrane and secretory proteins and how the HBP is reprogrammed during nutrient fluctuations to maintain proteostasis. We also consider how O-GlcNAcylation is coupled to nutrient availability and how this modification modulates cell signaling. We summarize how deregulation of protein N-glycosylation and O-GlcNAcylation can lead to diseases including cancer, diabetes, immunodeficiencies, and congenital disorders of glycosylation. We review the current pharmacological strategies to inhibit GFAT and other enzymes involved in the HBP or glycosylation and how engineered prodrugs could have better therapeutic efficacy for the treatment of diseases related to HBP deregulation.
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Affiliation(s)
- Alysta Paneque
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Harvey Fortus
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Julia Zheng
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Guy Werlen
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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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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An R, Chen H, Lei S, Li Y, Xu Y, He C. Abnormal decrement on high-frequency repetitive nerve stimulation in congenital myasthenic syndrome with GFPT1 mutations and review of literature. Front Neurol 2022; 13:926786. [PMID: 36188410 PMCID: PMC9520358 DOI: 10.3389/fneur.2022.926786] [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] [Received: 04/23/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022] Open
Abstract
Objectives Congenital myasthenic syndrome (CMS) is a clinically and genetically heterogeneous group of inherited disorders characterized by neuromuscular junction defects. Mutations in GFPT1 have been shown to underlie CMS. An increasing number of patients with CMS due to mutations in GFPT1 have been reported. However, a comprehensive review of clinical and genetic analyses of GFPT-related CMS worldwide is lacking, especially, given that the common or hotspot mutations in GFPT1 have not been reported. Here, we described the clinical and genetic findings of three patients with GFPT1 mutations from southwestern China and reviewed the clinical and genetic features of patients with GFPT1-related CMS worldwide. Methods Clinical, laboratory, electrophysiological, myopathological, and genetic analyses of three patients with GFPT1-related CMS from southwestern China were conducted, and a review of previously published or reported cases about congenital myasthenic syndrome with GFPT1 mutations in the PubMed database was made. Results The clinical, laboratory, electrophysiological, and myopathological features by muscle biopsy of three patients with GFPT1-related CMS were consistent with those of previously reported patients with GFPT1 mutations. Additionally, an abnormal decrement in high-frequency RNS was found. Two different homozygous missense mutations (c.331C>T, p.R111C; c.44C>T, p.T15M) were detected by whole-exome sequencing (WES) or targeted neuromuscular disorder gene panels. Conclusion A distinct decremental response to high-frequency RNS was found in three patients with GFPT1-related CMS from southwestern China, which has never been reported thus far. In addition, the location and degree of tubular aggregates (TAs) seemed to be associated with the severity of clinical symptoms and serum creatine kinase levels, further expanding the phenotypic spectrum of GFPT1-related CMS. Lastly, some potential hotspot mutations in GFPT1 have been found in GFPT1-CMS worldwide.
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Affiliation(s)
- Ran An
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
| | - Huijiao Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Song Lei
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, China
| | - Yi Li
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
| | - Yanming Xu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Yanming Xu
| | - Chengqi He
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, Chengdu, China
- Chengqi He
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Mensch A, Cordts I, Scholle L, Joshi PR, Kleeberg K, Emmer A, Beck-Woedl S, Park J, Haack TB, Stoltenburg-Didinger G, Zierz S, Deschauer M. GFPT1-Associated Congenital Myasthenic Syndrome Mimicking a Glycogen Storage Disease – Diagnostic Pitfalls in Myopathology Solved by Next-Generation-Sequencing. J Neuromuscul Dis 2022; 9:533-541. [DOI: 10.3233/jnd-220822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
GFPT1-related congenital myasthenic syndrome (CMS) is characterized by progressive limb girdle weakness, and less prominent involvement of facial, bulbar, or respiratory muscles. While tubular aggregates in muscle biopsy are considered highly indicative in GFPT1-associated CMS, excessive glycogen storage has not been described. Here, we report on three affected siblings with limb-girdle myasthenia due to biallelic pathogenic variants in GFPT1: the previously reported missense variant c.41G > A (p.Arg14Gln) and the novel truncating variant c.1265_1268del (p.Phe422TrpfsTer26). Patients showed progressive proximal atrophic muscular weakness with respiratory involvement, and a lethal disease course in adulthood. In the diagnostic workup at that time, muscle biopsy suggested a glycogen storage disease. Initially, Pompe disease was suspected. However, enzymatic activity of acid alpha-glucosidase was normal, and gene panel analysis including 38 genes associated with limb-girdle weakness (GAA included) remained unevocative. Hence, a non-specified glycogen storage myopathy was diagnosed. A decade later, the diagnosis of GFPT1-related CMS was established by genome sequencing. Myopathological reexamination showed pronounced glycogen accumulations, that were exclusively found in denervated muscle fibers. Only single fibers showed very small tubular aggregates, identified in evaluation of serial sections. This family demonstrates how diagnostic pitfalls can be addressed by an integrative approach including broad genetic analysis and re-evaluation of clinical as well as myopathological findings.
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Affiliation(s)
- Alexander Mensch
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Isabell Cordts
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Leila Scholle
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Pushpa Raj Joshi
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Kathleen Kleeberg
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Alexander Emmer
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Stefanie Beck-Woedl
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Joohyun Park
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tobias B. Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Gisela Stoltenburg-Didinger
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Stephan Zierz
- Department of Neurology, Martin Luther University Halle-Wittenberg and University Hospital Halle, Halle (Saale), Germany
| | - Marcus Deschauer
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
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Jiang K, Zheng Y, Lin J, Wu X, Yu Y, Zhu M, Fang X, Zhou M, Li X, Hong D. Diverse myopathological features in the congenital myasthenia syndrome with GFPT1 mutation. Brain Behav 2022; 12:e2469. [PMID: 34978387 PMCID: PMC8865156 DOI: 10.1002/brb3.2469] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 11/14/2021] [Accepted: 12/07/2021] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Mutations in the GFPT1 gene are associated with a particular subtype of congenital myasthenia syndrome (CMS) called limb-girdle myasthenia with tubular aggregates. However, not all patients show tubular aggregates in muscle biopsy, suggesting the diversity of myopathology should be further investigated. METHODS In this study, we reported two unrelated patients clinically characterized by easy fatigability, limb-girdle muscle weakness, positive decrements of repetitive stimulation, and response to pyridostigmine. The routine examinations of myopathology were conducted. The causative gene was explored by whole-exome screening. In addition, we summarized all GFPT1-related CMS patients with muscle biopsy in the literature. RESULTS Pathogenic biallelic GFPT1 mutations were identified in the two patients. In patient one, muscle biopsy indicated vacuolar myopathic changes and atypical pathological changes of myofibrillar myopathy characterized by desmin deposits, Z-disc disorganization, and electronic dense granulofilamentous aggregation. In patient two, muscle biopsy showed typical myopathy with tubular aggregates. Among the 51 reported GFPT1-related CMS patients with muscle biopsy, most of them showed tubular aggregates myopathy, while rimmed vacuolar myopathy, autophagic vacuolar myopathy, mitochondria-like myopathy, neurogenic myopathy, and unspecific myopathic changes were also observed in some patients. These extra-synaptic pathological changes might be associated with GFPT1-deficiency hypoglycosylation and altered function of muscle-specific glycoproteins, as well as partly responsible for the permanent muscle weakness and resistance to acetylcholinesterase inhibitor therapy. CONCLUSIONS Most patients with GFPT1-related CMS had tubular aggregates in the muscle biopsy, but some patients could show great diversities of the pathological change. The myopathological findings might be a biomarker to predict the prognosis of the disease.
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Affiliation(s)
- Kaiyan Jiang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yilei Zheng
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jing Lin
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaorong Wu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yanyan Yu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Min Zhu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xin Fang
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Meihong Zhou
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaobing Li
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Daojun Hong
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China.,Department of Medical Genetics, The First Affiliated Hospital of Nanchang University, Nanchang, China
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Gang Q, Bettencourt C, Brady S, Holton JL, Healy EG, McConville J, Morrison PJ, Ripolone M, Violano R, Sciacco M, Moggio M, Mora M, Mantegazza R, Zanotti S, Wang Z, Yuan Y, Liu WW, Beeson D, Hanna M, Houlden H. Genetic defects are common in myopathies with tubular aggregates. Ann Clin Transl Neurol 2021; 9:4-15. [PMID: 34908252 PMCID: PMC8791796 DOI: 10.1002/acn3.51477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/12/2021] [Accepted: 10/27/2021] [Indexed: 12/17/2022] Open
Abstract
Objective A group of genes have been reported to be associated with myopathies with tubular aggregates (TAs). Many cases with TAs still lack of genetic clarification. This study aims to explore the genetic background of cases with TAs in order to improve our knowledge of the pathogenesis of these rare pathological structures. Methods Thirty‐three patients including two family members with biopsy confirmed TAs were collected. Whole‐exome sequencing was performed on 31 unrelated index patients and a candidate gene search strategy was conducted. The identified variants were confirmed by Sanger sequencing. The wild‐type and the mutant p.Ala11Thr of ALG14 were transfected into human embryonic kidney 293 cells (HEK293), and western blot analysis was performed to quantify protein expression levels. Results Eleven index cases (33%) were found to have pathogenic variant or likely pathogenic variants in STIM1, ORAI1, PGAM2, SCN4A, CASQ1 and ALG14. Among them, the c.764A>T (p.Glu255Val) in STIM1 and the c.1333G>C (p.Val445Leu) in SCN4A were novel. Western blot analysis showed that the expression of ALG14 protein was severely reduced in the mutant ALG14 HEK293 cells (p.Ala11Thr) compared with wild type. The ALG14 variants might be associated with TAs in patients with complex multisystem disorders. Interpretation This study expands the phenotypic and genotypic spectrums of myopathies with TAs. Our findings further confirm previous hypothesis that genes related with calcium signalling pathway and N‐linked glycosylation pathway are the main genetic causes of myopathies with TAs.
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Affiliation(s)
- Qiang Gang
- Department of Neurology, Peking University First Hospital, 8 Xishiku Street, Xicheng District, Beijing, 100034, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, 100034, China.,Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK.,MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Conceição Bettencourt
- Queen Square Brain Bank for Neurological Disorders, London, UK.,Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Stefen Brady
- Oxford Muscle Service, John Radcliffe Hospital, Oxford, UK
| | - Janice L Holton
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK.,Queen Square Brain Bank for Neurological Disorders, London, UK
| | - Estelle G Healy
- Department of Neuropathology, Royal Victoria Hospital, Belfast, Northern Ireland
| | - John McConville
- Department of Neurology, Belfast City Hospital, Belfast, BT9 7AB, UK
| | - Patrick J Morrison
- Department of Genetic Medicine, Belfast City Hospital, Belfast, BT9 7AB, UK
| | - Michela Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Raffaella Violano
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Monica Sciacco
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Maurizio Moggio
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Marina Mora
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Isitituto Neurologico C. Besta, Milano, Italy
| | - Renato Mantegazza
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Isitituto Neurologico C. Besta, Milano, Italy
| | - Simona Zanotti
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Isitituto Neurologico C. Besta, Milano, Italy
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, 8 Xishiku Street, Xicheng District, Beijing, 100034, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, 100034, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, 8 Xishiku Street, Xicheng District, Beijing, 100034, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing, 100034, China
| | - Wei-Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Michael Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK.,MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK.,MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, Queen Square, London, UK.,Neurogenetics Laboratory, UCL Queen Square Institute of Neurology, Queen Square, WC1N 3BG, London, UK
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11
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Maggi L, Bonanno S, Altamura C, Desaphy JF. Ion Channel Gene Mutations Causing Skeletal Muscle Disorders: Pathomechanisms and Opportunities for Therapy. Cells 2021; 10:cells10061521. [PMID: 34208776 PMCID: PMC8234207 DOI: 10.3390/cells10061521] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/03/2021] [Accepted: 06/10/2021] [Indexed: 02/06/2023] Open
Abstract
Skeletal muscle ion channelopathies (SMICs) are a large heterogeneous group of rare genetic disorders caused by mutations in genes encoding ion channel subunits in the skeletal muscle mainly characterized by myotonia or periodic paralysis, potentially resulting in long-term disabilities. However, with the development of new molecular technologies, new genes and new phenotypes, including progressive myopathies, have been recently discovered, markedly increasing the complexity in the field. In this regard, new advances in SMICs show a less conventional role of ion channels in muscle cell division, proliferation, differentiation, and survival. Hence, SMICs represent an expanding and exciting field. Here, we review current knowledge of SMICs, with a description of their clinical phenotypes, cellular and molecular pathomechanisms, and available treatments.
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Affiliation(s)
- Lorenzo Maggi
- Neuroimmunology and Neuromuscular Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy;
- Correspondence:
| | - Silvia Bonanno
- Neuroimmunology and Neuromuscular Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy;
| | - Concetta Altamura
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, 70124 Bari, Italy; (C.A.); (J.-F.D.)
| | - Jean-François Desaphy
- Department of Biomedical Sciences and Human Oncology, School of Medicine, University of Bari Aldo Moro, 70124 Bari, Italy; (C.A.); (J.-F.D.)
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12
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Ruegenberg S, Mayr FAMC, Atanassov I, Baumann U, Denzel MS. Protein kinase A controls the hexosamine pathway by tuning the feedback inhibition of GFAT-1. Nat Commun 2021; 12:2176. [PMID: 33846315 PMCID: PMC8041777 DOI: 10.1038/s41467-021-22320-y] [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: 07/27/2020] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
The hexosamine pathway (HP) is a key anabolic pathway whose product uridine 5'-diphospho-N-acetyl-D-glucosamine (UDP-GlcNAc) is an essential precursor for glycosylation processes in mammals. It modulates the ER stress response and HP activation extends lifespan in Caenorhabditis elegans. The highly conserved glutamine fructose-6-phosphate amidotransferase 1 (GFAT-1) is the rate-limiting HP enzyme. GFAT-1 activity is modulated by UDP-GlcNAc feedback inhibition and via phosphorylation by protein kinase A (PKA). Molecular consequences of GFAT-1 phosphorylation, however, remain poorly understood. Here, we identify the GFAT-1 R203H substitution that elevates UDP-GlcNAc levels in C. elegans. In human GFAT-1, the R203H substitution interferes with UDP-GlcNAc inhibition and with PKA-mediated Ser205 phosphorylation. Our data indicate that phosphorylation affects the interactions of the two GFAT-1 domains to control catalytic activity. Notably, Ser205 phosphorylation has two discernible effects: it lowers baseline GFAT-1 activity and abolishes UDP-GlcNAc feedback inhibition. PKA controls the HP by uncoupling the metabolic feedback loop of GFAT-1.
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Affiliation(s)
- Sabine Ruegenberg
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany ,grid.6190.e0000 0000 8580 3777Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Felix A. M. C. Mayr
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ilian Atanassov
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Ulrich Baumann
- grid.6190.e0000 0000 8580 3777Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Martin S. Denzel
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing, Cologne, Germany ,grid.6190.e0000 0000 8580 3777CECAD - Cluster of Excellence, University of Cologne, Cologne, Germany ,grid.6190.e0000 0000 8580 3777Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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13
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Novel compound heterozygous variants in the GFPT1 gene leading to rare limb-girdle congenital myasthenic syndrome with rimmed vacuoles. Neurol Sci 2021; 42:3485-3490. [PMID: 33438142 DOI: 10.1007/s10072-020-05021-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 12/21/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Congenital myasthenic syndrome (CMS) is a heterogeneous group of rare disorders with impaired neuromuscular transmission caused by genetic defects, which is characterized by fatigable muscle weakness. CASE PRESENTATION Herein, we report a case of limb-girdle CMS (LG-CMS) in a 15-year-old Chinese girl with limb weakness and mild ptosis. The patient presented with well-defined clinical manifestations, muscle imaging, and electrophysiological features associated with CMS. On muscle biopsy, in addition to tubular aggregates identified, an extremely unusual pathological change of rimmed vacuoles in muscle fibers was observed. Whole-exome sequencing disclosed two novel heterozygous variants (c.14 T>A and c.581 T>C) in the human glutamine-fructose-6-phosphate transaminase 1 (GFPT1) gene, leading to the substitutions of phenylalanine to tyrosine (p.F5Y) and serine (p.F194S), respectively. Both variants were predicted to be likely pathogenic by SIFT, Polyphen-2, and Mutation Taster. Treatments with pyridostigmine bromide and albuterol produced a dramatic improvement. CONCLUSIONS Collectively, molecular genetic analysis and muscle biopsy play crucial roles in the diagnosis of GFPT1-related LG-CMS with rimmed vacuoles (a rare phenotype of CMS) and have important implications for treatment decision.
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14
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Silva-Rojas R, Laporte J, Böhm J. STIM1/ ORAI1 Loss-of-Function and Gain-of-Function Mutations Inversely Impact on SOCE and Calcium Homeostasis and Cause Multi-Systemic Mirror Diseases. Front Physiol 2020; 11:604941. [PMID: 33250786 PMCID: PMC7672041 DOI: 10.3389/fphys.2020.604941] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/15/2020] [Indexed: 12/19/2022] Open
Abstract
Store-operated Ca2+ entry (SOCE) is a ubiquitous and essential mechanism regulating Ca2+ homeostasis in all tissues, and controls a wide range of cellular functions including keratinocyte differentiation, osteoblastogenesis and osteoclastogenesis, T cell proliferation, platelet activation, and muscle contraction. The main SOCE actors are STIM1 and ORAI1. Depletion of the reticular Ca2+ stores induces oligomerization of the luminal Ca2+ sensor STIM1, and the oligomers activate the plasma membrane Ca2+ channel ORAI1 to trigger extracellular Ca2+ entry. Mutations in STIM1 and ORAI1 result in abnormal SOCE and lead to multi-systemic disorders. Recessive loss-of-function mutations are associated with CRAC (Ca2+ release-activated Ca2+) channelopathy, involving immunodeficiency and autoimmunity, muscular hypotonia, ectodermal dysplasia, and mydriasis. In contrast, dominant STIM1 and ORAI1 gain-of-function mutations give rise to tubular aggregate myopathy and Stormorken syndrome (TAM/STRMK), forming a clinical spectrum encompassing muscle weakness, thrombocytopenia, ichthyosis, hyposplenism, short stature, and miosis. Functional studies on patient-derived cells revealed that CRAC channelopathy mutations impair SOCE and extracellular Ca2+ influx, while TAM/STRMK mutations induce excessive Ca2+ entry through SOCE over-activation. In accordance with the opposite pathomechanisms underlying both disorders, CRAC channelopathy and TAM/STRMK patients show mirror phenotypes at the clinical and molecular levels, and the respective animal models recapitulate the skin, bones, immune system, platelet, and muscle anomalies. Here we review and compare the clinical presentations of CRAC channelopathy and TAM/STRMK patients and the histological and molecular findings obtained on human samples and murine models to highlight the mirror phenotypes in different tissues, and to point out potentially undiagnosed anomalies in patients, which may be relevant for disease management and prospective therapeutic approaches.
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Affiliation(s)
- Roberto Silva-Rojas
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Inserm U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Inserm U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Johann Böhm
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Inserm U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
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15
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Peche GA, Spiegelhalter C, Silva-Rojas R, Laporte J, Böhm J. Functional analyses of STIM1 mutations reveal a common pathomechanism for tubular aggregate myopathy and Stormorken syndrome. Neuropathology 2020; 40:559-569. [PMID: 33073872 DOI: 10.1111/neup.12692] [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: 12/23/2019] [Revised: 05/01/2020] [Accepted: 05/18/2020] [Indexed: 11/30/2022]
Abstract
Tubular aggregate myopathy (TAM) is a progressive disorder characterized by muscle weakness, cramps, and myalgia. TAM clinically overlaps with Stormorken syndrome (STRMK), combining TAM with miosis, thrombocytopenia, hyposplenism, ichthyosis, short stature, and dyslexia. TAM and STRMK arise from gain-of-function mutations in STIM1 (stromal interaction molecule 1) or ORAI1, both encoding key regulators of Ca2+ homeostasis, and mutations in either gene result in excessive extracellular Ca2+ entry. The pathomechanistic similarities and differences between TAM and STRMK are only partially understood. Here we provide functional in vitro experiments demonstrating that STIM1 harboring the TAM D84G or the STRMK R304W mutation similarly cluster and exert a dominant effect on the wild-type protein. Both mutants recruit ORAI1 to the clusters, increase cytosolic Ca2+ levels, promote major nuclear import of the Ca2+ -dependent transcription factor NFAT (nuclear factor of activated T cells), and trigger the formation of circular membrane stacks. In conclusion, the analyzed TAM and STRMK mutations have a comparable impact on STIM1 protein function and downstream effects of excessive Ca2+ entry, highlighting that TAM and STRMK involve a common pathomechanism.
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Affiliation(s)
- Georges Arielle Peche
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.,INSERM U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,University of Strasbourg, Illkirch, France
| | - Coralie Spiegelhalter
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.,INSERM U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,University of Strasbourg, Illkirch, France
| | - Roberto Silva-Rojas
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.,INSERM U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,University of Strasbourg, Illkirch, France
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.,INSERM U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,University of Strasbourg, Illkirch, France
| | - Johann Böhm
- Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch, France.,INSERM U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,University of Strasbourg, Illkirch, France
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16
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Ondruskova N, Cechova A, Hansikova H, Honzik T, Jaeken J. Congenital disorders of glycosylation: Still "hot" in 2020. Biochim Biophys Acta Gen Subj 2020; 1865:129751. [PMID: 32991969 DOI: 10.1016/j.bbagen.2020.129751] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/12/2020] [Accepted: 08/27/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Congenital disorders of glycosylation (CDG) are inherited metabolic diseases caused by defects in the genes important for the process of protein and lipid glycosylation. With the ever growing number of the known subtypes and discoveries regarding the disease mechanisms and therapy development, it remains a very active field of study. SCOPE OF REVIEW This review brings an update on the CDG-related research since 2017, describing the novel gene defects, pathobiomechanisms, biomarkers and the patients' phenotypes. We also summarize the clinical guidelines for the most prevalent disorders and the current therapeutical options for the treatable CDG. MAJOR CONCLUSIONS In the majority of the 23 new CDG, neurological involvement is associated with other organ disease. Increasingly, different aspects of cellular metabolism (e.g., autophagy) are found to be perturbed in multiple CDG. GENERAL SIGNIFICANCE This work highlights the recent trends in the CDG field and comprehensively overviews the up-to-date clinical recommendations.
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Affiliation(s)
- Nina Ondruskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Anna Cechova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Hansikova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Tomas Honzik
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
| | - Jaak Jaeken
- Department of Paediatrics and Centre for Metabolic Diseases, KU Leuven and University Hospital Leuven, Leuven, Belgium.
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17
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Claeys T, Goosens V, Racé V, Theys T, Thal DR, Depuydt CE, Claeys KG. Clinical and muscle MRI features in a family with tubular aggregate myopathy and novel STIM1 mutation. Neuromuscul Disord 2020; 30:709-718. [PMID: 32893083 DOI: 10.1016/j.nmd.2020.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 07/26/2020] [Accepted: 07/27/2020] [Indexed: 11/26/2022]
Abstract
Heterozygous mutations in the stromal interaction molecule-1-gene (STIM1) cause a clinical phenotype varying from tubular aggregate myopathy with single or multiple signs of Stormorken syndrome to the full Stormorken phenotype. We identified a novel heterozygous mutation c.325C > T (p.H109Y) in the EF-hand domain of STIM1 in six patients of a large Belgian family, and performed a detailed clinical (N = 6), histopathological (N = 2) and whole-body muscle MRI (N = 3) study. The clinical phenotype was characterized by a slowly progressive, predominant proximal muscle weakness in all patients (100%), and additional exercise-induced myalgia in three (60%). Patients experienced symptom onset between 10 and 20 years, remained ambulatory into late adulthood, showed elevated serum creatine kinase levels and tubular aggregates in type 1 and type 2 fibers on muscle biopsy. Interestingly, jaw contractures and hyperlaxity, as well as non-muscular multisystemic features such as menorrhagia, easy bruising and ichthyosis occurred in one patient, and miosis in another. Whole-body muscle MRI revealed predominant involvement of superficial neck extensors, subscapularis, obliquus abdominis externus, lumbar extensors, rectus femoris, biceps femoris longus, medial head of gastrocnemius and flexor hallucis longus. Our findings in patients with myopathy with tubular aggregates and a STIM1 mutation further support the concept of a continuous spectrum with Stormorken syndrome.
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Affiliation(s)
- Thomas Claeys
- Department of Neurology, Neuromuscular Reference Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Veerle Goosens
- Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Valérie Racé
- Centre for Human Genetics, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium; Department of Human Genetics, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Tom Theys
- Department of Neurosurgery, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Dietmar R Thal
- Department of Pathology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium; Laboratory for Neuropathology, Department of Imaging and Pathology, and Leuven Brain Institute, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Christophe E Depuydt
- Laboratory for Muscle diseases and Neuropathies, Department of Neurosciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Kristl G Claeys
- Department of Neurology, Neuromuscular Reference Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium; Laboratory for Muscle diseases and Neuropathies, Department of Neurosciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.
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18
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Szelinger S, Krate J, Ramsey K, Strom SP, Shieh PB, Lee H, Belnap N, Balak C, Siniard AL, Russell M, Richholt R, Both MD, Claasen AM, Schrauwen I, Nelson SF, Huentelman MJ, Craig DW, Yang SP, Moore SA, Sivakumar K, Narayanan V, Rangasamy S. Congenital myasthenic syndrome caused by a frameshift insertion mutation in GFPT1. NEUROLOGY-GENETICS 2020; 6:e468. [PMID: 32754643 PMCID: PMC7357421 DOI: 10.1212/nxg.0000000000000468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/26/2020] [Indexed: 12/17/2022]
Abstract
Objective Description of a new variant of the glutamine-fructose-6-phosphate transaminase 1 (GFPT1) gene causing congenital myasthenic syndrome (CMS) in 3 children from 2 unrelated families. Methods Muscle biopsies, EMG, and whole-exome sequencing were performed. Results All 3 patients presented with congenital hypotonia, muscle weakness, respiratory insufficiency, head lag, areflexia, and gastrointestinal dysfunction. Genetic analysis identified a homozygous frameshift insertion in the GFPT1 gene (NM_001244710.1: c.686dupC; p.Arg230Ter) that was shared by all 3 patients. In one of the patients, inheritance of the variant was through uniparental disomy (UPD) with maternal origin. Repetitive nerve stimulation and single-fiber EMG was consistent with the clinical diagnosis of CMS with a postjunctional defect. Ultrastructural evaluation of the muscle biopsy from one of the patients showed extremely attenuated postsynaptic folds at neuromuscular junctions and extensive autophagic vacuolar pathology. Conclusions These results expand on the spectrum of known loss-of-function GFPT1 mutations in CMS12 and in one family demonstrate a novel mode of inheritance due to UPD.
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Affiliation(s)
- Szabolcs Szelinger
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Jonida Krate
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Keri Ramsey
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Samuel P Strom
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Perry B Shieh
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Hane Lee
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Newell Belnap
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Chris Balak
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Ashley L Siniard
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Megan Russell
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Ryan Richholt
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Matt De Both
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Ana M Claasen
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Isabelle Schrauwen
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Stanley F Nelson
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Matthew J Huentelman
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - David W Craig
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Samuel P Yang
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Steven A Moore
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Kumaraswamy Sivakumar
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Vinodh Narayanan
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
| | - Sampathkumar Rangasamy
- theNeurogenomics Division (S.S., J.K., K.R., N.B., C.B., A.L.S., M.R., R.R., M.D.B., A.M.C., M.J.H, V.N., S.R.), Translational Genomics Research Institute, Center for Rare Childhood Disorders, Phoenix, AZ; Fulgent Genetics (S.P.S.), Temple City, CA; Department of Neurology (P.B.S.), University of California Los Angeles; David Geffen School of Medicine (P.B.S.), Los Angeles; Department of Pathology and Laboratory Medicine (H.L., S.F.N.), University of California, Los Angeles; Department of Human Genetics (H.L., S.F.N.), David Geffen School of Medicine; Department of Neurology (I.S.), Columbia University, Center for Statistical Genetics, New York; Department of Translational Genomics (D.W.C.), University of Southern California, Los Angeles; Providence Sacred Heart Medical Center and Children's Hospital (S.P.Y.), Spokane, WA; Department of Pathology (S.A.M), University of Iowa, Carver College of Medicine; and Neuromuscular Clinic and Research Center (K.S.), Phoenix, AZ
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19
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Morin G, Biancalana V, Echaniz-Laguna A, Noury JB, Lornage X, Moggio M, Ripolone M, Violano R, Marcorelles P, Maréchal D, Renaud F, Maurage CA, Tard C, Cuisset JM, Laporte J, Böhm J. Tubular aggregate myopathy and Stormorken syndrome: Mutation spectrum and genotype/phenotype correlation. Hum Mutat 2019; 41:17-37. [PMID: 31448844 DOI: 10.1002/humu.23899] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/29/2019] [Accepted: 08/21/2019] [Indexed: 11/06/2022]
Abstract
Calcium (Ca2+ ) acts as a ubiquitous second messenger, and normal cell and tissue physiology strictly depends on the precise regulation of Ca2+ entry, storage, and release. Store-operated Ca2+ entry (SOCE) is a major mechanism controlling extracellular Ca2+ entry, and mainly relies on the accurate interplay between the Ca2+ sensor STIM1 and the Ca2+ channel ORAI1. Mutations in STIM1 or ORAI1 result in abnormal Ca2+ homeostasis and are associated with severe human disorders. Recessive loss-of-function mutations impair SOCE and cause combined immunodeficiency, while dominant gain-of-function mutations induce excessive extracellular Ca2+ entry and cause tubular aggregate myopathy (TAM) and Stormorken syndrome (STRMK). TAM and STRMK are spectra of the same multisystemic disease characterized by muscle weakness, miosis, thrombocytopenia, hyposplenism, ichthyosis, dyslexia, and short stature. To date, 42 TAM/STRMK families have been described, and here we report five additional families for which we provide clinical, histological, ultrastructural, and genetic data. In this study, we list and review all new and previously reported STIM1 and ORAI1 cases, discuss the pathomechanisms of the mutations based on the known functions and the protein structure of STIM1 and ORAI1, draw a genotype/phenotype correlation, and delineate an efficient screening strategy for the molecular diagnosis of TAM/STRMK.
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Affiliation(s)
- Gilles Morin
- Clinical Genetics, Amiens University Hospital, Amiens, France.,University of Picardy Jules Verne, EA 4666, Amiens, France.,Department of translational medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
| | - Valérie Biancalana
- Department of translational medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Inserm U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France.,Laboratoire Diagnostic Génétique, CHRU, Strasbourg, France
| | - Andoni Echaniz-Laguna
- Department of Neurology, APHP, CHU de Bicêtre, Le Kremlin Bicêtre, France.,French National Reference Center for Rare Neuropathies (NNERF), Le Kremlin Bicêtre, France.,Inserm U1195 & Paris-Sud University, Le Kremlin Bicêtre, France
| | | | - Xavière Lornage
- Department of translational medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Inserm U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France
| | - Maurizio Moggio
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Michela Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Raffaella Violano
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Denis Maréchal
- Department of Neurology, CHRU Cavale Blanche, Brest, France
| | - Florence Renaud
- Department of Pathology, Lille University Hospital, Lille, France
| | | | - Céline Tard
- CHU Lille, Inserm U1171, Service de neurologie, Centre de Référence des Maladies Neuromusculaires Nord Est Ile-de-France, Lille University, Lille, France
| | | | - Jocelyn Laporte
- Department of translational medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Inserm U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France
| | - Johann Böhm
- Department of translational medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Inserm U1258, Illkirch, France.,CNRS UMR7104, Illkirch, France.,Strasbourg University, Illkirch, France
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20
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Luo HY, Zhao L, Mao CY, Yang ZH, Yang J, Wang YL, Niu HX, Liu YT, Shi CH, Xu YM. Novel compound heterozygous GFPT1 mutations in a family with limb-girdle myasthenia with tubular aggregates. Neuromuscul Disord 2019; 29:549-553. [PMID: 31255525 DOI: 10.1016/j.nmd.2019.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/06/2019] [Accepted: 05/22/2019] [Indexed: 02/07/2023]
Abstract
Limb-girdle myasthenia with tubular aggregates, a subtype of congenital myasthenic syndrome, is an extremely rare autosomal recessive genetic disease characterized by prominent limb-girdle weakness and good response to acetylcholinesterase inhibitor therapy. Herein, we reported two novel mutations of GFPT1 gene in a Chinese pedigree. Two siblings presented with fatigue, weakness of limb-girdle and decrement of the muscle action potential with repetitive nerve stimulation. Thus, myasthenia gravis was initially suspected, but anti-AChR antibodies were negative. Two novel missense mutations (p.Lys154Asn and p.Asn363Ser) in GFPT1 were identified through genetic testing conducted on 167 well-established genes associated with muscular diseases by targeted high throughput sequencing. Both mutations have not been recorded in the dsSNP database, Exome Aggregation Consortium database and 1000 Genomes Project database. The mutation sites were co-segregated with the phenotype and conserved between the different species. The mutations were not found in the 200 unrelated normal controls. Muscle biopsies revealed tubular aggregates, in accordance with previous reports with GFPT1 mutations. Subsequently, dramatic improvement in strength occurred following anti-cholinesterase therapy. Our study will be helpful for the diagnosis and treatment for Limb-girdle myasthenia with tubular aggregates.
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Affiliation(s)
- Hai-Yang Luo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China; Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China
| | - Lu Zhao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Cheng-Yuan Mao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Zhi-Hua Yang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Jing Yang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Yan-Lin Wang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Hui-Xia Niu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Yu-Tao Liu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China
| | - Chang-He Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China.
| | - Yu-Ming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, 1 Jian-she East Road, Zhengzhou 450000, Henan, China; Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, Henan, China.
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21
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Matsumoto C, Mori-Yoshimura M, Noguchi S, Endo Y, Oya Y, Murata M, Nishino I, Takahashi Y. Phenotype of a limb-girdle congenital myasthenic syndrome patient carrying a GFPT1 mutation. Brain Dev 2019; 41:470-473. [PMID: 30846217 DOI: 10.1016/j.braindev.2018.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 09/11/2018] [Accepted: 12/17/2018] [Indexed: 11/30/2022]
Abstract
We report a 38-year-old woman who presented with mild proximal dominant muscle weakness and fatigability that fluctuated during menstruation and treatment with ephedrine-containing medication. The patient had been diagnosed with "congenital myopathy with tubular aggregates" by muscle biopsy at age 19. Her revised diagnosis was congenital myasthenic syndrome (CMS) caused by a mutation in GFPT1 (2p13.3 [MIM 610542], c.722_723insG homozygote, CMS-GFPT1) based on a screening gene analysis. Muscle CT revealed diffuse atrophy of proximal and axial muscles focused on the vastus lateralis, hamstrings, medial gastrocnemius and soleus muscles. Oral administration of pyridostigmine bromide clearly ameliorated weakness and fatigability. This is the first reported case of CMS-GFPT1 in Japan. Since CMS symptoms are reactive to treatment, it is important for clinicians to make an accurate diagnosis at an early stage to improve patient QOL. Tubular aggregates in muscle biopsy and day-to-day fluctuations are important features of the disorder. Quantitative muscle strength measurement was effective for evaluating treatment efficacy.
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Affiliation(s)
- Chihiro Matsumoto
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Madoka Mori-Yoshimura
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan.
| | - Satoru Noguchi
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan; Medical Genome Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Yukari Endo
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan; Medical Genome Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Yasushi Oya
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Miho Murata
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan; Medical Genome Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
| | - Yuji Takahashi
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8551, Japan
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22
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Issop Y, Hathazi D, Khan MM, Rudolf R, Weis J, Spendiff S, Slater CR, Roos A, Lochmüller H. GFPT1 deficiency in muscle leads to myasthenia and myopathy in mice. Hum Mol Genet 2019; 27:3218-3232. [PMID: 29905857 PMCID: PMC6121184 DOI: 10.1093/hmg/ddy225] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Glutamine-fructose-6-phosphate transaminase 1 (GFPT1) is the rate-limiting enzyme in the hexosamine biosynthetic pathway which yields precursors required for protein and lipid glycosylation. Mutations in GFPT1 and other genes downstream of this pathway cause congenital myasthenic syndrome (CMS) characterized by fatigable muscle weakness owing to impaired neurotransmission. The precise pathomechanisms at the neuromuscular junction (NMJ) owing to a deficiency in GFPT1 is yet to be discovered. One of the challenges we face is the viability of Gfpt1−/− knockout mice. In this study, we use Cre/LoxP technology to generate a muscle-specific GFPT1 knockout mouse model, Gfpt1tm1d/tm1d, characteristic of the human CMS phenotype. Our data suggest a critical role for muscle derived GFPT1 in the development of the NMJ, neurotransmission, skeletal muscle integrity and highlight that a deficiency in skeletal muscle alone is sufficient to cause morphological postsynaptic NMJ changes that are accompanied by presynaptic alterations despite the conservation of neuronal GFPT1 expression. In addition to the conventional morphological NMJ changes and fatigable muscle weakness, Gfpt1tm1d/tm1d mice display a progressive myopathic phenotype with the presence of tubular aggregates in muscle, characteristic of the GFPT1-CMS phenotype. We further identify an upregulation of skeletal muscle proteins glypican-1, farnesyltransferase/geranylgeranyltransferase type-1 subunit α and muscle-specific kinase, which are known to be involved in the differentiation and maintenance of the NMJ. The Gfpt1tm1d/tm1d model allows for further investigation of pathophysiological consequences on genes and pathways downstream of GFPT1 likely to involve misglycosylation or hypoglycosylation of NMJs and muscle targets.
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Affiliation(s)
- Yasmin Issop
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle, UK
| | - Denisa Hathazi
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V, Dortmund, Germany
| | - Muzamil Majid Khan
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Rüdiger Rudolf
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.,Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany.,Institute of Molecular and Cell Biology, Mannheim University of Applied Sciences, Mannheim, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Sally Spendiff
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle, UK
| | - Clarke R Slater
- Institute of Neuroscience, Newcastle University, Newcastle, UK
| | - Andreas Roos
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle, UK.,Leibniz-Institut für Analytische Wissenschaften-ISAS e.V, Dortmund, Germany
| | - Hanns Lochmüller
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle, UK.,Department of Neuropediatrics and Muscle Disorders,Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany.,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
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23
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Abstract
OBJECTIVES Congenital myasthenic syndromes (CMSs) are a genotypically and phenotypically heterogeneous group of neuromuscular disorders, which have in common an impaired neuromuscular transmission. Since the field of CMSs is steadily expanding, the present review aimed at summarizing and discussing current knowledge and recent advances concerning the etiology, clinical presentation, diagnosis, and treatment of CMSs. METHODS Systematic literature review. RESULTS Currently, mutations in 32 genes are made responsible for autosomal dominant or autosomal recessive CMSs. These mutations concern 8 presynaptic, 4 synaptic, 15 post-synaptic, and 5 glycosilation proteins. These proteins function as ion-channels, enzymes, or structural, signalling, sensor, or transporter proteins. The most common causative genes are CHAT, COLQ, RAPSN, CHRNE, DOK7, and GFPT1. Phenotypically, these mutations manifest as abnormal fatigability or permanent or fluctuating weakness of extra-ocular, facial, bulbar, axial, respiratory, or limb muscles, hypotonia, or developmental delay. Cognitive disability, dysmorphism, neuropathy, or epilepsy are rare. Low- or high-frequency repetitive nerve stimulation may show an abnormal increment or decrement, and SF-EMG an increased jitter or blockings. Most CMSs respond favourably to acetylcholine-esterase inhibitors, 3,4-diamino-pyridine, salbutamol, albuterol, ephedrine, fluoxetine, or atracurium. CONCLUSIONS CMSs are an increasingly recognised group of genetically transmitted defects, which usually respond favorably to drugs enhancing the neuromuscular transmission. CMSs need to be differentiated from neuromuscular disorders due to muscle or nerve dysfunction.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Veterinary University of Vienna, Postfach 20, 1180, Vienna, Austria.
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24
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Helman G, Sharma S, Crawford J, Patra B, Jain P, Bent SJ, Urtizberea JA, Saran RK, Taft RJ, van der Knaap MS, Simons C. Leukoencephalopathy due to variants in GFPT1-associated congenital myasthenic syndrome. Neurology 2019; 92:e587-e593. [PMID: 30635494 DOI: 10.1212/wnl.0000000000006886] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 12/06/2018] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE To determine the molecular etiology of disease in 4 individuals from 2 unrelated families who presented with proximal muscle weakness and features suggestive of mitochondrial disease. METHODS Clinical information and neuroimaging were reviewed. Genome sequencing was performed on affected individuals and biological parents. RESULTS All affected individuals presented with muscle weakness and difficulty walking. In one family, both children had neonatal respiratory distress while the other family had 2 children with episodic deteriorations. In each family, muscle biopsy demonstrated ragged red fibers. MRI was suggestive of a mitochondrial leukoencephalopathy, with extensive deep cerebral white matter T2 hyperintense signal and selective involvement of the middle blade of the corpus callosum. Through genome sequencing, homozygous GFPT1 missense variants were identified in the affected individuals of each family. The variants detected (p.Arg14Leu and p.Thr151Lys) are absent from population databases and predicted to be damaging by in silico prediction tools. Following the genetic diagnosis, nerve conduction studies were performed and demonstrated a decremental response to repetitive nerve stimulation, confirming the diagnosis of myasthenia. Treatment with pyridostigmine was started in one family with favorable response. CONCLUSIONS GFPT1 encodes a widely expressed protein that controls the flux of glucose into the hexosamine-biosynthesis pathway that produces precursors for glycosylation of proteins. GFPT1 variants and defects in other enzymes of this pathway have previously been associated with congenital myasthenia. These findings identify leukoencephalopathy as a previously unrecognized phenotype in GFPT1-related disease and suggest that mitochondrial dysfunction could contribute to this disorder.
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Affiliation(s)
- Guy Helman
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Suvasini Sharma
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Joanna Crawford
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Bijoy Patra
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Puneet Jain
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Stephen J Bent
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - J Andoni Urtizberea
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Ravindra K Saran
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Ryan J Taft
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands.
| | - Cas Simons
- From the Murdoch Children's Research Institute (G.H., C.S.), Parkville, Melbourne; Institute for Molecular Bioscience (G.H., J.C., C.S.), the University of Queensland, Brisbane, Australia; Neurology Division (S.S., B.P., P.J.), Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India; Division of Neurology (P.J.), Department of Pediatrics, the Hospital for Sick Children, Toronto, Canada; Data61 (S.J.B.), Commonwealth Scientific and Industrial Research Organisation, Brisbane, Australia; Hôpital Marin (J.A.U.), Centre Neuromusculaire, Filnemus, Hendaye, France; Department of Pathology (R.K.S.), G.B. Pant Hospital, New Delhi, India; Illumina, Inc. (R.J.T.), San Diego, CA; Department of Child Neurology (M.S.v.d.K.), Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience; and Department of Functional Genomics (M.S.v.d.K.), Neuroscience Campus Amsterdam, the Netherlands.
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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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Yoshimura K, Morihata H, Takeda K, Sakoda S, Yuan JH, Nakano S. [A case of hyperkalemic periodic paralysis presenting progressive myopathy with tubular aggregates]. Rinsho Shinkeigaku 2018; 58:663-667. [PMID: 30369522 DOI: 10.5692/clinicalneurol.cn-001137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A 33-year-old man admitted to our hospital for the evaluation of progressive muscular atrophy of his left lower leg. From his childhood, he had suffered from transient attacks of limb paralysis and myalgia lasting about 1 hour. At age 30, the muscle weakness and atrophy of his left lower leg emerged and progressed gradually. Muscle MR images showed atrophy and fat replacement in left lower leg, and muscle biopsy revealed tubular aggregates (TA). Genetic analysis showed heterozygous c.2111C>T/p.T704M missense mutation of SCN4A gene, which causes hyperkalemic periodic paralysis (HyperPP). Although HyperPP is rare, it is quite critical for clinicians to recognize that the patients of HyperPP often present progressive myopathy. We emphasize the importance of paying attention to progressive myopathy and discuss the pathological mechanism of myopathy through this case report.
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Affiliation(s)
- Kenji Yoshimura
- Department of Neurology, Osaka City General Hospital
- Present address: Department of Neurology, Graduate School of Medicine, Kyoto University
| | | | | | - Shunichi Sakoda
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
| | - Jun-Hui Yuan
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences
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27
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Abstract
OBJECTIVES To investigate the mutational spectrum and genotype-phenotype correlation in Indian patients with congenital myasthenic syndrome (CMS), using next-generation sequencing of 5 genes. METHODS CHRNE, COLQ, DOK7, RAPSN, and GFPT1 were sequenced in 25 affected patients. RESULTS We found clinically significant variants in 18 patients, of which variants in CHRNE were the most common, and 9 were novel. A common pathogenic COLQ variant was also detected in 4 patients with isolated limb-girdle congenital myasthenia. CONCLUSIONS Targeted screening of 5 genes is an effective alternate test for CMS, and an affordable one even in a developing country such as India. In addition, we recommend that patients with isolated limb-girdle congenital myasthenia be screened initially for the common COLQ pathogenic variant. This study throws the first light on the genetic landscape of CMSs in India.
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28
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[Congenital myasthenic syndromes in adulthood : Challenging, rare but treatable]. DER NERVENARZT 2018; 90:148-159. [PMID: 29974128 DOI: 10.1007/s00115-018-0562-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The congenital myasthenic syndromes (CMS) represent a heterogeneous group of diseases with a broad spectrum of phenotypes. The common characteristic is an inherited genetic defect of the neuromuscular junction. Although in some patients the specific gene defect remains to be detected, the increasing identification of causative genes in recent years has already provided unique insights into the functionality of structural proteins at the neuromuscular junction. Neonatal and early childhood onset is observed in most CMS subtypes; however, late onset in adolescence or adulthood also occurs and establishing the diagnosis at these stages imposes particular challenges. To enable appropriate therapeutic interventions for an at least in principle treatable condition, determining the genetic cause is warranted. In this overview, the critical clinical and diagnostic features of the different CMS subtypes are presented and illustrated using typical cases. Furthermore, specific diagnostic clues are outlined. Finally, the overlap between CMS and muscular dystrophies is discussed. Illustrating characteristic patient examples, the essential clinical and additional diagnostic findings of various CMS subtypes and special diagnostic indications are presented.
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29
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Rodríguez Cruz PM, Palace J, Beeson D. The Neuromuscular Junction and Wide Heterogeneity of Congenital Myasthenic Syndromes. Int J Mol Sci 2018; 19:ijms19061677. [PMID: 29874875 PMCID: PMC6032286 DOI: 10.3390/ijms19061677] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/17/2018] [Accepted: 05/21/2018] [Indexed: 01/16/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are genetic disorders characterised by impaired neuromuscular transmission. This review provides an overview on CMS and highlights recent advances in the field, including novel CMS causative genes and improved therapeutic strategies. CMS due to mutations in SLC5A7 and SLC18A3, impairing the synthesis and recycling of acetylcholine, have recently been described. In addition, a novel group of CMS due to mutations in SNAP25B, SYT2, VAMP1, and UNC13A1 encoding molecules implicated in synaptic vesicles exocytosis has been characterised. The increasing number of presynaptic CMS exhibiting CNS manifestations along with neuromuscular weakness demonstrate that the myasthenia can be only a small part of a much more extensive disease phenotype. Moreover, the spectrum of glycosylation abnormalities has been increased with the report that GMPPB mutations can cause CMS, thus bridging myasthenic disorders with dystroglycanopathies. Finally, the discovery of COL13A1 mutations and laminin α5 deficiency has helped to draw attention to the role of extracellular matrix proteins for the formation and maintenance of muscle endplates. The benefit of β2-adrenergic agonists alone or combined with pyridostigmine or 3,4-Dyaminopiridine is increasingly being reported for different subtypes of CMS including AChR-deficiency and glycosylation abnormalities, thus expanding the therapeutic repertoire available.
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Affiliation(s)
- Pedro M Rodríguez Cruz
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford OX3 9DS, UK.
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
| | - David Beeson
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
- Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford OX3 9DS, UK.
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30
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Witherick J, Brady S. Update on muscle disease. J Neurol 2018; 265:1717-1725. [DOI: 10.1007/s00415-018-8856-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/30/2018] [Indexed: 12/24/2022]
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Sewry CA, Wallgren-Pettersson C. Myopathology in congenital myopathies. Neuropathol Appl Neurobiol 2018; 43:5-23. [PMID: 27976420 DOI: 10.1111/nan.12369] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 12/03/2016] [Indexed: 12/18/2022]
Abstract
Congenital myopathies are clinically and genetically a heterogeneous group of early onset neuromuscular disorders, characterized by hypotonia and muscle weakness. Clinical severity and age of onset are variable. Many patients are severely affected at birth while others have a milder, moderately progressive or nonprogressive phenotype. Respiratory weakness is a major clinical aspect that requires regular monitoring. Causative mutations in several genes have been identified that are inherited in a dominant, recessive or X-linked manner, or arise de novo. Muscle biopsies show characteristic pathological features such as nemaline rods/bodies, cores, central nuclei or caps. Small type 1 fibres expressing slow myosin are a common feature and may sometimes be the only abnormality. Small cores (minicores) devoid of mitochondria and areas showing variable myofibrillar disruption occur in several neuromuscular disorders including several forms of congenital myopathy. Muscle biopsies can also show more than one structural defect. There is considerable clinical, pathological and genetic overlap with mutations in one gene resulting in more than one pathological feature, and the same pathological feature being associated with defects in more than one gene. Increasing application of whole exome sequencing is broadening the clinical and pathological spectra in congenital myopathies, but pathology still has a role in clarifying the pathogenicity of gene variants as well as directing molecular analysis.
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Affiliation(s)
- C A Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, UK.,Wolfson Centre for Inherited Neuromuscular Diseases, RJAH Orthopaedic Hospital, Oswestry, UK
| | - C Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
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Durmus H, Shen XM, Serdaroglu-Oflazer P, Kara B, Parman-Gulsen Y, Ozdemir C, Brengman J, Deymeer F, Engel AG. Congenital myasthenic syndromes in Turkey: Clinical clues and prognosis with long term follow-up. Neuromuscul Disord 2018; 28:315-322. [PMID: 29395675 PMCID: PMC5924610 DOI: 10.1016/j.nmd.2017.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 11/07/2017] [Accepted: 11/20/2017] [Indexed: 11/28/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a group of hereditary disorders affecting the neuromuscular junction. Here, we present clinical, electrophysiological and genetic findings of 69 patients from 51 unrelated kinships from Turkey. Genetic tests of 60 patients were performed at Mayo Clinic. Median follow-up time was 9.8 years (range 1-22 years). The most common CMS was primary acetylcholine receptor (AChR) deficiency (31/51) and the most common mutations in AChR were c.1219 + 2T > G (12/51) and c.1327delG (6/51) in CHRNE. Four of our 5 kinships with AChE deficiency carried p.W148X that truncates the collagen domain of COLQ, and was previously reported only in patients from Turkey. These were followed by GFPT1 deficiency (4/51), DOK7 deficiency (3/51), slow channel CMS (3/51), fast channel CMS (3/51), choline acetyltransferase deficiency (1/51) and a CMS associated with desmin deficiency (1/51). Distribution of muscle weakness was sometimes useful in giving a clue to the CMS subtype. Presence of repetitive compound muscle action potentials pointed to AChE deficiency or slow channel CMS. Our experience confirms that one needs to be cautious using pyridostigmine, since it can worsen some types of CMS. Ephedrine/salbutamol were very effective in AChE and DOK7 deficiencies and were useful as adjuncts in other types of CMS. Long follow-up gave us a chance to assess progression of the disease, and to witness 12 mainly uneventful pregnancies in 8 patients. In this study, we describe some new phenotypes and detail the clinical features of the well-known CMS.
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Affiliation(s)
- Hacer Durmus
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Xin-Ming Shen
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Piraye Serdaroglu-Oflazer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Bulent Kara
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Yesim Parman-Gulsen
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Coskun Ozdemir
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey
| | - Joan Brengman
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Feza Deymeer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Capa, 34390, Istanbul, Turkey.
| | - Andrew G Engel
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
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Lee M, Beeson D, Palace J. Therapeutic strategies for congenital myasthenic syndromes. Ann N Y Acad Sci 2018; 1412:129-136. [DOI: 10.1111/nyas.13538] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Manon Lee
- Nuffield Department of Clinical Neurosciences; John Radcliffe Hospital; Oxford United Kingdom
| | - David Beeson
- The Weatherall Institute of Molecular Medicine, John Radcliffe Hospital; University of Oxford; Oxford United Kingdom
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences; John Radcliffe Hospital; Oxford United Kingdom
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Beeson D, Cossins J, Rodriguez-Cruz P, Maxwell S, Liu WW, Palace J. Myasthenic syndromes due to defects in COL13A1 and in the N-linked glycosylation pathway. Ann N Y Acad Sci 2018; 1413:163-169. [DOI: 10.1111/nyas.13576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 12/11/2022]
Affiliation(s)
- David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neuroscience; Weatherall Institute of Molecular Medicine; The John Radcliffe Oxford UK
| | - Judith Cossins
- Neurosciences Group, Nuffield Department of Clinical Neuroscience; Weatherall Institute of Molecular Medicine; The John Radcliffe Oxford UK
| | - Pedro Rodriguez-Cruz
- Neurosciences Group, Nuffield Department of Clinical Neuroscience; Weatherall Institute of Molecular Medicine; The John Radcliffe Oxford UK
| | - Susan Maxwell
- Neurosciences Group, Nuffield Department of Clinical Neuroscience; Weatherall Institute of Molecular Medicine; The John Radcliffe Oxford UK
| | - Wei-Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neuroscience; Weatherall Institute of Molecular Medicine; The John Radcliffe Oxford UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neuroscience; Level 3 The West Wing; The John Radcliffe Oxford UK
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35
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Natera-de Benito D, Töpf A, Vilchez JJ, González-Quereda L, Domínguez-Carral J, Díaz-Manera J, Ortez C, Bestué M, Gallano P, Dusl M, Abicht A, Müller JS, Senderek J, García-Ribes A, Muelas N, Evangelista T, Azuma Y, McMacken G, Paipa Merchan A, Rodríguez Cruz PM, Camacho A, Jiménez E, Miranda-Herrero MC, Santana-Artiles A, García-Campos O, Dominguez-Rubio R, Olivé M, Colomer J, Beeson D, Lochmüller H, Nascimento A. Molecular characterization of congenital myasthenic syndromes in Spain. Neuromuscul Disord 2017; 27:1087-1098. [PMID: 29054425 DOI: 10.1016/j.nmd.2017.08.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
Congenital myasthenic syndromes (CMS) are a heterogeneous group of genetic disorders, all of which impair neuromuscular transmission. Epidemiological data and frequencies of gene mutations are scarce in the literature. Here we describe the molecular genetic and clinical findings of sixty-four genetically confirmed CMS patients from Spain. Thirty-six mutations in the CHRNE, RAPSN, COLQ, GFPT1, DOK7, CHRNG, GMPPB, CHAT, CHRNA1, and CHRNB1 genes were identified in our patients, with five of them not reported so far. These data provide an overview on the relative frequencies of the different CMS subtypes in a large Spanish population. CHRNE mutations are the most common cause of CMS in Spain, accounting for 27% of the total. The second most common are RAPSN mutations. We found a higher rate of GFPT1 mutations in comparison with other populations. Remarkably, several founder mutations made a large contribution to CMS in Spain: RAPSN c.264C > A (p.Asn88Lys), CHRNE c.130insG (Glu44Glyfs*3), CHRNE c.1353insG (p.Asn542Gluf*4), DOK7 c.1124_1127dup (p.Ala378Serfs*30), and particularly frequent in Spain in comparison with other populations, COLQ c.1289A > C (p.Tyr430Ser). Furthermore, we describe phenotypes and distinguishing clinical signs associated with the various CMS genes which might help to identify specific CMS subtypes to guide diagnosis and management.
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Affiliation(s)
- D Natera-de Benito
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain.
| | - A Töpf
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - J J Vilchez
- Department of Neurology, Hospital Universitari La Fe, Universitat de Valencia, CIBERER U763, Valencia, Spain
| | - L González-Quereda
- Department of Genetics, Hospital de la Santa Creu i Sant Pau and CIBERER U705, Barcelona, Spain
| | - J Domínguez-Carral
- Department of Pediatrics, Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - J Díaz-Manera
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona and Centre for Biomedical Network Research on Rare Diseases (CIBERER), Barcelona, Spain
| | - C Ortez
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
| | - M Bestué
- Department of Neurology, Hospital General San Jorge, Huesca, Spain
| | - P Gallano
- Department of Genetics, Hospital de la Santa Creu i Sant Pau and CIBERER U705, Barcelona, Spain
| | - M Dusl
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
| | - A Abicht
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany; Medical Genetics Center, Munich, Germany
| | - J S Müller
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - J Senderek
- Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
| | - A García-Ribes
- Department of Pediatrics, Hospital Universitario Cruces, Bilbao, Spain
| | - N Muelas
- Department of Neurology, Hospital Universitari La Fe, Universitat de Valencia, CIBERER U763, Valencia, Spain
| | - T Evangelista
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - Y Azuma
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - G McMacken
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - A Paipa Merchan
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - P M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - A Camacho
- Department of Pediatric Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - E Jiménez
- Department of Pediatrics, Hospital Universitario Rey Juan Carlos, Madrid, Spain
| | - M C Miranda-Herrero
- Department of Neuropediatrics, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - A Santana-Artiles
- Department of Neuropediatrics, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - O García-Campos
- Department of Neuropediatrics, Hospital Virgen de la Salud, Toledo, Spain
| | - R Dominguez-Rubio
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - M Olivé
- Neuropathology Unit, Department of Pathology and Neuromuscular Unit, IDIBELL-Hospital Universitari de Bellvitge, Barcelona, Spain
| | - J Colomer
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
| | - D Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford OX3 9DS, UK
| | - H Lochmüller
- John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, UK
| | - A Nascimento
- Department of Neuromuscular Diseases, Hospital Sant Joan de Déu, CIBERER U703, Barcelona, Spain
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36
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Mutations in GFPT1-related congenital myasthenic syndromes are associated with synaptic morphological defects and underlie a tubular aggregate myopathy with synaptopathy. J Neurol 2017; 264:1791-1803. [DOI: 10.1007/s00415-017-8569-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/03/2017] [Accepted: 07/11/2017] [Indexed: 12/22/2022]
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37
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Yiş U, Becker K, Kurul SH, Uyanik G, Bayram E, Haliloğlu G, Polat Aİ, Ayanoğlu M, Okur D, Tosun AF, Serdaroğlu G, Yilmaz S, Topaloğlu H, Anlar B, Cirak S, Engel AG. Genetic Landscape of Congenital Myasthenic Syndromes From Turkey: Novel Mutations and Clinical Insights. J Child Neurol 2017; 32:759-765. [PMID: 28464723 PMCID: PMC5655993 DOI: 10.1177/0883073817705252] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Congenital myasthenic syndromes are clinically and genetically heterogeneous disorders of neuromuscular transmission. Most are treatable, but certain subtypes worsen with cholinesterase inhibitors. This underlines the importance of genetic diagnosis. Here, the authors report on cases with genetically proven congenital myasthenic syndromes from Turkey. The authors retrospectively reviewed their experience of all patients with congenital myasthenic syndromes, referred over a 5-year period (2011-2016) to the Child Neurology Department of Dokuz Eylül University, Izmir, Turkey. In addition, PubMed was searched for published cases of genetically proven congenital myasthenic syndromes originating from Turkey. In total, the authors identified 43 (8 new patients, 35 recently published patients) cases. Defects in the acetylcholine receptor (n = 15; 35%) were the most common type, followed by synaptic basal-lamina associated (n = 14; 33%) and presynaptic syndromes (n = 10; 23%). The authors had only 3 cases (7%) who had defects in endplate development. One patient had mutation GFPT1 gene (n = 1; 2%). Knowledge on congenital myasthenic syndromes and related genes in Turkey will lead to prompt diagnosis and treatment of these rare neuromuscular disorders.
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Affiliation(s)
- Uluç Yiş
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Kerstin Becker
- Cologne University, Department of Pediatrics, Center for Molecular Medicine Cologne, Cologne, GERMANY
| | - Semra Hız Kurul
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Gökhan Uyanik
- Center for Medical Genetics, Hanusch Hospital, Vienna, AUSTRIA
- Medical Faculty, Sigmund Freud University, Vienna, AUSTRIA
| | - Erhan Bayram
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Göknur Haliloğlu
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Ayşe İpek Polat
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Müge Ayanoğlu
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Derya Okur
- Dokuz Eylül University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Ayşe Fahriye Tosun
- Adnan Menderes University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Aydın, TURKEY
| | - Gül Serdaroğlu
- Ege University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Sanem Yilmaz
- Ege University, School of Medicine, Department of Pediatrics, Division of Child Neurology, İzmir, TURKEY
| | - Haluk Topaloğlu
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Banu Anlar
- Hacettepe University, School of Medicine, Department of Pediatrics, Division of Child Neurology, Ankara, TURKEY
| | - Sebahattin Cirak
- Cologne University, Department of Pediatrics, Center for Molecular Medicine Cologne, Cologne, GERMANY
| | - Andrew G. Engel
- Mayo Clinic, Rochester, Department of Neurology, MN 55905, USA
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Brady S, Healy EG, Gang Q, Parton M, Quinlivan R, Jacob S, Curtis E, Al-Sarraj S, Sewry CA, Hanna MG, Houlden H, Beeson D, Holton JL. Tubular Aggregates and Cylindrical Spirals Have Distinct Immunohistochemical Signatures. J Neuropathol Exp Neurol 2016; 75:1171-1178. [DOI: 10.1093/jnen/nlw096] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Rodríguez Cruz PM, Belaya K, Basiri K, Sedghi M, Farrugia ME, Holton JL, Liu WW, Maxwell S, Petty R, Walls TJ, Kennett R, Pitt M, Sarkozy A, Parton M, Lochmüller H, Muntoni F, Palace J, Beeson D. Clinical features of the myasthenic syndrome arising from mutations in GMPPB. J Neurol Neurosurg Psychiatry 2016; 87:802-9. [PMID: 27147698 PMCID: PMC6047737 DOI: 10.1136/jnnp-2016-313163] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/31/2016] [Indexed: 11/04/2022]
Abstract
BACKGROUND Congenital myasthenic syndrome (CMS) due to mutations in GMPPB has recently been reported confirming the importance of glycosylation for the integrity of neuromuscular transmission. METHODS Review of case notes of patients with mutations in GMPPB to identify the associated clinical, neurophysiological, pathological and laboratory features. In addition, serum creatine kinase (CK) levels within the Oxford CMS cohort were retrospectively analysed to assess its usefulness in the differential diagnosis of this new entity. RESULTS All patients had prominent limb-girdle weakness with minimal or absent craniobulbar manifestations. Presentation was delayed beyond infancy with proximal muscle weakness and most patients recall poor performance in sports during childhood. Neurophysiology showed abnormal neuromuscular transmission only in the affected muscles and myopathic changes. Muscle biopsy showed dystrophic features and reduced α-dystroglycan glycosylation. In addition, myopathic changes were present on muscle MRI. CK was significantly increased in serum compared to other CMS subtypes. Patients were responsive to pyridostigimine alone or combined with 3,4-diaminopyridine and/or salbutamol. CONCLUSIONS Patients with GMPPB-CMS have phenotypic features aligned with CMS subtypes harbouring mutations within the early stages of the glycosylation pathway. Additional features shared with the dystroglycanopathies include myopathic features, raised CK levels and variable mild cognitive delay. This syndrome underlines that CMS can occur in the absence of classic myasthenic manifestations such as ptosis and ophthalmoplegia or facial weakness, and links myasthenic disorders with dystroglycanopathies. This report should facilitate the recognition of this disorder, which is likely to be underdiagnosed and can benefit from symptomatic treatment.
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Affiliation(s)
- Pedro M Rodríguez Cruz
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Katsiaryna Belaya
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Keivan Basiri
- Neurology Department, Neuroscience Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maryam Sedghi
- Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Maria Elena Farrugia
- Department of Neurology, Institute of Neurological Sciences, The Queen Elizabeth University Hospital, Glasgow, UK
| | - Janice L Holton
- Department of Molecular Neurosciences, UCL Institute of Neurology, London, UK MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Wei Wei Liu
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Susan Maxwell
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Richard Petty
- Department of Neurology, Institute of Neurological Sciences, The Queen Elizabeth University Hospital, Glasgow, UK
| | - Timothy J Walls
- Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Robin Kennett
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Matthew Pitt
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Anna Sarkozy
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Matt Parton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Hanns Lochmüller
- Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre & MRC Centre for Neuromuscular Diseases, UCL Institute of Child Health, London, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - David Beeson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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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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Willems AP, van Engelen BGM, Lefeber DJ. Genetic defects in the hexosamine and sialic acid biosynthesis pathway. Biochim Biophys Acta Gen Subj 2015; 1860:1640-54. [PMID: 26721333 DOI: 10.1016/j.bbagen.2015.12.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/18/2015] [Accepted: 12/19/2015] [Indexed: 01/10/2023]
Abstract
BACKGROUND Congenital disorders of glycosylation are caused by defects in the glycosylation of proteins and lipids. Classically, gene defects with multisystem disease have been identified in the ubiquitously expressed glycosyltransferases required for protein N-glycosylation. An increasing number of defects are being described in sugar supply pathways for protein glycosylation with tissue-restricted clinical symptoms. SCOPE OF REVIEW In this review, we address the hexosamine and sialic acid biosynthesis pathways in sugar metabolism. GFPT1, PGM3 and GNE are essential for synthesis of nucleotide sugars uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) and cytidine-5'-monophospho-N-acetylneuraminic acid (CMP-sialic acid) as precursors for various glycosylation pathways. Defects in these enzymes result in contrasting clinical phenotypes of congenital myasthenia, immunodeficiency or adult-onset myopathy, respectively. We therefore discuss the biochemical mechanisms of known genetic defects in the hexosamine and CMP-sialic acid synthesis pathway in relation to the clinical phenotypes. MAJOR CONCLUSIONS Both UDP-GlcNAc and CMP-sialic acid are important precursors for diverse protein glycosylation reactions and for conversion into other nucleotide-sugars. Defects in the synthesis of these nucleotide sugars might affect a wide range of protein glycosylation reactions. Involvement of multiple glycosylation pathways might contribute to disease phenotype, but the currently available biochemical information on sugar metabolism is insufficient to understand why defects in these pathways present with tissue-specific phenotypes. GENERAL SIGNIFICANCE Future research on the interplay between sugar metabolism and different glycosylation pathways in a tissue- and cell-specific manner will contribute to elucidation of disease mechanisms and will create new opportunities for therapeutic intervention. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.
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Affiliation(s)
- Anke P Willems
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Centre, Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboudumc Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Baziel G M van Engelen
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Centre, Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Dirk J Lefeber
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Centre, Box 9101, 6500 HB Nijmegen, The Netherlands; Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboudumc Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands.
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Wedatilake Y, Plagnol V, Anderson G, Paine SML, Clayton PT, Jacques TS, Rahman S. Tubular aggregates caused by serine active site containing 1 (SERAC1) mutations in a patient with a mitochondrial encephalopathy. Neuropathol Appl Neurobiol 2015; 41:399-402. [PMID: 25345337 PMCID: PMC4964926 DOI: 10.1111/nan.12190] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 10/21/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Yehani Wedatilake
- Genetics and Genomic Medicine, UCL Institute of Child Health, London, UK
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43
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Global N-linked Glycosylation is Not Significantly Impaired in Myoblasts in Congenital Myasthenic Syndromes Caused by Defective Glutamine-Fructose-6-Phosphate Transaminase 1 (GFPT1). Biomolecules 2015; 5:2758-81. [PMID: 26501342 PMCID: PMC4693256 DOI: 10.3390/biom5042758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/28/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022] Open
Abstract
Glutamine-fructose-6-phosphate transaminase 1 (GFPT1) is the first enzyme of the hexosamine biosynthetic pathway. It transfers an amino group from glutamine to fructose-6-phosphate to yield glucosamine-6-phosphate, thus providing the precursor for uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) synthesis. UDP-GlcNAc is an essential substrate for all mammalian glycosylation biosynthetic pathways and N-glycan branching is especially sensitive to alterations in the concentration of this sugar nucleotide. It has been reported that GFPT1 mutations lead to a distinct sub-class of congenital myasthenic syndromes (CMS) termed “limb-girdle CMS with tubular aggregates”. CMS are hereditary neuromuscular transmission disorders in which neuromuscular junctions are impaired. To investigate whether alterations in protein glycosylation at the neuromuscular junction might be involved in this impairment, we have employed mass spectrometric strategies to study the N-glycomes of myoblasts and myotubes derived from two healthy controls, three GFPT1 patients, and four patients with other muscular diseases, namely CMS caused by mutations in DOK7, myopathy caused by mutations in MTND5, limb girdle muscular dystrophy type 2A (LGMD2A), and Pompe disease. A comparison of the relative abundances of bi-, tri-, and tetra-antennary N-glycans in each of the cell preparations revealed that all samples exhibited broadly similar levels of branching. Moreover, although some differences were observed in the relative abundances of some of the N-glycan constituents, these variations were modest and were not confined to the GFPT1 samples. Therefore, GFPT1 mutations in CMS patients do not appear to compromise global N-glycosylation in muscle cells.
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Belaya K, Rodríguez Cruz PM, Liu WW, Maxwell S, McGowan S, Farrugia ME, Petty R, Walls TJ, Sedghi M, Basiri K, Yue WW, Sarkozy A, Bertoli M, Pitt M, Kennett R, Schaefer A, Bushby K, Parton M, Lochmüller H, Palace J, Muntoni F, Beeson D. Mutations in GMPPB cause congenital myasthenic syndrome and bridge myasthenic disorders with dystroglycanopathies. Brain 2015; 138:2493-504. [PMID: 26133662 PMCID: PMC4547052 DOI: 10.1093/brain/awv185] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 05/04/2015] [Indexed: 01/10/2023] Open
Abstract
Congenital myasthenic syndromes are associated with impairments in neuromuscular transmission. Belaya et al. show that mutations of the glycosylation pathway enzyme GMPPB, which has previously been implicated in muscular dystrophy dystroglycanopathy, also cause a congenital myasthenic syndrome. This differential diagnosis is important to ensure that affected individuals receive appropriate medication. Congenital myasthenic syndromes are inherited disorders that arise from impaired signal transmission at the neuromuscular junction. Mutations in at least 20 genes are known to lead to the onset of these conditions. Four of these, ALG2, ALG14, DPAGT1 and GFPT1, are involved in glycosylation. Here we identify a fifth glycosylation gene, GMPPB, where mutations cause congenital myasthenic syndrome. First, we identified recessive mutations in seven cases from five kinships defined as congenital myasthenic syndrome using decrement of compound muscle action potentials on repetitive nerve stimulation on electromyography. The mutations were present through the length of the GMPPB, and segregation, in silico analysis, exon trapping, cell transfection followed by western blots and immunostaining were used to determine pathogenicity. GMPPB congenital myasthenic syndrome cases show clinical features characteristic of congenital myasthenic syndrome subtypes that are due to defective glycosylation, with variable weakness of proximal limb muscle groups while facial and eye muscles are largely spared. However, patients with GMPPB congenital myasthenic syndrome had more prominent myopathic features that were detectable on muscle biopsies, electromyography, muscle magnetic resonance imaging, and through elevated serum creatine kinase levels. Mutations in GMPPB have recently been reported to lead to the onset of muscular dystrophy dystroglycanopathy. Analysis of four additional GMPPB-associated muscular dystrophy dystroglycanopathy cases by electromyography found that a defective neuromuscular junction component is not always present. Thus, we find mutations in GMPPB can lead to a wide spectrum of clinical features where deficit in neuromuscular transmission is the major component in a subset of cases. Clinical recognition of GMPPB-associated congenital myasthenic syndrome may be complicated by the presence of myopathic features, but correct diagnosis is important because affected individuals can respond to appropriate treatments.
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Affiliation(s)
- Katsiaryna Belaya
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Pedro M Rodríguez Cruz
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Wei Wei Liu
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Susan Maxwell
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Simon McGowan
- 3 Computational Biology Research Group, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Maria E Farrugia
- 4 Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - Richard Petty
- 4 Department of Neurology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK
| | - Timothy J Walls
- 5 Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - Maryam Sedghi
- 6 Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Keivan Basiri
- 7 Neurology Department, Neuroscience Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Wyatt W Yue
- 8 Structural Genomics Consortium, University of Oxford, Oxford, OX3 7DQ, UK
| | - Anna Sarkozy
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK 10 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Marta Bertoli
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Matthew Pitt
- 11 Department of Clinical Neurophysiology, Great Ormond Street Hospital for children NHS foundation trust, London WC1N 3JH
| | - Robin Kennett
- 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Andrew Schaefer
- 5 Department of Neurology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK
| | - Kate Bushby
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Matt Parton
- 10 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Hanns Lochmüller
- 9 Institute of Genetic Medicine, John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases, Newcastle University, Newcastle upon Tyne, NE1 3BZ, UK
| | - Jacqueline Palace
- 2 Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Francesco Muntoni
- 12 Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, UCL Institute of Child Health, London, WC1N 1EH, UK
| | - David Beeson
- 1 Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
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Inherited disorders of the neuromuscular junction: an update. J Neurol 2014; 261:2234-43. [PMID: 25305004 DOI: 10.1007/s00415-014-7520-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 09/23/2014] [Indexed: 10/24/2022]
Abstract
Congenital myasthenic syndromes (CMSs) are a group of heterogeneous inherited disorders caused by mutations in genes affecting the function and structure of the neuromuscular junction. This review updates the reader on established and novel subtypes of congenital myasthenia, and the treatment strategies for these increasingly heterogeneous disorders. The discovery of mutations associated with the N-glycosylation pathway and in the family of serine peptidases has shown that causative genes encoding ubiquitously expressed molecules can produce defects at the human neuromuscular junction. By contrast, mutations in lipoprotein-like receptor 4 (LRP4), a long-time candidate gene for congenital myasthenia, and a novel phenotype of myasthenia with distal weakness and atrophy due to mutations in AGRN have now been described. In addition, a pathogenic splicing mutation in a nonfunctional exon of CHRNA1 has been reported emphasizing the importance of analysing nonfunctional exons in genetic analysis. The benefit of salbutamol and ephedrine alone or combined with pyridostigmine or 3,4-DAP is increasingly being reported for particular subtypes of CMS.
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Abstract
PURPOSE OF REVIEW Congenital myasthenic syndromes (CMSs) form a heterogeneous group of genetic diseases characterized by a dysfunction of neuromuscular transmission because of mutations in numerous genes. This review will focus on the causative genes recently identified and on the therapy of CMSs. RECENT FINDINGS Advances in exome sequencing allowed the discovery of a new group of genes that did not code for the known molecular components of the neuromuscular junction, and the definition of a new group of glycosylation-defective CMS. Rather than the specific drugs used, some of them having been known for decades, it is the rigorous therapeutic strategy that is now offered to the patient in relation to the identified mutated gene that is novel and promising. SUMMARY In addition to the above main points, we also present new data on the genes that were already known with an emphasis on the clinic and on animal models that may be of use to understand the pathophysiology of the disease. We also stress not only the diagnosis difficulties between congenital myopathies and CMSs, but also the continuum that may exist between the two.
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Klein A, Pitt MC, McHugh JC, Niks EH, Sewry CA, Phadke R, Feng L, Manzur AY, Tirupathi S, DeVile C, Jayawant S, Finlayson S, Palace J, Muntoni F, Beeson D, Robb SA. DOK7 congenital myasthenic syndrome in childhood: Early diagnostic clues in 23 children. Neuromuscul Disord 2013; 23:883-91. [DOI: 10.1016/j.nmd.2013.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 05/24/2013] [Accepted: 06/05/2013] [Indexed: 10/26/2022]
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Hoshi T, Tezuka T, Yokoyama K, Iemura SI, Natsume T, Yamanashi Y. Mesdc2 plays a key role in cell-surface expression of Lrp4 and postsynaptic specialization in myotubes. FEBS Lett 2013; 587:3749-54. [PMID: 24140340 DOI: 10.1016/j.febslet.2013.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/24/2013] [Accepted: 10/03/2013] [Indexed: 01/01/2023]
Abstract
Low-density lipoprotein receptor-related protein 4 (Lrp4) is essential for pre- and post-synaptic specialization at the neuromuscular junction (NMJ), an indispensable synapse between a motor nerve and skeletal muscle. Muscle-specific receptor tyrosine kinase MuSK must form a complex with Lrp4 to organize postsynaptic specialization at NMJs. Here, we show that the chaperon Mesdc2 binds to the intracellular form of Lrp4 and promotes its glycosylation and cell-surface expression. Furthermore, knockdown of Mesdc2 suppresses cell-surface expression of Lrp4, activation of MuSK, and postsynaptic specialization in muscle cells. These results suggest that Mesdc2 plays an essential role in NMJ formation by promoting Lrp4 maturation.
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Affiliation(s)
- Taisuke Hoshi
- Division of Genetics, Department of Cancer Biology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
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50
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Finlayson S, Palace J, Belaya K, Walls TJ, Norwood F, Burke G, Holton JL, Pascual-Pascual SI, Cossins J, Beeson D. Clinical features of congenital myasthenic syndrome due to mutations in DPAGT1. J Neurol Neurosurg Psychiatry 2013; 84:1119-25. [PMID: 23447650 PMCID: PMC6044426 DOI: 10.1136/jnnp-2012-304716] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND A newly defined congenital myasthenic syndrome (CMS) caused by DPAGT1 mutations has recently been reported. While many other CMS-associated proteins have discrete roles localised to the neuromuscular junction, DPAGT1 is ubiquitously expressed, modifying many proteins, and as such is an unexpected cause of isolated neuromuscular involvement. METHODS We present detailed clinical characteristics of five patients with CMS caused by DPAGT1 mutations. RESULTS Patients have prominent limb girdle weakness and minimal craniobulbar symptoms. Tubular aggregates on muscle biopsy are characteristic but may not be apparent on early biopsies. Typical myasthenic features such as pyridostigmine and 3, 4- diaminopyridine responsiveness, and decrement on repetitive nerve stimulation are present. CONCLUSIONS These patients mimic myopathic disorders and are likely to be under-diagnosed. The descriptions here should facilitate recognition of this disorder. In particular minimal craniobulbar involvement and tubular aggregates on muscle biopsy help to distinguish DPAGT1 CMS from the majority of other forms of CMS. Patients with DPAGT1 CMS share similar clinical features with patients who have CMS caused by mutations in GFPT1, another recently identified CMS subtype.
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Affiliation(s)
- Sarah Finlayson
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
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