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Kediha MI, Tazir M, Magnouche C, Sternberg D, Belarbi S, Eymard B, Ali Pacha L. Congenital myasthenic syndrome by mutation of the ColQ gene: Phenotypic and evolutionary profile of three Algerian families. Rev Neurol (Paris) 2023:S0035-3787(23)00754-3. [PMID: 36764859 DOI: 10.1016/j.neurol.2022.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/24/2022] [Accepted: 09/29/2022] [Indexed: 02/10/2023]
Abstract
BACKGROUND Congenital myasthenic syndromes (CMS) are rare genetic neuromuscular disorders. The COLQ gene encoding the collagenous subunit of the acetyl cholinesterase enzyme tail is implicated in a synaptic form of CMS (also called type 5, according to the new gene table 2020 classification). OBJECTIVE To study the clinical phenotype of three families with COLQ gene mutations. METHODS We report a series of three consanguineous families, with seven affected patients, carrying three different mutations of the COLQ gene, one of which has never been reported in the literature before. RESULTS We studied their clinical and paraclinical phenotypes, and try to compare the three families as well as compare them with other series carrying COLQ gene mutations reported in the literature. CONCLUSION COLQ gene mutations have phenotypic particularities that must be recognized to propose appropriate genetic study.
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Affiliation(s)
- M I Kediha
- Neurology department, Mustapha Bacha university Hospital, Algiers, Algeria.
| | - M Tazir
- Neurology department, Mustapha Bacha university Hospital, Algiers, Algeria
| | - C Magnouche
- Neurology department, Ali Ait Idir university Hospital, Algiers, Algeria
| | - D Sternberg
- Myogenetics laboratory, Pitié Salpetriere university hospital, Paris, France
| | - S Belarbi
- Neurology department, Ali Ait Idir university Hospital, Algiers, Algeria
| | - B Eymard
- Neurology department, Pitié Saleptriere university hospital, Paris, France
| | - L Ali Pacha
- Neurology department, Mustapha Bacha university Hospital, Algiers, Algeria
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Ding Q, Shen D, Dai Y, Hu Y, Guan Y, Liu M, Cui L. Mechanism hypotheses for the electrophysiological manifestations of two cases of endplate acetylcholinesterase deficiency related congenital myasthenic syndrome. J Clin Neurosci 2017; 48:229-232. [PMID: 29150079 DOI: 10.1016/j.jocn.2017.10.084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/23/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To summarize the electrophysiological characteristics of two cases of endplate acetylcholinesterase deficiency (EAD) related congenital myasthenic syndrome (CMS) caused by COLQ mutation and to discuss the possible mechanism of these electrophysiological phenomena. METHODS Electrophysiological examinations were conducted including nerve conduction studies, routine electromyography (EMG), repetitive nerve stimulation (RNS) and single fiber EMG (SFEMG). The ulnar nerve was also stimulated at 50 Hz followed by 0.5 Hz to record the recovery process of compound muscle action potential (CMAP). RESULTS Repetitive CMAP (R-CMAP) was found in motor nerve conduction in both cases. Needle EMG showed myogenic damages and SFEMG showed remarkably increased jitter values. Of note, the amplitude of CMAP and R-CMAP showed regular changing trends, and so did their time intervals in RNS studies. CONCLUSIONS The change patterns of CMAP and R-CMAP, in combination with other electrophysiological features are very useful for the diagnosis of EAD related CMS, especially in predicting the presence of correct gene mutations.
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Affiliation(s)
- Qingyun Ding
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Dongchao Shen
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Yi Dai
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Youfang Hu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Yuzhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China; Neuroscience Center, Chinese Academy of Medical Sciences, Beijing 100730, China.
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China; Neuroscience Center, Chinese Academy of Medical Sciences, Beijing 100730, China.
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Bahar E, Kim H, Yoon H. ER Stress-Mediated Signaling: Action Potential and Ca(2+) as Key Players. Int J Mol Sci 2016; 17:ijms17091558. [PMID: 27649160 PMCID: PMC5037829 DOI: 10.3390/ijms17091558] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/06/2016] [Accepted: 09/09/2016] [Indexed: 01/24/2023] Open
Abstract
The proper functioning of the endoplasmic reticulum (ER) is crucial for multiple cellular activities and survival. Disturbances in the normal ER functions lead to the accumulation and aggregation of unfolded proteins, which initiates an adaptive response, the unfolded protein response (UPR), in order to regain normal ER functions. Failure to activate the adaptive response initiates the process of programmed cell death or apoptosis. Apoptosis plays an important role in cell elimination, which is essential for embryogenesis, development, and tissue homeostasis. Impaired apoptosis can lead to the development of various pathological conditions, such as neurodegenerative and autoimmune diseases, cancer, or acquired immune deficiency syndrome (AIDS). Calcium (Ca(2+)) is one of the key regulators of cell survival and it can induce ER stress-mediated apoptosis in response to various conditions. Ca(2+) regulates cell death both at the early and late stages of apoptosis. Severe Ca(2+) dysregulation can promote cell death through apoptosis. Action potential, an electrical signal transmitted along the neurons and muscle fibers, is important for conveying information to, from, and within the brain. Upon the initiation of the action potential, increased levels of cytosolic Ca(2+) (depolarization) lead to the activation of the ER stress response involved in the initiation of apoptosis. In this review, we discuss the involvement of Ca(2+) and action potential in ER stress-mediated apoptosis.
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Affiliation(s)
- Entaz Bahar
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea.
| | - Hyongsuk Kim
- Department of Electronics Engineering, Chonbuk National University, Jeonju 54896, Jeonbuk, Korea.
| | - Hyonok Yoon
- College of Pharmacy, Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 52828, Gyeongnam, Korea.
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Clinical and molecular analysis of a novel COLQ missense mutation causing congenital myasthenic syndrome in a Syrian family. Pediatr Neurol 2014; 51:165-9. [PMID: 24938146 DOI: 10.1016/j.pediatrneurol.2014.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/12/2014] [Accepted: 03/15/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND Congenital myasthenic syndromes with end-plate acetylcholinesterase deficiency are rare autosomal recessive disorders characterized by onset of the disease in early childhood, general weakness exacerbated by exertion, ophthalmoplegia, and refractoriness to anticholinesterase drugs. To date, all reported cases have been attributed to mutations in 18 genes including the COLQ gene that encodes a specific collagen that anchors acetylcholinesterase at the basal lamina of the neuromuscular junction. We identified a Syrian family with two children of consanguineous parents from two branches affected with congenital myasthenic syndrome with end-plate acetylcholinesterase deficiency. METHOD The absence of acetylcholinesterase antibodies was demonstrated biochemically. Consequently, all the coding regions, exon-intron boundaries, and the 5' and 3' untranslated regions of the COLQ gene were amplified and sequenced using the Sanger sequencing method. RESULTS We observed that the severity of the phenotype in the two affected children differed. One child had mild symptoms that included difficulties in gait and feeding with mild respiratory insufficiency. Her sibling died in the first months of life because of severe respiratory failure. The second patient had severe symptoms from birth and has been mechanically ventilated. DNA sequencing revealed a novel homozygous single nucleotide substitution mutation (c.1010T>C) in the COLQ gene in both patients. This substitution leads to a missense amino acid substitution at position 337 of the protein (p.Ile337Thr). This mutation is likely to impair ColQ's trimeric organization and therefore its anchoring within the synaptic basal lamina. CONCLUSION We identified the molecular cause underlying congenital myasthenic syndrome in two patients. The marked phenotypic variation suggests that other factors including modifier genes may affect the severity of this disease.
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Mori S, Kubo S, Akiyoshi T, Yamada S, Miyazaki T, Hotta H, Desaki J, Kishi M, Konishi T, Nishino Y, Miyazawa A, Maruyama N, Shigemoto K. Antibodies against muscle-specific kinase impair both presynaptic and postsynaptic functions in a murine model of myasthenia gravis. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:798-810. [PMID: 22142810 DOI: 10.1016/j.ajpath.2011.10.031] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 10/04/2011] [Accepted: 10/25/2011] [Indexed: 01/17/2023]
Abstract
Antibodies against acetylcholine receptors (AChRs) cause pathogenicity in myasthenia gravis (MG) patients through complement pathway-mediated destruction of postsynaptic membranes at neuromuscular junctions (NMJs). However, antibodies against muscle-specific kinase (MuSK), which constitute a major subclass of antibodies found in MG patients, do not activate the complement pathway. To investigate the pathophysiology of MuSK-MG and establish an experimental autoimmune MG (EAMG) model, we injected MuSK protein into mice deficient in complement component five (C5). MuSK-injected mice simultaneously developed severe muscle weakness, accompanied by an electromyographic pattern such as is typically observed in MG patients. In addition, we observed morphological and functional defects in the NMJs of EAMG mice, demonstrating that complement activation is not necessary for the onset of MuSK-MG. Furthermore, MuSK-injected mice exhibited acetylcholinesterase (AChE) inhibitor-evoked cholinergic hypersensitivity, as is observed in MuSK-MG patients, and a decrease in both AChE and the AChE-anchoring protein collagen Q at postsynaptic membranes. These findings suggest that MuSK is indispensable for the maintenance of NMJ structure and function, and that disruption of MuSK activity by autoantibodies causes MG. This mouse model of EAMG could be used to develop appropriate medications for the treatment of MuSK-MG in humans.
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Affiliation(s)
- Shuuichi Mori
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
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Mun'im A, Isoda H, Seki M, Negishi O, Ozawa T. Estrogenic and Acetylcholinesterase-Enhancement Activity of a New Isoflavone, 7,2',4'-Trihydroxyisoflavone-4'-O-beta-D-Glucopyranoside from Crotalaria Sessililflora. Cytotechnology 2011; 43:127-34. [PMID: 19003217 DOI: 10.1023/b:cyto.0000039899.67160.18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A new isoflavone, 7,2',4'-trihydroxyisoflavone-4'-O-beta-D-glucopyranoside has been isolated from the aerial part of Crotalaria sessiliflora. The isoflavone glucoside enhanced the proliferation of the MCF-7 human breast cancer cell line, which possesses estrogen receptor (ER) and responds to estrogen in culture. The estrogenic property of the isoflavone glucoside was blocked by the known ER antagonist tamoxifen, indicating the involvement of the ER. Furthermore, the isoflavone glucoside was found to enhance the acetylcholinesterase (AChE) activity of the rat neuronal cell line PC12 at low concentrations of nerve growth factor (NGF).
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Affiliation(s)
- Abdul Mun'im
- Institute of Applied Biochemistry, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
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The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka. PLoS Med 2008; 5:e147. [PMID: 18630983 PMCID: PMC2459203 DOI: 10.1371/journal.pmed.0050147] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2007] [Accepted: 05/22/2008] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Intermediate syndrome (IMS) is a major cause of death from respiratory failure following acute organophosphate poisoning. The objective of this study was to determine repetitive nerve stimulation (RNS) predictors of IMS that would assist in patient management and clinical research. METHODS AND FINDINGS Seventy-eight consenting symptomatic patients with organophosphate poisoning were assessed prospectively with daily physical examination and RNS. RNS was done on the right and left median and ulnar nerves at 1, 3, 10, 15, 20, and 30 Hz. The study was conducted as a prospective observational cohort study in the Central Province, Sri Lanka. IMS was diagnosed in ten out of 78 patients using a priori clinical diagnostic criteria, and five of them developed respiratory failure. All ten patients showed progressive RNS changes correlating with the severity of IMS. A decrement-increment was observed at intermediate and high frequencies preceding the onset of clinical signs of IMS. As the patient developed clinical signs of IMS, decrement-increment was progressively noted at low and intermediate frequencies and a combination of decrement-increment and repetitive fade or severe decrement was noted at high frequencies. Severe decrement preceded respiratory failure in four patients. Thirty patients developed forme fruste IMS with less severe weakness not progressing to respiratory failure whose RNS was characterized by decrement-increment or a combination of decrement-increment and repetitive fade but never severe decrements. CONCLUSIONS Characteristic changes in RNS, preceding the development of IMS, help to identify a subgroup of patients at high risk of developing respiratory failure. The forme fruste IMS with the characteristic early changes on RNS indicates that IMS is a spectrum disorder. RNS changes are objective and precede the diagnosis and complications of IMS. Thus they may be useful in clinical management and research.
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Schreiner F, Hoppenz M, Klaeren R, Reimann J, Woelfle J. Novel COLQ mutation 950delC in synaptic congenital myasthenic syndrome and symptomatic heterozygous relatives. Neuromuscul Disord 2007; 17:262-5. [PMID: 17300939 DOI: 10.1016/j.nmd.2006.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 10/28/2006] [Accepted: 11/27/2006] [Indexed: 10/23/2022]
Abstract
The synaptic form of congenital myasthenic syndrome (CMS) is a rare autosomal recessive disease affecting neuromuscular transmission. Mutations in the COLQ gene that encodes the collagenic tail subunit (ColQ) of asymmetric acetylcholinesterase lead to endplate acetylcholinesterase deficiency. We report two children suffering from synaptic CMS due to two compound heterozygous COLQ mutations, IVS1-1G>A and a novel mutation, 950delC. Furthermore, we found familial occurrence of congenital ptosis in heterozygous carriers of 950delC, mimicking a dominant negative effect. Considering the lack of a clear genotype-phenotype-relation in synaptic CMS, several authors speculated on the influence of additional modifying factors. Consequently, involvement of such factors in this report of familial congenital ptosis cannot be excluded.
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Affiliation(s)
- Felix Schreiner
- Children's Hospital, University of Bonn, Adenauerallee 119, 53113 Bonn, Germany
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Abstract
PURPOSE OF REVIEW Congenital myasthenic syndromes are a heterogeneous group of diseases caused by genetic defects affecting neuromuscular transmission. In this article, a strategy that leads to the diagnosis of congenital myasthenic syndromes is presented, and recent advances in the clinical, genetic and molecular aspects of congenital myasthenic syndrome are outlined. RECENT FINDINGS Besides the identification of new mutations in genes already known to be implicated in congenital myasthenic syndromes (genes for the acetylcholine receptor subunits and the collagen tail of acetylcholinesterase), mutations in other genes have more recently been discovered and characterized (genes for choline acetyltransferase, rapsyn, and the muscle sodium channel SCN4A). Fluoxetine has recently been proposed as an alternative treatment for 'slow channel' congenital myasthenic syndrome. SUMMARY The characterization of congenital myasthenic syndromes comprises two complementary steps: establishing the diagnosis and identifying the pathophysiological type of congenital myasthenic syndrome. Characterization of the type of congenital myasthenic syndrome has allowed it to be classified as caused by presynaptic, synaptic and postsynaptic defects. A clinically and muscle histopathologically oriented genetic study has identified several genes in which mutations cause the disease. Despite comprehensive characterization, the phenotypic expression of one given gene involved is variable, and the aetiology of many congenital myasthenic syndromes remains to be discovered.
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Affiliation(s)
- Daniel Hantaï
- Inserm U582 and Unité Clinique de Pathologie Neuromusculaire, Institut de Myologie, Hôpital de la Salpêtrière, Paris, France.
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Isoda H, Talorete TPN, Kimura M, Maekawa T, Inamori Y, Nakajima N, Seki H. Phytoestrogens genistein and daidzin enhance the acetylcholinesterase activity of the rat pheochromocytoma cell line PC12 by binding to the estrogen receptor. Cytotechnology 2002; 40:117-23. [PMID: 19003112 PMCID: PMC3449519 DOI: 10.1023/a:1023903220539] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Some compounds derived from plants have been known to possess estrogenic properties and can thus alter the physiology of higher organisms. Genistein and daidzin are examples of these phytoestrogens, which have recently been the subject of extensive research. In this study, genistein and daidzin were found to enhance the acetylcholinesterase (AChE) activity of the rat neuronal cell line PC12 at concentrations as low as 0.08 muM by binding to the estrogen receptor (ER). Results have shown that this enhancement was effectively blocked by the known estrogen receptor antagonist tamoxifen, indicating the involvement of the ER in AChE induction. That genistein and daidzin are estrogenic were confirmed in a cell proliferation assay using the human breast cancer cell line MCF7. This proliferation was also blocked by tamoxifen, again indicating the involvement of the ER. On the other hand, incubating the PC12 cells in increasing concentrations of 17 beta-estradiol (E2) did not lead to enhanced AChE activity, even in the presence of genistein or daidzin. This suggests that mere binding of an estrogenic compound to the ER does not necessarily lead to enhanced AChE activity. Moreover, the effect of the phytoestrogens on AChE activity cannot be expressed in the presence of E2 since they either could not compete with the natural ligand in binding to the ER or that E2 down-regulates its own receptor. This study clearly suggests that genistein and daidzin enhance AChE activityin PC12 cells by binding to the ER; however, the actual mechanism of enhancement is not known.
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Affiliation(s)
- Hiroko Isoda
- National Institute of Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, Japan
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