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Huang W, Zhang S, Lin J, Ding Y, Jiang N, Zhang J, Zhao H, Chen F. Rare loss-of-function variants in FLNB cause non-syndromic orofacial clefts. J Genet Genomics 2024; 51:222-229. [PMID: 37003352 DOI: 10.1016/j.jgg.2023.03.012] [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: 12/21/2022] [Revised: 02/24/2023] [Accepted: 03/17/2023] [Indexed: 04/03/2023]
Abstract
Orofacial clefts (OFCs) are the most common congenital craniofacial disorders, of which the etiology is closely related to rare coding variants. Filamin B (FLNB) is an actin-binding protein implicated in bone formation. FLNB mutations have been identified in several types of syndromic OFCs and previous studies suggest a role of FLNB in the onset of non-syndromic OFCs (NSOFCs). Here, we report two rare heterozygous variants (p.P441T and p.G565R) in FLNB in two unrelated hereditary families with NSOFCs. Bioinformatics analysis suggests that both variants may disrupt the function of FLNB. In mammalian cells, p.P441T and p.G565R variants are less potent to induce cell stretches than wild type FLNB, suggesting that they are loss-of-function mutations. Immunohistochemistry analysis demonstrates that FLNB is abundantly expressed during palatal development. Importantly, Flnb-/- embryos display cleft palates and previously defined skeletal defects. Taken together, our findings reveal that FLNB is required for development of palates in mice and FLNB is a bona fide causal gene for NSOFCs in humans.
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Affiliation(s)
- Wenbin Huang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China; Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, China; Guangdong Provincial High-level Clinical Key Specialty, Guangdong Province Engineering Research Center of Oral Disease Diagnosis and Treatment, Department of Orthodontics, Stomatological Center, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong 518036, China
| | - Shiying Zhang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Jiuxiang Lin
- Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Yi Ding
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Nan Jiang
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory for Digital Stomatology, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, NMPA Key Laboratory for Dental Materials, Beijing, 100101, China; Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, China
| | - Jieni Zhang
- Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
| | - Huaxiang Zhao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710004, China.
| | - Feng Chen
- National Center for Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory for Digital Stomatology, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, NMPA Key Laboratory for Dental Materials, Beijing, 100101, China; Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
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Onnée M, Bénézit A, Bastu S, Nadaj-Pakleza A, Lannes B, Ader F, Thèze C, Cintas P, Cances C, Carlier RY, Metay C, Cossée M, Malfatti E. The FLNC Ala1186Val Variant Linked to Cytoplasmic Body Myopathy and Cardiomyopathy Causes Protein Instability. Biomedicines 2024; 12:322. [PMID: 38397924 PMCID: PMC10887408 DOI: 10.3390/biomedicines12020322] [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: 12/29/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
Filamin C-related disorders include myopathies and cardiomyopathies linked to variants in the FLNC gene. Filamin C belongs to a family of actin-binding proteins involved in sarcomere stability. This study investigates the pathogenic impact of the FLNC c.3557C > T (p.Ala1186Val) pathogenic variant associated with an early-onset cytoplasmic body myopathy and cardiomyopathy in three unrelated patients. We performed clinical imaging and myopathologic and genetic characterization of three patients with an early-onset myopathy and cardiomyopathy. Bioinformatics analysis, variant interpretation, and protein structure analysis were performed to validate and assess the effects of the filamin C variant. All patients presented with a homogeneous clinical phenotype marked by a severe contractural myopathy, leading to loss of gait. There was prominent respiratory involvement and restrictive or hypertrophic cardiomyopathies. The Ala1186Val variant is located in the interstrand loop involved in intradomain stabilization and/or interdomain interactions with neighbor Ig-like domains. 3D modeling highlights local structural changes involving nearby residues and probably impacts the protein stability, causing protein aggregation in the form of cytoplasmic bodies. Myopathologic studies have disclosed the prominent aggregation and upregulation of the aggrephagy-associated proteins LC3B and p62. As a whole, the Ala1186Val variant in the FLNC gene provokes a severe myopathy with contractures, respiratory involvement, and cardiomyopathy due to protein aggregation in patients' muscles.
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Affiliation(s)
- Marion Onnée
- Institut Mondor de Recherche Biomédicale, Université Paris Est Créteil, Institut National de la Santé et de la Recherche Médicale U955, 94010 Créteil, France; (M.O.); (S.B.)
| | - Audrey Bénézit
- Neurologie et Réanimation Pédiatrique, Assistance Publique–Hôpitaux de Paris, Université Paris Saclay, Département Médico-Universitaire Santé de l’Enfant et de l’Adolescent, Hôpital Raymond Poincaré, 92380 Garches, France;
| | - Sultan Bastu
- Institut Mondor de Recherche Biomédicale, Université Paris Est Créteil, Institut National de la Santé et de la Recherche Médicale U955, 94010 Créteil, France; (M.O.); (S.B.)
| | - Aleksandra Nadaj-Pakleza
- Centre de Référence des Maladies Neuromusculaires Nord Est Ile-de-France, Service de Neurologie, Hôpitaux Universitaires de Strasbourg, 67200 Strasbourg, France;
- European Reference Network, EURO-NMD, Neuromuscular Centre at Hautepierre Hospital, Hôpitaux Universitaires de Strasbourg, 67200 Strasbourg, France
| | - Béatrice Lannes
- Département de Pathologie, Hôpitaux Universitaires de Strasbourg, 67091 Strasbourg, France;
| | - Flavie Ader
- Assistance Publique–Hôpitaux de Paris, Sorbonne Université, Département Médico-Universitaire BioGem, Unité Fonctionnelle de Cardiogénétique et Myogénétique Moléculaire et Cellulaire, 75013 Paris, France;
- Institut National de la Santé et de la Recherche Médicale UMRS1166, Université Paris Cité, 75006 Paris, France
| | - Corinne Thèze
- Laboratoire de Génétique Moléculaire, Centre Hospitalier Universitaire de Montpellier, Université de Montpellier, 34095 Montpellier, France;
| | - Pascal Cintas
- Centre de Référence des Maladies Neuromusculaires AOC (Atlantique-Occitanie-Caraïbes), Département de Neurologie, Hôpital Pierre-Paul Riquet, Centre Hospitalier Universitaire de Toulouse, 31059 Toulouse, France; (P.C.); (M.C.)
| | - Claude Cances
- Centre de Référence des Maladies Neuromusculaires AOC (Atlantique-Occitanie-Caraïbes), Unité de Neurologie Pédiatrique, Hôpital des Enfants, Centre Hospitalier Universitaire de Toulouse, 31059 Toulouse, France;
| | - Robert-Yves Carlier
- Assistance Publique–Hôpitaux de Paris, Groupe Hospitalier Universitaire Paris Saclay, Département Médico-Universitaire Smart Imaging, Service d’Imagerie Médicale, Institut National de la Santé et de la Recherche Médicale UMR1179, Hôpital Raymond Poincaré, 92380 Garches, France;
| | - Corinne Metay
- Unité Fonctionnelle de Cardiogénétique et Myogénétique Moléculaire et Cellulaire, Centre de Génétique Moléculaire et Chromosomique, Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Institut de Myologie, Groupe Hospitalier La Pitié-Salpêtrière, 75013 Paris, France;
| | - Mireille Cossée
- Centre de Référence des Maladies Neuromusculaires AOC (Atlantique-Occitanie-Caraïbes), Département de Neurologie, Hôpital Pierre-Paul Riquet, Centre Hospitalier Universitaire de Toulouse, 31059 Toulouse, France; (P.C.); (M.C.)
- PhyMedExp, Université de Montpellier, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, 34295 Montpellier, France
| | - Edoardo Malfatti
- Institut Mondor de Recherche Biomédicale, Université Paris Est Créteil, Institut National de la Santé et de la Recherche Médicale U955, 94010 Créteil, France; (M.O.); (S.B.)
- Assistance Publique–Hôpitaux de Paris, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Hôpital Henri Mondor, 94000 Créteil, France
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Skolka MP, Naddaf E. Exploring challenges in the management and treatment of inclusion body myositis. Curr Opin Rheumatol 2023; 35:404-413. [PMID: 37503813 PMCID: PMC10552844 DOI: 10.1097/bor.0000000000000958] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
PURPOSE OF REVIEW This review provides an overview of the management and treatment landscape of inclusion body myositis (IBM), while highlighting the current challenges and future directions. RECENT FINDINGS IBM is a slowly progressive myopathy that predominantly affects patients over the age of 40, leading to increased morbidity and mortality. Unfortunately, a definitive cure for IBM remains elusive. Various clinical trials targeting inflammatory and some of the noninflammatory pathways have failed. The search for effective disease-modifying treatments faces numerous hurdles including variability in presentation, diagnostic challenges, poor understanding of pathogenesis, scarcity of disease models, a lack of validated outcome measures, and challenges related to clinical trial design. Close monitoring of swallowing and respiratory function, adapting an exercise routine, and addressing mobility issues are the mainstay of management at this time. SUMMARY Addressing the obstacles encountered by patients with IBM and the medical community presents a multitude of challenges. Effectively surmounting these hurdles requires embracing cutting-edge research strategies aimed at enhancing the management and treatment of IBM, while elevating the quality of life for those affected.
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Kumar P, Paramasivam G, Prabhu MA, Devasia T, Rajasekhar M. A novel FLNC variation associated with restrictive cardiomyopathy with an unusually long clinical course — A case report. GENE REPORTS 2023. [DOI: 10.1016/j.genrep.2023.101769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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Atang AE, Rebbeck RT, Thomas DD, Avery AW. Cardiomyopathy-associated variants alter the structure and function of the α-actinin-2 actin-binding domain. Biochem Biophys Res Commun 2023; 670:12-18. [PMID: 37271035 DOI: 10.1016/j.bbrc.2023.05.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/15/2023] [Indexed: 06/06/2023]
Abstract
Hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and restrictive cardiomyopathy (RCM) are characterized by thickening, thinning, or stiffening, respectively, of the ventricular myocardium, resulting in diastolic or systolic dysfunction that can lead to heart failure and sudden cardiac death. Recently, variants in the ACTN2 gene, encoding the protein α-actinin-2, have been reported in HCM, DCM, and RCM patients. However, functional data supporting the pathogenicity of these variants is limited, and potential mechanisms by which these variants cause disease are largely unexplored. Currently, NIH ClinVar lists 34 ACTN2 missense variants, identified in cardiomyopathy patients, which we predict are likely to disrupt actin binding, based on their localization to specific substructures in the α-actinin-2 actin binding domain (ABD). We investigated the molecular consequences of three ABD localized, HCM-associated variants: A119T, M228T and T247 M. Using circular dichroism, we demonstrate that the mutant ABD proteins can attain a well-folded state. However, thermal denaturation studies show that all three mutations are destabilizing, suggesting a structural disruption. Importantly, A119T decreased actin binding, and M228T and T247M cause increased actin binding. We suggest that altered actin binding underlies pathogenesis for cardiomyopathy mutations localizing to the ABD of α-actinin-2.
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Affiliation(s)
- Alexandra E Atang
- Department of Chemistry, Oakland University, Rochester, MI, 48309-4479, USA
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, 55455, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, 55455, USA
| | - Adam W Avery
- Department of Chemistry, Oakland University, Rochester, MI, 48309-4479, USA.
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6
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Sellung D, Heil L, Daya N, Jacobsen F, Mertens-Rill J, Zhuge H, Döring K, Piran M, Milting H, Unger A, Linke WA, Kley R, Preusse C, Roos A, Fürst DO, Ven PFMVD, Vorgerd M. Novel Filamin C Myofibrillar Myopathy Variants Cause Different Pathomechanisms and Alterations in Protein Quality Systems. Cells 2023; 12:cells12091321. [PMID: 37174721 PMCID: PMC10177260 DOI: 10.3390/cells12091321] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Myofibrillar myopathies (MFM) are a group of chronic muscle diseases pathophysiologically characterized by accumulation of protein aggregates and structural failure of muscle fibers. A subtype of MFM is caused by heterozygous mutations in the filamin C (FLNC) gene, exhibiting progressive muscle weakness, muscle structural alterations and intracellular protein accumulations. Here, we characterize in depth the pathogenicity of two novel truncating FLNc variants (p.Q1662X and p.Y2704X) and assess their distinct effect on FLNc stability and distribution as well as their impact on protein quality system (PQS) pathways. Both variants cause a slowly progressive myopathy with disease onset in adulthood, chronic myopathic alterations in muscle biopsy including the presence of intracellular protein aggregates. Our analyses revealed that p.Q1662X results in FLNc haploinsufficiency and p.Y2704X in a dominant-negative FLNc accumulation. Moreover, both protein-truncating variants cause different PQS alterations: p.Q1662X leads to an increase in expression of several genes involved in the ubiquitin-proteasome system (UPS) and the chaperone-assisted selective autophagy (CASA) system, whereas p.Y2704X results in increased abundance of proteins involved in UPS activation and autophagic buildup. We conclude that truncating FLNC variants might have different pathogenetic consequences and impair PQS function by diverse mechanisms and to varying extents. Further studies on a larger number of patients are necessary to confirm our observations.
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Affiliation(s)
- Dominik Sellung
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Lorena Heil
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Nassam Daya
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Frank Jacobsen
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Janine Mertens-Rill
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Heidi Zhuge
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Kristina Döring
- Department of Human Genetics, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Misagh Piran
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Andreas Unger
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Rudi Kley
- Department of Neurology and Clinical Neurophysiology, St. Marien-Hospital Borken, 46325 Borken, Germany
| | - Corinna Preusse
- Department of Neuropathology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Andreas Roos
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Matthias Vorgerd
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, 44789 Bochum, Germany
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Guhathakurta P, Rebbeck RT, Denha SA, Keller AR, Carter AL, Atang AE, Svensson B, Thomas DD, Hays TS, Avery AW. Early-phase drug discovery of β-III-spectrin actin-binding modulators for treatment of spinocerebellar ataxia type 5. J Biol Chem 2023; 299:102956. [PMID: 36731793 PMCID: PMC9978034 DOI: 10.1016/j.jbc.2023.102956] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/01/2023] Open
Abstract
β-III-Spectrin is a key cytoskeletal protein that localizes to the soma and dendrites of cerebellar Purkinje cells and is required for dendritic arborization and signaling. A spinocerebellar ataxia type 5 L253P mutation in the cytoskeletal protein β-III-spectrin causes high-affinity actin binding. Previously we reported a cell-based fluorescence assay for identification of small-molecule actin-binding modulators of the L253P mutant β-III-spectrin. Here we describe a complementary, in vitro, fluorescence resonance energy transfer (FRET) assay that uses purified L253P β-III-spectrin actin-binding domain (ABD) and F-actin. To validate the assay for high-throughput compatibility, we first confirmed that our 50% FRET signal was responsive to swinholide A, an actin-severing compound, and that this yielded excellent assay quality with a Z' value > 0.77. Second, we screened a 2684-compound library of US Food and Drug Administration-approved drugs. Importantly, the screening identified numerous compounds that decreased FRET between fluorescently labeled L253P ABD and F-actin. The activity and target of multiple Hit compounds were confirmed in orthologous cosedimentation actin-binding assays. Through future medicinal chemistry, the Hit compounds can potentially be developed into a spinocerebellar ataxia type 5-specific therapeutic. Furthermore, our validated FRET-based in vitro high-throughput screening platform is poised for screening large compound libraries for β-III-spectrin ABD modulators.
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Affiliation(s)
- Piyali Guhathakurta
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sarah A Denha
- Department of Chemistry, Oakland University, Rochester, Michigan, USA
| | - Amanda R Keller
- Department of Chemistry, Oakland University, Rochester, Michigan, USA
| | - Anna L Carter
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexandra E Atang
- Department of Chemistry, Oakland University, Rochester, Michigan, USA
| | - Bengt Svensson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Thomas S Hays
- Department of Genetics, Cellular Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | - Adam W Avery
- Department of Chemistry, Oakland University, Rochester, Michigan, USA.
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Savarese M, Jokela M, Udd B. Distal myopathy. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:497-519. [PMID: 37562883 DOI: 10.1016/b978-0-323-98818-6.00002-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Distal myopathies are a group of genetic, primary muscle diseases. Patients develop progressive weakness and atrophy of the muscles of forearm, hands, lower leg, or feet. Currently, over 20 different forms, presenting a variable age of onset, clinical presentation, disease progression, muscle involvement, and histological findings, are known. Some of them are dominant and some recessive. Different variants in the same gene are often associated with either dominant or recessive forms, although there is a lack of a comprehensive understanding of the genotype-phenotype correlations. This chapter provides a description of the clinicopathologic and genetic aspects of distal myopathies emphasizing known etiologic and pathophysiologic mechanisms.
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Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Manu Jokela
- Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, Tampere, Finland; Division of Clinical Neurosciences, Department of Neurology, Turku University Hospital, Turku, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland; Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, Tampere, Finland; Department of Neurology, Vaasa Central Hospital, Vaasa, Finland.
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9
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Padhan SK, Bag J, Panda M, Biswal BK, Sahoo H, Mishra M, Sahu SN. Synthesis of First Coumarin Fluorescent Dye for Actin Visualization. Bioconjug Chem 2022; 33:2113-2120. [PMID: 36264777 DOI: 10.1021/acs.bioconjchem.2c00332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Selective fluorescence imaging of actin protein hugely depends on the fluorescently labeled actin-binding domain (ABD). Thus, it is always a challenging task to image the actin protein (in vivo or in vitro) directly with an ABD-free system. To overcome the limitations of actin imaging without an ABD, we have designed a facile and cost-effective red fluorescent coumarin dye 7-hydroxy-4-methyl-8-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-ylimino)methyl-2H-chromen-2-one (CTC) for actin binding. The selective binding of the dye was investigated using the gut and eye of the model organism Drosophila melanogaster and C2C12 and SCC-9 cell lines. Our result suggests two major advantages of CTC over the dyes presently used for imaging actin proteins. First, the dye can bind to actin efficiently without any secondary intermediate. Second, it is much more stable at room temperature and exhibits excellent photostability. To the best of our knowledge, this is the first fluorescent dye that can bind to the actin protein without employing any secondary intermediate/actin-binding domain. These findings could pave the way for many biologists and physicists to successfully employ the CTC dye for imaging and tracking actin proteins by fluorescence microscopy in various in vivo and in vitro systems.
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Affiliation(s)
- Subrata Kumar Padhan
- School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Sambalpur 768019, Odisha, India
| | - Janmejaya Bag
- Neural Developmental Biology Lab, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Munmun Panda
- Cancer Drug Resistance Lab, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Bijesh Kumar Biswal
- Cancer Drug Resistance Lab, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Harekrushna Sahoo
- Biophysical and Protein Chemistry Lab, Department of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Monalisa Mishra
- Neural Developmental Biology Lab, Department of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Satya Narayan Sahu
- School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Sambalpur 768019, Odisha, India
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Cardiovascular Involvement in Pediatric FLNC Variants: A Case Series of Fourteen Patients. J Cardiovasc Dev Dis 2022; 9:jcdd9100332. [PMID: 36286284 PMCID: PMC9604120 DOI: 10.3390/jcdd9100332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Filamin C is a protein specifically expressed in myocytes and cardiomyocytes and is involved in several biological functions, including sarcomere contractile activity, signaling, cellular adhesion, and repair. FLNC variants are associated with different disorders ranging from striated muscle (myofibrillar distal or proximal) myopathy to cardiomyopathies (CMPs) (restrictive, hypertrophic, and dilated), or both. The outcome depends on functional consequences of the detected variants, which result either in FLNC haploinsufficiency or in an aberrant protein, the latter affecting sarcomere structure leading to protein aggregates. Cardiac manifestations of filaminopathies are most often described as adult onset CMPs and limited reports are available in children or on other cardiac spectrums (congenital heart defects-CHDs, or arrhythmias). Here we report on 13 variants in 14 children (2.8%) out of 500 pediatric patients with early-onset different cardiac features ranging from CMP to arrhythmias and CHDs. In one patient, we identified a deletion encompassing FLNC detected by microarray, which was overlooked by next generation sequencing. We established a potential genotype-phenotype correlation of the p.Ala1186Val variant in severe and early-onset restrictive cardiomyopathy (RCM) associated with a limb-girdle defect (two new patients in addition to the five reported in the literature). Moreover, in three patients (21%), we identified a relatively frequent finding of long QT syndrome (LQTS) associated with RCM (n = 2) and a hypertrabeculated left ventricle (n = 1). RCM and LQTS in children might represent a specific red flag for FLNC variants. Further studies are warranted in pediatric cohorts to delineate potential expanding phenotypes related to FLNC.
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11
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Muravyev A, Vershinina T, Tesner P, Sjoberg G, Fomicheva Y, Čajbiková NN, Kozyreva A, Zhuk S, Mamaeva E, Tarnovskaya S, Jornholt J, Sokolnikova P, Pervunina T, Vasichkina E, Sejersen T, Kostareva A. Rare clinical phenotype of filaminopathy presenting as restrictive cardiomyopathy and myopathy in childhood. Orphanet J Rare Dis 2022; 17:358. [PMID: 36104822 PMCID: PMC9476594 DOI: 10.1186/s13023-022-02477-5] [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: 03/02/2022] [Accepted: 08/13/2022] [Indexed: 11/10/2022] Open
Abstract
Background FLNC is one of the few genes associated with all types of cardiomyopathies, but it also underlies neuromuscular phenotype. The combination of concomitant neuromuscular and cardiac involvement is not often observed in filaminopathies and the impact of this on the disease prognosis has hitherto not been analyzed. Results Here we provide a detailed clinical, genetic, and structural prediction analysis of distinct FLNC-associated phenotypes based on twelve pediatric cases. They include early-onset restrictive cardiomyopathy (RCM) in association with congenital myopathy. In all patients the initial diagnosis was established during the first year of life and in five out of twelve (41.7%) patients the first symptoms were observed at birth. RCM was present in all patients, often in combination with septal defects. No ventricular arrhythmias were noted in any of the patients presented here. Myopathy was confirmed by neurological examination, electromyography, and morphological studies. Arthrogryposes was diagnosed in six patients and remained clinically meaningful with increasing age in three of them. One patient underwent successful heart transplantation at the age of 18 years and two patients are currently included in the waiting list for heart transplantation. Two died due to congestive heart failure. One patient had ICD instally as primary prevention of SCD. In ten out of twelve patients the disease was associated with missense variants and only in two cases loss of function variants were detected. In half of the described cases, an amino acid substitution A1186V, altering the structure of IgFLNc10, was found. Conclusions The present description of twelve cases of early-onset restrictive cardiomyopathy with congenital myopathy and FLNC mutation, underlines a distinct unique phenotype that can be suggested as a separate clinical form of filaminopathies. Amino acid substitution A1186V, which was observed in half of the cases, defines a mutational hotspot for the reported combination of myopathy and cardiomyopathy. Several independent molecular mechanisms of FLNC mutations linked to filamin structure and function can explain the broad spectrum of FLNC-associated phenotypes. Early disease presentation and unfavorable prognosis of heart failure demanding heart transplantation make awareness of this clinical form of filaminopathy of great clinical importance. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02477-5.
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12
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Velardo D, D'Angelo MG, Citterio A, Panzeri E, Napoli L, Cinnante C, Moggio M, Comi GP, Ronchi D, Bassi MT. Case Reports: Novel Missense Variants in the Filamin C Actin Binding Domain Cause Variable Phenotypes. Front Neurol 2022; 13:930039. [PMID: 35903116 PMCID: PMC9315448 DOI: 10.3389/fneur.2022.930039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/22/2022] [Indexed: 11/24/2022] Open
Abstract
Filamin C is a large dimeric actin-binding protein, most prevalent in skeletal and cardiac muscle Z-discs, where it participates in sarcomere mechanical stabilization and intracellular signaling, interacting with numerous binding partners. Dominant heterozygous mutations of Filamin C gene cause several forms of myopathy and structural or arrhythmogenic cardiomyopathy. In this report we describe clinical and molecular findings of two Italian patients, in whom we identified two novel missense variants located within the Filamin C actin binding domain. Muscle imaging, histological and ultrastructural findings are also reported. Our results underline the extreme inter- and intrafamilial variability of clinical manifestations, hence the need to extend the investigation also to asymptomatic relatives, and the relevance of a broad diagnostic approach involving muscle electron microscopy, skeletal muscle magnetic resonance imaging and next generation sequencing techniques.
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Affiliation(s)
- Daniele Velardo
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
- *Correspondence: Daniele Velardo
| | - Maria Grazia D'Angelo
- NeuroMuscular Unit, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) E. Medea, Bosisio Parini, Italy
| | - Andrea Citterio
- Laboratory of Molecular Biology, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) E. Medea, Bosisio Parini, Italy
| | - Elena Panzeri
- Laboratory of Molecular Biology, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) E. Medea, Bosisio Parini, Italy
| | - Laura Napoli
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
| | - Claudia Cinnante
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuroradiology Unit, Milan, Italy
- Department of Radiology, Istituto Auxologico Italiano, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS), Milan, Italy
| | - Maurizio Moggio
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
| | - Giacomo Pietro Comi
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Milan, Italy
- Department of Pathophysiology and Transplantation, Dino Ferrari Center, Neuroscience Section, University of Milan, Milan, Italy
| | - Dario Ronchi
- Department of Pathophysiology and Transplantation, Dino Ferrari Center, Neuroscience Section, University of Milan, Milan, Italy
| | - Maria Teresa Bassi
- Laboratory of Molecular Biology, Scientific Institute for Research, Hospitalization and Healthcare (IRCCS) E. Medea, Bosisio Parini, Italy
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13
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Genetic Insights into Primary Restrictive Cardiomyopathy. J Clin Med 2022; 11:jcm11082094. [PMID: 35456187 PMCID: PMC9027761 DOI: 10.3390/jcm11082094] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 12/04/2022] Open
Abstract
Restrictive cardiomyopathy is a rare cardiac disease causing severe diastolic dysfunction, ventricular stiffness and dilated atria. In consequence, it induces heart failure often with preserved ejection fraction and is associated with a high mortality. Since it is a poor clinical prognosis, patients with restrictive cardiomyopathy frequently require heart transplantation. Genetic as well as non-genetic factors contribute to restrictive cardiomyopathy and a significant portion of cases are of unknown etiology. However, the genetic forms of restrictive cardiomyopathy and the involved molecular pathomechanisms are only partially understood. In this review, we summarize the current knowledge about primary genetic restrictive cardiomyopathy and describe its genetic landscape, which might be of interest for geneticists as well as for cardiologists.
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Matsumura T, Inoue K, Toyooka K, Inoue M, Iida A, Saito Y, Nishikawa T, Moriuchi K, Beck G, Nishino I, Fujimura H. Clinical trajectory of a patient with filaminopathy who developed arrhythmogenic cardiomyopathy, myofibrillar myopathy, and multiorgan tumors. Neuromuscul Disord 2021; 31:1282-1286. [PMID: 34857437 DOI: 10.1016/j.nmd.2021.10.002] [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: 02/19/2021] [Revised: 08/05/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022]
Abstract
We report a case of a patient presenting with arrhythmogenic cardiomyopathy, myofibrillar myopathy, and multiorgan tumors. A 41-year-old woman with a history of hypertrophic cardiomyopathy, diagnosed at 6 years of age, developed scoliosis after puberty. Following spinal surgery to address the scoliosis, she developed recurrent severe arrhythmia and heart failure. She developed hypoventilation at age 29 years. Proximal dominant weakness and mild elevation of serum creatine kinase indicated possible myopathy. Myofibrillar myopathy was diagnosed by muscle biopsy at age 30 year. Acute abdomen was repeatedly reported from age 33 years, eventually leading to a diagnosis of gastric polyp and erosive ulcer. A urinary bladder tumor was found at age 35 years, and breast cancer was diagnosed at age 40 years. Whole exome sequencing detected a heterozygous missense mutation in Filamin C. Recent evidences suggest that filamins are associated with tumors, and this case further highlights the clinical spectrum of filaminopathy.
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Affiliation(s)
- Tsuyoshi Matsumura
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, Toneyama 5-1-1, Toyonaka, Osaka 560-8552, Japan.
| | - Kimiko Inoue
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, Toneyama 5-1-1, Toyonaka, Osaka 560-8552, Japan
| | - Keiko Toyooka
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, Toneyama 5-1-1, Toyonaka, Osaka 560-8552, Japan
| | - Michio Inoue
- Department of Neuromuscular Research, National Center of Neurology, Psychiatry, Ogawahigashi 4-1-1, Kodaira, Tokyo 187-8551, Japan
| | - Aritoshi Iida
- Department of Neuromuscular Research, National Center of Neurology, Psychiatry, Ogawahigashi 4-1-1, Kodaira, Tokyo 187-8551, Japan
| | - Yoshihiko Saito
- Department of Neuromuscular Research, National Center of Neurology, Psychiatry, Ogawahigashi 4-1-1, Kodaira, Tokyo 187-8551, Japan
| | - Tatsuya Nishikawa
- Department of Onco-Cardiology, Osaka International Cancer Institute, Otemae 3-1-69, Chuo-ku, Osaka City, Osaka, 541-8567, Japan
| | - Kenji Moriuchi
- Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Kishibe-Shinmachi 6-1, Suita, Osaka 564-8565, Japan
| | - Goichi Beck
- Department of Neurology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, Osaka 565-0871, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Center of Neurology, Psychiatry, Ogawahigashi 4-1-1, Kodaira, Tokyo 187-8551, Japan
| | - Harutoshi Fujimura
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, Toneyama 5-1-1, Toyonaka, Osaka 560-8552, Japan
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Abstract
Cardiomyopathy affects approximately 1 in 500 adults and is the leading cause of death. Familial cases are common, and mutations in many genes are involved in cardiomyopathy, especially those in genes encoding cytoskeletal, sarcomere, and nuclear envelope proteins. Filamin C is an actin-binding protein encoded by filamin C (FLNC) gene and participates in sarcomere stability maintenance. FLNC was first demonstrated to be a causal gene of myofibrillar myopathy; recently, it has been found that FLNC mutation plays a critical role in the pathogenesis of cardiomyopathy. In this review, we summarized the physiological roles of filamin C in cardiomyocytes and the genetic evidence for links between FLNC mutations and cardiomyopathies. Truncated FLNC is enriched in dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Non-truncated FLNC is enriched in hypertrophic cardiomyopathy and restrictive cardiomyopathy. Two major pathomechanisms in FLNC-related cardiomyopathy have been described: protein aggregation resulting from non-truncating mutations and haploinsufficiency triggered by filamin C truncation. Therefore, it is important to understand the cellular biology and molecular regulation of FLNC to design new therapies to treat patients with FLNC-related cardiomyopathy.
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16
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Chen L, Chen DF, Dong HL, Liu GL, Wu ZY. A novel frameshift ACTN2 variant causes a rare adult-onset distal myopathy with multi-minicores. CNS Neurosci Ther 2021; 27:1198-1205. [PMID: 34170073 PMCID: PMC8446211 DOI: 10.1111/cns.13697] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 02/07/2023] Open
Abstract
Introduction Distal myopathies are a group of rare muscle disorders characterized by selective or predominant weakness in the feet and/or hands. In 2019, ACTN2 gene was firstly identified to be a cause of a new adult‐onset distal muscular dystrophy calling actininopathy and another distinctly different myopathy, named multiple structured core disease (MsCD). Thus, the various phenotypes and limited mutations in ACTN2‐related myopathy make the genotype‐phenotype correlation hard to understand. Aims To investigate the clinical features and histological findings in a Chinese family with distal myopathy. Whole exome sequencing and several functional studies were performed to explore the pathogenesis of the disease. Results We firstly identified a novel frameshift variant (c.2504delT, p.Phe835Serfs*66) within ACTN2 in a family including three patients. The patients exhibited adult‐onset distal myopathy with multi‐minicores, which, interestingly, was more like a combination of MsCD and actininopathy. Moreover, functional analysis using muscle samples revealed that the variant significantly increased the expression level of α‐actinin‐2 and resulted in abnormal Z‐line organization of muscle fiber. Vitro studies suggested aggregate formations might be involved in the pathogenesis of the disease. Conclusion Our results expanded the phenotypes of ACTN2‐related myopathy and provided helpful information to clarify the molecular mechanisms.
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Affiliation(s)
- Lei 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
| | - Dian-Fu 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
| | - 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
| | - 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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17
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Kley RA, Leber Y, Schrank B, Zhuge H, Orfanos Z, Kostan J, Onipe A, Sellung D, Güttsches AK, Eggers B, Jacobsen F, Kress W, Marcus K, Djinovic-Carugo K, van der Ven PFM, Fürst DO, Vorgerd M. FLNC-Associated Myofibrillar Myopathy: New Clinical, Functional, and Proteomic Data. NEUROLOGY-GENETICS 2021; 7:e590. [PMID: 34235269 PMCID: PMC8237399 DOI: 10.1212/nxg.0000000000000590] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/28/2020] [Indexed: 11/15/2022]
Abstract
Objective To determine whether a new indel mutation in the dimerization domain of filamin C (FLNc) causes a hereditary myopathy with protein aggregation in muscle fibers, we clinically and molecularly studied a German family with autosomal dominant myofibrillar myopathy (MFM). Methods We performed mutational analysis in 3 generations, muscle histopathology, and proteomic studies of IM protein aggregates. Functional consequences of the FLNC mutation were investigated with interaction and transfection studies and biophysics molecular analysis. Results Eight patients revealed clinical features of slowly progressive proximal weakness associated with a heterozygous c.8025_8030delCAAGACinsA (p.K2676Pfs*3) mutation in FLNC. Two patients exhibited a mild cardiomyopathy. MRI of skeletal muscle revealed lipomatous changes typical for MFM with FLNC mutations. Muscle biopsies showed characteristic MFM findings with protein aggregation and lesion formation. The proteomic profile of aggregates was specific for MFM-filaminopathy and indicated activation of the ubiquitin-proteasome system (UPS) and autophagic pathways. Functional studies revealed that mutant FLNc is misfolded, unstable, and incapable of forming homodimers and heterodimers with wild-type FLNc. Conclusions This new MFM-filaminopathy family confirms that expression of mutant FLNC leads to an adult-onset muscle phenotype with intracellular protein accumulation. Mutant FLNc protein is biochemically compromised and leads to dysregulation of protein quality control mechanisms. Proteomic analysis of MFM protein aggregates is a potent method to identify disease-relevant proteins, differentiate MFM subtypes, evaluate the relevance of gene variants, and identify novel MFM candidate genes.
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Affiliation(s)
- Rudolf Andre Kley
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Yvonne Leber
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Bertold Schrank
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Heidi Zhuge
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Zacharias Orfanos
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Julius Kostan
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Adekunle Onipe
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Dominik Sellung
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Anne Katrin Güttsches
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Britta Eggers
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Frank Jacobsen
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Wolfram Kress
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Katrin Marcus
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Kristina Djinovic-Carugo
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Peter F M van der Ven
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Dieter O Fürst
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Matthias Vorgerd
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
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18
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Fadel S, Walker AE. The Postmortem Interpretation of Cardiac Genetic Variants of Unknown Significance in Sudden Death in the Young: A Case Report and Review of the Literature. Acad Forensic Pathol 2021; 10:166-175. [PMID: 33815637 DOI: 10.1177/1925362120984868] [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: 05/18/2020] [Accepted: 10/04/2020] [Indexed: 11/16/2022]
Abstract
Sudden cardiac death (SCD) in adolescents and young adults is a major traumatic event for families and communities. In these cases, it is not uncommon to have a negative autopsy with structurally and histologically normal heart. Such SCD cases are generally attributed to channelopathies, which include long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Our understanding of the causes for SCDs has changed significantly with the advancements in molecular and genetic studies, where many mutations are now known to be associated with certain channelopathies. Postmortem analysis provides great value in informing decision-making with regard to screening tests and prophylactic measures that should be taken to prevent sudden death in first degree relatives of the decedent. As this is a rapidly advancing field, our ability to identify genetic mutations has surpassed our ability to interpret them. This led to a unique challenge in genetic testing called variants of unknown significance (VUS). VUSs present a diagnostic dilemma and uncertainty for clinicians and patients with regard to next steps. Caution should be exercised when interpreting VUSs since misinterpretation can result in mismanagement of patients and their families. A case of a young adult man with drowning as his proximate cause of death is presented in circumstances where cardiac genetic testing was indicated and undertaken. Eight VUSs in genes implicated in inheritable cardiac dysfunction were identified and the interpretation of VUSs in this scenario is discussed.
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19
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The Role of Z-disc Proteins in Myopathy and Cardiomyopathy. Int J Mol Sci 2021; 22:ijms22063058. [PMID: 33802723 PMCID: PMC8002584 DOI: 10.3390/ijms22063058] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/07/2021] [Accepted: 03/11/2021] [Indexed: 12/11/2022] Open
Abstract
The Z-disc acts as a protein-rich structure to tether thin filament in the contractile units, the sarcomeres, of striated muscle cells. Proteins found in the Z-disc are integral for maintaining the architecture of the sarcomere. They also enable it to function as a (bio-mechanical) signalling hub. Numerous proteins interact in the Z-disc to facilitate force transduction and intracellular signalling in both cardiac and skeletal muscle. This review will focus on six key Z-disc proteins: α-actinin 2, filamin C, myopalladin, myotilin, telethonin and Z-disc alternatively spliced PDZ-motif (ZASP), which have all been linked to myopathies and cardiomyopathies. We will summarise pathogenic variants identified in the six genes coding for these proteins and look at their involvement in myopathy and cardiomyopathy. Listing the Minor Allele Frequency (MAF) of these variants in the Genome Aggregation Database (GnomAD) version 3.1 will help to critically re-evaluate pathogenicity based on variant frequency in normal population cohorts.
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20
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Schänzer A, Schumann E, Zengeler D, Gulatz L, Maroli G, Ahting U, Sprengel A, Gräf S, Hahn A, Jux C, Acker T, Fürst DO, Rupp S, Schuld J, van der Ven PFM. The p.Ala2430Val mutation in filamin C causes a "hypertrophic myofibrillar cardiomyopathy". J Muscle Res Cell Motil 2021; 42:381-397. [PMID: 33710525 DOI: 10.1007/s10974-021-09601-1] [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: 04/03/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) often leads to heart failure. Mutations in sarcomeric proteins are most frequently the cause of HCM but in many patients the gene defect is not known. Here we report on a young man who was diagnosed with HCM shortly after birth. Whole exome sequencing revealed a mutation in the FLNC gene (c.7289C > T; p.Ala2430Val) that was previously shown to cause aggregation of the mutant protein in transfected cells. Myocardial tissue from patients with this mutation has not been analyzed before and thus, the underlying etiology is not well understood. Myocardial tissue of our patient obtained during myectomy at the age of 23 years was analyzed in detail by histochemistry, immunofluorescence staining, electron microscopy and western blot analysis. Cardiac histology showed a pathology typical for myofibrillar myopathy with myofibril disarray and abnormal protein aggregates containing BAG3, desmin, HSPB5 and filamin C. Analysis of sarcomeric and intercalated disc proteins showed focally reduced expression of the gap junction protein connexin43 and Xin-positive sarcomeric lesions in the cardiomyocytes of our patient. In addition, autophagy pathways were altered with upregulation of LC3-II, WIPI1 and HSPB5, 6, 7 and 8. We conclude that the p.Ala2430Val mutation in FLNC most probably is associated with HCM characterized by abnormal intercalated discs, disarray of myofibrils and aggregates containing Z-disc proteins similar to myofibrillar myopathy, which supports the pathological effect of the mutation.
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Affiliation(s)
- Anne Schänzer
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany.
| | - Elisabeth Schumann
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Diana Zengeler
- Center for Genomics and Transcriptomics (CeGat) GmbH, Tübingen, Germany
| | - Lisann Gulatz
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Giovanni Maroli
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Uwe Ahting
- Institute of Human Genetics, Technical University of Munich (TUM), Munich, Germany
| | - Anke Sprengel
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Sabine Gräf
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Andreas Hahn
- Department of Child Neurology, Justus Liebig University, Giessen, Germany
| | - Christian Jux
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Till Acker
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Stefan Rupp
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Julia Schuld
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
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21
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Williams ZJ, Velez-Irizarry D, Petersen JL, Ochala J, Finno CJ, Valberg SJ. Candidate gene expression and coding sequence variants in Warmblood horses with myofibrillar myopathy. Equine Vet J 2021; 53:306-315. [PMID: 32453872 PMCID: PMC7864122 DOI: 10.1111/evj.13286] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/18/2020] [Accepted: 05/02/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Myofibrillar myopathy (MFM) of unknown aetiology has recently been identified in Warmblood (WB) horses. In humans, 16 genes have been implicated in various MFM-like disorders. OBJECTIVES To identify variants in 16 MFM candidate genes and compare allele frequencies of all variants between MFM WB and non-MFM WB and coding variants with moderate or severe predicted effects in MFM WB with publicly available data of other breeds. To compare differential gene expression and muscle fibre contractile force between MFM and non-MFM WB. STUDY DESIGN Case-control. ANIMALS 8 MFM WB, 8 non-MFM WB, 33 other WB, 32 Thoroughbreds, 80 Quarter Horses and 77 horses of other breeds in public databases. METHODS Variants were called within transcripts of 16 candidate genes using gluteal muscle mRNA sequences aligned to EquCab3.0 and allele frequencies compared by Fisher's exact test among MFM WB, non-MFM WB and public sequences across breeds. Candidate gene differential expression was determined between MFM and non-MFM WB by fitting a negative binomial generalised log-linear model per gene (false discovery rate <0.05). The maximal isometric force/cross-sectional area generated by isolated membrane-permeabilised muscle fibres was determined. RESULTS None of the 426 variants identified in 16 candidate genes were associated with MFM including 26 missense variants. Breed-specific differences existed in allele frequencies. Candidate gene differential expression and muscle fibre-specific force did not differ between MFM WB (143.1 ± 34.7 kPa) and non-MFM WB (140.2 ± 43.7 kPa) (P = .8). MAIN LIMITATIONS RNA-seq-only assays transcripts expressed in skeletal muscle. Other possible candidate genes were not evaluated. CONCLUSIONS Evidence for association of variants with a disease is essential because coding sequence variants are common in the equine genome. Variants identified in MFM candidate genes, including two coding variants offered as commercial MFM equine genetic tests, did not associate with the WB MFM phenotype.
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Affiliation(s)
- Zoë J. Williams
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
| | - Deborah Velez-Irizarry
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
| | - Jessica L. Petersen
- Department of Animal Science, University of Nebraska Lincoln, Lincoln, NE, USA
| | - Julien Ochala
- Faculty of Life Sciences and Medicine, King’s College London, London, UK
| | - Carrie J. Finno
- University of California at Davis, School of Veterinary Medicine, Davis, CA, USA
| | - Stephanie J. Valberg
- Large Animal Clinical Sciences, Michigan State University, College of Veterinary Medicine, East Lansing, MI, USA
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22
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Evangelista T, Lornage X, Carlier PG, Bassez G, Brochier G, Chanut A, Lacène E, Bui MT, Metay C, Oppermann U, Böhm J, Laporte J, Romero NB. A Heterozygous Mutation in the Filamin C Gene Causes an Unusual Nemaline Myopathy With Ring Fibers. J Neuropathol Exp Neurol 2021; 79:908-914. [PMID: 32607581 DOI: 10.1093/jnen/nlaa052] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Indexed: 11/13/2022] Open
Abstract
Autosomal dominant pathogenic variants in the filamin C gene (FLNC) have been associated with myofibrillar myopathies, distal myopathies, and isolated cardiomyopathies. Mutations in different functional domains of FLNC can cause various clinical phenotypes. A novel heterozygous missense variant c.608G>A, p.(Cys203Tyr) in the actin binding domain of FLCN was found to cause an upper limb distal myopathy (MIM #614065). The muscle MRI findings are similar to those observed in FLNC-myofibrillar myopathy (MIM #609524). However, the muscle biopsy revealed >20% of muscle fibers with nemaline bodies, in addition to numerous ring fibers and a predominance of type 1 fibers. Overall, this case shows some unique and rare aspects of FLNC-myopathy constituting a new morphologic phenotype of FLNC-related myopathies.
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Affiliation(s)
- Teresinha Evangelista
- From the Neuromuscular Morphology Unit, Myology Institute.,Sorbonne Université, AP-HP, INSERM, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Xavière Lornage
- Department of Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch, France
| | | | - Guillaume Bassez
- From the Neuromuscular Morphology Unit, Myology Institute.,Sorbonne Université, AP-HP, INSERM, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Guy Brochier
- From the Neuromuscular Morphology Unit, Myology Institute.,Sorbonne Université, AP-HP, INSERM, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Anais Chanut
- From the Neuromuscular Morphology Unit, Myology Institute
| | - Emmanuelle Lacène
- From the Neuromuscular Morphology Unit, Myology Institute.,Sorbonne Université, AP-HP, INSERM, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Mai-Thao Bui
- From the Neuromuscular Morphology Unit, Myology Institute
| | - Corinne Metay
- AP-HP, Centre de Génétique Moléculaire et Chromosomique, UF de Cardiomyogénétique et Myogénétique Moléculaire et Cellulaire, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Ursula Oppermann
- Department of Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch, France
| | - Johann Böhm
- Department of Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch, France
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM U1258, CNRS UMR7104, Université de Strasbourg, Illkirch, France
| | - Norma B Romero
- From the Neuromuscular Morphology Unit, Myology Institute.,Sorbonne Université, AP-HP, INSERM, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
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23
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Rozas P, Pinto C, Martínez Traub F, Díaz R, Pérez V, Becerra D, Ojeda P, Ojeda J, Wright MT, Mella J, Plate L, Henríquez JP, Hetz C, Medinas DB. Protein disulfide isomerase ERp57 protects early muscle denervation in experimental ALS. Acta Neuropathol Commun 2021; 9:21. [PMID: 33541434 PMCID: PMC7863244 DOI: 10.1186/s40478-020-01116-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/30/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease that affects motoneurons. Mutations in superoxide dismutase 1 (SOD1) have been described as a causative genetic factor for ALS. Mice overexpressing ALS-linked mutant SOD1 develop ALS symptoms accompanied by histopathological alterations and protein aggregation. The protein disulfide isomerase family member ERp57 is one of the main up-regulated proteins in tissue of ALS patients and mutant SOD1 mice, whereas point mutations in ERp57 were described as possible risk factors to develop the disease. ERp57 catalyzes disulfide bond formation and isomerization in the endoplasmic reticulum (ER), constituting a central component of protein quality control mechanisms. However, the actual contribution of ERp57 to ALS pathogenesis remained to be defined. Here, we studied the consequences of overexpressing ERp57 in experimental ALS using mutant SOD1 mice. Double transgenic SOD1G93A/ERp57WT animals presented delayed deterioration of electrophysiological activity and maintained muscle innervation compared to single transgenic SOD1G93A littermates at early-symptomatic stage, along with improved motor performance without affecting survival. The overexpression of ERp57 reduced mutant SOD1 aggregation, but only at disease end-stage, dissociating its role as an anti-aggregation factor from the protection of neuromuscular junctions. Instead, proteomic analysis revealed that the neuroprotective effects of ERp57 overexpression correlated with increased levels of synaptic and actin cytoskeleton proteins in the spinal cord. Taken together, our results suggest that ERp57 operates as a disease modifier at early stages by maintaining motoneuron connectivity.
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Affiliation(s)
- Pablo Rozas
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Cristina Pinto
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Concepción, Chile
| | - Francisca Martínez Traub
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Rodrigo Díaz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Viviana Pérez
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Concepción, Chile
| | - Daniela Becerra
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Patricia Ojeda
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Jorge Ojeda
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Concepción, Chile
| | - Madison T Wright
- Department of Chemistry and Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Jessica Mella
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Concepción, Chile
| | - Lars Plate
- Department of Chemistry and Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Juan Pablo Henríquez
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA Bio-Bio), Universidad de Concepción, Concepción, Chile
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile.
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.
- Buck Institute for Research on Aging, Novato, CA, USA.
| | - Danilo B Medinas
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Independencia 1027, P.O. Box 70086, Santiago, Chile.
- Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.
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24
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Qin X, Li P, Qu HQ, Liu Y, Xia Y, Chen S, Yang Y, Huang S, Wen P, Zhou X, Li X, Wang Y, Tian L, Hakonarson H, Wu Y, Zhuang J. FLNC and MYLK2 Gene Mutations in a Chinese Family with Different Phenotypes of Cardiomyopathy. Int Heart J 2021; 62:127-134. [PMID: 33455984 DOI: 10.1536/ihj.20-351] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mutations in the sarcomeric protein filamin C (FLNC) gene have been linked to hypertrophic cardiomyopathy (HCM), as they have been determined to increase the risk of ventricular arrhythmia and sudden death. Thus, in this study, we identified a novel missense mutation of FLNC in a Chinese family with HCM, and, interestingly, a second novel truncating mutation of MYLK2 was discobered in one family member with different phenotype.We performed whole-exome sequencing in a Chinese family with HCM of unknown cause. To determine and confirm the function of a novel mutation of FLNC, we introduced the mutant and wild-type gene into AC16 cells (human cardiomyocytes): we then used western blotting to analyze the expression of FLNC in subcellular fractions, and confocal microscope to observe the subcellular distribution of the protein.As per our findings, we were able to identify a novel missense single nucleotide variant (FLNC c.G5935A [p.A1979T]) in the family, which segregates with the disease. FLNC expression levels were observed to be equivalent in both wild-type and p.A1979T cardiomyocytes. However, the expression of the mutant protein has resulted in cytoplasmic protein aggregations, in contrast to wild-type FLNC, which was distributed in the cytoplasm and did not form aggregates. Unexpectedly, a second truncating mutation, NM_033118:exon8:c.G1138T:p.E380X of the MYLK2 gene, was identified in the mother of the proband with dilated cardiomyopathy, which was not found in other subjects.We then identified the FLNC A1979T mutation as a novel pathogenic variant associated with HCM in a Chinese family as well as a second causal mutation in a family member with a distinct phenotype. The possibility that there is more than one causal mutation in cardiomyopathy warrants clinical attention, especially for patients with atypical clinical features.
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Affiliation(s)
- Xianyu Qin
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Ping Li
- Prenatal Diagnosis Center, Department of Obstetrics and Gynecology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Hui-Qi Qu
- Center for Applied Genomics, The Children's Hospital of Philadelphia
| | - Yichuan Liu
- Center for Applied Genomics, The Children's Hospital of Philadelphia
| | - Yu Xia
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Shaoxian Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Yongchao Yang
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Shufang Huang
- Center for Applied Genomics, The Children's Hospital of Philadelphia
| | - Pengju Wen
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Xianwu Zhou
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Xiaofeng Li
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Yonghua Wang
- Prenatal Diagnosis Center, Department of Obstetrics and Gynecology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Lifeng Tian
- Center for Applied Genomics, The Children's Hospital of Philadelphia
| | - Hakon Hakonarson
- Center for Applied Genomics, The Children's Hospital of Philadelphia.,Department of Pediatrics and Division of Human Genetics, University of Pennsylvania
| | - Yueheng Wu
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Jian Zhuang
- Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
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25
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Rebbeck RT, Andrick AK, Denha SA, Svensson B, Guhathakurta P, Thomas DD, Hays TS, Avery AW. Novel drug discovery platform for spinocerebellar ataxia, using fluorescence technology targeting β-III-spectrin. J Biol Chem 2021; 296:100215. [PMID: 33839680 PMCID: PMC7948455 DOI: 10.1074/jbc.ra120.015417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/30/2020] [Accepted: 12/21/2020] [Indexed: 02/02/2023] Open
Abstract
Numerous diseases are linked to mutations in the actin-binding domains (ABDs) of conserved cytoskeletal proteins, including β-III-spectrin, α-actinin, filamin, and dystrophin. A β-III-spectrin ABD mutation (L253P) linked to spinocerebellar ataxia type 5 (SCA5) causes a dramatic increase in actin binding. Reducing actin binding of L253P is thus a potential therapeutic approach for SCA5 pathogenesis. Here, we validate a high-throughput screening (HTS) assay to discover potential disrupters of the interaction between the mutant β-III-spectrin ABD and actin in live cells. This assay monitors FRET between fluorescent proteins fused to the mutant ABD and the actin-binding peptide Lifeact, in HEK293-6E cells. Using a specific and high-affinity actin-binding tool compound, swinholide A, we demonstrate HTS compatibility with an excellent Z'-factor of 0.67 ± 0.03. Screening a library of 1280 pharmacologically active compounds in 1536-well plates to determine assay robustness, we demonstrate high reproducibility across plates and across days. We identified nine Hits that reduced FRET between Lifeact and ABD. Four of those Hits were found to reduce Lifeact cosedimentation with actin, thus establishing the potential of our assay for detection of actin-binding modulators. Concurrent to our primary FRET assay, we also developed a high-throughput compatible counter screen to remove undesirable FRET Hits. Using the FRET Hits, we show that our counter screen is sensitive to undesirable compounds that cause cell toxicity or ABD aggregation. Overall, our FRET-based HTS platform sets the stage to screen large compound libraries for modulators of β-III-spectrin, or disease-linked spectrin-related proteins, for therapeutic development.
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Affiliation(s)
- Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Anna K Andrick
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sarah A Denha
- Department of Chemistry, Oakland University, Rochester, Michigan, USA
| | - Bengt Svensson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Piyali Guhathakurta
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Thomas S Hays
- Department of Genetics, Cellular Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA
| | - Adam W Avery
- Department of Chemistry, Oakland University, Rochester, Michigan, USA; Department of Genetics, Cellular Biology, and Development, University of Minnesota, Minneapolis, Minnesota, USA.
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26
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Lamsoul I, Dupré L, Lutz PG. Molecular Tuning of Filamin A Activities in the Context of Adhesion and Migration. Front Cell Dev Biol 2020; 8:591323. [PMID: 33330471 PMCID: PMC7714767 DOI: 10.3389/fcell.2020.591323] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/05/2020] [Indexed: 01/08/2023] Open
Abstract
The dynamic organization of actin cytoskeleton meshworks relies on multiple actin-binding proteins endowed with distinct actin-remodeling activities. Filamin A is a large multi-domain scaffolding protein that cross-links actin filaments with orthogonal orientation in response to various stimuli. As such it plays key roles in the modulation of cell shape, cell motility, and differentiation throughout development and adult life. The essentiality and complexity of Filamin A is highlighted by mutations that lead to a variety of severe human disorders affecting multiple organs. One of the most conserved activity of Filamin A is to bridge the actin cytoskeleton to integrins, thereby maintaining the later in an inactive state. We here review the numerous mechanisms cells have developed to adjust Filamin A content and activity and focus on the function of Filamin A as a gatekeeper to integrin activation and associated adhesion and motility.
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Affiliation(s)
- Isabelle Lamsoul
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Loïc Dupré
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France.,Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria
| | - Pierre G Lutz
- Centre de Physiopathologie de Toulouse Purpan, INSERM, CNRS, Université de Toulouse, UPS, Toulouse, France
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27
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Savarese M, Sarparanta J, Vihola A, Jonson PH, Johari M, Rusanen S, Hackman P, Udd B. Panorama of the distal myopathies. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2020; 39:245-265. [PMID: 33458580 PMCID: PMC7783427 DOI: 10.36185/2532-1900-028] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Distal myopathies are genetic primary muscle disorders with a prominent weakness at onset in hands and/or feet. The age of onset (from early childhood to adulthood), the distribution of muscle weakness (upper versus lower limbs) and the histological findings (ranging from nonspecific myopathic changes to myofibrillar disarrays and rimmed vacuoles) are extremely variable. However, despite being characterized by a wide clinical and genetic heterogeneity, the distal myopathies are a category of muscular dystrophies: genetic diseases with progressive loss of muscle fibers. Myopathic congenital arthrogryposis is also a form of distal myopathy usually caused by focal amyoplasia. Massive parallel sequencing has further expanded the long list of genes associated with a distal myopathy, and contributed identifying as distal myopathy-causative rare variants in genes more often related with other skeletal or cardiac muscle diseases. Currently, almost 20 genes (ACTN2, CAV3, CRYAB, DNAJB6, DNM2, FLNC, HNRNPA1, HSPB8, KHLH9, LDB3, MATR3, MB, MYOT, PLIN4, TIA1, VCP, NOTCH2NLC, LRP12, GIPS1) have been associated with an autosomal dominant form of distal myopathy. Pathogenic changes in four genes (ADSSL, ANO5, DYSF, GNE) cause an autosomal recessive form; and disease-causing variants in five genes (DES, MYH7, NEB, RYR1 and TTN) result either in a dominant or in a recessive distal myopathy. Finally, a digenic mechanism, underlying a Welander-like form of distal myopathy, has been recently elucidated. Rare pathogenic mutations in SQSTM1, previously identified with a bone disease (Paget disease), unexpectedly cause a distal myopathy when combined with a common polymorphism in TIA1. The present review aims at describing the genetic basis of distal myopathy and at summarizing the clinical features of the different forms described so far.
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Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Jaakko Sarparanta
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Anna Vihola
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Neuromuscular Research Center, Department of Genetics, Fimlab Laboratories, Tampere, Finland
| | - Per Harald Jonson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Salla Rusanen
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
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28
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Almalki D, Ali A. Rare Genetic Variant of Distal Myopathy with Posterior Leg and Anterior Hand Involvement: Case Report. Open Neurol J 2020. [DOI: 10.2174/1874205x02014010093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Distal myopathies are a heterogeneous group of genetic muscle disorders characterized by weakness of distal muscle groups of the upper and lower extremities. The various types of distal myopathies can be clinically differentiated based on age at onset, pattern of muscle involvement, disease severity, and the mode of inheritance. We described a case of slowly progressive muscle weakness that involved one of the patients’ hand and posterior leg muscles. Her genetic study showed a rare variant that likely contributed to distal myopathy with posterior leg and anterior hand involvement (distal actin-binding domain [ABD]-filaminopathy). The disease is due to mutations on the actin-binding domain of the FLNC gene that encodes filamin C. This variant has been described only in one Italian family. This rare variant will expand our knowledge about the rare phenotype of distal myopathy with posterior leg and anterior hand involvement.
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29
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Knyazeva A, Khudiakov A, Vaz R, Muravyev A, Sukhareva K, Sejersen T, Kostareva A. FLNC Expression Level Influences the Activity of TEAD-YAP/TAZ Signaling. Genes (Basel) 2020; 11:genes11111343. [PMID: 33202721 PMCID: PMC7696573 DOI: 10.3390/genes11111343] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023] Open
Abstract
Filamin C (FLNC), being one of the major actin-binding proteins, is involved in the maintenance of key muscle cell functions. Inherited skeletal muscle and cardiac disorders linked to genetic variants in FLNC have attracted attention because of their high clinical importance and possibility of genotype-phenotype correlations. To further expand on the role of FLNC in muscle cells, we focused on detailed alterations of muscle cell properties developed after the loss of FLNC. Using the CRISPR/Cas9 method we generated a C2C12 murine myoblast cell line with stably suppressed Flnc expression. FLNC-deficient myoblasts have a significantly higher proliferation rate combined with an impaired cell migration capacity. The suppression of Flnc expression leads to inability to complete myogenic differentiation, diminished expression of Myh1 and Myh4, alteration of transcriptional dynamics of myogenic factors, such as Mymk and Myog, and deregulation of Hippo signaling pathway. Specifically, we identified elevated basal levels of Hippo activity in myoblasts with loss of FLNC, and ineffective reduction of Hippo signaling activity during myogenic differentiation. The latter was restored by Flnc overexpression. In summary, we confirmed the role of FLNC in muscle cell proliferation, migration and differentiation, and demonstrated for the first time the direct link between Flnc expression and activity of TEAD-YAP\TAZ signaling. These findings support a role of FLNC in regulation of essential muscle processes relying on mechanical as well as signaling mechanisms.
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Affiliation(s)
- Anastasia Knyazeva
- Almazov National Medical Research Centre, 197341 Saint-Petersburg, Russia; (A.K.); (A.M.); (K.S.); (A.K.)
- Correspondence:
| | - Aleksandr Khudiakov
- Almazov National Medical Research Centre, 197341 Saint-Petersburg, Russia; (A.K.); (A.M.); (K.S.); (A.K.)
| | - Raquel Vaz
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institute, 171 76 Stockholm, Sweden;
| | - Aleksey Muravyev
- Almazov National Medical Research Centre, 197341 Saint-Petersburg, Russia; (A.K.); (A.M.); (K.S.); (A.K.)
| | - Ksenia Sukhareva
- Almazov National Medical Research Centre, 197341 Saint-Petersburg, Russia; (A.K.); (A.M.); (K.S.); (A.K.)
- Graduate School of Life and Health Science, University of Verona, 10 37134 Verona, Italy
| | - Thomas Sejersen
- Department of Women’s and Children’s Health, Karolinska Institute, 171 77 Stockholm, Sweden;
| | - Anna Kostareva
- Almazov National Medical Research Centre, 197341 Saint-Petersburg, Russia; (A.K.); (A.M.); (K.S.); (A.K.)
- Department of Women’s and Children’s Health, Karolinska Institute, 171 77 Stockholm, Sweden;
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30
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Ravenscroft G, Clayton JS, Faiz F, Sivadorai P, Milnes D, Cincotta R, Moon P, Kamien B, Edwards M, Delatycki M, Lamont PJ, Chan SH, Colley A, Ma A, Collins F, Hennington L, Zhao T, McGillivray G, Ghedia S, Chao K, O'Donnell-Luria A, Laing NG, Davis MR. Neurogenetic fetal akinesia and arthrogryposis: genetics, expanding genotype-phenotypes and functional genomics. J Med Genet 2020; 58:609-618. [PMID: 33060286 DOI: 10.1136/jmedgenet-2020-106901] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/16/2020] [Accepted: 07/05/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Fetal akinesia and arthrogryposis are clinically and genetically heterogeneous and have traditionally been refractive to genetic diagnosis. The widespread availability of affordable genome-wide sequencing has facilitated accurate genetic diagnosis and gene discovery in these conditions. METHODS We performed next generation sequencing (NGS) in 190 probands with a diagnosis of arthrogryposis multiplex congenita, distal arthrogryposis, fetal akinesia deformation sequence or multiple pterygium syndrome. This sequencing was a combination of bespoke neurogenetic disease gene panels and whole exome sequencing. Only class 4 and 5 variants were reported, except for two cases where the identified variants of unknown significance (VUS) are most likely to be causative for the observed phenotype. Co-segregation studies and confirmation of variants identified by NGS were performed where possible. Functional genomics was performed as required. RESULTS Of the 190 probands, 81 received an accurate genetic diagnosis. All except two of these cases harboured class 4 and/or 5 variants based on the American College of Medical Genetics and Genomics guidelines. We identified phenotypic expansions associated with CACNA1S, CHRNB1, GMPPB and STAC3. We describe a total of 50 novel variants, including a novel missense variant in the recently identified gene for arthrogryposis with brain malformations-SMPD4. CONCLUSIONS Comprehensive gene panels give a diagnosis for a substantial proportion (42%) of fetal akinesia and arthrogryposis cases, even in an unselected cohort. Recently identified genes account for a relatively large proportion, 32%, of the diagnoses. Diagnostic-research collaboration was critical to the diagnosis and variant interpretation in many cases, facilitated genotype-phenotype expansions and reclassified VUS through functional genomics.
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Affiliation(s)
- Gina Ravenscroft
- Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia .,Faculty of Health and Medical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Joshua S Clayton
- Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia.,Faculty of Health and Medical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Fathimath Faiz
- PathWest Diagnostic Genomics, Nedlands, Western Australia, Australia
| | - Padma Sivadorai
- PathWest Diagnostic Genomics, Nedlands, Western Australia, Australia
| | - Di Milnes
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Rob Cincotta
- Maternal and Fetal Medicine, Mater Mothers' Hospital, Brisbane, Queensland, Australia
| | - Phillip Moon
- Department of Obstetrics, Redland Hospital, Cleveland, Queensland, Australia
| | - Ben Kamien
- Genetic Services WA, Women and Newborn Heath Service, Subiaco, Western Australia, Australia.,Hunter Genetics, Hunter New England Health, New Lambton, New South Wales, Australia
| | - Matthew Edwards
- Hunter Genetics, Hunter New England Health, New Lambton, New South Wales, Australia
| | - Martin Delatycki
- Victorian Clinical Genetics Service, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Phillipa J Lamont
- Neurology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Sophelia Hs Chan
- Paediatric Neurology Division, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Alison Colley
- Clinical Genetics Services SWSLHD, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Alan Ma
- Department of Clinical Genetics, Children's Hospital Westmead, Sydney, New South Wales, Australia
| | - Felicity Collins
- Clinical Genetics Department, Western Sydney Genetics Program, Children's Hospitalat Westmead, Westmead, New South Wales, Australia
| | - Lucinda Hennington
- Mercy Health, Mercy Hospital for Women, Heidelberg, Victoria, Australia.,Austin Health, Melbourne, Victoria, Australia.,Alfred Health, Melbourne, Victoria, Australia
| | - Teresa Zhao
- Victorian Clinical Genetics Service, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - George McGillivray
- Victorian Clinical Genetics Service, Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Sondhya Ghedia
- Department of Clinical Genetics, Royal North Shore Hospital, Sydney, New South Wales, Australia
| | - Katherine Chao
- Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts, USA
| | - Anne O'Donnell-Luria
- Center for Mendelian Genomics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts, USA
| | - Nigel G Laing
- Harry Perkins Institute of Medical Research, Perth, Western Australia, Australia.,Faculty of Health and Medical Sciences, University of Western Australia, Nedlands, Western Australia, Australia.,PathWest Diagnostic Genomics, Nedlands, Western Australia, Australia
| | - Mark R Davis
- PathWest Diagnostic Genomics, Nedlands, Western Australia, Australia
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31
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Kelley CA, Triplett O, Mallick S, Burkewitz K, Mair WB, Cram EJ. FLN-1/filamin is required to anchor the actomyosin cytoskeleton and for global organization of sub-cellular organelles in a contractile tissue. Cytoskeleton (Hoboken) 2020; 77:379-398. [PMID: 32969593 DOI: 10.1002/cm.21633] [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: 07/28/2020] [Revised: 09/11/2020] [Accepted: 09/17/2020] [Indexed: 01/01/2023]
Abstract
Actomyosin networks are organized in space, direction, size, and connectivity to produce coordinated contractions across cells. We use the C. elegans spermatheca, a tube composed of contractile myoepithelial cells, to study how actomyosin structures are organized. FLN-1/filamin is required for the formation and stabilization of a regular array of parallel, contractile, actomyosin fibers in this tissue. Loss of fln-1 results in the detachment of actin fibers from the basal surface, which then accumulate along the cell junctions and are stabilized by spectrin. In addition, actin and myosin are captured at the nucleus by the linker of nucleoskeleton and cytoskeleton complex (LINC) complex, where they form large foci. Nuclear positioning and morphology, distribution of the endoplasmic reticulum and the mitochondrial network are also disrupted. These results demonstrate that filamin is required to prevent large actin bundle formation and detachment, to prevent excess nuclear localization of actin and myosin, and to ensure correct positioning of organelles.
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Affiliation(s)
- Charlotte A Kelley
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Olivia Triplett
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Samyukta Mallick
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
| | - Kristopher Burkewitz
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA.,Department of Cell and Developmental Biology, Vanderbilt School of Medicine, Nashville, Tennessee, USA
| | - William B Mair
- Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, Massachusetts, USA
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, Massachusetts, USA
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32
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Luo YB, Peng Y, Lu Y, Li Q, Duan H, Bi F, Yang H. Expanding the Clinico-Genetic Spectrum of Myofibrillar Myopathy: Experience From a Chinese Neuromuscular Center. Front Neurol 2020; 11:1014. [PMID: 33041974 PMCID: PMC7522348 DOI: 10.3389/fneur.2020.01014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Myofibrillar myopathy is a group of hereditary neuromuscular disorders characterized by dissolution of myofibrils and abnormal intracellular accumulation of Z disc-related proteins. We aimed to characterize the clinical, physiological, pathohistological, and genetic features of Chinese myofibrillar myopathy patients from a single neuromuscular center. Methods: A total of 18 patients were enrolled. Demographic and clinical data were collected. Laboratory investigations, electromyography, and cardiac evaluation was performed. Routine and immunohistochemistry stainings against desmin, αB-crystallin, and BAG3 of muscle specimen were carried out. Finally, next-generation sequencing panel array for genes associated with hereditary neuromuscular disorders were performed. Results: Twelve pathogenic variants in DES, BAG3, FLNC, FHL1, and TTN were identified, of which seven were novel mutations. The novel DES c.1256C>T substitution is a high frequency mutation. The combined recessively/dominantly transmitted c.19993G>T and c.107545delG mutations in TTN gene cause a limb girdle muscular dystrophy phenotype with the classical myofibrillar myopathy histological changes. Conclusions: We report for the first time that hereditary myopathy with early respiratory failure patient can have peripheral nerve and severe spine involvement. The mutation in Ig-like domain 16 of FLNC is associated with the limb girdle type of filaminopathy, and the mutation in Ig-like domain 18 with distal myopathy type. These findings expand the phenotypic and genotypic correlation spectrum of myofibrillar myopathy.
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Affiliation(s)
- Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Yuyao Peng
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Yuling Lu
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Qiuxiang Li
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Huiqian Duan
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Fangfang Bi
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
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33
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Schuld J, Orfanos Z, Chevessier F, Eggers B, Heil L, Uszkoreit J, Unger A, Kirfel G, van der Ven PFM, Marcus K, Linke WA, Clemen CS, Schröder R, Fürst DO. Homozygous expression of the myofibrillar myopathy-associated p.W2710X filamin C variant reveals major pathomechanisms of sarcomeric lesion formation. Acta Neuropathol Commun 2020; 8:154. [PMID: 32887649 PMCID: PMC7650280 DOI: 10.1186/s40478-020-01001-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/22/2020] [Indexed: 01/06/2023] Open
Abstract
Filamin C (FLNc) is mainly expressed in striated muscle cells where it localizes to Z-discs, myotendinous junctions and intercalated discs. Recent studies have revealed numerous mutations in the FLNC gene causing familial and sporadic myopathies and cardiomyopathies with marked clinical variability. The most frequent myopathic mutation, p.W2710X, which is associated with myofibrillar myopathy, deletes the carboxy-terminal 16 amino acids from FLNc and abolishes the dimerization property of Ig-like domain 24. We previously characterized "knock-in" mice heterozygous for this mutation (p.W2711X), and have now investigated homozygous mice using protein and mRNA expression analyses, mass spectrometry, and extensive immunolocalization and ultrastructural studies. Although the latter mice display a relatively mild myopathy under normal conditions, our analyses identified major mechanisms causing the pathophysiology of this disease: in comparison to wildtype animals (i) the expression level of FLNc protein is drastically reduced; (ii) mutant FLNc is relocalized from Z-discs to particularly mechanically strained parts of muscle cells, i.e. myotendinous junctions and myofibrillar lesions; (iii) the number of lesions is greatly increased and these lesions lack Bcl2-associated athanogene 3 (BAG3) protein; (iv) the expression of heat shock protein beta-7 (HSPB7) is almost completely abolished. These findings indicate grave disturbances of BAG3-dependent and -independent autophagy pathways that are required for efficient lesion repair. In addition, our studies reveal general mechanisms of lesion formation and demonstrate that defective FLNc dimerization via its carboxy-terminal domain does not disturb assembly and basic function of myofibrils. An alternative, more amino-terminally located dimerization site might compensate for that loss. Since filamins function as stress sensors, our data further substantiate that FLNc is important for mechanosensing in the context of Z-disc stabilization and maintenance.
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Kölbel H, Roos A, van der Ven PFM, Evangelista T, Nolte K, Johnson K, Töpf A, Wilson M, Kress W, Sickmann A, Straub V, Kollipara L, Weis J, Fürst DO, Schara U. First clinical and myopathological description of a myofibrillar myopathy with congenital onset and homozygous mutation in FLNC. Hum Mutat 2020; 41:1600-1614. [PMID: 32516863 DOI: 10.1002/humu.24062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/17/2020] [Accepted: 06/07/2020] [Indexed: 02/06/2023]
Abstract
Filamin C (encoded by the FLNC gene) is a large actin-cross-linking protein involved in shaping the actin cytoskeleton in response to signaling events both at the sarcolemma and at myofibrillar Z-discs of cross-striated muscle cells. Multiple mutations in FLNC are associated with myofibrillar myopathies of autosomal-dominant inheritance. Here, we describe for the first time a boy with congenital onset of generalized muscular hypotonia and muscular weakness, delayed motor development but no cardiac involvement associated with a homozygous FLNC mutation c.1325C>G (p.Pro442Arg). We performed ultramorphological, proteomic, and functional investigations as well as immunological studies of known marker proteins for dominant filaminopathies. We show that the mutant protein is expressed in similar quantities as the wild-type variant in control skeletal muscle fibers. The proteomic signature of quadriceps muscle is altered and ultrastructural perturbations are evident. Moreover, filaminopathy marker proteins are comparable both in our homozygous and a dominant control case (c.5161delG). Biochemical investigations demonstrate that the recombinant mutant protein is less stable and more prone to degradation by proteolytic enzymes than the wild-type variant. The unusual congenital presentation of the disease clearly demonstrates that homozygosity for mutations in FLNC severely aggravates the phenotype.
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Affiliation(s)
- Heike Kölbel
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Teresinha Evangelista
- Neuromuscular Morphology Unit, Myology Institute, GHU Pitié-Salpêtrière, Paris, France
| | - Kay Nolte
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Katherine Johnson
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Ana Töpf
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Michael Wilson
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Wolfram Kress
- Department of Human Genetics, University of Würzburg, Würzburg, Germany
| | - Albert Sickmann
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.,Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.,Medizinische Proteom-Center (MPC), Medizinische Fakultät, Ruhr-Universität Bochum, Bochum, Germany
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University, Newcastle upon Tyne, UK
| | - Laxmikanth Kollipara
- Department of Bioanalytics, Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Ulrike Schara
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, Children's Hospital University of Essen, Essen, Germany
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Nicolau S, Liewluck T, Milone M. Myopathies with finger flexor weakness: Not only inclusion-body myositis. Muscle Nerve 2020; 62:445-454. [PMID: 32478919 DOI: 10.1002/mus.26914] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/29/2020] [Accepted: 05/03/2020] [Indexed: 12/11/2022]
Abstract
Muscle disorders are characterized by differential involvement of various muscle groups. Among these, weakness predominantly affecting finger flexors is an uncommon pattern, most frequently found in sporadic inclusion-body myositis. This finding is particularly significant when the full range of histopathological findings of inclusion-body myositis is not found on muscle biopsy. Prominent finger flexor weakness, however, is also observed in other myopathies. It occurs commonly in myotonic dystrophy types 1 and 2. In addition, individual reports and small case series have documented finger flexor weakness in sarcoid and amyloid myopathy, and in inherited myopathies caused by ACTA1, CRYAB, DMD, DYSF, FLNC, GAA, GNE, HNRNPDL, LAMA2, MYH7, and VCP mutations. Therefore, the finding of finger flexor weakness requires consideration of clinical, myopathological, genetic, electrodiagnostic, and sometimes muscle imaging findings to establish a diagnosis.
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Affiliation(s)
- Stefan Nicolau
- Department of Neurology, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota, 55905, USA
| | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota, 55905, USA
| | - Margherita Milone
- Department of Neurology, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota, 55905, USA
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Phosphoproteomics identifies dual-site phosphorylation in an extended basophilic motif regulating FILIP1-mediated degradation of filamin-C. Commun Biol 2020; 3:253. [PMID: 32444788 PMCID: PMC7244511 DOI: 10.1038/s42003-020-0982-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/01/2020] [Indexed: 01/10/2023] Open
Abstract
The PI3K/Akt pathway promotes skeletal muscle growth and myogenic differentiation. Although its importance in skeletal muscle biology is well documented, many of its substrates remain to be identified. We here studied PI3K/Akt signaling in contracting skeletal muscle cells by quantitative phosphoproteomics. We identified the extended basophilic phosphosite motif RxRxxp[S/T]xxp[S/T] in various proteins including filamin-C (FLNc). Importantly, this extended motif, located in a unique insert in Ig-like domain 20 of FLNc, is doubly phosphorylated. The protein kinases responsible for this dual-site phosphorylation are Akt and PKCα. Proximity proteomics and interaction analysis identified filamin A-interacting protein 1 (FILIP1) as direct FLNc binding partner. FILIP1 binding induces filamin degradation, thereby negatively regulating its function. Here, dual-site phosphorylation of FLNc not only reduces FILIP1 binding, providing a mechanism to shield FLNc from FILIP1-mediated degradation, but also enables fast dynamics of FLNc necessary for its function as signaling adaptor in cross-striated muscle cells. Reimann, Schwäble et al. perform quantitative proteomics to study PI3K/Akt signaling in contracting myotubes. They identify a dual-site phosphorylation motif in the actin cross-linker and signaling adaptor filamin C, which regulates its degradation and mobility, suggesting the importance of dual phosphorylation for filamin C function in striated muscle cells.
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37
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Structure and Function of Filamin C in the Muscle Z-Disc. Int J Mol Sci 2020; 21:ijms21082696. [PMID: 32295012 PMCID: PMC7216277 DOI: 10.3390/ijms21082696] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/22/2022] Open
Abstract
Filamin C (FLNC) is one of three filamin proteins (Filamin A (FLNA), Filamin B (FLNB), and FLNC) that cross-link actin filaments and interact with numerous binding partners. FLNC consists of a N-terminal actin-binding domain followed by 24 immunoglobulin-like repeats with two intervening calpain-sensitive hinges separating R15 and R16 (hinge 1) and R23 and R24 (hinge-2). The FLNC subunit is dimerized through R24 and calpain cleaves off the dimerization domain to regulate mobility of the FLNC subunit. FLNC is localized in the Z-disc due to the unique insertion of 82 amino acid residues in repeat 20 and necessary for normal Z-disc formation that connect sarcomeres. Since phosphorylation of FLNC by PKC diminishes the calpain sensitivity, assembly, and disassembly of the Z-disc may be regulated by phosphorylation of FLNC. Mutations of FLNC result in cardiomyopathy and muscle weakness. Although this review will focus on the current understanding of FLNC structure and functions in muscle, we will also discuss other filamins because they share high sequence similarity and are better characterized. We will also discuss a possible role of FLNC as a mechanosensor during muscle contraction.
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Verdonschot JAJ, Vanhoutte EK, Claes GRF, Helderman-van den Enden ATJM, Hoeijmakers JGJ, Hellebrekers DMEI, de Haan A, Christiaans I, Lekanne Deprez RH, Boen HM, van Craenenbroeck EM, Loeys BL, Hoedemaekers YM, Marcelis C, Kempers M, Brusse E, van Waning JI, Baas AF, Dooijes D, Asselbergs FW, Barge-Schaapveld DQCM, Koopman P, van den Wijngaard A, Heymans SRB, Krapels IPC, Brunner HG. A mutation update for the FLNC gene in myopathies and cardiomyopathies. Hum Mutat 2020; 41:1091-1111. [PMID: 32112656 PMCID: PMC7318287 DOI: 10.1002/humu.24004] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022]
Abstract
Filamin C (FLNC) variants are associated with cardiac and muscular phenotypes. Originally, FLNC variants were described in myofibrillar myopathy (MFM) patients. Later, high‐throughput screening in cardiomyopathy cohorts determined a prominent role for FLNC in isolated hypertrophic and dilated cardiomyopathies (HCM and DCM). FLNC variants are now among the more prevalent causes of genetic DCM. FLNC‐associated DCM is associated with a malignant clinical course and a high risk of sudden cardiac death. The clinical spectrum of FLNC suggests different pathomechanisms related to variant types and their location in the gene. The appropriate functioning of FLNC is crucial for structural integrity and cell signaling of the sarcomere. The secondary protein structure of FLNC is critical to ensure this function. Truncating variants with subsequent haploinsufficiency are associated with DCM and cardiac arrhythmias. Interference with the dimerization and folding of the protein leads to aggregate formation detrimental for muscle function, as found in HCM and MFM. Variants associated with HCM are predominantly missense variants, which cluster in the ROD2 domain. This domain is important for binding to the sarcomere and to ensure appropriate cell signaling. We here review FLNC genotype–phenotype correlations based on available evidence.
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Affiliation(s)
- Job A J Verdonschot
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Cardiology, Cardiovascular Research Institute (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Els K Vanhoutte
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Godelieve R F Claes
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | | | - Debby M E I Hellebrekers
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Amber de Haan
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Imke Christiaans
- Department of Clinical Genetics, Amsterdam University Medical Center, Amsterdam, The Netherlands.,Department of Clinical Genetics, University Medical Centre Groningen, Groningen, The Netherlands
| | - Ronald H Lekanne Deprez
- Department of Clinical Genetics, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Hanne M Boen
- Department of Cardiology, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | | | - Bart L Loeys
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Yvonne M Hoedemaekers
- Department of Clinical Genetics, University Medical Centre Groningen, Groningen, The Netherlands.,Department of Clinical Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Carlo Marcelis
- Department of Clinical Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Marlies Kempers
- Department of Clinical Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Esther Brusse
- Department of Neurology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands
| | - Jaap I van Waning
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands.,Department of Cardiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Annette F Baas
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Dennis Dooijes
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Folkert W Asselbergs
- Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | - Arthur van den Wijngaard
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Stephane R B Heymans
- Department of Cardiology, Cardiovascular Research Institute (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium.,The Netherlands Heart Institute, Utrecht, The Netherlands
| | - Ingrid P C Krapels
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Han G Brunner
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands.,Department of Clinical Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands.,Department of Genetics and Cell Biology, GROW Institute for Developmental Biology and Cancer, Maastricht University Medical Centre, Maastricht, The Netherlands
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Lee HCH, Wong S, Sheng B, Pan NYK, Leung YKF, Lau KKD, Cheng YS, Ho LC, Li R, Lee CN, Tsoi TH, Cheung YFN, Fu YPM, Kan NCA, Chu YP, Au WCL, Yeung HMJ, Li SH, Cheung CFM, Tong HF, Hung LYE, Chan TYC, Li CT, Tong TYT, Tong TWC, Leung HYC, Lee KH, Yeung SYS, Lee SYB, Lau TCG, Lam CW, Mak CM, Chan AYW. Clinical and pathological characterization of FLNC-related myofibrillar myopathy caused by founder variant c.8129G>A in Hong Kong Chinese. Clin Genet 2020; 97:747-757. [PMID: 32022900 DOI: 10.1111/cge.13715] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/17/2020] [Accepted: 01/28/2020] [Indexed: 12/18/2022]
Abstract
FLNC-related myofibrillar myopathy could manifest as autosomal dominant late-onset slowly progressive proximal muscle weakness; involvements of cardiac and/or respiratory functions are common. We describe 34 patients in nine families of FLNC-related myofibrillar myopathy in Hong Kong ethnic Chinese diagnosed over the last 12 years, in whom the same pathogenic variant c.8129G>A (p.Trp2710*) was detected. Twenty-six patients were symptomatic when diagnosed; four patients died of pneumonia and/or respiratory failure. Abnormal amorphous material or granulofilamentous masses were detected in half of the cases, with mitochondrial abnormalities noted in two-thirds. We also show by haplotype analysis the founder effect associated with this Hong Kong variant, which might have occurred 42 to 71 generations ago or around Tang and Song dynasties, and underlain a higher incidence of myofibrillar myopathy among Hong Kong Chinese. The late-onset nature and slowly progressive course of the highly penetrant condition could have significant impact on the family members, and an early diagnosis could benefit the whole family. Considering another neighboring founder variant in FLNC in German patients, we advocate development of specific therapies such as chaperone-based or antisense oligonucleotide strategies for this particular type of myopathy.
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Affiliation(s)
| | - Shun Wong
- Department of Pathology, Princess Margaret Hospital, Hong Kong.,Pathology Department, St. Paul's Hospital, Hong Kong
| | - Bun Sheng
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - Nin-Yuan Keith Pan
- Department of Diagnostic Radiology, Princess Margaret Hospital, Hong Kong
| | | | | | - Yue Sandy Cheng
- Department of Clinical Pathology, Pamela Youde Nethersole Eastern Hospital, Hong Kong.,Department of Clinical Laboratory, Gleneagles Hong Kong Hospital, Hong Kong
| | - Luen-Cheung Ho
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
| | - Richard Li
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - Chi-Nam Lee
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - Tak-Hong Tsoi
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | | | | | | | - Yim-Pui Chu
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - Wing-Chi Lisa Au
- Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | | | - Siu-Hung Li
- Department of Medicine, North District Hospital, Hong Kong
| | | | - Hok-Fung Tong
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | - Chi Terence Li
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | | | - Ka-Ho Lee
- Department of Pathology, Princess Margaret Hospital, Hong Kong
| | | | | | | | - Ching-Wan Lam
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Chloe Miu Mak
- Department of Pathology, Princess Margaret Hospital, Hong Kong
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Iqbal NS, Jascur TA, Harrison SM, Edwards AB, Smith LT, Choi ES, Arevalo MK, Chen C, Zhang S, Kern AJ, Scheuerle AE, Sanchez EJ, Xing C, Baker LA. Prune belly syndrome in surviving males can be caused by Hemizygous missense mutations in the X-linked Filamin A gene. BMC MEDICAL GENETICS 2020; 21:38. [PMID: 32085749 PMCID: PMC7035669 DOI: 10.1186/s12881-020-0973-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 02/12/2020] [Indexed: 12/12/2022]
Abstract
Background Prune belly syndrome (PBS) is a rare, multi-system congenital myopathy primarily affecting males that is poorly described genetically. Phenotypically, its morbidity spans from mild to lethal, however, all isolated PBS cases manifest three cardinal pathological features: 1) wrinkled flaccid ventral abdominal wall with skeletal muscle deficiency, 2) urinary tract dilation with poorly contractile smooth muscle, and 3) intra-abdominal undescended testes. Despite evidence for a genetic basis, previously reported PBS autosomal candidate genes only account for one consanguineous family and single cases. Methods We performed whole exome sequencing (WES) of two maternal adult half-brothers with syndromic PBS (PBS + Otopalatodigital spectrum disorder [OPDSD]) and two unrelated sporadic individuals with isolated PBS and further functionally validated the identified mutations. Results We identified three unreported hemizygous missense point mutations in the X-chromosome gene Filamin A (FLNA) (c.4952 C > T (p.A1448V), c.6727C > T (p.C2160R), c.5966 G > A (p.G2236E)) in two related cases and two unrelated sporadic individuals. Two of the three PBS mutations map to the highly regulatory, stretch-sensing Ig19–21 region of FLNA and enhance binding to intracellular tails of the transmembrane receptor β-integrin 1 (ITGβ1). Conclusions FLNA is a regulatory actin-crosslinking protein that functions in smooth muscle cells as a mechanosensing molecular scaffold, transmitting force signals from the actin-myosin motor units and cytoskeleton via binding partners to the extracellular matrix. This is the first evidence for an X-linked cause of PBS in multiple unrelated individuals and expands the phenotypic spectrum associated with FLNA in males surviving even into adulthood.
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Affiliation(s)
- Nida S Iqbal
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.
| | - Thomas A Jascur
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Steven M Harrison
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Angelena B Edwards
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Luke T Smith
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Erin S Choi
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Michelle K Arevalo
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Catherine Chen
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Shaohua Zhang
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Adam J Kern
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Angela E Scheuerle
- Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.,McDermott Center for Human Growth and Development, Department of Bioinformatics, Department of Clinical Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Emma J Sanchez
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA.,Children's Health Dallas, 2350 N. Stemmons Freeway, Suite F4300, Dallas, TX, 75207, USA
| | - Chao Xing
- McDermott Center for Human Growth and Development, Department of Bioinformatics, Department of Clinical Sciences, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA
| | - Linda A Baker
- Department of Urology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390, USA. .,Children's Health Dallas, 2350 N. Stemmons Freeway, Suite F4300, Dallas, TX, 75207, USA.
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41
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Harris AR, Belardi B, Jreij P, Wei K, Shams H, Bausch A, Fletcher DA. Steric regulation of tandem calponin homology domain actin-binding affinity. Mol Biol Cell 2019; 30:3112-3122. [PMID: 31693446 PMCID: PMC6938246 DOI: 10.1091/mbc.e19-06-0317] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/03/2019] [Accepted: 10/29/2019] [Indexed: 11/11/2022] Open
Abstract
Tandem calponin homology (CH1-CH2) domains are common actin-binding domains in proteins that interact with and organize the actin cytoskeleton. Despite regions of high sequence similarity, CH1-CH2 domains can have remarkably different actin-binding properties, with disease-associated point mutants known to increase as well as decrease affinity for F-actin. To investigate features that affect CH1-CH2 affinity for F-actin in cells and in vitro, we perturbed the utrophin actin-binding domain by making point mutations at the CH1-CH2 interface, replacing the linker domain, and adding a polyethylene glycol (PEG) polymer to CH2. Consistent with a previous model describing CH2 as a steric negative regulator of actin binding, we find that utrophin CH1-CH2 affinity is both increased and decreased by modifications that change the effective "openness" of CH1 and CH2 in solution. We also identified interface mutations that caused a large increase in affinity without changing solution "openness," suggesting additional influences on affinity. Interestingly, we also observe nonuniform subcellular localization of utrophin CH1-CH2 that depends on the N-terminal flanking region but not on bulk affinity. These observations provide new insights into how small sequence changes, such as those found in diseases, can affect CH1-CH2 binding properties.
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Affiliation(s)
- Andrew R. Harris
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
| | - Brian Belardi
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
| | - Pamela Jreij
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
| | - Kathy Wei
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
| | - Hengameh Shams
- Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720
| | - Andreas Bausch
- Lehrstuhl für Biophysik (E27), Technische Universität München, Garching 85748, Germany
| | - Daniel A. Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Chan Zuckerberg Biohub, San Francisco, CA 94158
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Sveinbjornsson G, Olafsdottir EF, Thorolfsdottir RB, Davidsson OB, Helgadottir A, Jonasdottir A, Jonasdottir A, Bjornsson E, Jensson BO, Arnadottir GA, Kristinsdottir H, Stephensen SS, Oskarsson G, Gudbjartsson T, Sigurdsson EL, Andersen K, Danielsen R, Arnar DO, Jonsdottir I, Thorsteinsdottir U, Sulem P, Thorgeirsson G, Gudbjartsson DF, Holm H, Stefansson K. Variants in NKX2-5 and FLNC Cause Dilated Cardiomyopathy and Sudden Cardiac Death. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e002151. [PMID: 30354339 DOI: 10.1161/circgen.117.002151] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Dilated cardiomyopathy (DCM) is an important cause of heart failure. Variants in >50 genes have been reported to cause DCM, but causative variants have been found in less than half of familial cases. Variants causing DCM in Iceland have not been reported before. METHODS We performed a genome-wide association study on DCM based on whole genome sequencing. We tested the association of 32.5 million sequence variants in 424 cases and 337 689 population controls in Iceland. RESULTS We identified 2 DCM variants in established cardiomyopathy genes, a missense variant p.Phe145Leu in NKX2-5 carried by 1 in 7100 Icelanders ( P=7.0×10-12) and a frameshift variant p.Phe1626Serfs*40 in FLNC carried by 1 in 3600 Icelanders ( P=2.1×10-10). Both variants associate with heart failure and sudden cardiac death. Additionally, p.Phe145Leu in NKX2-5 associates with high degree atrioventricular block and atrial septal defect ( P<1.4×10-4). The penetrance of serious heart disease among carriers of the NKX2-5 variant is high and higher than that of the FLNC variant. CONCLUSIONS Two rare variants in NKX2-5 and FLNC, carried by 1 in 2400 Icelanders, cause familial DCM in Iceland. These genes have recently been associated with DCM. Given the serious consequences of these variants, we suggest screening for them in individuals with DCM and their family members, with subsequent monitoring of carriers, offering early intervention.
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Affiliation(s)
- Gardar Sveinbjornsson
- deCODE genetics/Amgen, Inc, Reykjavik, Iceland (G.S., E.F.O., R.B.T., O.B.D., A.H.,School of Engineering and Natural Sciences (G.S., D.F.G.)
| | - Eva F Olafsdottir
- deCODE genetics/Amgen, Inc, Reykjavik, Iceland (G.S., E.F.O., R.B.T., O.B.D., A.H.,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.)
| | | | - Olafur B Davidsson
- deCODE genetics/Amgen, Inc, Reykjavik, Iceland (G.S., E.F.O., R.B.T., O.B.D., A.H
| | - Anna Helgadottir
- deCODE genetics/Amgen, Inc, Reykjavik, Iceland (G.S., E.F.O., R.B.T., O.B.D., A.H
| | | | | | - Eythor Bjornsson
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.)
| | - Brynjar O Jensson
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.)
| | - Gudny A Arnadottir
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.)
| | | | - Sigurdur S Stephensen
- Department of Pediatric Cardiology, Children's Hospital Reykjavik, Iceland (S.S.S., G.O.)
| | - Gylfi Oskarsson
- Department of Pediatric Cardiology, Children's Hospital Reykjavik, Iceland (S.S.S., G.O.)
| | - Tomas Gudbjartsson
- Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.).,Department of Cardiothoracic Surgery (T.G.)
| | - Emil L Sigurdsson
- Department of Family Medicine (E.L.S.), University of Iceland, Reykjavik.,Department of Development, Primary Health Care of the Capital Area, Reykjavik, Iceland (E.L.S.)
| | - Karl Andersen
- Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.).,Department of Medicine, Landspitali University Hospital, Reykjavik, Iceland (K.A., R.D., D.O.A., G.T.)
| | - Ragnar Danielsen
- Department of Medicine, Landspitali University Hospital, Reykjavik, Iceland (K.A., R.D., D.O.A., G.T.)
| | - David O Arnar
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.).,Department of Medicine, Landspitali University Hospital, Reykjavik, Iceland (K.A., R.D., D.O.A., G.T.)
| | - Ingileif Jonsdottir
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.).,Department of Immunology, Landspitali, The National University Hospital of Iceland, Reykjavik (I.J.)
| | - Unnur Thorsteinsdottir
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.)
| | - Patrick Sulem
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.)
| | - Gudmundur Thorgeirsson
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.).,Department of Medicine, Landspitali University Hospital, Reykjavik, Iceland (K.A., R.D., D.O.A., G.T.)
| | - Daniel F Gudbjartsson
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,School of Engineering and Natural Sciences (G.S., D.F.G.)
| | - Hilma Holm
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.)
| | - Kari Stefansson
- Adalbjorg Jonasdottir, Aslaug Jonasdottir, E.B., B.O.J., G.A.A., D.O.A., I.J., U.T., P.S., G.T., D.F.G., H.H., K.S.).,Faculty of Medicine (E.F.O., E.B., H.K., T.G., K.A., D.O.A., I.J., U.T., G.T., K.S.)
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A mutation in the filamin c gene causes myofibrillar myopathy with lower motor neuron syndrome: a case report. BMC Neurol 2019; 19:198. [PMID: 31421687 PMCID: PMC6697925 DOI: 10.1186/s12883-019-1410-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 07/23/2019] [Indexed: 11/13/2022] Open
Abstract
Background Myofibrillar myopathies (MFMs) are a genetically heterogeneous group of muscle disorders. Mutations in the filamin C gene (FLNC) have previously been identified in patients with MFM. The phenotypes of FLNC-related MFM are heterogeneous. Case presentation The patient was a 37-year-old male who first experienced weakness in the distal muscles of his hand, which eventually spread to the lower limbs and proximal muscles. Serum creatine kinase levels were moderately elevated. Obvious neuropathic changes in the electromyographic exam and edema changes in lower distal limb magnetic resonance imaging were observed. Histopathological examination revealed the presence of abnormal protein aggregates and angular atrophy in some muscle fibers. Ultrastructural analysis showed inordinate myofibrillar structures and dissolved myofilaments. DNA sequencing analysis detected a heterozygous missense mutation (c.7123G > A, p.V2375I) in the immunoglobulin (Ig)-like domain 21 of FLNC. Conclusions FLNC mutation c.7123G > A, p.V2375I in the immunoglobulin (Ig)-like domain 21 can be associated with distal myopathy with typical MFM features and lower motor neuron syndrome. Although electromyographic examination of our patient showed obvious neuropathic changes, MFM could not be excluded. Therefore, genetic testing is necessary to make an accurate diagnosis. Electronic supplementary material The online version of this article (10.1186/s12883-019-1410-7) contains supplementary material, which is available to authorized users.
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44
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Previtali SC, Scarlato M, Vezzulli P, Ruggieri A, Velardo D, Benedetti S, Torini G, Colombo B, Maggi L, Di Bella D, Gellera C, D'Angelo G, Mora M. Expanding the central nervous system disease spectrum associated with FLNC mutation. Muscle Nerve 2019; 59:E33-E37. [PMID: 30734317 DOI: 10.1002/mus.26443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 11/05/2022]
Affiliation(s)
- Stefano C Previtali
- InSpe (Institute of Experimental Neurology), Division of Neuroscience and Dept. of Neurology, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Marina Scarlato
- InSpe (Institute of Experimental Neurology), Division of Neuroscience and Dept. of Neurology, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Paolo Vezzulli
- Neuroradiology Department, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Alessandra Ruggieri
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniele Velardo
- InSpe (Institute of Experimental Neurology), Division of Neuroscience and Dept. of Neurology, IRCCS Ospedale San Raffaele, Milano, Italy.,Neuromuscular Disorders Unit, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Sara Benedetti
- Laboratory of Clinical Molecular Biology and Cytogenetics, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Giacomo Torini
- Genomic Unit for the Diagnosis of Human Pathologies, Division of Genetics and Cellular Biology, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Bruno Colombo
- InSpe (Institute of Experimental Neurology), Division of Neuroscience and Dept. of Neurology, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Lorenzo Maggi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniela Di Bella
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Grazia D'Angelo
- Neuromuscular Disorders Unit, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Marina Mora
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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45
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Gemelli C, Prada V, Fiorillo C, Fabbri S, Maggi L, Geroldi A, Gibertini S, Mandich P, Trevisan L, Fossa P, Tagliafico AS, Schenone A, Grandis M. A novel mutation in the N-terminal acting-binding domain of Filamin C protein causing a distal myofibrillar myopathy. J Neurol Sci 2019; 398:75-78. [PMID: 30685713 DOI: 10.1016/j.jns.2019.01.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/10/2019] [Accepted: 01/14/2019] [Indexed: 02/02/2023]
Abstract
Variants in Filamin C (FLNC) gene may cause either cardiomyopathies or different myopathies. We describe a family affected by a distal myopathy with autosomal dominant inheritance. The onset of the disease was in the third decade with gait impairment due to distal leg weakness. Subsequently, the disease progressed with an involvement of proximal lower limbs and hand muscles. Muscle biopsy, performed in one subject,identified relevant myofibrillar abnormalities. We performed a target gene panel testing for myofibrillar myopathies by NGS approach which identified a novel mutation in exon 3 of FLNC gene (c.A664G:p.M222V), within the N-terminal actin-binding (ABD) domain. This variant has been identified in all affected members of the family, thus supporting its pathogenic role. Differently from previously identified variants, our family showed a predominant leg involvement and myofibrillar aggregates, thus further expanding the spectrum of Filamin C related myopathies.
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Affiliation(s)
- Chiara Gemelli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy.
| | - Valeria Prada
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy
| | - Chiara Fiorillo
- Department of Neuroscience, Paediatric Neurology and Neuromuscular Disorders, Istituto Giannina Gaslini, University of Genova, Via Gerolamo Gaslini, 5, 16147 Genova, Italy
| | - Sabrina Fabbri
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy
| | - Lorenzo Maggi
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Via Celoria 11, 20133 Milano, Italy
| | - Alessandro Geroldi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy
| | - Sara Gibertini
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", Via Celoria 11, 20133 Milano, Italy
| | - Paola Mandich
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy; Ospedale Policlinico San Martino IRCCS-Medical Genetic Unit, Largo R. Benzi 10, 16132 Genoa, Italy
| | - Lucia Trevisan
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy; Ospedale Policlinico San Martino IRCCS-Medical Genetic Unit, Largo R. Benzi 10, 16132 Genoa, Italy
| | - Paola Fossa
- Department of Pharmacy, Section of Medicinal Chemistry, School of Medical and Pharmaceutical Sciences, University of Genova, Viale Benedetto XV 3, 16132 Genova, Italy
| | - Alberto Stefano Tagliafico
- Department of Health Sciences (DISSAL), Radiology Section, University of Genova, Via Pastore, 1-16132 Genova, Italy; Emergency Radiology, Policlinico San Martino, Largo Rosanna Benzi, 10-16132 Genova, Italy
| | - Angelo Schenone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy; Ospedale Policlinico San Martino IRCCS-Neurological Unit, Largo R. Benzi 10, 16132 Genoa, Italy
| | - Marina Grandis
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University of Genova, Largo Daneo 3, 16132 Genova, Italy; Ospedale Policlinico San Martino IRCCS-Neurological Unit, Largo R. Benzi 10, 16132 Genoa, Italy.
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46
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Milone M, Liewluck T. The unfolding spectrum of inherited distal myopathies. Muscle Nerve 2018; 59:283-294. [PMID: 30171629 DOI: 10.1002/mus.26332] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 12/30/2022]
Abstract
Distal myopathies are a group of rare muscle diseases characterized by distal weakness at onset. Although acquired myopathies can occasionally present with distal weakness, the majority of distal myopathies have a genetic etiology. Their age of onset varies from early-childhood to late-adulthood while the predominant muscle weakness can affect calf, ankle dorsiflexor, or distal upper limb muscles. A spectrum of muscle pathological changes, varying from nonspecific myopathic changes to rimmed vacuoles to myofibrillar pathology to nuclei centralization, have been noted. Likewise, the underlying molecular defect is heterogeneous. In addition, there is emerging evidence that distal myopathies can result from defective proteins encoded by genes causative of neurogenic disorders, be manifestation of multisystem proteinopathies or the result of the altered interplay between different genes. In this review, we provide an overview on the clinical, electrophysiological, pathological, and molecular aspects of distal myopathies, focusing on the most recent developments in the field. Muscle Nerve 59:283-294, 2019.
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Affiliation(s)
| | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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47
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Cui H, Wang J, Zhang C, Wu G, Zhu C, Tang B, Zou Y, Huang X, Hui R, Song L, Wang S. Mutation profile of FLNC gene and its prognostic relevance in patients with hypertrophic cardiomyopathy. Mol Genet Genomic Med 2018; 6:1104-1113. [PMID: 30411535 PMCID: PMC6305649 DOI: 10.1002/mgg3.488] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/30/2018] [Accepted: 09/14/2018] [Indexed: 01/18/2023] Open
Abstract
Background Filamin C (FLNC) mutation was reported as a cause of HCM, with a high probability of sudden cardiac death. However, the mutation profile of FLNC, and its relationship with phenotypic expression in HCM, remains to be elucidated. Methods In this study, FLNC gene was sequenced in 540 HCM patients and 307 healthy controls. Results We found that 39 (7.2%) patients carried FLNC mutations, with a similar frequency to that of controls (4.2%, p = 0.101). Pedigree analysis showed that mutations were not well segregated with HCM. The baseline characteristics between HCM patients, with and without mutations, were comparable. FLNC mutations did not increase the risk for either all‐cause mortality (HR 0.746, 95% CI 0.222–2.295, p = 0.575) or cardiac mortality (HR 0.615, 95% CI 0.153–1.947, p = 0.354) in HCM patients during a follow‐up of 4.7 ± 3.2 years. Moreover, there was no significant difference in survival free from sudden cardiac arrest (HR 0.721, 95% CI 0.128–3.667, p = 0.660) and heart failure (HR 0.757, 95% CI 0.318–1.642, p = 0.447). Conclusions FLNC mutations were common in both HCM patients and healthy population. The pathogenicity of FLNC mutations detected in HCM patients and its association with the clinical outcomes should be cautiously interpreted.
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Affiliation(s)
- Hao Cui
- Department of Cardiac Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jizheng Wang
- State Key Laboratory of Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ce Zhang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Guixin Wu
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Changsheng Zhu
- Department of Cardiac Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bing Tang
- Department of Cardiac Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yubao Zou
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaohong Huang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rutai Hui
- State Key Laboratory of Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lei Song
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuiyun Wang
- Department of Cardiac Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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48
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Schubert J, Tariq M, Geddes G, Kindel S, Miller EM, Ware SM. Novel pathogenic variants in filamin C identified in pediatric restrictive cardiomyopathy. Hum Mutat 2018; 39:2083-2096. [DOI: 10.1002/humu.23661] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/29/2018] [Accepted: 09/25/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Jeffrey Schubert
- Department of Molecular Genetics, Microbiology, and Biochemistry; University of Cincinnati College of Medicine; Cincinnati Ohio
- Departments of Pediatrics and Medical and Molecular Genetics; Indiana University School of Medicine; Indianapolis Indiana
| | - Muhammad Tariq
- Faculty of Applied Medical Science; University of Tabuk; Tabuk Kingdom of Saudi Arabia
| | - Gabrielle Geddes
- Department of Pediatrics; Medical College of Wisconsin; Milwaukee Wisconsin
| | - Steven Kindel
- Department of Pediatrics; Medical College of Wisconsin; Milwaukee Wisconsin
| | - Erin M. Miller
- Cincinnati Children's Hospital Medical Center; Cincinnati Ohio
| | - Stephanie M. Ware
- Departments of Pediatrics and Medical and Molecular Genetics; Indiana University School of Medicine; Indianapolis Indiana
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49
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Mangum KD, Ferns SJ. A novel familial truncating mutation in the filamin C gene associated with cardiac arrhythmias. Eur J Med Genet 2018; 62:282-285. [PMID: 30118858 DOI: 10.1016/j.ejmg.2018.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/25/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
Abstract
The authors report for the first time a novel mutation in the FLNC gene associated with cardiac arrhythmias in two half-siblings. The FLNC gene on chromosome 7q32 encodes filamin C, which stabilizes the actin network within the cardiomyocyte. The proband is an 8-year-old asymptomatic patient with frequent premature ventricular contractions noted on serial monitoring. Interestingly, the proband and his half-brother harbored a heterozygous 13 base pair deletion that resulted in a frameshift mutation and introduction of a premature stop codon. Notably, the proband also had a very tragic family history of sudden death in young individuals involving three generations and five family members. Because of their concerning family history and arrhythmias, both siblings underwent off-label implantable cardiac device placement for primary prevention of sudden cardiac death. Whether or not the FLNC mutation is associated with sudden cardiac death requires additional investigation and is beyond the scope of this manuscript. While previous studies have identified several mutations in the FLNC gene associated with dilated and hypertrophic cardiomyopathies, the goal of this study was to report a novel mutation in the FLNC gene that is associated with cardiac arrhythmias. The current study indicates that this mutation may help identify patients at risk for cardiac arrhythmias who would benefit from further cardiac evaluation.
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Affiliation(s)
- Kevin D Mangum
- University of North Carolina, School of Medicine, Chapel Hill, NC, United States.
| | - Sunita J Ferns
- University of North Carolina, School of Medicine, Chapel Hill, NC, United States; UNC Department of Pediatrics, Chapel Hill, NC, United States
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50
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Tucker NR, McLellan MA, Hu D, Ye J, Parsons VA, Mills RW, Clauss S, Dolmatova E, Shea MA, Milan DJ, Scott NS, Lindsay M, Lubitz SA, Domian IJ, Stone JR, Lin H, Ellinor PT. Novel Mutation in FLNC (Filamin C) Causes Familial Restrictive Cardiomyopathy. ACTA ACUST UNITED AC 2018; 10:CIRCGENETICS.117.001780. [PMID: 29212899 DOI: 10.1161/circgenetics.117.001780] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 09/11/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Restrictive cardiomyopathy (RCM) is a rare cardiomyopathy characterized by impaired diastolic ventricular function resulting in a poor clinical prognosis. Rarely, heritable forms of RCM have been reported, and mutations underlying RCM have been identified in genes that govern the contractile function of the cardiomyocytes. METHODS AND RESULTS We evaluated 8 family members across 4 generations by history, physical examination, electrocardiography, and echocardiography. Affected individuals presented with a pleitropic syndrome of progressive RCM, atrioventricular septal defects, and a high prevalence of atrial fibrillation. Exome sequencing of 5 affected members identified a single novel missense variant in a highly conserved residue of FLNC (filamin C; p.V2297M). FLNC encodes filamin C-a protein that acts as both a scaffold for the assembly and organization of the central contractile unit of striated muscle and also as a mechanosensitive signaling molecule during cell migration and shear stress. Immunohistochemical analysis of FLNC localization in cardiac tissue from an affected family member revealed a diminished localization at the z disk, whereas traditional localization at the intercalated disk was preserved. Stem cell-derived cardiomyocytes mutated to carry the effect allele had diminished contractile activity when compared with controls. CONCLUSION We have identified a novel variant in FLNC as pathogenic variant for familial RCM-a finding that further expands on the genetic basis of this rare and morbid cardiomyopathy.
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Affiliation(s)
- Nathan R Tucker
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Micheal A McLellan
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Dongjian Hu
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Jiangchuan Ye
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Victoria A Parsons
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Robert W Mills
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Sebastian Clauss
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Elena Dolmatova
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Marisa A Shea
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - David J Milan
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Nandita S Scott
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Mark Lindsay
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Steven A Lubitz
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Ibrahim J Domian
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - James R Stone
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Honghuang Lin
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.)
| | - Patrick T Ellinor
- From the Cardiovascular Research Center, Massachusetts General Hospital, Charlestown (N.R.T., M.A.M., D.H., J.Y., V.A.P., R.W.M., S.C., E.D., D.J.M., M.L., S.A.L., I.J.D., P.T.E.); Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA (N.R.T., J.Y., V.A.P., S.A.L., H.L., P.T.E.); Department of Medicine I, Klinikum Grosshadern, University of Munich (LMU), Germany (S.C.); German Centre for Cardiovascular Research, Partner site Munich, Germany (S.C.); Division of Cardiology (M.A.S., D.J.M., N.S.S., M.L., S.A.L., I.J.D., P.T.E.) and Department of Pathology, Center for Systems Biology (J.R.S.), Massachusetts General Hospital, Boston; and Computational Biomedicine Section, Department of Medicine, Boston University School of Medicine, MA (H.L.).
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