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Kang PB. Skipping, Steroids, and Genes: The First 7 Therapies for Duchenne Muscular Dystrophy. Neurology 2024; 102:e209210. [PMID: 38335475 DOI: 10.1212/wnl.0000000000209210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 12/18/2023] [Indexed: 02/12/2024] Open
Affiliation(s)
- Peter B Kang
- From the Greg Marzolf Jr. Muscular Dystrophy Center, Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis
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Weisburd B, Sharma R, Pata V, Reimand T, Ganesh VS, Austin-Tse C, Osei-Owusu I, O’Heir E, O’Leary M, Pais L, Stafki SA, Daugherty AL, Bönnemann CG, Donkervoort S, Haliloğlu G, Kang PB, Ravenscroft G, Laing N, Scott HS, Töpf A, Straub V, Pajusalu S, Õunap K, Tiao G, Rehm HL, O’Donnell-Luria A. Detecting missed diagnoses of spinal muscular atrophy in genome, exome, and panel sequencing datasets. medRxiv 2024:2024.02.11.24302646. [PMID: 38405995 PMCID: PMC10889006 DOI: 10.1101/2024.02.11.24302646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Spinal muscular atrophy (SMA) is a genetic disorder that causes progressive degeneration of lower motor neurons and the subsequent loss of muscle function throughout the body. It is the second most common recessive disorder in individuals of European descent and is present in all populations. Accurate tools exist for diagnosing SMA from short read and long read genome sequencing data. However, there are no publicly available tools for GRCh38-aligned data from panel or exome sequencing assays which continue to be used as first line tests for neuromuscular disorders. We therefore developed and extensively validated a new tool - SMA Finder - that can diagnose SMA not only in genome, but also exome and targeted sequencing samples aligned to GRCh37, GRCh38, or T2T-CHM13. It works by evaluating aligned reads that overlap the c.840 position of SMN1 and SMN2 in order to detect the most common molecular causes of SMA. We applied SMA Finder to 16,626 exomes and 3,911 genomes from heterogeneous rare disease cohorts sequenced at the Broad Institute Center for Mendelian Genomics as well as 1,157 exomes and 8,762 targeted sequencing samples from Tartu University Hospital. SMA Finder correctly identified all 16 known SMA cases and reported nine novel diagnoses which have since been confirmed by clinical testing, with another four novel diagnoses undergoing validation. Notably, out of the 29 total SMA positive cases, 21 had an initial clinical diagnosis of muscular dystrophy, congenital myasthenic syndrome, or congenital myopathy. This underscored the frequency with which SMA can be misdiagnosed as other neuromuscular disorders and confirmed the utility of using SMA Finder to reanalyze phenotypically diverse neuromuscular disease cohorts. Finally, we evaluated SMA Finder on 198,868 individuals that had both exome and genome sequencing data within the UK Biobank (UKBB) and found that SMA Finder's overall false positive rate was less than 1 / 200,000 exome samples, and its positive predictive value (PPV) was 96%. We also observed 100% concordance between UKBB exome and genome calls. This analysis showed that, even though it is located within a segmental duplication, the most common causal variant for SMA can be detected with comparable accuracy to monogenic disease variants in non-repetitive regions. Additionally, the high PPV demonstrated by SMA Finder, the existence of treatment options for SMA in which early diagnosis is imperative for therapeutic benefit, as well as widespread availability of clinical confirmatory testing for SMA, may warrant the addition of SMN1 to the ACMG list of genes with reportable secondary findings after genome and exome sequencing.
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Affiliation(s)
- Ben Weisburd
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Rakshya Sharma
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- UC Santa Cruz Genomics Institute, UCSC, Santa Cruz, CA, USA
| | - Villem Pata
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
- Anesthesiology and Intensive Care Clinic, Tartu University Hospital, Tartu, Estonia
| | - Tiia Reimand
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
- Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
| | - Vijay S. Ganesh
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Brigham & Women’s Hospital,Boston, MA, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Christina Austin-Tse
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ikeoluwa Osei-Owusu
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Emily O’Heir
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Melanie O’Leary
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Lynn Pais
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Seth A. Stafki
- Greg Marzolf Jr. Muscular Dystrophy Center, Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Audrey L. Daugherty
- Greg Marzolf Jr. Muscular Dystrophy Center, Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Carsten G. Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Göknur Haliloğlu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
- Division of Pediatric Neurology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Peter B. Kang
- Greg Marzolf Jr. Muscular Dystrophy Center, Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Gianina Ravenscroft
- Centre of Medical Research, The University of Western Australia, Perth, Western Australia, Australia
- Harry Perkins Institute for Medical Research, Perth, Western Australia, Australia
| | - Nigel Laing
- Centre of Medical Research, The University of Western Australia, Perth, Western Australia, Australia
- Harry Perkins Institute for Medical Research, Perth, Western Australia, Australia
| | - Hamish S. Scott
- Centre for Cancer Biology, An SA Pathology & UniSA Alliance, Adelaide, SA, Australia
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Sander Pajusalu
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
- Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
| | - Katrin Õunap
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
- Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
| | - Grace Tiao
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Heidi L. Rehm
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Anne O’Donnell-Luria
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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Kang PB, Jorand-Fletcher M, Zhang W, McDermott SW, Berry R, Chambers C, Wong KN, Mohamed Y, Thomas S, Venkatesh YS, Westfield C, Whitehead N, Johnson NE. Genetic Patterns of Selected Muscular Dystrophies in the Muscular Dystrophy Surveillance, Tracking, and Research Network. Neurol Genet 2023; 9:e200113. [PMID: 38045992 PMCID: PMC10692796 DOI: 10.1212/nxg.0000000000200113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 09/29/2023] [Indexed: 12/05/2023]
Abstract
Background and Objectives To report the genetic etiologies of Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy (LGMD), congenital muscular dystrophy (CMD), and distal muscular dystrophy (DD) in 6 geographically defined areas of the United States. Methods This was a cross-sectional, population-based study in which we studied the genes and variants associated with muscular dystrophy in individuals who were diagnosed with and received care for EDMD, LGMD, CMD, and DD from January 1, 2008, through December 31, 2016, in the 6 areas of the United States covered by the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet). Variants of unknown significance (VUSs) from the original genetic test reports were reanalyzed for changes in interpretation. Results Among 243 individuals with definite or probable muscular dystrophy, LGMD was the most common diagnosis (138 cases), followed by CMD (62 cases), DD (22 cases), and EDMD (21 cases). There was a higher proportion of male individuals compared with female individuals, which persisted after excluding X-linked genes (EMD) and autosomal genes reported to have skewed gender ratios (ANO5, CAV3, and LMNA). The most common associated genes were FKRP, CAPN3, ANO5, and DYSF. Reanalysis yielded more definitive variant interpretations for 60 of 144 VUSs, with a mean interval between the original clinical genetic test of 8.11 years for all 144 VUSs and 8.62 years for the 60 reclassified variants. Ten individuals were found to have monoallelic pathogenic variants in genes known to be primarily recessive. Discussion This study is distinct for being an examination of 4 types of muscular dystrophies in selected geographic areas of the United States. The striking proportion of resolved VUSs demonstrates the value of periodic re-examinations of these variants. Such re-examinations will resolve some genetic diagnostic ambiguities before initiating repeat testing or more invasive diagnostic procedures such as muscle biopsy. The presence of monoallelic pathogenic variants in recessive genes in our cohort indicates that some individuals with muscular dystrophy continue to face incomplete genetic diagnoses; further refinements in genetic knowledge and diagnostic approaches will optimize diagnostic information for these individuals.
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Affiliation(s)
- Peter B Kang
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Magali Jorand-Fletcher
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Wanfang Zhang
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Suzanne W McDermott
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Reba Berry
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Chelsea Chambers
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Kristen N Wong
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Yara Mohamed
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Shiny Thomas
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Y Swamy Venkatesh
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Christina Westfield
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Nedra Whitehead
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
| | - Nicholas E Johnson
- From the Paul & Sheila Wellstone Muscular Dystrophy Center (P.B.K.), Department of Neurology, and Institute for Translational Neuroscience, University of Minnesota, Minneapolis; Department of Pediatrics (M.J.-F., Y.M.), University of Florida College of Medicine, Gainesville; Department of Epidemiology and Biostatistics (W.Z.), University of South Carolina, Columbia; Department of Environmental, Occupational, and Geospatial Health Sciences (S.W.M.), Graduate School of Public Health and Health Policy, City University of New York; Division of Population Health Surveillance (R.B., C.W.), Bureau of Maternal and Child Health, South Carolina Department of Health and Environmental Control, Columbia; Department of Human and Molecular Genetics (C.C.), Virginia Commonwealth University, Richmond; Department of Pediatrics (K.N.W.), University of Utah, Salt Lake City; New York State Department of Health (S.T.), Albany; Department of Neurology (Y.S.V.), University of South Carolina, Columbia; RTI International (N.W.), Research Triangle Park, NC; and Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond
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Rathore G, Kang PB. Pediatric Neuromuscular Diseases. Pediatr Neurol 2023; 149:1-14. [PMID: 37757659 DOI: 10.1016/j.pediatrneurol.2023.08.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/25/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023]
Abstract
The diagnostic and referral workflow for children with neuromuscular disorders is evolving, particularly as newborn screening programs are expanding in tandem with novel therapeutic developments. However, for the children who present with symptoms and signs of potential neuromuscular disorders, anatomic localization, guided initially by careful history and physical examination, continues to be the cardinal initial step in the diagnostic evaluation. It is important to consider whether the localization is more likely to be in the lower motor neuron, peripheral nerve, neuromuscular junction, or muscle. After that, disease etiologies can be divided broadly into inherited versus acquired categories. Considerations of localization and etiologies will help generate a differential diagnosis, which in turn will guide diagnostic testing. Once a diagnosis is made, it is important to be aware of current treatment options, as a number of new therapies for some of these disorders have been approved in recent years. Families are also increasingly interested in clinical research, which may include natural history studies and interventional clinical trials. Such research has proliferated for rare neuromuscular diseases, leading to exciting advances in diagnostic and therapeutic technologies, promising dramatic changes in the landscape of these disorders in the years to come.
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Affiliation(s)
- Geetanjali Rathore
- Division of Neurology, Department of Pediatrics, University of Nebraska College of Medicine, Omaha, Nebraska
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota.
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Pacak CA, Suzuki-Hatano S, Khadir F, Daugherty AL, Sriramvenugopal M, Gosiker BJ, Kang PB, Cade WT. One episode of low intensity aerobic exercise prior to systemic AAV9 administration augments transgene delivery to the heart and skeletal muscle. J Transl Med 2023; 21:748. [PMID: 37875924 PMCID: PMC10598899 DOI: 10.1186/s12967-023-04626-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/13/2023] [Indexed: 10/26/2023] Open
Abstract
INTRODUCTION The promising potential of adeno-associated virus (AAV) gene delivery strategies to treat genetic disorders continues to grow with an additional three AAV-based therapies recently approved by the Food and Drug Administration and dozens of others currently under evaluation in clinical trials. With these developments, it has become increasingly apparent that the high doses currently needed for efficacy carry risks of toxicity and entail enormous manufacturing costs, especially for clinical grade products. Strategies to increase the therapeutic efficacy of AAV-mediated gene delivery and reduce the minimal effective dose would have a substantial impact on this field. We hypothesized that an exercise-induced redistribution of tissue perfusion in the body to favor specific target organs via acute aerobic exercise prior to systemic intravenous (IV) AAV administration could increase efficacy. BACKGROUND Aerobic exercise triggers an array of downstream physiological effects including increased perfusion of heart and skeletal muscle, which we expected could enhance AAV transduction. Prior preclinical studies have shown promising results for a gene therapy approach to treat Barth syndrome (BTHS), a rare monogenic cardioskeletal myopathy, and clinical studies have shown the benefit of low intensity exercise in these patients, making this a suitable disease in which to test the ability of aerobic exercise to enhance AAV transduction. METHODS Wild-type (WT) and BTHS mice were either systemically administered AAV9 or completed one episode of low intensity treadmill exercise immediately prior to systemic administration of AAV9. RESULTS We demonstrate that a single episode of acute low intensity aerobic exercise immediately prior to IV AAV9 administration improves marker transgene delivery in WT mice as compared to mice injected without the exercise pre-treatment. In BTHS mice, prior exercise improved transgene delivery and additionally increased improvement in mitochondrial gene transcription levels and mitochondrial function in the heart and gastrocnemius muscles as compared to mice treated without exercise. CONCLUSIONS Our findings suggest that one episode of acute low intensity aerobic exercise improves AAV9 transduction of heart and skeletal muscle. This low-risk, cost effective intervention could be implemented in clinical trials of individuals with inherited cardioskeletal disease as a potential means of improving patient safety for human gene therapy.
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Affiliation(s)
- Christina A Pacak
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA.
| | - Silveli Suzuki-Hatano
- College of Medicine, Department of Pediatrics, University of Florida, Gainesville, USA
| | - Fatemeh Khadir
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | - Audrey L Daugherty
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | | | - Bennett J Gosiker
- College of Medicine, Department of Pediatrics, University of Florida, Gainesville, USA
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, 420 Delaware St SE, Minneapolis, MN, 55455, USA
| | - William Todd Cade
- Physical Therapy Division, Department of Orthopaedic Surgery, Duke University School of Medicine, 311 Trent Drive, Durham, NC, 27710, USA.
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Morales-Rosado JA, Schwab TL, Macklin-Mantia SK, Foley AR, Pinto E Vairo F, Pehlivan D, Donkervoort S, Rosenfeld JA, Boyum GE, Hu Y, Cong ATQ, Lotze TE, Mohila CA, Saade D, Bharucha-Goebel D, Chao KR, Grunseich C, Bruels CC, Littel HR, Estrella EA, Pais L, Kang PB, Zimmermann MT, Lupski JR, Lee B, Schellenberg MJ, Clark KJ, Wierenga KJ, Bönnemann CG, Klee EW. Bi-allelic variants in HMGCR cause an autosomal-recessive progressive limb-girdle muscular dystrophy. Am J Hum Genet 2023; 110:989-997. [PMID: 37167966 PMCID: PMC10257193 DOI: 10.1016/j.ajhg.2023.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 04/19/2023] [Indexed: 05/13/2023] Open
Abstract
Statins are a mainstay intervention for cardiovascular disease prevention, yet their use can cause rare severe myopathy. HMG-CoA reductase, an essential enzyme in the mevalonate pathway, is the target of statins. We identified nine individuals from five unrelated families with unexplained limb-girdle like muscular dystrophy and bi-allelic variants in HMGCR via clinical and research exome sequencing. The clinical features resembled other genetic causes of muscular dystrophy with incidental high CPK levels (>1,000 U/L), proximal muscle weakness, variable age of onset, and progression leading to impaired ambulation. Muscle biopsies in most affected individuals showed non-specific dystrophic changes with non-diagnostic immunohistochemistry. Molecular modeling analyses revealed variants to be destabilizing and affecting protein oligomerization. Protein activity studies using three variants (p.Asp623Asn, p.Tyr792Cys, and p.Arg443Gln) identified in affected individuals confirmed decreased enzymatic activity and reduced protein stability. In summary, we showed that individuals with bi-allelic amorphic (i.e., null and/or hypomorphic) variants in HMGCR display phenotypes that resemble non-genetic causes of myopathy involving this reductase. This study expands our knowledge regarding the mechanisms leading to muscular dystrophy through dysregulation of the mevalonate pathway, autoimmune myopathy, and statin-induced myopathy.
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Affiliation(s)
- Joel A Morales-Rosado
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Quantitative Health Sciences, Division of Computational Biology, Mayo Clinic, Rochester, MN, USA
| | - Tanya L Schwab
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Sarah K Macklin-Mantia
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics at Mayo Clinic, Jacksonville, FL, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Filippo Pinto E Vairo
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA; Division of Neurology and Developmental Neuroscience and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA; Baylor Genetics Laboratories, Houston, TX, USA
| | - Grace E Boyum
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Anh T Q Cong
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Timothy E Lotze
- Division of Neurology and Developmental Neuroscience and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Carrie A Mohila
- Department of Pathology & Immunology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Dimah Saade
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Diana Bharucha-Goebel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA; Division of Neurology, Children's National Hospital, Washington, DC, USA
| | - Katherine R Chao
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christopher Grunseich
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Christine C Bruels
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Hannah R Littel
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Elicia A Estrella
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lynn Pais
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Michael T Zimmermann
- Bioinformatics Research and Development Laboratory, Genomics Sciences and Precision Medicine Center, Clinical and Translational Sciences Institute, Medical College of Wisconsin, Milwaukee, WI, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | | | - Karl J Clark
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Klaas J Wierenga
- Department of Clinical Genomics at Mayo Clinic, Jacksonville, FL, USA
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Quantitative Health Sciences, Division of Computational Biology, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
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7
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Stafki SA, Turner J, Littel HR, Bruels CC, Truong D, Knirsch U, Stettner GM, Graf U, Berger W, Kinali M, Jungbluth H, Pacak CA, Hughes J, Mirchi A, Derksen A, Vincent-Delorme C, Theil AF, Bernard G, Ellis D, Fassihi H, Lehmann AR, Laugel V, Mohammed S, Kang PB. The Spectrum of MORC2-Related Disorders: A Potential Link to Cockayne Syndrome. Pediatr Neurol 2023; 141:79-86. [PMID: 36791574 PMCID: PMC10098370 DOI: 10.1016/j.pediatrneurol.2023.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/21/2022] [Accepted: 01/19/2023] [Indexed: 01/27/2023]
Abstract
BACKGROUND Cockayne syndrome (CS) is a DNA repair disorder primarily associated with pathogenic variants in ERCC6 and ERCC8. As in other Mendelian disorders, there are a number of genetically unsolved CS cases. METHODS We ascertained five individuals with monoallelic pathogenic variants in MORC2, previously associated with three dominantly inherited phenotypes: an axonal form of Charcot-Marie-Tooth disease type 2Z; a syndrome of developmental delay, impaired growth, dysmorphic facies, and axonal neuropathy; and a rare form of spinal muscular atrophy. RESULTS One of these individuals bore a strong phenotypic resemblance to CS. We then identified monoallelic pathogenic MORC2 variants in three of five genetically unsolved individuals with a clinical diagnosis of CS. In total, we identified eight individuals with MORC2-related disorder, four of whom had clinical features strongly suggestive of CS. CONCLUSIONS Our findings indicate that some forms of MORC2-related disorder have phenotypic similarities to CS, including features of accelerated aging. Unlike classic DNA repair disorders, MORC2-related disorder does not appear to be associated with a defect in transcription-coupled nucleotide excision repair and follows a dominant pattern of inheritance with variants typically arising de novo. Such de novo pathogenic variants present particular challenges with regard to both initial gene discovery and diagnostic evaluations. MORC2 should be included in diagnostic genetic test panels targeting the evaluation of microcephaly and/or suspected DNA repair disorders. Future studies of MORC2 and its protein product, coupled with further phenotypic characterization, will help to optimize the diagnosis, understanding, and therapy of the associated disorders.
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Affiliation(s)
- Seth A Stafki
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Johnnie Turner
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Hannah R Littel
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Christine C Bruels
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Don Truong
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Ursula Knirsch
- Neuromuscular Center Zürich and Department of Pediatric Neurology, University Children's Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Georg M Stettner
- Neuromuscular Center Zürich and Department of Pediatric Neurology, University Children's Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Urs Graf
- Institute of Medical Molecular Genetics (IMMG), University of Zürich, Zürich, Switzerland
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics (IMMG), University of Zürich, Zürich, Switzerland; Neuroscience Center Zurich (NCZ), University and ETH Zürich, Zürich, Switzerland; Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
| | - Maria Kinali
- Department of Brain Sciences, Imperial College London and Portland Hospital HCA International, London, United Kingdom
| | - Heinz Jungbluth
- Evelina Children's Hospital and King's College London, University of Manchester, London, United Kingdom
| | - Christina A Pacak
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Jayne Hughes
- Amy and Friends Cockayne Syndrome/Trichothiodystrophy Support, Wirral, United Kingdom
| | - Amytice Mirchi
- Departments of Neurology and Neurosurgery and Pediatrics, McGill University, Montreal, Canada; Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Alexa Derksen
- Departments of Neurology and Neurosurgery and Pediatrics, McGill University, Montreal, Canada; Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
| | | | - Arjan F Theil
- Department of Molecular Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Geneviève Bernard
- Departments of Neurology and Neurosurgery and Pediatrics, McGill University, Montreal, Canada; Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada; Department of Human Genetics, McGill University, Montreal, Canada; Division of Medical Genetics, Department Specialized Medicine, McGill University Health Center, Montreal, Canada
| | - David Ellis
- South East Genomics Laboratory Hub, Guy's Hospital, London, United Kingdom
| | - Hiva Fassihi
- St. John's Institute of Dermatology, Rare Disease Centre, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Alan R Lehmann
- Genome Damage and Stability Centre, University of Sussex, Brighton, United Kingdom
| | - Vincent Laugel
- Service de Pédiatrie 1, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; Laboratoire de Génétique médicale, INSERM U1112, Institut de génétique médicale d'Alsace, Faculté de Médecine de Strasbourg, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Shehla Mohammed
- South East Thames Regional Genetics Service and Rare Diseases Centre Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Peter B Kang
- Department of Neurology and Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota.
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8
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Nascimento A, Bruels CC, Donkervoort S, Foley AR, Codina A, Milisenda JC, Estrella EA, Li C, Pijuan J, Draper I, Hu Y, Stafki SA, Pais LS, Ganesh VS, O'Donnell-Luria A, Syeda SB, Carrera-García L, Expósito-Escudero J, Yubero D, Martorell L, Pinal-Fernandez I, Lidov HGW, Mammen AL, Grau-Junyent JM, Ortez C, Palau F, Ghosh PS, Darras BT, Jou C, Kunkel LM, Hoenicka J, Bönnemann CG, Kang PB, Natera-de Benito D. Variants in DTNA cause a mild, dominantly inherited muscular dystrophy. Acta Neuropathol 2023; 145:479-496. [PMID: 36799992 PMCID: PMC10923638 DOI: 10.1007/s00401-023-02551-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/10/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023]
Abstract
DTNA encodes α-dystrobrevin, a component of the macromolecular dystrophin-glycoprotein complex (DGC) that binds to dystrophin/utrophin and α-syntrophin. Mice lacking α-dystrobrevin have a muscular dystrophy phenotype, but variants in DTNA have not previously been associated with human skeletal muscle disease. We present 12 individuals from four unrelated families with two different monoallelic DTNA variants affecting the coiled-coil domain of α-dystrobrevin. The five affected individuals from family A harbor a c.1585G > A; p.Glu529Lys variant, while the recurrent c.1567_1587del; p.Gln523_Glu529del DTNA variant was identified in the other three families (family B: four affected individuals, family C: one affected individual, and family D: two affected individuals). Myalgia and exercise intolerance, with variable ages of onset, were reported in 10 of 12 affected individuals. Proximal lower limb weakness with onset in the first decade of life was noted in three individuals. Persistent elevations of serum creatine kinase (CK) levels were detected in 11 of 12 affected individuals, 1 of whom had an episode of rhabdomyolysis at 20 years of age. Autism spectrum disorder or learning disabilities were reported in four individuals with the c.1567_1587 deletion. Muscle biopsies in eight affected individuals showed mixed myopathic and dystrophic findings, characterized by fiber size variability, internalized nuclei, and slightly increased extracellular connective tissue and inflammation. Immunofluorescence analysis of biopsies from five affected individuals showed reduced α-dystrobrevin immunoreactivity and variably reduced immunoreactivity of other DGC proteins: dystrophin, α, β, δ and γ-sarcoglycans, and α and β-dystroglycans. The DTNA deletion disrupted an interaction between α-dystrobrevin and syntrophin. Specific variants in the coiled-coil domain of DTNA cause skeletal muscle disease with variable penetrance. Affected individuals show a spectrum of clinical manifestations, with severity ranging from hyperCKemia, myalgias, and exercise intolerance to childhood-onset proximal muscle weakness. Our findings expand the molecular etiologies of both muscular dystrophy and paucisymptomatic hyperCKemia, to now include monoallelic DTNA variants as a novel cause of skeletal muscle disease in humans.
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Affiliation(s)
- Andres Nascimento
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Christine C Bruels
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Anna Codina
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Pathology, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Jose C Milisenda
- Department of Internal Medicine, Hospital Clinic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Elicia A Estrella
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Chengcheng Li
- Division of Pediatric Neurology, University of Florida College of Medicine, Gainesville, FL, 32610, USA
| | - Jordi Pijuan
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, 02111, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Seth A Stafki
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA
| | - Lynn S Pais
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Vijay S Ganesh
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Anne O'Donnell-Luria
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Safoora B Syeda
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Laura Carrera-García
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Jessica Expósito-Escudero
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Delia Yubero
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Loreto Martorell
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Iago Pinal-Fernandez
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hart G W Lidov
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew L Mammen
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Josep M Grau-Junyent
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Internal Medicine, Hospital Clinic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Carlos Ortez
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Francesc Palau
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Partha S Ghosh
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Cristina Jou
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Pathology, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Janet Hoenicka
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Peter B Kang
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA.
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA.
| | - Daniel Natera-de Benito
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain.
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain.
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9
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Koch RL, Soler-Alfonso C, Kiely BT, Asai A, Smith AL, Bali DS, Kang PB, Landstrom AP, Akman HO, Burrow TA, Orthmann-Murphy JL, Goldman DS, Pendyal S, El-Gharbawy AH, Austin SL, Case LE, Schiffmann R, Hirano M, Kishnani PS. Diagnosis and management of glycogen storage disease type IV, including adult polyglucosan body disease: A clinical practice resource. Mol Genet Metab 2023; 138:107525. [PMID: 36796138 DOI: 10.1016/j.ymgme.2023.107525] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/20/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023]
Abstract
Glycogen storage disease type IV (GSD IV) is an ultra-rare autosomal recessive disorder caused by pathogenic variants in GBE1 which results in reduced or deficient glycogen branching enzyme activity. Consequently, glycogen synthesis is impaired and leads to accumulation of poorly branched glycogen known as polyglucosan. GSD IV is characterized by a remarkable degree of phenotypic heterogeneity with presentations in utero, during infancy, early childhood, adolescence, or middle to late adulthood. The clinical continuum encompasses hepatic, cardiac, muscular, and neurologic manifestations that range in severity. The adult-onset form of GSD IV, referred to as adult polyglucosan body disease (APBD), is a neurodegenerative disease characterized by neurogenic bladder, spastic paraparesis, and peripheral neuropathy. There are currently no consensus guidelines for the diagnosis and management of these patients, resulting in high rates of misdiagnosis, delayed diagnosis, and lack of standardized clinical care. To address this, a group of experts from the United States developed a set of recommendations for the diagnosis and management of all clinical phenotypes of GSD IV, including APBD, to support clinicians and caregivers who provide long-term care for individuals with GSD IV. The educational resource includes practical steps to confirm a GSD IV diagnosis and best practices for medical management, including (a) imaging of the liver, heart, skeletal muscle, brain, and spine, (b) functional and neuromusculoskeletal assessments, (c) laboratory investigations, (d) liver and heart transplantation, and (e) long-term follow-up care. Remaining knowledge gaps are detailed to emphasize areas for improvement and future research.
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Affiliation(s)
- Rebecca L Koch
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA.
| | - Claudia Soler-Alfonso
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Bridget T Kiely
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Akihiro Asai
- Department of Pediatrics, University of Cincinnati Medical Center, Cincinnati, OH, USA; Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Ariana L Smith
- Division of Urology, Department of Surgery, University of Pennsylvania Health System, Philadelphia, PA, USA
| | - Deeksha S Bali
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center, Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Andrew P Landstrom
- Division of Cardiology, Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
| | - H Orhan Akman
- Department of Neurology, Columbia University Irving Medical Center, New York City, NY, USA
| | - T Andrew Burrow
- Section of Genetics and Metabolism, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, Little Rock, AR, USA
| | | | - Deberah S Goldman
- Adult Polyglucosan Body Disease Research Foundation, Brooklyn, NY, USA
| | - Surekha Pendyal
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Areeg H El-Gharbawy
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Stephanie L Austin
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Laura E Case
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA; Doctor of Physical Therapy Division, Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | | | - Michio Hirano
- Department of Neurology, Columbia University Irving Medical Center, New York City, NY, USA
| | - Priya S Kishnani
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
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10
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Maguina M, Kang PB, Tsai AC, Pacak CA. Peripheral neuropathies associated with DNA repair disorders. Muscle Nerve 2023; 67:101-110. [PMID: 36190439 PMCID: PMC10075233 DOI: 10.1002/mus.27721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 01/25/2023]
Abstract
Repair of genomic DNA is a fundamental housekeeping process that quietly maintains the health of our genomes. The consequences of a genetic defect affecting a component of this delicate mechanism are quite harmful, characterized by a cascade of premature aging that injures a variety of organs, including the nervous system. One part of the nervous system that is impaired in certain DNA repair disorders is the peripheral nerve. Chronic motor, sensory, and sensorimotor polyneuropathies have all been observed in affected individuals, with specific physiologies associated with different categories of DNA repair disorders. Cockayne syndrome has classically been linked to demyelinating polyneuropathies, whereas xeroderma pigmentosum has long been associated with axonal polyneuropathies. Three additional recessive DNA repair disorders are associated with neuropathies, including trichothiodystrophy, Werner syndrome, and ataxia-telangiectasia. Although plausible biological explanations exist for why the peripheral nerves are specifically vulnerable to impairments of DNA repair, specific mechanisms such as oxidative stress remain largely unexplored in this context, and bear further study. It is also unclear why different DNA repair disorders manifest with different types of neuropathy, and why neuropathy is not universally present in those diseases. Longitudinal physiological monitoring of these neuropathies with serial electrodiagnostic studies may provide valuable noninvasive outcome data in the context of future natural history studies, and thus the responses of these neuropathies may become sentinel outcome measures for future clinical trials of treatments currently in development such as adeno-associated virus gene replacement therapies.
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Affiliation(s)
- Melissa Maguina
- Medical Education Program, Nova Southeastern University, Fort Lauderdale, Florida
| | - Peter B Kang
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota.,Institute for Translational Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Ang-Chen Tsai
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Christina A Pacak
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota
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11
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Vargas‐Franco D, Kalra R, Draper I, Pacak CA, Asakura A, Kang PB. The Notch signaling pathway in skeletal muscle health and disease. Muscle Nerve 2022; 66:530-544. [PMID: 35968817 PMCID: PMC9804383 DOI: 10.1002/mus.27684] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 01/05/2023]
Abstract
The Notch signaling pathway is a key regulator of skeletal muscle development and regeneration. Over the past decade, the discoveries of three new muscle disease genes have added a new dimension to the relationship between the Notch signaling pathway and skeletal muscle: MEGF10, POGLUT1, and JAG2. We review the clinical syndromes associated with pathogenic variants in each of these genes, known molecular and cellular functions of their protein products with a particular focus on the Notch signaling pathway, and potential novel therapeutic targets that may emerge from further investigations of these diseases. The phenotypes associated with two of these genes, POGLUT1 and JAG2, clearly fall within the realm of muscular dystrophy, whereas the third, MEGF10, is associated with a congenital myopathy/muscular dystrophy overlap syndrome classically known as early-onset myopathy, areflexia, respiratory distress, and dysphagia. JAG2 is a canonical Notch ligand, POGLUT1 glycosylates the extracellular domain of Notch receptors, and MEGF10 interacts with the intracellular domain of NOTCH1. Additional genes and their encoded proteins relevant to muscle function and disease with links to the Notch signaling pathway include TRIM32, ATP2A1 (SERCA1), JAG1, PAX7, and NOTCH2NLC. There is enormous potential to identify convergent mechanisms of skeletal muscle disease and new therapeutic targets through further investigations of the Notch signaling pathway in the context of skeletal muscle development, maintenance, and disease.
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Affiliation(s)
| | - Raghav Kalra
- Division of Pediatric NeurologyUniversity of Florida College of MedicineGainesvilleFlorida
| | - Isabelle Draper
- Molecular Cardiology Research InstituteTufts Medical CenterBostonMassachusetts
| | - Christina A. Pacak
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
| | - Atsushi Asakura
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
| | - Peter B. Kang
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Institute for Translational NeuroscienceUniversity of Minnesota Medical SchoolMinneapolisMinnesota
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12
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Portwood KE, Albayram MS, Stone S, Zingariello CD, Sladky JT, Chim H, Kang PB. Clinical, electrophysiological, and imaging findings in childhood brachial plexus injury. Dev Med Child Neurol 2022; 64:1254-1261. [PMID: 35524644 PMCID: PMC9544348 DOI: 10.1111/dmcn.15255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 03/24/2022] [Accepted: 03/25/2022] [Indexed: 11/30/2022]
Abstract
AIM To assess the prognostic capabilities of various diagnostic modalities for childhood brachial plexus injuries (BPIs) and brachial plexus birth injury (BPBI) and postneonatal BPI. METHOD In this single-center retrospective cross-sectional study, we examined children with BPIs diagnosed or confirmed by electrodiagnostic studies between 2013 and 2020, and compared the prognostic value of various components of the electrophysiologic findings, magnetic resonance imaging (MRI) data, and the Active Movement Scale (AMS). We developed scoring systems for electrodiagnostic studies and MRI findings, including various components of nerve conduction studies and electromyography (EMG) for electrodiagnostic studies. RESULTS We identified 21 children (10 females and 11 males) aged 8 days to 21 years (mean 8y 6.95mo) who had a total of 30 electrodiagnostic studies, 14 brachial plexus MRI studies, and 10 surgical procedures. Among the diagnostic modalities assessed, brachial plexus MRI scores, EMG denervation scores, and mean total EMG scores were the most valuable in predicting surgical versus non-surgical outcomes. Correspondingly, a combined MRI/mean total EMG score provided prognostic value. INTERPRETATION Brachial plexus MRI scores and specific electrodiagnostic scores provide the most accurate prognostic information for children with BPI. Our grading scales can assist a multidisciplinary team in quantifying results of these studies and determining prognosis in this setting. WHAT THIS PAPER ADDS A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented. Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs). Composite electromyography scores have good prognostic value for childhood BPIs. Brachial plexus MRI has good prognostic value for childhood BPIs.
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Affiliation(s)
- Katherin E. Portwood
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Mehmet S. Albayram
- Department of RadiologyUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Sarah Stone
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Carla D. Zingariello
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - John T. Sladky
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Harvey Chim
- Division of Plastic and Reconstructive Surgery, Department of SurgeryUniversity of Florida College of MedicineGainesvilleFloridaUSA
| | - Peter B. Kang
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFloridaUSA,Paul & Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUnited States,Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUnited States,Institute for Translational NeuroscienceUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUSA
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13
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Bruels CC, Littel HR, Daugherty AL, Stafki S, Estrella EA, McGaughy ES, Truong D, Badalamenti JP, Pais L, Ganesh VS, O'Donnell-Luria A, Stalker HJ, Wang Y, Collins C, Behlmann A, Lemmers RJLF, van der Maarel SM, Laine R, Ghosh PS, Darras BT, Zingariello CD, Pacak CA, Kunkel LM, Kang PB. Diagnostic capabilities of nanopore long-read sequencing in muscular dystrophy. Ann Clin Transl Neurol 2022; 9:1302-1309. [PMID: 35734998 PMCID: PMC9380148 DOI: 10.1002/acn3.51612] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/05/2022] Open
Abstract
Many individuals with muscular dystrophies remain genetically undiagnosed despite clinical diagnostic testing, including exome sequencing. Some may harbor previously undetected structural variants (SVs) or cryptic splice sites. We enrolled 10 unrelated families: nine had muscular dystrophy but lacked complete genetic diagnoses and one had an asymptomatic DMD duplication. Nanopore genomic long-read sequencing identified previously undetected pathogenic variants in four individuals: an SV in DMD, an SV in LAMA2, and two single nucleotide variants in DMD that alter splicing. The DMD duplication in the asymptomatic individual was in tandem. Nanopore sequencing may help streamline genetic diagnostic approaches for muscular dystrophy.
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Affiliation(s)
- Christine C Bruels
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Hannah R Littel
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Audrey L Daugherty
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Seth Stafki
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Elicia A Estrella
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Emily S McGaughy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, 32610
| | - Don Truong
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Jonathan P Badalamenti
- University of Minnesota Genomics Center, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Lynn Pais
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Vijay S Ganesh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts.,Department of Neurology, Brigham and Women's Hospital, Boston, Massachusetts
| | - Anne O'Donnell-Luria
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Heather J Stalker
- Division of Genetics, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, 32610
| | - Yang Wang
- PerkinElmer Genomics, Pittsburgh, Pennsylvania
| | | | | | | | | | - Regina Laine
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Partha S Ghosh
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Carla D Zingariello
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, 32610
| | - Christina A Pacak
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota, 55455.,Institute for Translational Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
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14
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Holling T, Nampoothiri S, Tarhan B, Schneeberger PE, Vinayan KP, Yesodharan D, Roy AG, Radhakrishnan P, Alawi M, Rhodes L, Girisha KM, Kang PB, Kutsche K. Novel biallelic variants expand the SLC5A6-related phenotypic spectrum. Eur J Hum Genet 2022; 30:439-449. [PMID: 35013551 PMCID: PMC8747999 DOI: 10.1038/s41431-021-01033-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/09/2021] [Accepted: 12/17/2021] [Indexed: 11/09/2022] Open
Abstract
The sodium (Na+):multivitamin transporter (SMVT), encoded by SLC5A6, belongs to the sodium:solute symporter family and is required for the Na+-dependent uptake of biotin (vitamin B7), pantothenic acid (vitamin B5), the vitamin-like substance α-lipoic acid, and iodide. Compound heterozygous SLC5A6 variants have been reported in individuals with variable multisystemic disorder, including failure to thrive, developmental delay, seizures, cerebral palsy, brain atrophy, gastrointestinal problems, immunodeficiency, and/or osteopenia. We expand the phenotypic spectrum associated with biallelic SLC5A6 variants affecting function by reporting five individuals from three families with motor neuropathies. We identified the homozygous variant c.1285 A > G [p.(Ser429Gly)] in three affected siblings and a simplex patient and the maternally inherited c.280 C > T [p.(Arg94*)] variant and the paternally inherited c.485 A > G [p.(Tyr162Cys)] variant in the simplex patient of the third family. Both missense variants were predicted to affect function by in silico tools. 3D homology modeling of the human SMVT revealed 13 transmembrane helices (TMs) and Tyr162 and Ser429 to be located at the cytoplasmic facing region of TM4 and within TM11, respectively. The SLC5A6 missense variants p.(Tyr162Cys) and p.(Ser429Gly) did not affect plasma membrane localization of the ectopically expressed multivitamin transporter suggesting reduced but not abolished function, such as lower catalytic activity. Targeted therapeutic intervention yielded clinical improvement in four of the five patients. Early molecular diagnosis by exome sequencing is essential for timely replacement therapy in affected individuals.
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Affiliation(s)
- Tess Holling
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Sheela Nampoothiri
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences & Research Centre, Cochin, 682041, Kerala, India
| | - Bedirhan Tarhan
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, 32610, USA
| | - Pauline E Schneeberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
- Amedes MVZ Wagnerstibbe für Laboratoriumsmedizin, Hämostaseologie, Humangenetik und Mikrobiologie Hannover, 30159, Hannover, Germany
| | | | - Dhanya Yesodharan
- Department of Pediatric Genetics, Amrita Institute of Medical Sciences & Research Centre, Cochin, 682041, Kerala, India
| | - Arun Grace Roy
- Department of Neurology, Amrita Institute of Medical Sciences & Research Centre, Cochin, 682041, Kerala, India
| | - Periyasamy Radhakrishnan
- Suma Genomics Pvt. Ltd, Manipal Universal Technology Business Incubator (MUTBI), Manipal, 576104, India
| | - Malik Alawi
- Bioinformatics Core, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | | | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, 576104, India
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, 32610, USA.
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
- Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
- Institute for Translational Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
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15
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Affiliation(s)
| | - Meghan M McAnally
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis.,Department of Neurology, University of Minnesota Medical School, Minneapolis
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16
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Coppens S, Barnard AM, Puusepp S, Pajusalu S, Õunap K, Vargas-Franco D, Bruels CC, Donkervoort S, Pais L, Chao KR, Goodrich JK, England EM, Weisburd B, Ganesh VS, Gudmundsson S, O’Donnell-Luria A, Nigul M, Ilves P, Mohassel P, Siddique T, Milone M, Nicolau S, Maroofian R, Houlden H, Hanna MG, Quinlivan R, Toosi MB, Karimiani EG, Costagliola S, Deconinck N, Kadhim H, Macke E, Lanpher BC, Klee EW, Łusakowska A, Kostera-Pruszczyk A, Hahn A, Schrank B, Nishino I, Ogasawara M, El Sherif R, Stojkovic T, Nelson I, Bonne G, Cohen E, Boland-Augé A, Deleuze JF, Meng Y, Töpf A, Vilain C, Pacak CA, Rivera-Zengotita ML, Bönnemann CG, Straub V, Handford PA, Draper I, Walter GA, Kang PB. A form of muscular dystrophy associated with pathogenic variants in JAG2. Am J Hum Genet 2021; 108:1164. [PMID: 34087166 PMCID: PMC8206378 DOI: 10.1016/j.ajhg.2021.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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17
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Coppens S, Barnard AM, Puusepp S, Pajusalu S, Õunap K, Vargas-Franco D, Bruels CC, Donkervoort S, Pais L, Chao KR, Goodrich JK, England EM, Weisburd B, Ganesh VS, Gudmundsson S, O'Donnell-Luria A, Nigul M, Ilves P, Mohassel P, Siddique T, Milone M, Nicolau S, Maroofian R, Houlden H, Hanna MG, Quinlivan R, Beiraghi Toosi M, Ghayoor Karimiani E, Costagliola S, Deconinck N, Kadhim H, Macke E, Lanpher BC, Klee EW, Łusakowska A, Kostera-Pruszczyk A, Hahn A, Schrank B, Nishino I, Ogasawara M, El Sherif R, Stojkovic T, Nelson I, Bonne G, Cohen E, Boland-Augé A, Deleuze JF, Meng Y, Töpf A, Vilain C, Pacak CA, Rivera-Zengotita ML, Bönnemann CG, Straub V, Handford PA, Draper I, Walter GA, Kang PB. A form of muscular dystrophy associated with pathogenic variants in JAG2. Am J Hum Genet 2021; 108:840-856. [PMID: 33861953 PMCID: PMC8206160 DOI: 10.1016/j.ajhg.2021.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/26/2021] [Indexed: 02/09/2023] Open
Abstract
JAG2 encodes the Notch ligand Jagged2. The conserved Notch signaling pathway contributes to the development and homeostasis of multiple tissues, including skeletal muscle. We studied an international cohort of 23 individuals with genetically unsolved muscular dystrophy from 13 unrelated families. Whole-exome sequencing identified rare homozygous or compound heterozygous JAG2 variants in all 13 families. The identified bi-allelic variants include 10 missense variants that disrupt highly conserved amino acids, a nonsense variant, two frameshift variants, an in-frame deletion, and a microdeletion encompassing JAG2. Onset of muscle weakness occurred from infancy to young adulthood. Serum creatine kinase (CK) levels were normal or mildly elevated. Muscle histology was primarily dystrophic. MRI of the lower extremities revealed a distinct, slightly asymmetric pattern of muscle involvement with cores of preserved and affected muscles in quadriceps and tibialis anterior, in some cases resembling patterns seen in POGLUT1-associated muscular dystrophy. Transcriptome analysis of muscle tissue from two participants suggested misregulation of genes involved in myogenesis, including PAX7. In complementary studies, Jag2 downregulation in murine myoblasts led to downregulation of multiple components of the Notch pathway, including Megf10. Investigations in Drosophila suggested an interaction between Serrate and Drpr, the fly orthologs of JAG1/JAG2 and MEGF10, respectively. In silico analysis predicted that many Jagged2 missense variants are associated with structural changes and protein misfolding. In summary, we describe a muscular dystrophy associated with pathogenic variants in JAG2 and evidence suggests a disease mechanism related to Notch pathway dysfunction.
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Affiliation(s)
- Sandra Coppens
- Center of Human Genetics, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Alison M Barnard
- Department of Physical Therapy, University of Florida College of Public Health and Health Professions, Gainesville, FL 32610, USA
| | - Sanna Puusepp
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu 50406, Estonia; Institute of Clinical Medicine, University of Tartu, Tartu 50406, Estonia
| | - Sander Pajusalu
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu 50406, Estonia; Institute of Clinical Medicine, University of Tartu, Tartu 50406, Estonia
| | - Katrin Õunap
- Department of Clinical Genetics, United Laboratories, Tartu University Hospital, Tartu 50406, Estonia; Institute of Clinical Medicine, University of Tartu, Tartu 50406, Estonia
| | - Dorianmarie Vargas-Franco
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christine C Bruels
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, NINDS, NIH, Bethesda, MD 20892, USA
| | - Lynn Pais
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Katherine R Chao
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Julia K Goodrich
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Eleina M England
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ben Weisburd
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Vijay S Ganesh
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Neurology, Brigham & Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Sanna Gudmundsson
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Anne O'Donnell-Luria
- Broad Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Mait Nigul
- Department of Radiology, Tartu University Hospital, Tartu 50406, Estonia
| | - Pilvi Ilves
- Institute of Clinical Medicine, University of Tartu, Tartu 50406, Estonia; Department of Radiology, Tartu University Hospital, Tartu 50406, Estonia
| | - Payam Mohassel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, NINDS, NIH, Bethesda, MD 20892, USA
| | - Teepu Siddique
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | | | - Stefan Nicolau
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Reza Maroofian
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London WC1E 6BT, UK
| | - Henry Houlden
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London WC1E 6BT, UK
| | - Michael G Hanna
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London WC1E 6BT, UK
| | - Ros Quinlivan
- Department of Neuromuscular Disorders, University College London Institute of Neurology, London WC1E 6BT, UK
| | - Mehran Beiraghi Toosi
- Pediatric Neurology Department, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad 9176999311, Iran
| | - Ehsan Ghayoor Karimiani
- Molecular and Clinical Sciences Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK; Innovative Medical Research Center, Mashhad Branch, Islamic Azad University, Mashhad 9187147578, Iran
| | - Sabine Costagliola
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moleculaire, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Nicolas Deconinck
- Centre de Référence Neuromusculaire and Paediatric Neurology Department, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, 1020 Brussels, Belgium
| | - Hazim Kadhim
- Neuropathology Unit, Department of Anatomic Pathology and Reference Center for Neuromuscular Pathology, Brugmann University Hospital-Children's Hospital, Université Libre de Bruxelles, 1020 Brussels, Belgium
| | - Erica Macke
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Brendan C Lanpher
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN 55905, USA
| | - Anna Łusakowska
- Department of Neurology, Medical University of Warsaw, 02-091 Warsaw, Poland
| | | | - Andreas Hahn
- Department of Child Neurology, Justus-Liebig-University Giessen, 35390 Giessen, Germany
| | - Bertold Schrank
- Department of Neurology, DKD HELIOS Klinik Wiesbaden, 65191 Wiesbaden, Germany
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Masashi Ogasawara
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8551, Japan
| | - Rasha El Sherif
- Myo-Care Neuromuscular Center, Myo-Care National Foundation, Cairo 11865, Egypt
| | - Tanya Stojkovic
- APHP, Nord-Est/Ile-de-France Neuromuscular Reference Center, Myology Institute, Pitié-Salpêtrière Hospital, 75013 Paris, France; Sorbonne Université, INSERM, Center of Research in Myology, UMRS974, 75651 Paris Cedex 13, France
| | - Isabelle Nelson
- Sorbonne Université, INSERM, Center of Research in Myology, UMRS974, 75651 Paris Cedex 13, France
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Center of Research in Myology, UMRS974, 75651 Paris Cedex 13, France
| | - Enzo Cohen
- Sorbonne Université, INSERM, Center of Research in Myology, UMRS974, 75651 Paris Cedex 13, France
| | - Anne Boland-Augé
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Jean-François Deleuze
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine, 91057 Evry, France
| | - Yao Meng
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 3BZ, UK
| | - Catheline Vilain
- Center of Human Genetics, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA; Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, MN 55455, USA; Department of Neurology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | | | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, NINDS, NIH, Bethesda, MD 20892, USA
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne NE1 3BZ, UK
| | - Penny A Handford
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA
| | - Glenn A Walter
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA; Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, MN 55455, USA; Department of Neurology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; Institute for Translational Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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18
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Alexander MS, Hightower RM, Reid AL, Bennett AH, Iyer L, Slonim DK, Saha M, Kawahara G, Kunkel LM, Kopin AS, Gupta VA, Kang PB, Draper I. hnRNP L is essential for myogenic differentiation and modulates myotonic dystrophy pathologies. Muscle Nerve 2021; 63:928-940. [PMID: 33651408 DOI: 10.1002/mus.27216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/25/2021] [Accepted: 02/28/2021] [Indexed: 12/12/2022]
Abstract
INTRODUCTION RNA-binding proteins (RBPs) play an important role in skeletal muscle development and disease by regulating RNA splicing. In myotonic dystrophy type 1 (DM1), the RBP MBNL1 (muscleblind-like) is sequestered by toxic CUG repeats, leading to missplicing of MBNL1 targets. Mounting evidence from the literature has implicated other factors in the pathogenesis of DM1. Herein we sought to evaluate the functional role of the splicing factor hnRNP L in normal and DM1 muscle cells. METHODS Co-immunoprecipitation assays using hnRNPL and MBNL1 expression constructs and splicing profiling in normal and DM1 muscle cell lines were performed. Zebrafish morpholinos targeting hnrpl and hnrnpl2 were injected into one-cell zebrafish for developmental and muscle analysis. In human myoblasts downregulation of hnRNP L was achieved with shRNAi. Ascochlorin administration to DM1 myoblasts was performed and expression of the CUG repeats, DM1 splicing biomarkers, and hnRNP L expression levels were evaluated. RESULTS Using DM1 patient myoblast cell lines we observed the formation of abnormal hnRNP L nuclear foci within and outside the expanded CUG repeats, suggesting a role for this factor in DM1 pathology. We showed that the antiviral and antitumorigenic isoprenoid compound ascochlorin increased MBNL1 and hnRNP L expression levels. Drug treatment of DM1 muscle cells with ascochlorin partially rescued missplicing of established early biomarkers of DM1 and improved the defective myotube formation displayed by DM1 muscle cells. DISCUSSION Together, these studies revealed that hnRNP L can modulate DM1 pathologies and is a potential therapeutic target.
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Affiliation(s)
- Matthew S Alexander
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA.,Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.,Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Rylie M Hightower
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Andrea L Reid
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA
| | - Alexis H Bennett
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Lakshmanan Iyer
- Department of Neuroscience, Tufts University, Boston, Massachusetts, USA
| | - Donna K Slonim
- Department of Computer Science, Tufts University, Medford, Massachusetts, USA
| | - Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Genri Kawahara
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Alan S Kopin
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Vandana A Gupta
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Neurology, University of Florida College of Medicine, Gainesville, Florida, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, Florida, USA.,Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota, USA.,Neurology Department, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Isabelle Draper
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
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19
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Estrella EA, Kang PB. Hunting for the perfect test: Neuromuscular diagnosis in the age of genomic bounty. Muscle Nerve 2021; 63:282-284. [PMID: 33382457 DOI: 10.1002/mus.27160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/26/2020] [Accepted: 12/28/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Elicia A Estrella
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
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20
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Li C, Vargas-Franco D, Saha M, Davis RM, Manko KA, Draper I, Pacak CA, Kang PB. Megf10 deficiency impairs skeletal muscle stem cell migration and muscle regeneration. FEBS Open Bio 2020; 11:114-123. [PMID: 33159715 PMCID: PMC7780119 DOI: 10.1002/2211-5463.13031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/18/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
Biallelic loss‐of‐function MEGF10 mutations lead to MEGF10 myopathy, also known as early onset myopathy with areflexia, respiratory distress, and dysphagia (EMARDD). MEGF10 is expressed in muscle satellite cells, but the contribution of satellite cell dysfunction to MEGF10 myopathy is unclear. Myofibers and satellite cells were isolated and examined from Megf10−/− and wild‐type mice. A separate set of mice underwent repeated intramuscular barium chloride injections. Megf10−/− muscle satellite cells showed reduced proliferation and migration, while Megf10−/− mouse skeletal muscles showed impaired regeneration. Megf10 deficiency is associated with impaired muscle regeneration, due in part to defects in satellite cell function. Efforts to rescue Megf10 deficiency will have therapeutic implications for MEGF10 myopathy and other inherited muscle diseases involving impaired muscle regeneration.
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Affiliation(s)
- Chengcheng Li
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Dorianmarie Vargas-Franco
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Rachel M Davis
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Kelsey A Manko
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Department of Medicine, Tufts Medical Center, Boston, MA, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA.,Department of Molecular Genetics & Microbiology and Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL, USA
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21
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Baer S, Tuzin N, Kang PB, Mohammed S, Kubota M, van Ierland Y, Busa T, Rossi M, Morel G, Michot C, Baujat G, Durand M, Obringer C, Le May N, Calmels N, Laugel V. Growth charts in Cockayne syndrome type 1 and type 2. Eur J Med Genet 2020; 64:104105. [PMID: 33227433 DOI: 10.1016/j.ejmg.2020.104105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/08/2020] [Accepted: 11/15/2020] [Indexed: 11/29/2022]
Abstract
Cockayne syndrome (CS) is a multisystem degenerative disorder divided in 3 overlapping subtypes, with a continuous phenotypic spectrum: CS2 being the most severe form, CS1 the classical form and CS3 the late-onset form. Failure to thrive and growth difficulties are among the most consistent features of CS, leaving affected individuals vulnerable to numerous medical complications, including adverse effects of undernutrition, abrupt overhydration and overfeeding. There is thus a significant need for specific growth charts. We retrospectively collected growth parameters from genetically-confirmed CS1 and CS2 patients, used the GAMLSS package to construct specific CS growth charts compared to healthy children from WHO and CDC databases. Growth data were obtained from 88 CS patients with a total of 1626 individual growth data points. 49 patients were classified as CS1 and 39 as CS2 with confirmed mutations in CSB/ERCC6, CSA/ERCC8 or ERCC1 genes. Individuals with CS1 initially have normal growth parameters; microcephaly occurs from 2 months whereas onset of weight and height restrictions appear later, between 5 and 22 months. In CS2, growth parameters are already below standard references at birth or drop below the 5th percentile before 3 months. Microcephaly is the first parameter to show a delay, appearing around 2 months in CS1 and at birth in CS2. Height and head circumference are more severely affected in CS2 compared to CS1 whereas weight curves are similar in CS1 and CS2 patients. These new growth charts will serve as a practical tool to improve the nutritional management of children with CS.
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Affiliation(s)
- Sarah Baer
- Service de Pédiatrie 1, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
| | - Nicolas Tuzin
- Groupe Méthode en Recherche Clinique, Hôpitaux Universitaires de Strasbourg, Nouvel Hôpital Civil, Strasbourg, France
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, 32610, USA
| | - Shehla Mohammed
- South East Thames Regional Genetics Service, Guy's and St Thomas' Hospital, Great Maze Pond, London, SE1 9RT, UK
| | - Masaya Kubota
- Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
| | - Yvette van Ierland
- Erasmus University Medical Center, Department of Clinical Genetics, 3000 CA Rotterdam, The Netherlands; ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, The Netherlands
| | - Tiffany Busa
- Hôpital de la Timone, Medical Genetics, Marseille, Provence-Alpes-Côte d'Azur, France
| | - Massimiliano Rossi
- Centre de référence des anomalies du développement, Service de génétique, Hospices Civils de Lyon & Centre de Recherche en Neurosciences de Lyon, Inserm U1028, UMR CNRS 5292, GENDEV Team, Lyon 1-Claude Bernard University, Bron, France
| | - Godelieve Morel
- Service de Génétique Clinique, Centre de Référence Maladies Rares Centre Labellisé Anomalies du Développement-Ouest, Centre Hospitalier Universitaire de Rennes, 35033, Rennes, France
| | - Caroline Michot
- Service de génétique clinique, CRMR maladies osseuses constitutionnelles, INSERM UMR 1163, Université Paris-Descartes-Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades, Paris, France
| | - Geneviève Baujat
- Service de génétique clinique, CRMR maladies osseuses constitutionnelles, INSERM UMR 1163, Université Paris-Descartes-Sorbonne Paris Cité, Institut Imagine, Hôpital Necker Enfants Malades, Paris, France
| | - Myriam Durand
- Centre d'Investigation Clinique INSERM-CIC 1434, CHRU de Strasbourg, F - 67091, Strasbourg, France
| | - Cathy Obringer
- Laboratoire de Génétique médicale, INSERM U1112, Institut de génétique médicale d'Alsace, Faculté de Médecine de Strasbourg, Hôpitaux Universitaires de Strasbourg, France
| | - Nicolas Le May
- Laboratoire de Génétique médicale, INSERM U1112, Institut de génétique médicale d'Alsace, Faculté de Médecine de Strasbourg, Hôpitaux Universitaires de Strasbourg, France
| | - Nadège Calmels
- Laboratoire de Génétique médicale, INSERM U1112, Institut de génétique médicale d'Alsace, Faculté de Médecine de Strasbourg, Hôpitaux Universitaires de Strasbourg, France; Laboratoires de Diagnostic Génétique, Institut de génétique médicale d'Alsace, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, France
| | - Vincent Laugel
- Service de Pédiatrie 1, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France; Laboratoire de Génétique médicale, INSERM U1112, Institut de génétique médicale d'Alsace, Faculté de Médecine de Strasbourg, Hôpitaux Universitaires de Strasbourg, France
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22
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Zingariello CD, Elder ME, Kang PB. Rituximab as Adjunct Maintenance Therapy for Refractory Juvenile Myasthenia Gravis. Pediatr Neurol 2020; 111:40-43. [PMID: 32951658 DOI: 10.1016/j.pediatrneurol.2020.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Juvenile myasthenia gravis is a pediatric autoimmune disorder of the neuromuscular junction associated with substantial morbidity, for which standard therapies are not always efficacious. The objective of our study was to assess the tolerability and efficacy of rituximab use in children with refractory juvenile myasthenia gravis. METHODS We conduced a retrospective cohort study at a single tertiary care referral center to evaluate children with juvenile myasthenia gravis who were treated with rituximab. The clinical status of these participants before and after initiation of rituximab therapy was measured, focusing on numbers of hospital admissions, numbers of immunomodulatory or immunosuppressive medications needed, and Myasthenia Gravis Foundation of America severity class. RESULTS Five children with juvenile myasthenia gravis were ascertained who received rituximab as part of their regimen, four of whom had elevated acetylcholine receptor antibodies and one of whom had elevated muscle-specific kinase antibodies. After initiation of rituximab therapy, all participants experienced reduced numbers of immunomodulatory medications during the follow-up period (mean 11.6 months). Four of the five subjects experienced fewer juvenile myasthenia gravis-related hospital admissions and reduced (improved) Myasthenia Gravis Foundation of America classes, with no subjects having moderate or severe symptoms following treatment with rituximab. No significant adverse events were recorded for any of the participants. CONCLUSION Rituximab was well-tolerated and efficacious in this juvenile myasthenia gravis cohort. The beneficial effect of rituximab was most pronounced in the one participant with muscle-specific kinase antibodies.
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Affiliation(s)
- Carla D Zingariello
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Melissa E Elder
- Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida; Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida.
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23
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Laventhal NT, Graham RJ, Rasmussen SA, Urion DK, Kang PB. Ethical decision-making for children with neuromuscular disorders in the COVID-19 crisis. Neurology 2020; 95:260-265. [PMID: 32482844 DOI: 10.1212/wnl.0000000000009936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 05/22/2020] [Indexed: 11/15/2022] Open
Abstract
The sudden appearance and proliferation of coronavirus disease 2019 has forced societies and governmental authorities across the world to confront the possibility of resource constraints when critical care facilities are overwhelmed by the sheer numbers of grievously ill patients. As governments and health care systems develop and update policies and guidelines regarding the allocation of resources, patients and families affected by chronic disabilities, including many neuromuscular disorders that affect children and young adults, have become alarmed at the possibility that they may be determined to have less favorable prognoses due to their underlying diagnoses and thus be assigned to lower priority groups. It is important for health care workers, policymakers, and government officials to be aware that the long-term prognoses for children and young adults with neuromuscular disorders are often more promising than previously believed due to a better understanding of the natural history of these diseases, benefits of multidisciplinary supportive care, and novel molecular therapies that can dramatically improve the disease course. Although the realities of a global pandemic have the potential to require a shift from our usual, highly individualistic standards of care to crisis standards of care, shifting priorities should nonetheless be informed by good facts. Resource allocation guidelines with the potential to affect children and young adults with neuromuscular disorders should take into account the known trajectory of acute respiratory illness in this population and rely primarily on contemporary long-term outcome data.
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Affiliation(s)
- Naomi T Laventhal
- From the Division of Neonatal-Perinatal Medicine (N.T.L.), Department of Pediatrics, University of Michigan School of Medicine and C.S. Mott Children's Hospital; Center for Bioethics and Social Sciences in Medicine (N.T.L.), University of Michigan, Ann Arbor, MI; Department of Anesthesiology (R.J.G.), Critical Care and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia (R.J.G.), Harvard Medical School, Boston, MA; Department of Pediatrics (S.A.R.), University of Florida College of Medicine; Department of Epidemiology (S.A.R.), University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, FL; Department of Neurology (D.K.U.), Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine; and Department of Neurology and Department of Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine, Gainesville, FL
| | - Robert J Graham
- From the Division of Neonatal-Perinatal Medicine (N.T.L.), Department of Pediatrics, University of Michigan School of Medicine and C.S. Mott Children's Hospital; Center for Bioethics and Social Sciences in Medicine (N.T.L.), University of Michigan, Ann Arbor, MI; Department of Anesthesiology (R.J.G.), Critical Care and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia (R.J.G.), Harvard Medical School, Boston, MA; Department of Pediatrics (S.A.R.), University of Florida College of Medicine; Department of Epidemiology (S.A.R.), University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, FL; Department of Neurology (D.K.U.), Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine; and Department of Neurology and Department of Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine, Gainesville, FL
| | - Sonja A Rasmussen
- From the Division of Neonatal-Perinatal Medicine (N.T.L.), Department of Pediatrics, University of Michigan School of Medicine and C.S. Mott Children's Hospital; Center for Bioethics and Social Sciences in Medicine (N.T.L.), University of Michigan, Ann Arbor, MI; Department of Anesthesiology (R.J.G.), Critical Care and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia (R.J.G.), Harvard Medical School, Boston, MA; Department of Pediatrics (S.A.R.), University of Florida College of Medicine; Department of Epidemiology (S.A.R.), University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, FL; Department of Neurology (D.K.U.), Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine; and Department of Neurology and Department of Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine, Gainesville, FL
| | - David K Urion
- From the Division of Neonatal-Perinatal Medicine (N.T.L.), Department of Pediatrics, University of Michigan School of Medicine and C.S. Mott Children's Hospital; Center for Bioethics and Social Sciences in Medicine (N.T.L.), University of Michigan, Ann Arbor, MI; Department of Anesthesiology (R.J.G.), Critical Care and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia (R.J.G.), Harvard Medical School, Boston, MA; Department of Pediatrics (S.A.R.), University of Florida College of Medicine; Department of Epidemiology (S.A.R.), University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, FL; Department of Neurology (D.K.U.), Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine; and Department of Neurology and Department of Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine, Gainesville, FL
| | - Peter B Kang
- From the Division of Neonatal-Perinatal Medicine (N.T.L.), Department of Pediatrics, University of Michigan School of Medicine and C.S. Mott Children's Hospital; Center for Bioethics and Social Sciences in Medicine (N.T.L.), University of Michigan, Ann Arbor, MI; Department of Anesthesiology (R.J.G.), Critical Care and Pain Medicine, Boston Children's Hospital and Department of Anaesthesia (R.J.G.), Harvard Medical School, Boston, MA; Department of Pediatrics (S.A.R.), University of Florida College of Medicine; Department of Epidemiology (S.A.R.), University of Florida College of Medicine and College of Public Health and Health Professions, Gainesville, FL; Department of Neurology (D.K.U.), Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine; and Department of Neurology and Department of Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine, Gainesville, FL.
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24
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Kang PB, McMillan HJ, Kuntz NL, Lehky TJ, Alter KE, Fitzpatrick KF, El Kosseifi C, Quijano-Roy S. Utility and practice of electrodiagnostic testing in the pediatric population: An AANEM consensus statement. Muscle Nerve 2020; 61:143-155. [PMID: 31724199 DOI: 10.1002/mus.26752] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 11/06/2019] [Indexed: 12/17/2022]
Abstract
Nerve conduction studies and needle electromyography, collectively known as electrodiagnostic (EDX) studies, have been available for pediatric patients for decades, but the accessibility of this diagnostic modality and the approach to testing vary significantly depending on the physician and institution. The maturation of molecular diagnostic approaches and other diagnostic technologies such as neuromuscular ultrasound indicate that an analysis of current needs and practices for EDX studies in the pediatric population is warranted. The American Association of Neuromuscular & Electrodiagnostic Medicine convened a consensus panel to perform literature searches, share collective experiences, and develop a consensus statement. The panel found that electrodiagnostic studies continue to have high utility for the diagnosis of numerous childhood neuromuscular disorders, and that standardized approaches along with the use of high-quality reference values are important to maximize the diagnostic yield of these tests in infants, children, and adolescents.
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Affiliation(s)
- Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
| | - Hugh J McMillan
- Department of Pediatrics, University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Nancy L Kuntz
- Department of Pediatrics, Northwestern University Feinberg School of Medicine and Lurie Children's Hospital, Chicago, Illinois
| | - Tanya J Lehky
- National Institute of Neurological Disorders and Stroke, Bethesda, Maryland
| | - Katharine E Alter
- Functional and Applied Biomechanics Section, Rehabilitation Medicine, National Institutes of Health Clinical Center, Bethesda, Maryland
| | - Kevin F Fitzpatrick
- Inova Neuroscience and Spine Institute, Inova Fairfax Hospital, Falls Church, Virginia
| | - Charbel El Kosseifi
- Centre de Référence Maladies Neuromusculaires, Service de Neurologie, Réanimation et Réeducation Pédiatriques, Hôpital Raymond Poincaré, Garches, France
| | - Susana Quijano-Roy
- Centre de Référence Maladies Neuromusculaires, Service de Neurologie, Réanimation et Réeducation Pédiatriques, Hôpital Raymond Poincaré, Garches, France
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25
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Saha M, Rizzo SA, Ramanathan M, Hightower RM, Santostefano KE, Terada N, Finkel RS, Berg JS, Chahin N, Pacak CA, Wagner RE, Alexander MS, Draper I, Kang PB. Selective serotonin reuptake inhibitors ameliorate MEGF10 myopathy. Hum Mol Genet 2020; 28:2365-2377. [PMID: 31267131 DOI: 10.1093/hmg/ddz064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/18/2019] [Accepted: 03/21/2019] [Indexed: 02/02/2023] Open
Abstract
MEGF10 myopathy is a rare inherited muscle disease that is named after the causative gene, MEGF10. The classic phenotype, early onset myopathy, areflexia, respiratory distress and dysphagia, is severe and immediately life-threatening. There are no disease-modifying therapies. We performed a small molecule screen and follow-up studies to seek a novel therapy. A primary in vitro drug screen assessed cellular proliferation patterns in Megf10-deficient myoblasts. Secondary evaluations were performed on primary screen hits using myoblasts derived from Megf10-/- mice, induced pluripotent stem cell-derived myoblasts from MEGF10 myopathy patients, mutant Drosophila that are deficient in the homologue of MEGF10 (Drpr) and megf10 mutant zebrafish. The screen yielded two promising candidates that are both selective serotonin reuptake inhibitors (SSRIs), sertraline and escitalopram. In depth follow-up analyses demonstrated that sertraline was highly effective in alleviating abnormalities across multiple models of the disease including mouse myoblast, human myoblast, Drosophila and zebrafish models. Sertraline also restored deficiencies of Notch1 in disease models. We conclude that SSRIs show promise as potential therapeutic compounds for MEGF10 myopathy, especially sertraline. The mechanism of action may involve the Notch pathway.
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Affiliation(s)
- Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Skylar A Rizzo
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA.,Medosome Biotec, Alachua, FL, USA
| | - Manashwi Ramanathan
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | - Rylie M Hightower
- Department of Pediatrics, Division of Pediatric Neurology, Children's of Alabama and the University of Alabama at Birmingham, Birmingham, AL, USA.,University of Alabama Birmingham, Center for Exercise Medicine Birmingham, AL, USA
| | - Katherine E Santostefano
- Center for Cellular Reprogramming, Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Naohiro Terada
- Center for Cellular Reprogramming, Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Richard S Finkel
- Division of Pediatric Neurology, Nemours Children's Hospital, Orlando, FL, USA
| | - Jonathan S Berg
- Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Nizar Chahin
- Department of Neurology, Neuromuscular Division, Oregon Health and Science University, Portland, Oregon, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Matthew S Alexander
- Department of Pediatrics, Division of Pediatric Neurology, Children's of Alabama and the University of Alabama at Birmingham, Birmingham, AL, USA.,University of Alabama Birmingham, Center for Exercise Medicine Birmingham, AL, USA.,Department of Genetics, University of Alabama Birmingham, Birmingham, AL, USA.,Civitan International Research Center at University of Alabama Birmingham, Birmingham, AL, USA
| | - Isabelle Draper
- Department of Medicine, Tufts Medical Center, Molecular Cardiology Research Institute, Boston, MA, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA.,Department of Molecular Genetics and Microbiology and Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL, USA
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26
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Pacak CA, Kang PB. The End of the Beginning: The Journey to Molecular Therapies for Spinal Muscular Atrophy. Pediatr Neurol 2020; 102:1-2. [PMID: 31481328 DOI: 10.1016/j.pediatrneurol.2019.07.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 07/29/2019] [Accepted: 07/31/2019] [Indexed: 11/24/2022]
Affiliation(s)
- Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida; Department of Neurology, University of Florida College of Medicine, Gainesville, Florida; Genetics Institute and Myology Institute, University of Florida, Gainesville, Florida.
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Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a rare muscular dystrophy, but is particularly important to diagnose due to frequent life-threatening cardiac complications. EDMD classically presents with muscle weakness, early contractures, cardiac conduction abnormalities and cardiomyopathy, although the presence and severity of these manifestations vary by subtype and individual. Associated genes include EMD, LMNA, SYNE1, SYNE2, FHL1, TMEM43, SUN1, SUN2, and TTN, encoding emerin, lamin A/C, nesprin-1, nesprin-2, FHL1, LUMA, SUN1, SUN2, and titin, respectively. The Online Mendelian Inheritance in Man database recognizes subtypes 1 through 7, which captures most but not all of the associated genes. Genetic diagnosis is essential whenever available, but traditional diagnostic tools can help steer the evaluation toward EDMD and assist with interpretation of equivocal genetic test results. Management is primarily supportive, but it is important to monitor patients closely, especially for potential cardiac complications. There is a high potential for progress in the treatment of EDMD in the coming years.
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Affiliation(s)
- Scott A Heller
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida
| | - Renata Shih
- Congenital Heart Center, University of Florida College of Medicine, Gainesville, Florida
| | - Raghav Kalra
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Department of Neurology, University of Florida College of Medicine, Gainesville, Florida.,Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,Genetics Institute and Myology Institute, University of Florida, Gainesville, Florida
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28
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Zupanc ML, Cohen BH, Kang PB, Mandelbaum DE, Mink J, Mintz M, Tilton A, Trescher W. Child neurology in the 21st century. Neurology 2019; 94:75-82. [DOI: 10.1212/wnl.0000000000008784] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 10/29/2019] [Indexed: 11/15/2022] Open
Abstract
In September 2017, the Child Neurology Society (CNS) convened a special task force to review the practice of child neurology in the United States. This was deemed a necessity by our membership, as our colleagues expressed discouragement and burnout by the increase in workload without additional resources; reliance on work relative value units (wRVUs) as the sole basis of compensation; a push by administrators for providers to see more patients with less allotted time; and lack of administrative, educational, and research support. The CNS Task Force designed and distributed a survey to multiple academic divisions of various sizes, as well as to private practices. Our findings were strikingly similar across different practices, demonstrating high workloads, lack of resources, poor electronic medical record support, and high provider symptoms of fatigue and burnout. From the results, the CNS Task Force has concluded that wRVUs cannot be the sole basis of compensation for child neurology. We have also made several specific recommendations for alleviating the current situation, including innovative ways to fund child neurology as well as ways to enhance job satisfaction.
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Abstract
OBJECTIVE To analyze the outcomes of a cohort of children diagnosed with Mycoplasma pneumoniae encephalitis whose treatment regimens included intravenous immunoglobulin (IVIG). METHODS A retrospective study was performed at a single center between 2011 and 2016 of children diagnosed with Mycoplasma pneumoniae encephalitis whose acute treatment regimen included IVIG. Details of therapeutic interventions and the clinical course were retrieved from medical records via an institutionally approved protocol. The modified Rankin score was used to quantify outcomes. RESULTS Four children met inclusion criteria, 3 of whom had prodromal symptoms of infection lasting 5 to 7 days before onset of their neurologic symptoms. One patient presented with neurologic symptoms with no clinical prodrome. The initial treatment regimen included systemic corticosteroids, antibiotics, or both. IVIG was administered for a total dose of 2 g/kg divided over 2 to 4 days to all 4 children. All children showed clinical improvement after IVIG. The 3 children with prodromal symptoms showed immediate and dramatic clinical improvement after IVIG therapy. DISCUSSION The immediate response to immunomodulatory therapy in the patients with prodrome suggests that the neurologic syndrome may be caused at least in part by an autoimmune process. The child who did not respond to IVIG had no prodrome, and also had normal electroencephalographic (EEG) and brain magnetic resonance imaging (MRI) findings. These cases suggest that early administration of IVIG should be considered in patients suspected of having Mycoplasma encephalitis, particularly in those who have had prodromal symptoms.
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Affiliation(s)
- Mebratu Daba
- Carilion Children’s Pediatric Neurology, Roanoke, VA,
USA
| | - Peter B. Kang
- Division of Pediatric Neurology, Department of Pediatrics,
University of Florida College of Medicine, Gainesville, FL, USA,Department of Neurology, University of Florida College of Medicine,
Gainesville, FL, USA
| | - John Sladky
- Division of Pediatric Neurology, Department of Pediatrics,
University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Robert M. Lawrence
- Division of Infectious Diseases, Department of Pediatrics,
University of Florida College of Medicine, Gainesville, FL, USA
| | - Suman Ghosh
- Division of Pediatric Neurology, Department of Pediatrics,
University of Florida College of Medicine, Gainesville, FL, USA,Department of Neurology, University of Florida College of Medicine,
Gainesville, FL, USA,Suman Ghosh, MD, Division of Pediatric
Neurology, University of Florida College of Medicine, PO Box 100296,
Gainesville, FL 32610, USA.
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30
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Ghosh S, Miskimen ACC, Brady J, Robinson MA, Zou B, Weiss M, Kang PB. Neurodevelopmental outcomes at 9-14 months gestational age after treatment of neonatal seizures due to brain injury. Childs Nerv Syst 2019; 35:1571-1578. [PMID: 31278442 PMCID: PMC6959470 DOI: 10.1007/s00381-019-04286-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 06/30/2019] [Indexed: 02/06/2023]
Abstract
PURPOSE Infants with brain injury are susceptible to developmental delays. Survivors of neonatal seizures are at risk for developmental delay, epilepsy, and further neurological comorbidities. Despite advances in neonatal critical care, the prevalence of adverse long-term outcomes and seizure recurrence remains unchanged. Our goal is to determine if early treatment of neonatal seizures with phenobarbital or levetiracetam is associated with worse neurodevelopmental outcomes in brain-injured infants. METHODS We conducted a retrospective cohort study of 119 infants admitted between 2013 and 2017 who were at risk for developmental delay and assessed in our clinic. We compared brain injury infants with neonatal seizures to brain injury infants without neonatal seizures using Bayley scores (BSID III) at 9-14 months gestational age. A comparison of Bayley scores between those exposed to phenobarbital and levetiracetam was conducted. RESULTS Twenty-two children with neonatal seizures scored lower than 53 children without seizures in all domains with significant values in composite scores for cognitive function (p = 0.003) and language (p = 0.031). We found no difference in scores at 9-14 months between infants exposed to phenobarbital versus levetiracetam. CONCLUSIONS Our results suggest that in infants with brain injury, the occurrence of neonatal seizures has an adverse effect on neurodevelopmental outcomes. The choice of antiseizure medication may not play a significant role in their outcomes.
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Affiliation(s)
- Suman Ghosh
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, 1600 SW Archer Rd, Gainesville, FL, 32610, USA.
| | - Andrea C Cabassa Miskimen
- College of Liberal Arts and Sciences at the University of Florida, College of Medicine, Gainesville, FL
| | - Janet Brady
- University of Florida Rehabilitation for Kids, Gainesville, FL
| | - Matthew A Robinson
- Department of Biostatistics, University of Florida College of Medicine, Gainesville, FL
| | - Baiming Zou
- Department of Biostatistics, University of Florida College of Medicine, Gainesville, FL
| | - Michael Weiss
- Division of Neonatology at University of Florida College of Medicine, Gainesville, FL
| | - Peter B. Kang
- Division of Pediatric Neurology, University of Florida College of Medicine, Gainesville, FL
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31
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Suzuki-Hatano S, Sriramvenugopal M, Ramanathan M, Soustek M, Byrne BJ, Cade WT, Kang PB, Pacak CA. Increased mtDNA Abundance and Improved Function in Human Barth Syndrome Patient Fibroblasts Following AAV- TAZ Gene Delivery. Int J Mol Sci 2019; 20:E3416. [PMID: 31336787 PMCID: PMC6678701 DOI: 10.3390/ijms20143416] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/29/2022] Open
Abstract
Barth syndrome (BTHS) is a rare, X-linked, mitochondrial disorder caused by mutations in the gene encoding tafazzin. BTHS results in cardiomyopathy, muscle fatigue, and neutropenia in patients. Tafazzin is responsible for remodeling cardiolipin, a key structural lipid of the inner mitochondrial membrane. As symptoms can vary in severity amongst BTHS patients, we sought to compare mtDNA copy numbers, mitochondrial fragmentation, and functional parameters between primary dermal BTHS fibroblasts isolated from patients with two different mutations in the TAZ locus. To confirm cause‒effect relationships and further support the development of gene therapy for BTHS, we also characterized the BTHS cells following adeno-associated virus (AAV)-TAZ transduction. Our data show that, in response to AAV-TAZ transduction, these remarkably dynamic organelles show recovery of mtDNA copy numbers, mitochondrial structure, and mitochondrial function, providing additional evidence to support the therapeutic potential of AAV-mediated gene delivery for BTHS. This study also demonstrates the direct relationship between healthy mitochondrial membrane structure and maintenance of proper levels of mtDNA copy numbers.
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Affiliation(s)
- Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Mughil Sriramvenugopal
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Manash Ramanathan
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Meghan Soustek
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Peter B Kang
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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32
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Draper I, Saha M, Stonebreaker H, Salomon RN, Matin B, Kang PB. The impact of Megf10/Drpr gain-of-function on muscle development in Drosophila. FEBS Lett 2019; 593:680-696. [PMID: 30802937 DOI: 10.1002/1873-3468.13348] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 11/07/2022]
Abstract
Recessive mutations in multiple epidermal growth factor-like domains 10 (MEGF10) underlie a rare congenital muscle disease known as MEGF10 myopathy. MEGF10 and its Drosophila homolog Draper (Drpr) are transmembrane receptors expressed in muscle and glia. Drpr deficiency is known to result in muscle abnormalities in flies. In the current study, flies that ubiquitously overexpress Drpr, or mouse Megf10, display developmental arrest. The phenotype is reproduced with overexpression in muscle, but not in other tissues, and with overexpression during intermediate stages of myogenesis, but not in myoblasts. We find that tubular muscle subtypes are particularly sensitive to Megf10/Drpr overexpression. Complementary genetic analyses show that Megf10/Drpr and Notch may interact to regulate myogenesis. Our findings provide a basis for investigating MEGF10 in muscle development using Drosophila.
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Affiliation(s)
- Isabelle Draper
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA
| | | | - Robert N Salomon
- Department of Pathology and Laboratory Medicine, Tufts Medical Center, Boston, MA, USA
| | - Bahar Matin
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA.,Department of Neurology, Boston Children's Hospital, MA, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA.,Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL, USA
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33
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Bruels CC, Li C, Mendoza T, Khan J, Reddy HM, Estrella EA, Ghosh PS, Darras BT, Lidov HGW, Pacak CA, Kunkel LM, Modave F, Draper I, Kang PB. Identification of a pathogenic mutation in ATP2A1 via in silico analysis of exome data for cryptic aberrant splice sites. Mol Genet Genomic Med 2019; 7:e552. [PMID: 30688039 PMCID: PMC6418371 DOI: 10.1002/mgg3.552] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/12/2018] [Accepted: 12/02/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Pathogenic mutations causing aberrant splicing are often difficult to detect. Standard variant analysis of next-generation sequence (NGS) data focuses on canonical splice sites. Noncanonical splice sites are more difficult to ascertain. METHODS We developed a bioinformatics pipeline that screens existing NGS data for potentially aberrant novel essential splice sites (PANESS) and performed a pilot study on a family with a myotonic disorder. Further analyses were performed via qRT-PCR, immunoblotting, and immunohistochemistry. RNAi knockdown studies were performed in Drosophila to model the gene deficiency. RESULTS The PANESS pipeline identified a homozygous ATP2A1 variant (NC_000016.9:g.28905928G>A; NM_004320.4:c.1287G>A:p.(Glu429=)) that was predicted to cause the omission of exon 11. Aberrant splicing of ATP2A1 was confirmed via qRT-PCR, and abnormal expression of the protein product sarcoplasmic/endoplasmic reticulum Ca++ ATPase 1 (SERCA1) was demonstrated in quadriceps femoris tissue from the proband. Ubiquitous knockdown of SERCA led to lethality in Drosophila, as did knockdown targeting differentiating or fusing myoblasts. CONCLUSIONS This study confirms the potential of novel in silico algorithms to detect cryptic mutations in existing NGS data; expands the phenotypic spectrum of ATP2A1 mutations beyond classic Brody myopathy; and suggests that genetic testing of ATP2A1 should be considered in patients with clinical myotonia.
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Affiliation(s)
- Christine C. Bruels
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFlorida
| | - Chengcheng Li
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFlorida
| | - Tonatiuh Mendoza
- Department of Health Outcomes & Biomedical InformaticsUniversity of Florida College of MedicineGainesvilleFlorida
| | - Jamillah Khan
- Department of Health Outcomes & Biomedical InformaticsUniversity of Florida College of MedicineGainesvilleFlorida
| | - Hemakumar M. Reddy
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFlorida
- Present address:
Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode Island
| | - Elicia A. Estrella
- Division of Genetics & GenomicsBoston Children’s Hospital and Harvard Medical SchoolBostonMassachusetts
| | - Partha S. Ghosh
- Department of NeurologyBoston Children’s Hospital and Harvard Medical SchoolBostonMassachusetts
| | - Basil T. Darras
- Department of NeurologyBoston Children’s Hospital and Harvard Medical SchoolBostonMassachusetts
| | - Hart G. W. Lidov
- Department of PathologyBoston Children’s Hospital and Harvard Medical SchoolBostonMassachusetts
| | - Christina A. Pacak
- Department of PediatricsUniversity of Florida College of MedicineGainesvilleFlorida
| | - Louis M. Kunkel
- Division of Genetics & GenomicsBoston Children’s Hospital and Harvard Medical SchoolBostonMassachusetts
| | - François Modave
- Department of Health Outcomes & Biomedical InformaticsUniversity of Florida College of MedicineGainesvilleFlorida
- Present address:
Health Sciences Division, Department of Medicine, Center for Health Outcomes and Informatics ResearchLoyola University ChicagoChicagoIllinois
| | - Isabelle Draper
- Molecular Cardiology Research InstituteTufts Medical CenterBostonMassachusetts
| | - Peter B. Kang
- Division of Pediatric Neurology, Department of PediatricsUniversity of Florida College of MedicineGainesvilleFlorida
- Department of Molecular Genetics & MicrobiologyUniversity of Florida College of MedicineGainesvilleFlorida
- Department of NeurologyUniversity of Florida College of MedicineGainesvilleFlorida
- Genetics Institute and Myology InstituteUniversity of FloridaGainesvilleFlorida
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34
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Suzuki-Hatano S, Saha M, Soustek MS, Kang PB, Byrne BJ, Cade WT, Pacak CA. AAV9- TAZ Gene Replacement Ameliorates Cardiac TMT Proteomic Profiles in a Mouse Model of Barth Syndrome. Mol Ther Methods Clin Dev 2019; 13:167-179. [PMID: 30788385 PMCID: PMC6369239 DOI: 10.1016/j.omtm.2019.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 01/16/2019] [Indexed: 12/23/2022]
Abstract
Barth syndrome (BTHS) is a rare mitochondrial disease that causes severe cardiomyopathy and has no disease-modifying therapy. It is caused by recessive mutations in the gene tafazzin (TAZ), which encodes tafazzin-an acyltransferase that remodels the inner mitochondrial membrane lipid cardiolipin. To identify novel mechanistic pathways involved in BTHS and evaluate the effects of gene therapy on proteomic profiles, we performed a multiplex tandem mass tagging (TMT) quantitative proteomics analysis to compare protein expression profiles from heart lysates isolated from BTHS, healthy wild-type (WT), and BTHS treated with adeno-associated virus serotype 9 (AAV9)-TAZ gene replacement as neonates or adults. 197 proteins with ≥2 unique peptides were identified. Of these, 91 proteins were significantly differentially expressed in BTHS compared to WT controls. Cause-effect relationships between tafazzin deficiency and altered protein profiles were confirmed through demonstrated significant improvements in expression levels following administration of AAV9-TAZ. The importance of TMEM65 in Cx43 localization to cardiac intercalated discs was revealed as a novel consequence of tafazzin deficiency that was improved following gene therapy. This study identifies novel mechanistic pathways involved in the pathophysiology of BTHS, demonstrates the ability of gene delivery to improve protein expression profiles, and provides support for clinical translation of AAV9-TAZ gene therapy.
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Affiliation(s)
- Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Madhurima Saha
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Meghan S Soustek
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Peter B Kang
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Barry J Byrne
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - W Todd Cade
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA
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35
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Smith G, Bell SK, Sladky JT, Kang PB, Albayram MS. Lumbosacral ventral spinal nerve root atrophy identified on MRI in a case of spinal muscular atrophy type II. Clin Imaging 2018; 53:134-137. [PMID: 30340076 DOI: 10.1016/j.clinimag.2018.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/08/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022]
Abstract
Spinal muscular atrophies are rare genetic disorders most often caused by homozygous deletion mutations in SMN1 that lead to progressive neurodegeneration of anterior horn cells. Ventral spinal root atrophy is a consistent pathological finding in post-mortem examinations of patients who suffered from various subtypes of spinal muscular atrophy; however, corresponding radiographic findings have not been previously reported. We present a patient with hypotonia and weakness who was found to have ventral spinal root atrophy in the lumbosacral region on MRI and was subsequently diagnosed with spinal muscular atrophy. More systematic analyses of imaging studies in spinal muscular atrophy will help determine whether such findings have the potential to serve as reliable diagnostic markers for clinical evaluations or as outcome measure for clinical trials.
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Affiliation(s)
- Garrett Smith
- Department of Radiology, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - Stephanie K Bell
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - John T Sladky
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - Mehmet S Albayram
- Department of Radiology, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
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36
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Suzuki-Hatano S, Saha M, Rizzo SA, Witko RL, Gosiker BJ, Ramanathan M, Soustek MS, Jones MD, Kang PB, Byrne BJ, Cade WT, Pacak CA. AAV-Mediated TAZ Gene Replacement Restores Mitochondrial and Cardioskeletal Function in Barth Syndrome. Hum Gene Ther 2018; 30:139-154. [PMID: 30070157 DOI: 10.1089/hum.2018.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Barth syndrome (BTHS) is a rare mitochondrial disease that affects heart and skeletal muscle and has no curative treatment. It is caused by recessive mutations in the X-linked gene TAZ, which encodes tafazzin. To develop a clinically relevant gene therapy to restore tafazzin function and treat BTHS, three different adeno-associated virus serotype 9 vectors were tested and compared to identify the optimal promoter-cytomegalovirus (CMV), desmin (Des), or a native tafazzin promoter (Taz)-for TAZ expression following intravenous administration of 1 × 1013 vector genomes/kilogram to a mouse model of BTHS as either neonates (1-2 days of age) or adults (3 months of age). At 5 months of age, evaluations of biodistribution and TAZ expression levels, mouse activity assessments, fatigue in response to exercise, muscle strength, cardiac function, mitochondrial structure, oxygen consumption, and electron transport chain complex activity assays were performed to measure the extent of improvement in treated mice. Each promoter was scored for significant improvement over untreated control mice and significant improvement compared with the other two promoters for every measurement and within each age of administration. All three of the promoters resulted in significant improvements in a majority of the assessments compared with untreated BTHS controls. When scored for overall effectiveness as a gene therapy, the Des promoter was found to provide improvement in the most assessments, followed by the CMV promoter, and finally Taz regardless of injection age. This study provides substantial support for translation of an adeno-associated virus serotype 9-mediated TAZ gene replacement strategy using a Des promoter for human BTHS patients in the clinic.
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Affiliation(s)
- Silveli Suzuki-Hatano
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Madhurima Saha
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Skylar A Rizzo
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Rachael L Witko
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Bennett J Gosiker
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Manashwi Ramanathan
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Meghan S Soustek
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - Michael D Jones
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - Barry J Byrne
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
| | - W Todd Cade
- 3 Program in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
| | - Christina A Pacak
- 1 Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida.,2 Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida
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37
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Saha M, Reddy HM, Salih MA, Estrella E, Jones MD, Mitsuhashi S, Cho KA, Suzuki-Hatano S, Rizzo SA, Hamad MH, Mukhtar MM, Hamed AA, Elseed MA, Lek M, Valkanas E, MacArthur DG, Kunkel LM, Pacak CA, Draper I, Kang PB. Impact of PYROXD1 deficiency on cellular respiration and correlations with genetic analyses of limb-girdle muscular dystrophy in Saudi Arabia and Sudan. Physiol Genomics 2018; 50:929-939. [PMID: 30345904 DOI: 10.1152/physiolgenomics.00036.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Next-generation sequencing is commonly used to screen for pathogenic mutations in families with Mendelian disorders, but due to the pace of discoveries, gaps have widened for some diseases between genetic and pathophysiological knowledge. We recruited and analyzed 16 families with limb-girdle muscular dystrophy (LGMD) of Arab descent from Saudi Arabia and Sudan who did not have confirmed genetic diagnoses. The analysis included both traditional and next-generation sequencing approaches. Cellular and metabolic studies were performed on Pyroxd1 siRNA C2C12 myoblasts and controls. Pathogenic mutations were identified in eight of the 16 families. One Sudanese family of Arab descent residing in Saudi Arabia harbored a homozygous c.464A>G, p.Asn155Ser mutation in PYROXD1, a gene recently reported in association with myofibrillar myopathy and whose protein product reduces thiol residues. Pyroxd1 deficiency in murine C2C12 myoblasts yielded evidence for impairments of cellular proliferation, migration, and differentiation, while CG10721 (Pyroxd1 fly homolog) knockdown in Drosophila yielded a lethal phenotype. Further investigations indicated that Pyroxd1 does not localize to mitochondria, yet Pyroxd1 deficiency is associated with decreased cellular respiration. This study identified pathogenic mutations in half of the LGMD families from the cohort, including one in PYROXD1. Developmental impairments were demonstrated in vitro for Pyroxd1 deficiency and in vivo for CG10721 deficiency, with reduced metabolic activity in vitro for Pyroxd1 deficiency.
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Affiliation(s)
- Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Hemakumar M Reddy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Mustafa A Salih
- Division of Neurology, Department of Pediatrics, King Saud University , Riyadh , Saudi Arabia
| | - Elicia Estrella
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School , Boston, Massachusetts
| | - Michael D Jones
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Satomi Mitsuhashi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School , Boston, Massachusetts
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Silveli Suzuki-Hatano
- Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Skylar A Rizzo
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Muddathir H Hamad
- Division of Neurology, Department of Pediatrics, King Saud University , Riyadh , Saudi Arabia
| | - Maowia M Mukhtar
- The Institute of Endemic Diseases, University of Khartoum , Khartoum , Sudan
| | - Ahlam A Hamed
- Department of Paediatrics and Child Health, Faculty of Medicine, University of Khartoum , Khartoum , Sudan
| | - Maha A Elseed
- Department of Paediatrics and Child Health, Faculty of Medicine, University of Khartoum , Khartoum , Sudan
| | - Monkol Lek
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts.,Broad Institute of the Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Elise Valkanas
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts.,Broad Institute of the Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Daniel G MacArthur
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School , Boston, Massachusetts.,Broad Institute of the Massachusetts Institute of Technology and Harvard University , Cambridge, Massachusetts
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School , Boston, Massachusetts
| | - Christina A Pacak
- Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Tufts Medical Center , Boston, Massachusetts
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine , Gainesville, Florida.,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine , Gainesville, Florida.,Genetics Institute and Myology Institute, University of Florida , Gainesville, Florida
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Affiliation(s)
- Carla D Zingariello
- From the Department of Neurology (C.D.Z.), University of Pennsylvania, Philadelphia; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, and Departments of Neurology (P.B.K.), and Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine; and Genetics Institute and Myology Institute (P.B.K.), University of Florida, Gainesville
| | - Peter B Kang
- From the Department of Neurology (C.D.Z.), University of Pennsylvania, Philadelphia; Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, and Departments of Neurology (P.B.K.), and Molecular Genetics and Microbiology (P.B.K.), University of Florida College of Medicine; and Genetics Institute and Myology Institute (P.B.K.), University of Florida, Gainesville.
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Burns DT, Donkervoort S, Müller JS, Knierim E, Bharucha-Goebel D, Faqeih EA, Bell SK, AlFaifi AY, Monies D, Millan F, Retterer K, Dyack S, MacKay S, Morales-Gonzalez S, Giunta M, Munro B, Hudson G, Scavina M, Baker L, Massini TC, Lek M, Hu Y, Ezzo D, AlKuraya FS, Kang PB, Griffin H, Foley AR, Schuelke M, Horvath R, Bönnemann CG. Variants in EXOSC9 Disrupt the RNA Exosome and Result in Cerebellar Atrophy with Spinal Motor Neuronopathy. Am J Hum Genet 2018; 102:858-873. [PMID: 29727687 PMCID: PMC5986733 DOI: 10.1016/j.ajhg.2018.03.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/06/2018] [Indexed: 12/30/2022] Open
Abstract
The exosome is a conserved multi-protein complex that is essential for correct RNA processing. Recessive variants in exosome components EXOSC3, EXOSC8, and RBM7 cause various constellations of pontocerebellar hypoplasia (PCH), spinal muscular atrophy (SMA), and central nervous system demyelination. Here, we report on four unrelated affected individuals with recessive variants in EXOSC9 and the effect of the variants on the function of the RNA exosome in vitro in affected individuals' fibroblasts and skeletal muscle and in vivo in zebrafish. The clinical presentation was severe, early-onset, progressive SMA-like motor neuronopathy, cerebellar atrophy, and in one affected individual, congenital fractures of the long bones. Three affected individuals of different ethnicity carried the homozygous c.41T>C (p.Leu14Pro) variant, whereas one affected individual was compound heterozygous for c.41T>C (p.Leu14Pro) and c.481C>T (p.Arg161∗). We detected reduced EXOSC9 in fibroblasts and skeletal muscle and observed a reduction of the whole multi-subunit exosome complex on blue-native polyacrylamide gel electrophoresis. RNA sequencing of fibroblasts and skeletal muscle detected significant >2-fold changes in genes involved in neuronal development and cerebellar and motor neuron degeneration, demonstrating the widespread effect of the variants. Morpholino oligonucleotide knockdown and CRISPR/Cas9-mediated mutagenesis of exosc9 in zebrafish recapitulated aspects of the human phenotype, as they have in other zebrafish models of exosomal disease. Specifically, portions of the cerebellum and hindbrain were absent, and motor neurons failed to develop and migrate properly. In summary, we show that variants in EXOSC9 result in a neurological syndrome combining cerebellar atrophy and spinal motoneuronopathy, thus expanding the list of human exosomopathies.
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40
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Karakis I, Georghiou S, Jones HR, Darras BT, Kang PB. Electrophysiologic Features of Radial Neuropathy in Childhood and Adolescence. Pediatr Neurol 2018; 81:14-18. [PMID: 29506771 DOI: 10.1016/j.pediatrneurol.2018.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 01/12/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND We analyzed the clinical and electrophysiologic patterns of nerve injury in pediatric patients with radial neuropathy. METHODS This is a retrospective analysis of 19 children and adolescents with radial neuropathy. RESULTS The mean subject age was 12 years (range one month to 19 years), 56% were female, and 53% had traumatic etiologies. Weakness in the finger and wrist extensors was the prevailing complaint (82%). Predominant localization was at the posterior interosseous nerve (37%), followed by the radial nerve below the spiral groove (32%), the radial nerve at the spiral groove (26%), and the radial nerve above the spiral groove (5%). Extensor indicis proprius compound muscle action potential amplitude was reduced in 86% of cases when tested, with a median axon loss estimate of 78%. The radial sensory nerve action potential amplitude was reduced in 53% of all cases, and in 83% of cases affecting the main radial trunk with a median axon loss estimate of 100%. For neuropathy affecting the main radial trunk, there was a high correlation of extensor indicis proprius median axon loss estimate and radial sensory nerve action potential median axon loss estimate (r = 0.72, P = 0.02). Neurogenic changes were seen in the extensor indicis proprius, extensor digitorum communis, extensor carpi radialis, and brachioradialis in 88%, 94%, 60%, and 44% of cases, respectively. Pathophysiology was demyelinating in 10%, axonal in 58%, and mixed in 32%. CONCLUSIONS In contrast to adults, where localization at the spiral groove predominates, radial neuropathy in children and adolescents is commonly localized at the posterior interosseous nerve or at the distal main radial trunk. Pediatric radial neuropathy is frequently of traumatic etiology and axonal pathophysiology.
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Affiliation(s)
- Ioannis Karakis
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Neurology, Lahey Clinic, Burlington, Massachusetts; Department of Neurology, Emory University School of Medicine, Atlanta, Georgia
| | - Sofia Georghiou
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - H Royden Jones
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Neurology, Lahey Clinic, Burlington, Massachusetts
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Peter B Kang
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida; Department of Neurology, University of Florida College of Medicine, Gainesville, Florida.
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41
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Saha M, Mitsuhashi S, Jones MD, Manko K, Reddy HM, Bruels CC, Cho KA, Pacak CA, Draper I, Kang PB. Consequences of MEGF10 deficiency on myoblast function and Notch1 interactions. Hum Mol Genet 2018; 26:2984-3000. [PMID: 28498977 DOI: 10.1093/hmg/ddx189] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/08/2017] [Indexed: 01/22/2023] Open
Abstract
Mutations in MEGF10 cause early onset myopathy, areflexia, respiratory distress, and dysphagia (EMARDD), a rare congenital muscle disease, but the pathogenic mechanisms remain largely unknown. We demonstrate that short hairpin RNA (shRNA)-mediated knockdown of Megf10, as well as overexpression of the pathogenic human p.C774R mutation, leads to impaired proliferation and migration of C2C12 cells. Myoblasts from Megf10-/- mice and Megf10-/-/mdx double knockout (dko) mice also show impaired proliferation and migration compared to myoblasts from wild type and mdx mice, whereas the dko mice show histological abnormalities that are not observed in either single mutant mouse. Cell proliferation and migration are known to be regulated by the Notch receptor, which plays an essential role in myogenesis. Reciprocal co-immunoprecipitation studies show that Megf10 and Notch1 interact via their respective intracellular domains. These interactions are impaired by the pathogenic p.C774R mutation. Megf10 regulation of myoblast function appears to be mediated at least in part via interactions with key components of the Notch signaling pathway, and defects in these interactions may contribute to the pathogenesis of EMARDD.
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Affiliation(s)
- Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Satomi Mitsuhashi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michael D Jones
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kelsey Manko
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Hemakumar M Reddy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christine C Bruels
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Christina A Pacak
- Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Department of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL 32610, USA
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42
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Cummings BB, Marshall JL, Tukiainen T, Lek M, Donkervoort S, Foley AR, Bolduc V, Waddell LB, Sandaradura SA, O'Grady GL, Estrella E, Reddy HM, Zhao F, Weisburd B, Karczewski KJ, O'Donnell-Luria AH, Birnbaum D, Sarkozy A, Hu Y, Gonorazky H, Claeys K, Joshi H, Bournazos A, Oates EC, Ghaoui R, Davis MR, Laing NG, Topf A, Kang PB, Beggs AH, North KN, Straub V, Dowling JJ, Muntoni F, Clarke NF, Cooper ST, Bönnemann CG, MacArthur DG. Improving genetic diagnosis in Mendelian disease with transcriptome sequencing. Sci Transl Med 2017; 9:9/386/eaal5209. [PMID: 28424332 DOI: 10.1126/scitranslmed.aal5209] [Citation(s) in RCA: 430] [Impact Index Per Article: 61.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/29/2017] [Indexed: 12/21/2022]
Abstract
Exome and whole-genome sequencing are becoming increasingly routine approaches in Mendelian disease diagnosis. Despite their success, the current diagnostic rate for genomic analyses across a variety of rare diseases is approximately 25 to 50%. We explore the utility of transcriptome sequencing [RNA sequencing (RNA-seq)] as a complementary diagnostic tool in a cohort of 50 patients with genetically undiagnosed rare muscle disorders. We describe an integrated approach to analyze patient muscle RNA-seq, leveraging an analysis framework focused on the detection of transcript-level changes that are unique to the patient compared to more than 180 control skeletal muscle samples. We demonstrate the power of RNA-seq to validate candidate splice-disrupting mutations and to identify splice-altering variants in both exonic and deep intronic regions, yielding an overall diagnosis rate of 35%. We also report the discovery of a highly recurrent de novo intronic mutation in COL6A1 that results in a dominantly acting splice-gain event, disrupting the critical glycine repeat motif of the triple helical domain. We identify this pathogenic variant in a total of 27 genetically unsolved patients in an external collagen VI-like dystrophy cohort, thus explaining approximately 25% of patients clinically suggestive of having collagen VI dystrophy in whom prior genetic analysis is negative. Overall, this study represents a large systematic application of transcriptome sequencing to rare disease diagnosis and highlights its utility for the detection and interpretation of variants missed by current standard diagnostic approaches.
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Affiliation(s)
- Beryl B Cummings
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA.,Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Jamie L Marshall
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Taru Tukiainen
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Monkol Lek
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA.,School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Veronique Bolduc
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leigh B Waddell
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Sarah A Sandaradura
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Gina L O'Grady
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Elicia Estrella
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hemakumar M Reddy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Fengmei Zhao
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Ben Weisburd
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Konrad J Karczewski
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Anne H O'Donnell-Luria
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Daniel Birnbaum
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA.,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
| | - Anna Sarkozy
- Dubowitz Neuromuscular Centre, University College London Institute of Child Health, London WC1N 1EH, U.K
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hernan Gonorazky
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Kristl Claeys
- Department of Neurology, University Hospitals Leuven and University of Leuven (Katholieke Universiteit Leuven), Leuven 3000, Belgium
| | - Himanshu Joshi
- Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Adam Bournazos
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Emily C Oates
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Roula Ghaoui
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Mark R Davis
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia 6009, Australia
| | - Nigel G Laing
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, Perth, Western Australia 6009, Australia.,Harry Perkins Institute of Medical Research, University of Western Australia, Perth, Western Australia 6009, Australia
| | - Ana Topf
- John Walton Muscular Dystrophy Research Centre, MRC (Medical Research Council) Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, U.K
| | | | - Peter B Kang
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.,Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Alan H Beggs
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Kathryn N North
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Melbourne, Victoria 3052, Australia
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, MRC (Medical Research Council) Centre for Neuromuscular Diseases, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne NE1 3BZ, U.K
| | - James J Dowling
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, University College London Institute of Child Health, London WC1N 1EH, U.K
| | - Nigel F Clarke
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Sandra T Cooper
- School of Paediatrics and Child Health, University of Sydney, Sydney, New South Wales 2006, Australia.,Institute for Neuroscience and Muscle Research, Kids Research Institute, The Children's Hospital at Westmead, Sydney, New South Wales 2145, Australia
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel G MacArthur
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA. .,Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA 02142, USA
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43
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Karakis I, Liew W, Fournier HS, Jones HR, Darras BT, Kang PB. Electrophysiologic features of ulnar neuropathy in childhood and adolescence. Clin Neurophysiol 2017; 128:751-755. [PMID: 28319875 DOI: 10.1016/j.clinph.2017.01.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/11/2016] [Accepted: 01/08/2017] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To analyze patterns of nerve injury in pediatric ulnar neuropathy (PUN). METHODS Retrospective analysis of 49 children with PUN. RESULTS Sensory loss in digit V was the prevailing complaint (89%). Predominant localization was at the elbow (55%). Diminished ulnar SNAP was the most common abnormality (71%) with median axon loss estimate (MAXE) of 62%. Dorsal ulnar cutaneous (DUC) sensory nerve action potential (SNAP) was reduced in 55% with MAXE of 43%. Abductor digiti minimi (ADM) and first dorsal interosseous (FDI) compound muscle action potential (CMAP) were reduced half of the time, with MAXE of 30% and 28% respectively. There was high correlation between ulnar sensory MAXE and ADM MAXE (r=0.76, p<0.0001), FDI MAXE (r=0.81, p<0.0001) and DUC MAXE (r=0.60, p=0.0048). Neurogenic changes were seen in the ADM, FDI, flexor carpi ulnaris (FCU) and flexor digitorum profundus IV (FDP IV) in 79%, 77%, 25% and 35% respectively. Pathophysiology was demyelinating in 27%, axonal in 59% and mixed in 14%. CONCLUSIONS In proximal axonal lesions, sensory fibers to digit V and motor fibers to distal muscles are predominantly affected, whereas in demyelinating lesions, slowing occurs twice as frequently as conduction block. SIGNIFICANCE There is frequent axonal and fascicular injury in PUN.
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Affiliation(s)
- Ioannis Karakis
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Department of Neurology, Lahey Clinic, Burlington, MA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Wendy Liew
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Department of Neurology, KK Women's & Children's Hospital, Singapore
| | - Heather Szelag Fournier
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - H Royden Jones
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Department of Neurology, Lahey Clinic, Burlington, MA, USA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Peter B Kang
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA; Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA; Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA.
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Gilbert DL, Horn PS, Kang PB, Mintz M, Joshi SM, Ruch-Ross H, Bale JF. Child Neurology Recruitment and Training: Views of Residents and Child Neurologists From the 2015 AAP/CNS Workforce Survey. Pediatr Neurol 2017; 66:89-95. [PMID: 27955837 DOI: 10.1016/j.pediatrneurol.2016.08.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND To assess and compare resident and practicing child neurologists' attitudes regarding recruitment and residency training in child neurology. METHODS A joint task force of the American Academy of Pediatrics and the Child Neurology Society conducted an electronic survey of child neurology residents (n = 305), practicing child neurologists (n = 1290), and neurodevelopmental disabilities specialists (n = 30) in 2015. Descriptive and multivariate analyses were performed. RESULTS Response rates were 32% for residents (n = 97; 36% male; 65% Caucasian) and 40% for practitioners (n = 523; 63% male; 80% Caucasian; 30% lifetime certification). Regarding recruitment, 70% (n = 372) attributed difficulties recruiting medical students to insufficient early exposure. Although 68% (n = 364) reported that their medical school required a neurology clerkship, just 28% (n = 152) reported a child neurology component. Regarding residency curriculum, respondents supported increased training emphasis for genetics, neurodevelopmental disabilities, and multiple other subspecialty areas. Major changes in board certification requirements were supported, with 73% (n = 363) favoring reduced adult neurology training (strongest predictors: fewer years since medical school P = 0.003; and among practicing child neurologists, working more half-day clinics per week P = 0.005). Furthermore, 58% (n = 289) favored an option to reduce total training to 4 years, with 1 year of general pediatrics. Eighty-two percent (n = 448) would definitely or probably choose child neurology again. CONCLUSIONS These findings provide support for recruitment efforts emphasizing early exposure of medical students to child neurology. Increased subspecialty exposure and an option for major changes in board certification requirements are favored by a significant number of respondents.
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Affiliation(s)
- Donald L Gilbert
- Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
| | - Paul S Horn
- Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Mark Mintz
- The Center for Neurological and Neurodevelopmental Health (CNNH) and the Clinical Research Center of New Jersey (CRCNJ), Voorhees, New Jersey
| | - Sucheta M Joshi
- Division of Pediatric Neurology, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Holly Ruch-Ross
- Division of Workforce and Medical Education Policy, American Academy of Pediatrics, Elk Grove Village, Illinois
| | - James F Bale
- Division of Pediatric Neurology, University of Utah School of Medicine, Salt Lake City, Utah
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Liew WKM, Pacak CA, Visyak N, Darras BT, Bousvaros A, Kang PB. Longitudinal Patterns of Thalidomide Neuropathy in Children and Adolescents. J Pediatr 2016; 178:227-232. [PMID: 27567409 DOI: 10.1016/j.jpeds.2016.07.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/15/2016] [Accepted: 07/27/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To characterize the longitudinal clinical and electrophysiological patterns of thalidomide neuropathy in children and adolescents. STUDY DESIGN Retrospective analysis of clinical records at a tertiary care children's hospital, including serial electrophysiological studies. RESULTS Sixteen patients aged 6-24 years received thalidomide to treat Crohn's disease from 2002 to 2012. Nine subjects had electrophysiological evidence of sensorimotor axonal polyneuropathy, 8 of whom had sensory and/or motor symptoms. The patients with polyneuropathy received thalidomide for 5 weeks to 52 months, with cumulative doses ranging from 1.4 to 207.7 g. All subjects with cumulative doses greater than 60 g developed polyneuropathy, and 4 of the 5 subjects who received thalidomide for more than 20 months developed polyneuropathy. The 7 subjects who had normal neurophysiological studies received therapy for 1 week to 25 months, with cumulative doses ranging from 0.7 to 47 g. In contrast to some previous reports, several patients had sensorimotor polyneuropathies, rather than pure sensory neuropathies. In patients with neuropathy who received therapy for more than 24 months and had 3 or more electromyography studies, the severity of the neuropathy plateaued. CONCLUSIONS Factors in addition to the total dose may contribute to the risk profile for thalidomide neuropathy, including pharmacogenetic susceptibilities. The severity of the neuropathy does not worsen relentlessly. Children, adolescents, and young adults receiving thalidomide should undergo regular neurophysiological studies to monitor for neuropathy.
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Affiliation(s)
- Wendy K M Liew
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Neurology Service, Department of Pediatrics, KK Women's and Children's Hospital, Singapore
| | - Christina A Pacak
- Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL
| | - Nicole Visyak
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Athos Bousvaros
- Division of Gastroenterology, Hepatology, and Nutrition, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Peter B Kang
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL.
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Massaad MJ, Zhou J, Tsuchimoto D, Chou J, Jabara H, Janssen E, Glauzy S, Olson BG, Morbach H, Ohsumi TK, Schmitz K, Kyriacos M, Kane J, Torisu K, Nakabeppu Y, Notarangelo LD, Chouery E, Megarbane A, Kang PB, Al-Idrissi E, Aldhekri H, Meffre E, Mizui M, Tsokos GC, Manis JP, Al-Herz W, Wallace SS, Geha RS. Deficiency of base excision repair enzyme NEIL3 drives increased predisposition to autoimmunity. J Clin Invest 2016; 126:4219-4236. [PMID: 27760045 DOI: 10.1172/jci85647] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 09/06/2016] [Indexed: 12/17/2022] Open
Abstract
Alterations in the apoptosis of immune cells have been associated with autoimmunity. Here, we have identified a homozygous missense mutation in the gene encoding the base excision repair enzyme Nei endonuclease VIII-like 3 (NEIL3) that abolished enzymatic activity in 3 siblings from a consanguineous family. The NEIL3 mutation was associated with fatal recurrent infections, severe autoimmunity, hypogammaglobulinemia, and impaired B cell function in these individuals. The same homozygous NEIL3 mutation was also identified in an asymptomatic individual who exhibited elevated levels of serum autoantibodies and defective peripheral B cell tolerance, but normal B cell function. Further analysis of the patients revealed an absence of LPS-responsive beige-like anchor (LRBA) protein expression, a known cause of immunodeficiency. We next examined the contribution of NEIL3 to the maintenance of self-tolerance in Neil3-/- mice. Although Neil3-/- mice displayed normal B cell function, they exhibited elevated serum levels of autoantibodies and developed nephritis following treatment with poly(I:C) to mimic microbial stimulation. In Neil3-/- mice, splenic T and B cells as well as germinal center B cells from Peyer's patches showed marked increases in apoptosis and cell death, indicating the potential release of self-antigens that favor autoimmunity. These findings demonstrate that deficiency in NEIL3 is associated with increased lymphocyte apoptosis, autoantibodies, and predisposition to autoimmunity.
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Su X, Kang PB, Russell JA, Simmons Z. Ethical issues in the evaluation of adults with suspected genetic neuromuscular disorders. Muscle Nerve 2016; 54:997-1006. [PMID: 27615030 DOI: 10.1002/mus.25400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2016] [Indexed: 12/13/2022]
Abstract
Genetic testing is rapidly becoming an increasingly significant part of the diagnostic armamentarium of neuromuscular clinicians. Although technically easy to order, the results of such testing, whether positive or negative, have potentially enormous consequences for the individual tested and for family members. As a result, ethical considerations must be in the forefront of the physician's agenda when obtaining genetic testing. Informed consent is an important starting point for discussions between physicians and patients, but the counseling embedded in the informed consent process must be an ongoing part of subsequent interactions, including return of results and follow-up. Patient autonomy, including the right to know and right not-to-know results, must be respected. Considerations of capacity, physician beneficence and nonmaleficence, and privacy all play roles in the process. Muscle Nerve 54: 997-1006, 2016.
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Affiliation(s)
- Xiaowei Su
- Department of Neurology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Peter B Kang
- Division of Pediatric Neurology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - James A Russell
- Section of Neurology, Lahey Hospital and Medical Center, Burlington, Massachusetts, USA
| | - Zachary Simmons
- Departments of Neurology and Humanities, Penn State Hershey Medical Center, 30 Hope Drive, Hershey, Pennsylvania, 17033, USA
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48
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Karakis I, Khoshnoodi M, Liew W, Nguyen ES, Jones HR, Darras BT, Kang PB. Electrophysiologic features of fibular neuropathy in childhood and adolescence. Muscle Nerve 2016; 55:693-697. [PMID: 27615598 DOI: 10.1002/mus.25403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 08/25/2016] [Accepted: 09/07/2016] [Indexed: 11/06/2022]
Abstract
INTRODUCTION We studied patterns of nerve injury in pediatric common fibular (peroneal) neuropathy (CFN). METHODS A retrospective analysis was performed on data from 53 children with CFN at a pediatric electromyography laboratory. RESULTS Conduction block at the fibular head was present in 35% of patients. Deep fibular axonal loss was identified in 77%, while superficial fibular axonal loss was identified in 45%. The pathophysiology was predominantly axonal in 72%, mostly demyelinating in 6%, and mixed in 22%. Predominantly demyelinating lesions at the fibular head demonstrated sparing of the superficial fibular sensory nerve (P = 0.01, Fischer exact test). Predominantly axonal lesions had a moderate correlation between superficial and deep fibular axonal loss (Spearman r = 0.52; P = 0.0001). CONCLUSIONS There is frequent axonal and fascicular injury in pediatric CFN, similar to adults. Deep and superficial fibular nerve involvements correlate in axonal lesions, whereas superficial fibular sensory fibers are often spared in demyelinating lesions. Muscle Nerve, 2016 Muscle Nerve 55: 693-697, 2017.
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Affiliation(s)
- Ioannis Karakis
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, Lahey Clinic, Burlington, Massachusetts, USA.,Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Mohammad Khoshnoodi
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Wendy Liew
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, KK Women's & Children's Hospital, Singapore
| | - Elizabeth S Nguyen
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - H Royden Jones
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neurology, Lahey Clinic, Burlington, Massachusetts, USA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter B Kang
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
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49
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Kang PB, Bale JF, Mintz M, Joshi SM, Gilbert DL, Radabaugh C, Ruch-Ross H. The child neurology clinical workforce in 2015: Report of the AAP/CNS Joint Taskforce. Neurology 2016; 87:1384-92. [PMID: 27566740 DOI: 10.1212/wnl.0000000000003147] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 05/09/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES More than a decade has passed since the last major workforce survey of child neurologists in the United States; thus, a reassessment of the child neurology workforce is needed, along with an inaugural assessment of a new related field, neurodevelopmental disabilities. METHODS The American Academy of Pediatrics and the Child Neurology Society conducted an electronic survey in 2015 of child neurologists and neurodevelopmental disabilities specialists. RESULTS The majority of respondents participate in maintenance of certification, practice in academic medical centers, and offer subspecialty care. EEG reading and epilepsy care are common subspecialty practice areas, although many child neurologists have not had formal training in this field. In keeping with broader trends, medical school debts are substantially higher than in the past and will often take many years to pay off. Although a broad majority would choose these fields again, there are widespread dissatisfactions with compensation and benefits given the length of training and the complexity of care provided, and frustrations with mounting regulatory and administrative stresses that interfere with clinical practice. CONCLUSIONS Although not unique to child neurology and neurodevelopmental disabilities, such issues may present barriers for the recruitment of trainees into these fields. Creative approaches to enhance the recruitment of the next generation of child neurologists and neurodevelopmental disabilities specialists will benefit society, especially in light of all the exciting new treatments under development for an array of chronic childhood neurologic disorders.
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Affiliation(s)
- Peter B Kang
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL.
| | - James F Bale
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
| | - Mark Mintz
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
| | - Sucheta M Joshi
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
| | - Donald L Gilbert
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
| | - Carrie Radabaugh
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
| | - Holly Ruch-Ross
- From the Division of Pediatric Neurology (P.B.K.), Department of Pediatrics, University of Florida College of Medicine, Gainesville; Division of Pediatric Neurology (J.F.B.), University of Utah School of Medicine, Salt Lake City; The Center for Neurological and Neurodevelopmental Health and the Clinical Research Center of New Jersey (M.M.), Voorhees; Division of Pediatric Neurology (S.M.J.), Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor; Division of Pediatric Neurology (D.L.G.), Cincinnati Children's Hospital Medical Center, OH; and American Academy of Pediatrics Division of Workforce and Medical Education Policy (C.R., H.R.-R.), Elk Grove Village, IL
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50
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Reddy HM, Hamed SA, Lek M, Mitsuhashi S, Estrella E, Jones MD, Mahoney LJ, Duncan AR, Cho KA, Macarthur DG, Kunkel LM, Kang PB. Homozygous nonsense mutation in SGCA is a common cause of limb-girdle muscular dystrophy in Assiut, Egypt. Muscle Nerve 2016; 54:690-5. [PMID: 26934379 DOI: 10.1002/mus.25094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 01/18/2023]
Abstract
INTRODUCTION The genetic causes of limb-girdle muscular dystrophy (LGMD) have been studied in numerous countries, but such investigations have been limited in Egypt. METHODS A cohort of 30 families with suspected LGMD from Assiut, Egypt, was studied using immunohistochemistry, homozygosity mapping, Sanger sequencing, and whole exome sequencing. RESULTS Six families were confirmed to have pathogenic mutations, 4 in SGCA and 2 in DMD. Of these, 3 families harbored a single nonsense mutation in SGCA, suggesting that this may be a common mutation in Assiut, Egypt, originating from a founder effect. CONCLUSIONS The Assiut region in Egypt appears to share at least several of the common LGMD genes found in other parts of the world. It is notable that 4 of the 6 mutations were ascertained by means of whole exome sequencing, even though it was the last approach adopted. This illustrates the power of this technique for identifying causative mutations for muscular dystrophies. Muscle Nerve 54: 690-695, 2016.
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Affiliation(s)
- Hemakumar M Reddy
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Sherifa A Hamed
- Department of Neurology and Psychiatry, Assiut University Hospital, Assiut, Egypt
| | - Monkol Lek
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, USA
| | - Satomi Mitsuhashi
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Elicia Estrella
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Michael D Jones
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Lane J Mahoney
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Anna R Duncan
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610
| | - Daniel G Macarthur
- Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, USA
| | - Louis M Kunkel
- Division of Genetics & Genomics, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Peter B Kang
- Division of Pediatric Neurology, University of Florida College of Medicine, PO Box 100296, Gainesville, Florida, USA, 32610. .,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA.
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