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Sutinen A, Jones NC, Hoffmann SV, Ruskamo S, Kursula P. Conformational analysis of membrane-proximal segments of GDAP1 in a lipidic environment using synchrotron radiation suggests a mode of assembly at the mitochondrial outer membrane. Biophys Chem 2023; 303:107113. [PMID: 37778197 DOI: 10.1016/j.bpc.2023.107113] [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: 07/10/2023] [Revised: 09/19/2023] [Accepted: 09/24/2023] [Indexed: 10/03/2023]
Abstract
The mitochondrial outer membrane creates a diffusion barrier between the cytosol and the mitochondrial intermembrane space, allowing the exchange of metabolic products, important for efficient mitochondrial function in neurons. The ganglioside-induced differentiation-associated protein 1 (GDAP1) is a mitochondrial outer membrane protein with a critical role in mitochondrial dynamics and metabolic balance in neurons. Missense mutations in the GDAP1 gene are linked to the most common human peripheral neuropathy, Charcot-Marie-Tooth disease (CMT). GDAP1 is a distant member of the glutathione-S-transferase (GST) superfamily, with unknown enzymatic properties or functions at the molecular level. The structure of the cytosol-facing GST-like domain has been described, but there is no consensus on how the protein interacts with the mitochondrial outer membrane. Here, we describe a model for GDAP1 assembly on the membrane using peptides vicinal to the GDAP1 transmembrane domain. We used oriented circular dichroism spectroscopy (OCD) with synchrotron radiation to study the secondary structure and orientation of GDAP1 segments at the outer and inner surfaces of the outer mitochondrial membrane. These experiments were complemented by small-angle X-ray scattering, providing the first experimental structural models for full-length human GDAP1. The results indicate that GDAP1 is bound into the membrane via a single transmembrane helix, flanked by two peripheral helices interacting with the outer and inner leaflets of the mitochondrial outer membrane in different orientations. Impairment of these interactions could be a mechanism for CMT in the case of missense mutations affecting these segments instead of the GST-like domain.
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Affiliation(s)
- Aleksi Sutinen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Oulu, Finland; Department of Biomedicine, University of Bergen, Bergen, Norway.
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Manzoor U, Ali A, Ali SL, Abdelkarem O, Kanwal S, Alotaibi SS, Baazeem A, Baiduissenova A, Yktiyarov A, Hajar A, Olzhabay A. Mutational screening of GDAP1 in dysphonia associated with Charcot-Marie-Tooth disease: clinical insights and phenotypic effects. J Genet Eng Biotechnol 2023; 21:119. [PMID: 37966693 PMCID: PMC10651813 DOI: 10.1186/s43141-023-00568-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 10/26/2023] [Indexed: 11/16/2023]
Abstract
INTRODUCTION Mutations in GDAP1 (Ganglioside-induced differentiation-associated protein 1) gene are linked to Charcot-Marie-Tooth disease (CMT), a Heterogenous group of disorders with multiple phenotypes, characterized by peripheral nerve dysfunction that can lead to vocal cord paralysis and diaphragmatic dysfunction. MAIN BODY All three affected children of this chosen family have manifested the same clinical symptoms with progressive weakness, mild sensory impairment, and absent tendon reflexes in their early years. Electrodiagnostic analysis displayed an axonal type of neuropathy in affected patients. Sequencing of the GDAP1 gene was requested for all members of the family. Diagnostic assessments included pulmonary and vocal cord function tests, as well as phrenic and peripheral nerve conduction studies. Pathogenicity of GDAP1 variant p.Pro419Leu with axonal CMT2 and autosomal recessive inheritance was confirmed via in silico analysis. Patients with GDAP1 mutations showed dysphonia, speech difficulties, and the characteristic symptoms of CMT. The severity of symptoms correlated with the presence of a type of GDAP1 mutation. Patients with normal vocal cords and pulmonary function exhibited milder symptoms compared to those with GDAP1 mutations. Our study provides clinical insights into the phenotypic effects of GDAP1 mutations in CMT patients. The findings highlight the adverse clinical course and severe disability associated with GDAP1 mutations, including weak limb and laryngeal muscles. CONCLUSION Patients with GDAP1 mutations and autosomal recessive neuropathy present with dysphonia and require interventions such as surgery, braces, physical therapy, and exercise. Early diagnosis and comprehensive clinical evaluations are crucial for managing CMT patients with GDAP1 mutations.
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Affiliation(s)
- Uzma Manzoor
- Department of Clinical Biochemistry, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan.
| | - Awais Ali
- Department of Biochemistry, Abdul wali Khan University Mardan, Mardan, 23200, Pakistan
| | - S Luqman Ali
- Department of Biochemistry, Abdul wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Omneya Abdelkarem
- Department of Chemical Pathology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Sumaira Kanwal
- Department of Clinical Biochemistry, COMSATS University Islamabad, Sahiwal Campus, Sahiwal, Pakistan
| | - Saqer S Alotaibi
- Department of Biotechnology, College of Science, Taif University, P.O.Box 11099, 21944, Taif, Saudi Arabia
| | - Alaa Baazeem
- Department of Biology, College of Science, Taif University, P.O. Box 11099, 21944, Taif, Saudi Arabia
| | - Aliya Baiduissenova
- Department of Microbiology and Virology, Astana Medical University, Astana City, 010000, Kazakhstan
| | - Ayaz Yktiyarov
- Department of Microbiology and Virology, Astana Medical University, Astana City, 010000, Kazakhstan
| | - Azraida Hajar
- Department of Biology, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech, Morocco
| | - Abay Olzhabay
- Department of Otorhinolaryngology, Astana Medical University, Astana City, 010000, Kazakhstan
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Sutinen A, Nguyen GTT, Raasakka A, Muruganandam G, Loris R, Ylikallio E, Tyynismaa H, Bartesaghi L, Ruskamo S, Kursula P. Structural insights into Charcot-Marie-Tooth disease-linked mutations in human GDAP1. FEBS Open Bio 2022; 12:1306-1324. [PMID: 35509130 PMCID: PMC9249340 DOI: 10.1002/2211-5463.13422] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/25/2022] [Accepted: 05/03/2022] [Indexed: 11/11/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral polyneuropathy in humans, and its different subtypes are linked to mutations in dozens of different genes. Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) cause two types of CMT, demyelinating CMT4A and axonal CMT2K. The GDAP1-linked CMT genotypes are mainly missense point mutations. Despite clinical profiling and in vivo studies on the mutations, the etiology of GDAP1-linked CMT is poorly understood. Here, we describe the biochemical and structural properties of the Finnish founding CMT2K mutation H123R as well as CMT2K-linked R120W, both of which are autosomal dominant mutations. The disease variant proteins retain close to normal structure and solution behaviour, but both present a significant decrease in thermal stability. Using GDAP1 variant crystal structures, we identify a side chain interaction network between helices ⍺3, ⍺6, and ⍺7, which is affected by CMT mutations, as well as a hinge in the long helix ⍺6, which is linked to structural flexibility. Structural analysis of GDAP1 indicates that CMT may arise from disruption of specific intra- and intermolecular interaction networks, leading to alterations in GDAP1 structure and stability, and eventually, insufficient motor and sensory neuron function.
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Affiliation(s)
- Aleksi Sutinen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Giang Thi Tuyet Nguyen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, Norway
| | - Gopinath Muruganandam
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Belgium
| | - Remy Loris
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Belgium
| | - Emil Ylikallio
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Finland.,Clinical Neurosciences, Helsinki University Hospital, Neurology, Finland
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Finland
| | | | - Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland.,Department of Biomedicine, University of Bergen, Norway
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Lehtilahti M, Kallio M, Majamaa K, Kärppä M. Phenotype of Patients With Charcot-Marie-Tooth With the p.His123Arg Mutation in GDAP1 in Northern Finland. NEUROLOGY-GENETICS 2021; 7:e629. [PMID: 34632054 PMCID: PMC8495501 DOI: 10.1212/nxg.0000000000000629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/22/2021] [Accepted: 08/11/2021] [Indexed: 11/24/2022]
Abstract
Background and Objectives Mutations in the ganglioside-induced differentiation-associated protein 1 (GDAP1) gene cause autosomal dominant or autosomal recessive forms of Charcot-Marie-Tooth disease (CMT). Our aim was to study the clinical phenotype of patients with CMT caused by heterozygous p.His123Arg in GDAP1. Methods Twenty-three Finnish patients were recruited from a population-based cohort and through family investigation. Each patient was examined clinically and electrophysiologically. The Neuropathy Symptom Score and the Neuropathy Disability Score (NDS) were used in clinical evaluation. Results The median age at onset of symptoms was 17 years among patients with p.His123Arg in GDAP1. Motor symptoms were markedly more common than sensory symptoms at onset. All patients had distal weakness in lower extremities, and 17 (74%) patients had proximal weakness. Muscle atrophy and pes cavus were also common. Nineteen (82%) patients had sensory symptoms such as numbness or pain. The disease progressed with age, and the NDS increased 8.5 points per decade. Electrodiagnostic testing revealed length-dependent, sensory and motor axonal polyneuropathy. EDx findings were asymmetrical in 14 patients. Genealogic study of the families suggested a founder effect. Discussion We found that CMT in patients with p.His123Arg in GDAP1 is relatively mild and slow in progression.
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Affiliation(s)
- Maria Lehtilahti
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital (M.L., K.M., M.Kärppä); Research Unit of Clinical Neuroscience, University of Oulu (M.L., K.M., M.Kärppä); Department of Neurology, Oulu University Hospital (M.L., K.M., M.Kärppä); Department of Clinical Neurophysiology, Medical Research Center Oulu, Oulu University Hospital (M.Kallio); Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu (M.Kallio), Oulu, Finland
| | - Mika Kallio
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital (M.L., K.M., M.Kärppä); Research Unit of Clinical Neuroscience, University of Oulu (M.L., K.M., M.Kärppä); Department of Neurology, Oulu University Hospital (M.L., K.M., M.Kärppä); Department of Clinical Neurophysiology, Medical Research Center Oulu, Oulu University Hospital (M.Kallio); Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu (M.Kallio), Oulu, Finland
| | - Kari Majamaa
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital (M.L., K.M., M.Kärppä); Research Unit of Clinical Neuroscience, University of Oulu (M.L., K.M., M.Kärppä); Department of Neurology, Oulu University Hospital (M.L., K.M., M.Kärppä); Department of Clinical Neurophysiology, Medical Research Center Oulu, Oulu University Hospital (M.Kallio); Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu (M.Kallio), Oulu, Finland
| | - Mikko Kärppä
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital (M.L., K.M., M.Kärppä); Research Unit of Clinical Neuroscience, University of Oulu (M.L., K.M., M.Kärppä); Department of Neurology, Oulu University Hospital (M.L., K.M., M.Kärppä); Department of Clinical Neurophysiology, Medical Research Center Oulu, Oulu University Hospital (M.Kallio); Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu (M.Kallio), Oulu, Finland
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Wu R, Lv H, Wang H, Wang Z, Yuan Y. The Pathological Features of Common Hereditary Mitochondrial Dynamics Neuropathy. Front Neurosci 2021; 15:705277. [PMID: 34366782 PMCID: PMC8341155 DOI: 10.3389/fnins.2021.705277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/28/2021] [Indexed: 01/02/2023] Open
Abstract
Objectives Mitofusin 2 and ganglioside-induced differentiation-associated protein 1 are two main mitochondrial dynamics-related proteins. Dysfunction of these two proteins leads to different subtypes of Charcot–Marie–Tooth disease type 2A (CMT2A) and CMT2K. This study aims to report the pathological difference between CMT2A and CMT2K in a large cohort. Methods Thirty patients with molecularly confirmed CMT2A and nine with CMT2K were identified by next-generation sequencing. Sural nerve biopsies were performed in 29 patients. Results The patients with both diseases showed length-dependent neuropathy with distal weakness, sensory loss, and no deep tendon reflex. Optic neuropathy appeared in 3/30 (10%) patients with CMT2A. Tendon contracture appeared in 4/9 (50.0%) patients with CMT2K. Sural biopsy revealed the loss of both myelinated and unmyelinated nerve fibers. Closely packed, irregularly oriented neurofilaments were observed in axons of unmyelinated nerve fibers in both diseases. Another important finding was the ubiquitous presence of smaller, rounded, and fragmented mitochondria in CMT2A and elongated mitochondria in CMT2K in the myelinated and unmyelinated axons. Conclusion This study confirmed large diversity in phenotypes between CMT2A and CMT2K. Mitochondrial dynamics-related variations can induce different mitochondrial morphological changes and neurofilament accumulation in axons.
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Affiliation(s)
- Rui Wu
- Department of Neurology, Peking University First Hospital, Beijing, China.,Department of Neurology, Shandong Provincial Hospital, Shandong University, Jinan, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Hui Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing, China
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Schiavon CR, Shadel GS, Manor U. Impaired Mitochondrial Mobility in Charcot-Marie-Tooth Disease. Front Cell Dev Biol 2021; 9:624823. [PMID: 33598463 PMCID: PMC7882694 DOI: 10.3389/fcell.2021.624823] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/05/2021] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a progressive, peripheral neuropathy and the most commonly inherited neurological disorder. Clinical manifestations of CMT mutations are typically limited to peripheral neurons, the longest cells in the body. Currently, mutations in at least 80 different genes are associated with CMT and new mutations are regularly being discovered. A large portion of the proteins mutated in axonal CMT have documented roles in mitochondrial mobility, suggesting that organelle trafficking defects may be a common underlying disease mechanism. This review will focus on the potential role of altered mitochondrial mobility in the pathogenesis of axonal CMT, highlighting the conceptional challenges and potential experimental and therapeutic opportunities presented by this "impaired mobility" model of the disease.
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Affiliation(s)
- Cara R. Schiavon
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Gerald S. Shadel
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, United States
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Taniguchi T, Ando M, Okamoto Y, Yoshimura A, Higuchi Y, Hashiguchi A, Shiga K, Hayashida A, Hatano T, Ishiura H, Mitsui J, Hattori N, Mizuno T, Nakagawa M, Tsuji S, Takashima H. Genetic spectrum of Charcot-Marie-Tooth disease associated with myelin protein zero gene variants in Japan. Clin Genet 2020; 99:359-375. [PMID: 33179255 PMCID: PMC7898366 DOI: 10.1111/cge.13881] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 11/04/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022]
Abstract
We aimed to reveal the genetic features associated with MPZ variants in Japan. From April 2007 to August 2017, 64 patients with 23 reported MPZ variants and 21 patients with 17 novel MPZ variants were investigated retrospectively. Variation in MPZ variants and the pathogenicity of novel variants was examined according to the American College of Medical Genetics standards and guidelines. Age of onset, cranial nerve involvement, serum creatine kinase (CK), and cerebrospinal fluid (CSF) protein were also analyzed. We identified 64 CMT patients with reported MPZ variants. The common variants observed in Japan were different from those observed in other countries. We identified 11 novel pathogenic variants from 13 patients. Six novel MPZ variants in eight patients were classified as likely benign or uncertain significance. Cranial nerve involvement was confirmed in 20 patients. Of 30 patients in whom serum CK levels were evaluated, eight had elevated levels. Most of the patients had age of onset >20 years. In another subset of 30 patients, 18 had elevated CSF protein levels; four of these patients had spinal diseases and two had enlarged nerve root or cauda equina. Our results suggest genetic diversity across patients with MPZ variants.
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Affiliation(s)
- Takaki Taniguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Masahiro Ando
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yuji Okamoto
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.,Department of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan
| | - Akiko Yoshimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yujiro Higuchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Kensuke Shiga
- Department of Neurology, Matsushita Memorial Hospital, Osaka, Japan.,Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Arisa Hayashida
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Taku Hatano
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Hiroyuki Ishiura
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jun Mitsui
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University School of Medicine, Tokyo, Japan
| | - Toshiki Mizuno
- Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Masanori Nakagawa
- Department of Neurology, Kyoto prefectural University of Medicine, Kyoto, Japan.,North Medical Center, Kyoto prefectural University of Medicine, Kyoto, Japan
| | - Shoji Tsuji
- Department of Molecular Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Institute of Medical Genomics, International University of Health and Welfare, Chiba, Japan
| | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
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Chen CX, Li JQ, Dong HL, Liu GL, Bai G, Wu ZY. Identification and functional characterization of novel GDAP1 variants in Chinese patients with Charcot-Marie-Tooth disease. Ann Clin Transl Neurol 2020; 7:2381-2392. [PMID: 33136338 PMCID: PMC7732252 DOI: 10.1002/acn3.51233] [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: 07/22/2020] [Revised: 09/14/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Objective To identify and characterize the pathogenicity of novel variants in Chinese patients with Charcot–Marie–Tooth disease. Methods Multiplex ligation‐dependent probe amplification (MLPA) and whole‐exome sequencing (WES) were performed in 30 unrelated CMT patients. Minigene assay was used to verify the effect of a novel splicing variant (c.694+1G>A) on pre‐mRNA. Primary fibroblast cell lines were established from skin biopsies to characterize the biological effects of the novel variants p.L26R and p.S169fs. The mitochondrial structure was observed by an electron microscope. The expression level of protein was analyzed by Western Blotting. Mitochondrial dynamics and mitochondrial membrane potential (MMP, Δψm) were analyzed via immunofluorescence study. Mitochondrial ATP levels were analyzed via bioluminescence assay. The rate of oxygen consumption was measured with a Seahorse Bioscience XF‐96 extracellular flux analyzer. Results We identified 10 pathogenic variants in three known CMT related genes, including three novel variants (p.L26R, p.S169fs, c.694+1G>A) and one known pathogenic variant (p.R120W) in GDAP1. Further, we described the clinical features of patients carrying pathogenic variants in GDAP1 and found that almost all Chinese CMT patients with GDAP1 variants present axonal type. The effect of c.694+1G>A on pre‐mRNA was verified via minigene splice assay. Cellular biological effects showed ultrastructure damage of mitochondrial, reduced protein levels, different patterns of mitochondrial dynamics, decreased mitochondrial membrane potential (Δψm), ATP content, and defects in respiratory capacity in the patient carrying p.L26R and p.S169fs in GDAP1. Interpretation Our results broaden the genetic spectrum of GDAP1 and provided functional evidence for mitochondrial pathways in the pathogenesis of GDAP1 variants.
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Affiliation(s)
- Cong-Xin Chen
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Jia-Qi Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Hai-Lin Dong
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Gong-Lu Liu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Ge Bai
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
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9
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Novel GDAP1 Mutation in a Vietnamese Family with Charcot-Marie-Tooth Disease. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7132494. [PMID: 31179332 PMCID: PMC6507255 DOI: 10.1155/2019/7132494] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/21/2018] [Accepted: 04/14/2019] [Indexed: 01/09/2023]
Abstract
Background Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth (CMT) disease and over 80 different mutations have been identified so far. This study analyzed the clinical and genetic characteristics of a Vietnamese CMT family that was affected by a novel GDAP1 mutation. Methods We present three children of a family with progressive weakness, mild sensory loss, and absent tendon reflexes. Electrodiagnostic analyses displayed an axonal type of neuropathy in affected patients. Sequencing of GDAP1 gene was requested for all members of the family. Results All affected individuals manifested identical clinical symptoms of motor and sensory impairments within the first three years of life, and nerve conduction study indicated the axonal degeneration. A homozygous GDAP1 variant (c.667_671dup) was found in the three affected children as recessive inheritance pattern. The mutation leads to a premature termination codon that shortens GDAP1 protein (p.Gln224Hisfs∗37). Further testing showed heterozygous c.667_671dup variant in the parents. Discussion Our study expands the mutational spectrum of GDAP1-related CMT disease with the new and unreported GDAP1 variant. Alterations in GDAP1 gene should be evaluated as CMT causing variants in the Vietnamese population, predominantly axonal form of neuropathy in CMT disease.
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10
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Qin L, Yang C, Lü T, Li L, Zong D, Wu Y. [Analysis of GDAP1 gene mutation in a pedigree with autosomal dominant Charcot-Marie-Tooth disease]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:63-68. [PMID: 30692068 DOI: 10.12122/j.issn.1673-4254.2019.01.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the molecular genetic mechanism of Charcot- Marie-Tooth (CMT) disease in a pedigree. METHODS Genomic DNA was extracted from the peripheral blood of the family members of a pedigree with autosomal dominant CMT disease, and 65 candidate genes of the proband were screened using target exon capture and the next generation sequencing, and the suspicious genes were verified using Sanger sequencing. PolyPhen-2, PROVEAN and SIFT software were used to predict the function of the mutant genes, and PyMOL-1 software was used to simulate the mutant protein structure. RESULTS A heterozygous missense mutation [c.371A>G (p.Y124C)] was detected in exon 3 of GDAP1 gene of the proband. This heterozygous mutation was also detected in both the proband's mother and her brother, but not in her father. Multiple sequence alignment analysis showed that tyrosine at codon 124 of GDAP1 protein was highly conserved. All the 3 prediction software predicted that the mutation was harmful. Molecular structure simulation showed a weakened interaction force between the amino acid residues at codon 124 and the surrounding amino acid residues to affect the overall stability of the protein. CONCLUSIONS The mutation of GDAP1 gene may be related to the pathogenesis of autosomal dominant AD-CMT in this pedigree. The newly discovered c.371A>G mutation (p.Y124C) expands the mutation spectrum of GDAP1 gene, but further study is needed to clarify the underlying pathogenesis.
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Affiliation(s)
- Li Qin
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
| | - Canhong Yang
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
| | - Tianming Lü
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
| | - Lanying Li
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
| | - Dandan Zong
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
| | - Yueying Wu
- Department of Neurology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, China
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Pakhrin PS, Xie Y, Hu Z, Li X, Liu L, Huang S, Wang B, Yang Z, Zhang J, Liu X, Xia K, Tang B, Zhang R. Genotype–phenotype correlation and frequency of distribution in a cohort of Chinese Charcot–Marie–Tooth patients associated with GDAP1 mutations. J Neurol 2018; 265:637-646. [DOI: 10.1007/s00415-018-8743-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/13/2017] [Accepted: 01/07/2018] [Indexed: 01/08/2023]
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12
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Yuan JH, Hashiguchi A, Okamoto Y, Yoshimura A, Ando M, Shiomi K, Saito K, Takahashi M, Ichinose K, Ohmichi T, Ichikawa K, Tadashi A, Takigawa H, Shibayama H, Takashima H. Clinical and mutational spectrum of Japanese patients with recessive variants in SH3TC2. J Hum Genet 2018; 63:281-287. [PMID: 29321516 DOI: 10.1038/s10038-017-0388-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/12/2017] [Accepted: 10/26/2017] [Indexed: 02/04/2023]
Abstract
SH3TC2, known as the causative gene of autosomal recessive demyelinating Charcot-Marie-Tooth type 4C (CMT4C), was also found linked to a mild mononeuropathy of the median nerve with an autosomal dominant inheritance pattern. Using DNA microarray, Illumina MiSeq, and Ion proton, we carried out gene panel sequencing among 1483 Japanese CMT patients, containing 397 patients with demyelinating CMT. From seven patients with demyelinating CMT, we identified eight recessive variants in the SH3TC2 gene, consisting of five novel (pathogenic/likely pathogenic) and three reported variants. Additionally, from two patients with axonal CMT, we detected a reported recessive variant, p.Arg77Trp, which was herein reclassified as variant with unknown significance. Of the seven CMT4C patients (six females and one male), 2/7 patients developed symptoms at their first decade, and 5/7 patients lost their ambulation around age 50. Scoliosis was observed from more than half (4/7) of these patients, whereas hearing loss is the most common symptom of central nervous system (6/7). No median nerve mononeuropathy was recorded from their family members. We identified recessive variants in SH3TC2 from 1.76% of demyelinating CMT patients. An uncommon gender difference was recognized and the wild spectrum of these variants suggests mutational diversity of SH3TC2 in Japan.
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Affiliation(s)
- Jun-Hui Yuan
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Akihiro Hashiguchi
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yuji Okamoto
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Akiko Yoshimura
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Masahiro Ando
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kazutaka Shiomi
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, University of Miyazaki, Miyazaki, Japan
| | - Kayoko Saito
- Institute of Medical Genetics, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan
| | - Makoto Takahashi
- Department of Neurology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Keiko Ichinose
- Department of Neurology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takuma Ohmichi
- Department of Neurology, NHO Maizuru Medical Center, Kyoto, Japan
| | - Kazushi Ichikawa
- Department of Pediatrics, Odawara Municipal Hospital, Kanagawa, Japan
| | - Adachi Tadashi
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Hiroshi Takigawa
- Division of Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Tottori, Japan
| | | | - Hiroshi Takashima
- Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
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