1
|
Oatmen K, Camelo-Piragua S, Zaghloul N. Novel mutation in the MYH2 gene in a symptomatic neonate with a hereditary myosin myopathy. J Neonatal Perinatal Med 2021; 15:63-68. [PMID: 34459418 DOI: 10.3233/npm-210780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Hereditary myosin myopathies are muscle disorders caused by mutations in myosin heavy chain genes. The MYH2 gene encodes the fast 2A skeletal muscle isoform, and mutations manifest as joint contractures, muscle weakness, and external ophthalmoplegia. Muscle biopsy shows decreased type 2A fibers, and vacuoles are sometimes present in adults with progressive disease. PRESENTATION OF CASE This case describes a full term baby boy with hypotonia, dysmorphic features, dysphagia, and aspiration. Whole genome sequencing detected a novel heterozygous variant in the MYH2 gene. Muscle biopsy showed decreased type 2A fibers and vacuoles in myofibers. DISCUSSION Hypotonia and dysphagia are common in infants with a MYH2 myopathy. However, dysmorphic features and vacuoles on biopsy have not previous been described in infants with MYH2 myopathies. CONCLUSION This case reports an unusual phenotype of a rare neonatal-onset congenital myopathy associated with a novel heterozygous variant in MYH2.
Collapse
Affiliation(s)
- K Oatmen
- Department of Pediatrics, University of Arizona, Tucson, AZ, USA
| | - S Camelo-Piragua
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - N Zaghloul
- Department of Pediatrics, Division of Neonatology, University of Arizona, Tucson, AZ, USA
| |
Collapse
|
2
|
Madigan NN, Polzin MJ, Cui G, Liewluck T, Alsharabati MH, Klein CJ, Windebank AJ, Mer G, Milone M. Filamentous tangles with nemaline rods in MYH2 myopathy: a novel phenotype. Acta Neuropathol Commun 2021; 9:79. [PMID: 33926564 PMCID: PMC8082902 DOI: 10.1186/s40478-021-01168-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/21/2021] [Indexed: 11/30/2022] Open
Abstract
The MYH2 gene encodes the skeletal muscle myosin heavy chain IIA (MyHC-IIA) isoform, which is expressed in the fast twitch type 2A fibers. Autosomal dominant or recessive pathogenic variants in MYH2 lead to congenital myopathy clinically featured by ophthalmoparesis and predominantly proximal weakness. MYH2-myopathy is pathologically characterized by loss and atrophy of type 2A fibers. Additional myopathological abnormalities have included rimmed vacuoles containing small p62 positive inclusions, 15–20 nm tubulofilaments, minicores and dystrophic changes. We report an adult patient with late-pediatric onset MYH2-myopathy caused by two heterozygous pathogenic variants: c.3331C>T, p.Gln1111* predicted to result in truncation of the proximal tail region of MyHC-IIA, and c.1546T>G, p.Phe516Val, affecting a highly conserved amino acid within the highly conserved catalytic motor head relay loop. This missense variant is predicted to result in a less compact loop domain and in turn could affect the protein affinity state. The patient’s genotype is accompanied by a novel myopathological phenotype characterized by centralized large myofilamentous tangles associated with clusters of nemaline rods, and ring fibers, in addition to the previously reported rimmed vacuoles, paucity and atrophy of type 2A fibers. Electron microscopy demonstrated wide areas of disorganized myofibrils which were oriented in various planes of direction and entrapped multiple nemaline rods, as corresponding to the large tangles with rods seen on light microscopy. Nemaline rods were rarely observed also in nuclei. We speculate that the mutated MyHC-IIA may influence myofibril disorganization. While nemaline rods have been described in myopathies caused by pathogenic variants in genes encoding several sarcomeric proteins, to our knowledge, nemaline rods have not been previously described in MYH2-myopathy.
Collapse
|
3
|
Transcriptome Analysis of the Anti-TGFβ Effect of Schisandra chinensis Fruit Extract and Schisandrin B in A7r5 Vascular Smooth Muscle Cells. Life (Basel) 2021; 11:life11020163. [PMID: 33672474 PMCID: PMC7926316 DOI: 10.3390/life11020163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/14/2021] [Accepted: 02/17/2021] [Indexed: 12/19/2022] Open
Abstract
Schisandra chinensis fruit extract (SCE) has been used as a traditional medicine for treating vascular diseases. However, little is known about how SCE and schisandrin B (SchB) affect transcriptional output-a crucial factor for shaping the fibrotic responses of the transforming growth factor β (TGFβ) signaling pathways in in vascular smooth muscle cells (VSMC). In this study, to assess the pharmacological effect of SCE and SchB on TGFβ-induced transcriptional output, we performed DNA microarray experiments in A7r5 VSMCs. We found that TGFβ induced distinctive changes in the gene expression profile and that these changes were considerably reversed by SCE and SchB. Gene Set Enrichment Analysis (GSEA) with Hallmark signature suggested that SCE or SchB inhibits a range of fibrosis-associated biological processes, including inflammation, cell proliferation and migration. With our VSMC-specific transcriptional interactome network, master regulator analysis identified crucial transcription factors that regulate the expression of SCE- and SchB-effective genes (i.e., TGFβ-reactive genes whose expression are reversed by SCE and SchB). Our results provide novel perspective and insight into understanding the pharmacological action of SCE and SchB at the transcriptome level and will support further investigations to develop multitargeted strategies for the treatment of vascular fibrosis.
Collapse
|
4
|
Telese R, Pagliarani S, Lerario A, Ciscato P, Fagiolari G, Cassandrini D, Grimoldi N, Conte G, Cinnante C, Santorelli FM, Comi GP, Sciacco M, Peverelli L. MYH2 myopathy, a new case expands the clinical and pathological spectrum of the recessive form. Mol Genet Genomic Med 2020; 8:e1320. [PMID: 32578970 PMCID: PMC7507101 DOI: 10.1002/mgg3.1320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 12/10/2019] [Accepted: 04/28/2020] [Indexed: 11/18/2022] Open
Abstract
Background Hereditary myosin myopathies are a group of rare muscle disorders, caused by mutations in genes encoding for skeletal myosin heavy chains (MyHCs). MyHCIIa is encoded by MYH2 and is expressed in fast type 2A and 2B muscle fibers. MYH2 mutations are responsible for an autosomal dominant (AD) progressive myopathy, characterized by the presence of rimmed vacuoles and by a reduction in the number and size of type 2A fibers, and a recessive early onset myopathy characterized by complete loss of type 2A fibers. Recently, a patient with a homozygous mutation but presenting a dominant phenotype has been reported. Methods The patient was examined thoroughly and two muscle biopsies were performed through the years. NGS followed by confirmation in Sanger sequencing was used to identify the genetic cause. Results We describe the second case presenting with late‐onset ophthalmoparesis, ptosis, diffuse muscle weakness, and histopathological features typical for AD forms but with a recessive MYH2 genotype. Conclusion This report contributes to expand the clinical and genetic spectrum of MYH2 myopathies and to increase the awareness of these very rare diseases.
Collapse
Affiliation(s)
- Roberta Telese
- Department of Neurosciences, Imaging and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Serena Pagliarani
- Dino Ferrari Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Alberto Lerario
- Neuromuscular and Rare diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Patrizia Ciscato
- Neuromuscular and Rare diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Gigliola Fagiolari
- Neuromuscular and Rare diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Nadia Grimoldi
- University of Milan, Neurosurgey Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Giorgio Conte
- Neuroradiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Claudia Cinnante
- Neuroradiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | | | - Giacomo P Comi
- Dino Ferrari Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy
| | - Monica Sciacco
- Neuromuscular and Rare diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Lorenzo Peverelli
- Neuromuscular and Rare diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| |
Collapse
|
5
|
Abstract
The congenital myopathies form a large clinically and genetically heterogeneous group of disorders. Currently mutations in at least 27 different genes have been reported to cause a congenital myopathy, but the number is expected to increase due to the accelerated use of next-generation sequencing methods. There is substantial overlap between the causative genes and the clinical and histopathologic features of the congenital myopathies. The mode of inheritance can be autosomal recessive, autosomal dominant or X-linked. Both dominant and recessive mutations in the same gene can cause a similar disease phenotype, and the same clinical phenotype can also be caused by mutations in different genes. Clear genotype-phenotype correlations are few and far between.
Collapse
Affiliation(s)
- Katarina Pelin
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland; The Folkhälsan Institute of Genetics, Folkhälsan Research Center, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland.
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, and Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
6
|
Smith HS, Swint JM, Lalani SR, Yamal JM, de Oliveira Otto MC, Castellanos S, Taylor A, Lee BH, Russell HV. Clinical Application of Genome and Exome Sequencing as a Diagnostic Tool for Pediatric Patients: a Scoping Review of the Literature. Genet Med 2019; 21:3-16. [PMID: 29760485 DOI: 10.1038/s41436-018-0024-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/20/2018] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Availability of clinical genomic sequencing (CGS) has generated questions about the value of genome and exome sequencing as a diagnostic tool. Analysis of reported CGS application can inform uptake and direct further research. This scoping literature review aims to synthesize evidence on the clinical and economic impact of CGS. METHODS PubMed, Embase, and Cochrane were searched for peer-reviewed articles published between 2009 and 2017 on diagnostic CGS for infant and pediatric patients. Articles were classified according to sample size and whether economic evaluation was a primary research objective. Data on patient characteristics, clinical setting, and outcomes were extracted and narratively synthesized. RESULTS Of 171 included articles, 131 were case reports, 40 were aggregate analyses, and 4 had a primary economic evaluation aim. Diagnostic yield was the only consistently reported outcome. Median diagnostic yield in aggregate analyses was 33.2% but varied by broad clinical categories and test type. CONCLUSION Reported CGS use has rapidly increased and spans diverse clinical settings and patient phenotypes. Economic evaluations support the cost-saving potential of diagnostic CGS. Multidisciplinary implementation research, including more robust outcome measurement and economic evaluation, is needed to demonstrate clinical utility and cost-effectiveness of CGS.
Collapse
Affiliation(s)
- Hadley Stevens Smith
- Baylor College of Medicine, The University of Texas School of Public Health, Houston, Texas, USA
| | - J Michael Swint
- The University of Texas School of Public Health, The Center for Clinical Research and Evidence-Based Medicine, The University of Texas McGovern Medical School, Houston, Texas, USA
| | - Seema R Lalani
- Baylor College of Medicine, Baylor Genetics Laboratory, Houston, Texas, USA
| | - Jose-Miguel Yamal
- The University of Texas School of Public Health, Houston, Texas, USA
| | | | | | - Amy Taylor
- Texas Medical Center Library, Houston, Texas, USA
| | | | - Heidi V Russell
- Texas Children's Hospital, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
7
|
Findlay AR, Harms MB, Pestronk A, Weihl CC. Homozygous recessive MYH2 mutation mimicking dominant MYH2 associated myopathy. Neuromuscul Disord 2018; 28:675-679. [PMID: 29934118 DOI: 10.1016/j.nmd.2018.05.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 03/30/2018] [Accepted: 05/12/2018] [Indexed: 01/14/2023]
Abstract
Mutations in MYH2 that encodes myosin heavy chain IIa cause both dominant and recessively inherited myopathies. Patients with dominantly inherited MYH2 missense mutations present with ophthalmoplegia and progressive proximal limb weakness. Muscle biopsy reveals rimmed vacuoles and inclusions, prompting this entity to initially be described as hereditary inclusion body myopathy 3. In contrast, patients with recessive MYH2 mutations have early onset, non-progressive, diffuse weakness and ophthalmoplegia. Muscle biopsy reveals near or complete absence of type 2A fibers with no vacuole or inclusion pathology. We describe a patient with childhood onset ophthalmoplegia, progressive proximal muscle weakness beginning in adolescence, and muscle biopsy with myopathic changes and rimmed vacuoles. Although this patient's disease course and histopathology is consistent with dominant MYH2 mutations, whole exome sequencing revealed a c.737 G>A p.Arg246His homozygous MYH2 variant. These findings expand the clinical and pathologic phenotype of recessive MYH2 myopathies.
Collapse
Affiliation(s)
- Andrew R Findlay
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St Louis, MO 63110, United States
| | | | - Alan Pestronk
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St Louis, MO 63110, United States
| | - Conrad C Weihl
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St Louis, MO 63110, United States.
| |
Collapse
|
8
|
Congenital myopathies: disorders of excitation-contraction coupling and muscle contraction. Nat Rev Neurol 2018; 14:151-167. [PMID: 29391587 DOI: 10.1038/nrneurol.2017.191] [Citation(s) in RCA: 194] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The congenital myopathies are a group of early-onset, non-dystrophic neuromuscular conditions with characteristic muscle biopsy findings, variable severity and a stable or slowly progressive course. Pronounced weakness in axial and proximal muscle groups is a common feature, and involvement of extraocular, cardiorespiratory and/or distal muscles can implicate specific genetic defects. Central core disease (CCD), multi-minicore disease (MmD), centronuclear myopathy (CNM) and nemaline myopathy were among the first congenital myopathies to be reported, and they still represent the main diagnostic categories. However, these entities seem to belong to a much wider phenotypic spectrum. To date, congenital myopathies have been attributed to mutations in over 20 genes, which encode proteins implicated in skeletal muscle Ca2+ homeostasis, excitation-contraction coupling, thin-thick filament assembly and interactions, and other mechanisms. RYR1 mutations are the most frequent genetic cause, and CCD and MmD are the most common subgroups. Next-generation sequencing has vastly improved mutation detection and has enabled the identification of novel genetic backgrounds. At present, management of congenital myopathies is largely supportive, although new therapeutic approaches are reaching the clinical trial stage.
Collapse
|
9
|
Hunter DG. Infantile and Early Acquired Ophthalmoplegic Syndromes. J Binocul Vis Ocul Motil 2018; 68:7-9. [PMID: 30196778 DOI: 10.1080/2576117x.2017.1416039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ophthalmoplegia is rare in infants and may present either as a static or a progressing deficit. In this report, I will summarize the major causes of ophthalmoplegia when it presents in infancy or early childhood. Strategies for narrowing the differential diagnosis will also be considered.
Collapse
Affiliation(s)
- David G Hunter
- a Department of Ophthalmology , Boston Children's Hospital , Boston , Massachusetts
- b Department of Ophthalmology , Harvard Medical School , Boston , Massachusetts
| |
Collapse
|