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Zambon AA, Waldrop MA, Alles R, Weiss RB, Conroy S, Moore-Clingenpeel M, Previtali S, Flanigan KM. Phenotypic Spectrum of Dystrophinopathy Due to Duchenne Muscular Dystrophy Exon 2 Duplications. Neurology 2022; 98:e730-e738. [PMID: 34937785 PMCID: PMC8865888 DOI: 10.1212/wnl.0000000000013246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 12/13/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES To describe the phenotypic spectrum of dystrophinopathy in a large cohort of individuals with DMD exon 2 duplications (Dup2), who may be particularly amenable to therapies directed at restoring expression of either full-length dystrophin or nearly full-length dystrophin through utilization of the DMD exon 5 internal ribosome entry site (IRES). METHODS In this retrospective observational study, we analyzed data from large genotype-phenotype databases (the United Dystrophinopathy Project [UDP] and the Italian DMD network) and classified participants into Duchenne muscular dystrophy (DMD), intermediate muscular dystrophy (IMD), or Becker muscular dystrophy (BMD) phenotypes. Log-rank tests for time-to-event variables were used to compare age at loss of ambulation (LOA) in participants with Dup2 vs controls without Dup2 in the UDP database and for comparisons between steroid-treated vs steroid-naive participants with Dup2. RESULTS Among 66 participants with Dup2 (UDP = 40, Italy = 26), 61% were classified as DMD, 9% as IMD, and 30% as BMD. Median age at last observation was 15.4 years (interquartile range 8.79-26.0) and 75% had been on corticosteroids for at least 6 months. Age at LOA differed significantly between participants with Dup2 DMD and historical controls without Dup2 DMD (p < 0.001). Valid spirometry was limited but suggested a delay in the typical age-related decline in forced vital capacity and 24 of 55 participants with adequate cardiac data had cardiomyopathy. DISCUSSION Some patients with Dup2 display a milder disease course than controls without Dup2 DMD, and prolonged ambulation with corticosteroids suggests the potential of IRES activation as a molecular mechanism. As Dup2-targeted therapies reach clinical applications, this information is critical to aid in the interpretation of the efficacy of new treatments.
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Affiliation(s)
- Alberto A Zambon
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Megan A Waldrop
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Roxane Alles
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Robert B Weiss
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Sara Conroy
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Melissa Moore-Clingenpeel
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Stefano Previtali
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City
| | - Kevin M Flanigan
- From Inspe and Division of Neuroscience (A.A.Z., S.P.), IRCCS Ospedale San Raffaele, Milan, Italy; The Center for Gene Therapy, Abigail Wexner Research Institute (M.A.W., R.A., K.M.F.), and Biostatistics Research Core (S.C., M.M.-C.), Nationwide Children's Hospital, Columbus, OH; Departments of Pediatrics and Neurology (M.A.W., K.M.F.), Ohio State University Medical Center, Columbus; and Department of Human Genetics (R.B.W.), University of Utah, Salt Lake City.
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Andrews JG, Conway K, Westfield C, Trout C, Meaney FJ, Mathews K, Ciafaloni E, Cunniff C, Fox DJ, Matthews D, Pandya S. Implementation of Duchenne Muscular Dystrophy Care Considerations. Pediatrics 2018; 142:peds.2017-4006. [PMID: 29925575 DOI: 10.1542/peds.2017-4006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/17/2018] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is an X-linked disorder characterized by progressive muscle weakness and multisystem involvement. Recent advances in management of individuals with DMD have prolonged survival. Lack of standardized care spurred an international collaboration to develop consensus-based care considerations for diagnosis and management. In this study, we evaluate adherence to considerations at selected sites. METHODS We collaborated with the Muscular Dystrophy Surveillance, Tracking, and Research Network. Our sample included males with DMD and Becker muscular dystrophy <21 years as of December 31, 2010, with 1 health care encounter on or after January 1, 2012. We collected data from medical records on encounters occurring January 1, 2012, through December 31, 2014. Adherence was determined when frequency of visits or assessments were at or above recommendations for selected care considerations. RESULTS Our analytic sample included 299 individuals, 7% of whom (20/299) were classified as childhood-onset Becker muscular dystrophy. Adherence for neuromuscular and respiratory clinician visits was 65% for the cohort; neuromuscular assessments and corticosteroid side effect monitoring measures ranged from 16% to 68%. Adherence was 83% for forced vital capacity and ≤58% for other respiratory diagnostics. Cardiologist assessments and echocardiograms were found for at least 84%. Transition planning for education or health care was documented for 31% of eligible males. CONCLUSIONS Medical records data were used to identify areas in which practice aligns with the care considerations. However, there remains inconsistency across domains and insufficiency in critical areas. More research is needed to explain this variability and identify reliable methods to measure outcomes.
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Affiliation(s)
| | | | | | | | - F John Meaney
- Department of Pediatrics, University of Arizona, Tucson, Arizona
| | | | - Emma Ciafaloni
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, New York
| | - Christopher Cunniff
- Department of Pediatrics, Weill Cornell Medical College, New York City, New York; and
| | - Deborah J Fox
- Bureau of Environmental and Occupational Epidemiology
| | - Dennis Matthews
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Colorado, Aurora, Colorado
| | - Shree Pandya
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, New York
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Landfeldt E, Lindgren P, Guglieri M, Lochmüller H, Bushby K. Compliance to care guidelines for Duchenne muscular dystrophy in Italy. Neuromuscul Disord 2016; 28:100. [PMID: 29198861 DOI: 10.1016/j.nmd.2016.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/21/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Erik Landfeldt
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - Peter Lindgren
- Medical Management Centre, Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm, Sweden
| | - Michela Guglieri
- Newcastle University John Walton Muscular Dystrophy Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Hanns Lochmüller
- Newcastle University John Walton Muscular Dystrophy Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Katharine Bushby
- Newcastle University John Walton Muscular Dystrophy Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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