1
|
Haidong L, Yin L, Ping C, Xianzhao Z, Qi Q, Xiaoli M, Zheng L, Wenhao C, Yaguang Z, Qianqian Q. Clinico-pathological and gene features of 15 nemaline myopathy patients from a single Chinese neuromuscular center. Acta Neurol Belg 2024; 124:91-99. [PMID: 37525074 PMCID: PMC10874337 DOI: 10.1007/s13760-023-02333-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND Nemaline myopathy, the most common of the congenital myopathies, is caused by various genetic mutations. In this study, we attempted to investigate the clinical features, muscle pathology and genetic features of 15 patients with nemaline myopathy. RESULTS Among the 15 patients, there were 9 (60.00%) males and 6 (40.00%) females, and 9 (60.00%) of them came from three families respectively. The age of seeing a doctor ranged from 9 to 52 years old, the age of onset was from 5 to 23 years old, and the duration of disease ranged from 3 to 35 years. Ten out of the 15 patients had high arched palate and elongated face. Only one patient had mild respiratory muscle involvement and none had dysphagia. Muscle biopsies were performed in 9 out of the 15 patients. Pathologically, muscle fibers of different sizes, atrophic muscle fibers and compensatory hypertrophic fibers could be found, and occasionally degenerated and necrotic muscle fibers were observed. Different degrees of nemaline bodies aggregation could be seen in all 9 patients. The distribution of type I and type II muscle fibers were significantly abnormal in patients with nemaline myopathy caused by NEB gene, however, it was basically normal in patients with nemaline myopathy caused by TPM3 gene and ACTA1 gene. Electron microscopic analysis of 6 patients showed that nemaline bodies aggregated between myofibrils were found in 5(83.33%) cases, and most of them were located near the Z band, but no intranuclear rods were found. The gene analysis of 15 NM patients showed that three NM-related genes were harbored, including 11 (73.33%) patients with NEB, 3 (20.00%) patients with TPM3, and 1 (6.67%) patient with ACTA1, respectively. A total of 12 mutation sites were identified and included 10 (83.33%) mutations in exon and 2(16.67%) mutations in intron. CONCLUSIONS The clinical phenotype of nemaline myopathy is highly heterogeneous. Muscle pathology shows that nemaline bodies aggregation is an important feature for the diagnosis of NM. NEB is the most frequent causative gene in this cohort. The splicing mutation, c.21522 + 3A > G may be the hotspot mutation of the NEB gene in Chinese NM patients.
Collapse
Affiliation(s)
- Lv Haidong
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Liu Yin
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei Province, People's Republic of China
| | - Chen Ping
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Zheng Xianzhao
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Qian Qi
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Ma Xiaoli
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Lv Zheng
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Cui Wenhao
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Zhou Yaguang
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China
| | - Qu Qianqian
- Department of Neurology, Jiaozuo People's Hospital of Henan Province, Henan, 454002, Henan Province, People's Republic of China.
| |
Collapse
|
2
|
Lehtokari VL, Similä M, Tammepuu M, Wallgren-Pettersson C, Strang-Karlsson S, Hiekkala S. Self-reported functioning among patients with ultra-rare nemaline myopathy or a related disorder in Finland: a pilot study. Orphanet J Rare Dis 2023; 18:374. [PMID: 38037113 PMCID: PMC10691147 DOI: 10.1186/s13023-023-02973-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 11/18/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND Nemaline myopathy (NM) and related disorders (NMr) form a heterogenous group of ultra-rare (1:50,000 live births or less) congenital muscle disorders. To elucidate the self-reported physical, psychological, and social functioning in the daily lives of adult persons with congenital muscle disorders, we designed a survey using items primarily from the Patient Reported Outcomes Measurement Information System, PROMIS®, and conducted a pilot study in patients with NM and NMr in Finland. The items were linked to International Classification of Functioning, Disability and Health (ICF) categories. RESULTS In total, 20 (62.5%) out of 32 invited persons resident in Finland participated in the study; 12 had NM and 8 NMr, 15 were women and 5 men aged 19-75 years. Sixteen (80%) were ambulatory and 4 (20%) NM patients used wheelchairs. The results from the PROMIS measuring system and ICF categories both indicated that non-ambulatory patients of this study faced more challenges in all areas of functioning than ambulatory ones, but the differences were smaller in the domains measuring psychological and social functioning than in physical functioning. In addition, the COVID-19 pandemic adversely affected the functioning of non-ambulatory patients more than that of ambulatory patients. The interindividual differences were, however, noticeable. CONCLUSIONS To our knowledge, this pilot study is the first comprehensive survey-based study of the physical, psychological, and social functioning of adult persons with nemaline myopathy or related disorders. The results indicate vulnerability of non-ambulatory patients being at higher risk to a decrease in general functioning during global or national exceptional periods. The responses also gave directions for modifying and improving the survey for future studies.
Collapse
Affiliation(s)
- Vilma-Lotta Lehtokari
- Folkhälsan Research Center, Helsinki, Finland.
- Medicum, University of Helsinki, Helsinki, Finland.
| | - Minna Similä
- Clinical Nutrition Unit, Internal Medicine and Rehabilitation, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Marianne Tammepuu
- Department of Paediatric Neurology, New Children's Hospital, Helsinki University Hospital, Helsinki, Finland
| | | | - Sonja Strang-Karlsson
- Department of Clinical Genetics, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sinikka Hiekkala
- The Finnish Association of People with Physical Disabilities, Helsinki, Finland
| |
Collapse
|
3
|
Moreno CAM, Artilheiro MC, Fonseca ATQSM, Camelo CG, de Medeiros GC, Sassi FC, de Andrade CRF, Donkervoort S, Silva AMS, Dalfior-Junior L, Abath-Neto OL, Reed UC, Bönnemann C, Zanoteli E. Clinical Manifestation of Nebulin-Associated Nemaline Myopathy. Neurol Genet 2023; 9:e200056. [PMID: 36714460 PMCID: PMC9879277 DOI: 10.1212/nxg.0000000000200056] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 11/28/2022] [Indexed: 01/26/2023]
Abstract
Background and Objectives Nemaline myopathy (NM) is a genetically heterogeneous inherited myopathy related with at least 12 genes, whereas pathogenic variants in NEB gene are the most common genetic cause. The clinical spectrum of NM caused by NEB pathogenic variants (NM-NEB) is very broad, ranging from mild to severe presentations manifesting with generalized weakness, as well as respiratory and bulbar involvement. There is currently not enough data regarding the progression of the disease. In this study, we present a genotypic and phenotypic spectrum of 33 patients with NM caused by NEB variants (NM-NEB) classified according to age groups and the use of ventilatory support. We focused on interventional support, genotype-phenotype correlation, and association between respiratory, bulbar, and motor systems in groups of patients stratified by age and by the use of ventilatory support (VS). Methods Clinical and genetic data from patients with NM-NEB followed up in one specialized center were collected through regular consultations. Patients were evaluated regarding motor, bulbar, and respiratory functions. Results Thirty-three patients with NM-NEB were evaluated consisting of 15 females and 18 males with an average age of 18 (±12) years and a median of 17 (±11) years. 32% of patients with NM-NEB used a G tube, 35% were not able to walk without support, and 55% needed VS. Scoliosis and dysphagia were more common among patients who used VS. Described for the first time, half of the patients presented tongue atrophy in a triple furrow pattern, and the presence of the atrophy was associated with dysphagia. Comparing the patients grouped by age, we found that, proportionally, older patients had more scoliosis and respiratory dysfunction than younger groups, suggesting the progression of the disease in these domains. In addition to that, we showed that VS use was associated with scoliosis and dysphagia. Discussion NM-NEB is a very debilitating disease. There is an association between scoliosis and respiratory dysfunction while patients using VS have more often scoliosis than the no-VS group. Triple furrow tongue atrophy is a novel and frequent finding, which is directly associated with dysphagia. Grouping patients by age suggested disease stability in motor and swallow function, but a progression in respiratory dysfunction and skeletal deformities. All observations are relevant in the management care of patients with NM.
Collapse
Affiliation(s)
- Cristiane Araujo Martins Moreno
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Mariana Cunha Artilheiro
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Alulin Tacio Quadros Santos Monteiro Fonseca
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Clara Gontijo Camelo
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Gisele Chagas de Medeiros
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Fernanda Chiarion Sassi
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Claudia Regina Furquim de Andrade
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Sandra Donkervoort
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Andre Macedo Serafim Silva
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Luiz Dalfior-Junior
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Osorio Lopes Abath-Neto
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Umbertina Conti Reed
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Carsten Bönnemann
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Edmar Zanoteli
- Department of Neurology (C.A.M.M., M.C.A., A.T.Q.S.M.F., C.G.C., A.M.S.S., U.C.R., E.Z.), School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Department of Physical Therapy (G.C.M., F.C.S., C.R.F.A.), Speech Language and Hearing Science Adn Occupational Therapy, School of Medicine, Universidade de São Paulo (FMUSP), Brazil; Neuromuscular and Neurogenetic Disorders of Childhood Section (S.D., C.B.), National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD; Department of Neurology, Hospital Santa Marcelina (L.D.J.), São Paulo, Brazil; and Department of Pathology (O.L.A.-N.), Division of Neuropathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| |
Collapse
|
4
|
Savarese M, Jokela M, Udd B. Distal myopathy. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:497-519. [PMID: 37562883 DOI: 10.1016/b978-0-323-98818-6.00002-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Distal myopathies are a group of genetic, primary muscle diseases. Patients develop progressive weakness and atrophy of the muscles of forearm, hands, lower leg, or feet. Currently, over 20 different forms, presenting a variable age of onset, clinical presentation, disease progression, muscle involvement, and histological findings, are known. Some of them are dominant and some recessive. Different variants in the same gene are often associated with either dominant or recessive forms, although there is a lack of a comprehensive understanding of the genotype-phenotype correlations. This chapter provides a description of the clinicopathologic and genetic aspects of distal myopathies emphasizing known etiologic and pathophysiologic mechanisms.
Collapse
Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Manu Jokela
- Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, Tampere, Finland; Division of Clinical Neurosciences, Department of Neurology, Turku University Hospital, Turku, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland; Neuromuscular Research Center, Department of Neurology, Tampere University and University Hospital, Tampere, Finland; Department of Neurology, Vaasa Central Hospital, Vaasa, Finland.
| |
Collapse
|
5
|
Laitila J, Wallgren-Pettersson C. Recent advances in nemaline myopathy. Neuromuscul Disord 2021; 31:955-967. [PMID: 34561123 DOI: 10.1016/j.nmd.2021.07.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 11/18/2022]
Abstract
The nemaline myopathies constitute a large proportion of the congenital or structural myopathies. Common to all patients is muscle weakness and the presence in the muscle biopsy of nemaline rods. The causative genes are at least twelve, encoding structural or regulatory proteins of the thin filament, and the clinical picture as well as the histological appearance on muscle biopsy vary widely. Here, we suggest a renewed clinical classification to replace the original one, summarise what is known about the pathogenesis from mutations in each causative gene to the forms of nemaline myopathy described to date, and provide perspectives on pathogenetic mechanisms possibly open to therapeutic modalities.
Collapse
Affiliation(s)
- Jenni Laitila
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Department of Biomedical Sciences, University of Copenhagen, Denmark.
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| |
Collapse
|
6
|
Sagath L, Lehtokari VL, Välipakka S, Vihola A, Gardberg M, Hackman P, Pelin K, Jokela M, Kiiski K, Udd B, Wallgren-Pettersson C. Congenital asymmetric distal myopathy with hemifacial weakness caused by a heterozygous large de novo mosaic deletion in nebulin. Neuromuscul Disord 2021; 31:539-545. [PMID: 33933294 DOI: 10.1016/j.nmd.2021.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 11/25/2022]
Abstract
We report the first mosaic mutation, a deletion of exons 11-107, identified in the nebulin gene in a Finnish patient presenting with a predominantly distal congenital myopathy and asymmetric muscle weakness. The female patient is ambulant and currently 26 years old. Muscle biopsies showed myopathic features with type 1 fibre predominance, strikingly hypotrophic type 2 fibres and central nuclei, but no nemaline bodies. The deletion was detected in a copy number variation analysis based on next-generation sequencing data. The parents of the patient did not carry the deletion. Mosaicism was detected using a custom, targeted comparative genomic hybridisation array. Expression of the truncated allele, less than half the size of full-length nebulin, was confirmed by Western blotting. The clinical and histological picture resembled that of a family with a slightly smaller deletion, and that in patients with recessively inherited distal forms of nebulin-caused myopathy. Asymmetry, however, was a novel feature.
Collapse
Affiliation(s)
- Lydia Sagath
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland.
| | - Vilma-Lotta Lehtokari
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| | - Salla Välipakka
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| | - Anna Vihola
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Neuromuscular Research Centre, Fimlab Laboratories, Tampere University and University Hospital, Tampere, Finland
| | - Maria Gardberg
- Department of Pathology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| | - Katarina Pelin
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Manu Jokela
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland; Laboratory of Genetics, HUS Diagnostic Centre, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Kirsi Kiiski
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Laboratory of Genetics, HUS Diagnostic Centre, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland; Neuromuscular Research Centre, Tampere University and University Hospital, Tampere, Finland; Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Research Center, Helsinki, Finland; Department of Medical Genetics, Medicum, University of Helsinki, Finland
| |
Collapse
|
7
|
Savarese M, Välipakka S, Johari M, Hackman P, Udd B. Is Gene-Size an Issue for the Diagnosis of Skeletal Muscle Disorders? J Neuromuscul Dis 2021; 7:203-216. [PMID: 32176652 PMCID: PMC7369045 DOI: 10.3233/jnd-190459] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human genes have a variable length. Those having a coding sequence of extraordinary length and a high number of exons were almost impossible to sequence using the traditional Sanger-based gene-by-gene approach. High-throughput sequencing has partly overcome the size-related technical issues, enabling a straightforward, rapid and relatively inexpensive analysis of large genes. Several large genes (e.g. TTN, NEB, RYR1, DMD) are recognized as disease-causing in patients with skeletal muscle diseases. However, because of their sheer size, the clinical interpretation of variants in these genes is probably the most challenging aspect of the high-throughput genetic investigation in the field of skeletal muscle diseases. The main aim of this review is to discuss the technical and interpretative issues related to the diagnostic investigation of large genes and to reflect upon the current state of the art and the future advancements in the field.
Collapse
Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Salla Välipakka
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland.,Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland.,Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
| |
Collapse
|
8
|
Savarese M, Sarparanta J, Vihola A, Jonson PH, Johari M, Rusanen S, Hackman P, Udd B. Panorama of the distal myopathies. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2020; 39:245-265. [PMID: 33458580 PMCID: PMC7783427 DOI: 10.36185/2532-1900-028] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Distal myopathies are genetic primary muscle disorders with a prominent weakness at onset in hands and/or feet. The age of onset (from early childhood to adulthood), the distribution of muscle weakness (upper versus lower limbs) and the histological findings (ranging from nonspecific myopathic changes to myofibrillar disarrays and rimmed vacuoles) are extremely variable. However, despite being characterized by a wide clinical and genetic heterogeneity, the distal myopathies are a category of muscular dystrophies: genetic diseases with progressive loss of muscle fibers. Myopathic congenital arthrogryposis is also a form of distal myopathy usually caused by focal amyoplasia. Massive parallel sequencing has further expanded the long list of genes associated with a distal myopathy, and contributed identifying as distal myopathy-causative rare variants in genes more often related with other skeletal or cardiac muscle diseases. Currently, almost 20 genes (ACTN2, CAV3, CRYAB, DNAJB6, DNM2, FLNC, HNRNPA1, HSPB8, KHLH9, LDB3, MATR3, MB, MYOT, PLIN4, TIA1, VCP, NOTCH2NLC, LRP12, GIPS1) have been associated with an autosomal dominant form of distal myopathy. Pathogenic changes in four genes (ADSSL, ANO5, DYSF, GNE) cause an autosomal recessive form; and disease-causing variants in five genes (DES, MYH7, NEB, RYR1 and TTN) result either in a dominant or in a recessive distal myopathy. Finally, a digenic mechanism, underlying a Welander-like form of distal myopathy, has been recently elucidated. Rare pathogenic mutations in SQSTM1, previously identified with a bone disease (Paget disease), unexpectedly cause a distal myopathy when combined with a common polymorphism in TIA1. The present review aims at describing the genetic basis of distal myopathy and at summarizing the clinical features of the different forms described so far.
Collapse
Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Jaakko Sarparanta
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Anna Vihola
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Neuromuscular Research Center, Department of Genetics, Fimlab Laboratories, Tampere, Finland
| | - Per Harald Jonson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Salla Rusanen
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
| |
Collapse
|
9
|
Wang H, Nie X, Li X, Fang Y, Wang D, Wang W, Hu Y, Liu Z, Cao C. Bioinformatics Analysis and High-Throughput Sequencing to Identify Differentially Expressed Genes in Nebulin Gene (NEB) Mutations Mice. Med Sci Monit 2020; 26:e922953. [PMID: 32390000 PMCID: PMC7241215 DOI: 10.12659/msm.922953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND High-throughput sequencing of the pathological tissue of 59 patients with thyroid cancer was compared with the normal population. It was found that the mutation frequency of the Nebulin gene (NEB) at amino acid 1133 locus of thyroid cancer patients was much higher than that of the normal population, suggesting that NEB mutation may be related to thyroid cancer. Therefore, we constructed the NEB mutant mice for further investigation. MATERIAL AND METHODS The RNA extracted from the thyroid of wild-type and NEB mutant mice was analyzed by high-throughput sequencing, and the differential expression was analyzed by edgeR software. Several differentially expressed genes were selected for quantitative real-time PCR (qRT-PCR) verification, and these genes were analyzed with Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. RESULTS A total of 624 genes were significantly enriched. Analysis of GO function and pathway significant enrichment showed that differentially expressed genes were enriched in thyroid cancer, myocardial contraction, and autoimmune thyroid disease. The qRT-PCR results were consistent with the high-throughput sequencing results. CONCLUSIONS Our data indicate that the expression of some cancer-driving genes and cancer suppressor genes are significantly changed in NEB mutant mice compared to wild-type mice, which suggests that NEB function plays an important role in regulating the expression of cancer-related genes in the thyroid gland.
Collapse
Affiliation(s)
- Haoyong Wang
- School of Food Biological Engineering, Hubei University of Technology, Wuhan, Hubei, China (mainland)
| | - Xiaoyue Nie
- School of Food Biological Engineering, Hubei University of Technology, Wuhan, Hubei, China (mainland)
| | - Xin Li
- School of Food Biological Engineering, Hubei University of Technology, Wuhan, Hubei, China (mainland)
| | - Yi Fang
- Department of Endocrinology, The Fifth Medical Center, Chinese People's Liberation Army (PLA) General Hospital, Beijing, China (mainland)
| | - Dandan Wang
- Department of Endocrinology, The Fifth Medical Center, Chinese People's Liberation Army (PLA) General Hospital, Beijing, China (mainland)
| | | | - Yong Hu
- Laboratory of Genetic Engineering, Beijing Institute of Biotechnology, Beijing, China (mainland)
| | - Zijing Liu
- Laboratory of Genetic Engineering, Beijing Institute of Biotechnology, Beijing, China (mainland)
| | - Cheng Cao
- Laboratory of Genetic Engineering, Beijing Institute of Biotechnology, Beijing, China (mainland)
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW Congenital muscular dystrophies and congenital myopathies are a heterogeneous group of disorders resulting in hypotonia, muscle weakness, and dystrophic or myopathic features on muscle biopsy. This article summarizes the clinical and genetic aspects of these disorders. RECENT FINDINGS Historically, diagnoses of congenital muscular dystrophy and congenital myopathy have been made by clinical features and histopathology; however, recent advances in genetics have changed diagnostic practice by relying more heavily on genetic findings. This article reviews the clinical and genetic features of the most common congenital muscular dystrophies including laminin subunit alpha 2 (LAMA2)-related (merosin deficient), collagen VI-related, and α-dystroglycan-related congenital muscular dystrophies and reviews the most common congenital myopathies including nemaline rod, core, and centronuclear myopathies. With the increasing accessibility of genetic testing, the number of genes found to be associated with these disorders has increased dramatically. A wide spectrum of severity and onset (from birth to adulthood) exist across all subtypes. Progression and other features are variable depending on the subtype and severity of the specific genetic mutation. SUMMARY Congenital muscular dystrophy and congenital myopathy are increasingly recognized disorders. A growing appreciation for the breadth of phenotypic variability and overlap between established subtypes has challenged long-standing phenotypic and histopathologic classifications of these disorders but has driven a greater understanding of pathogenesis and opened the door to the development of novel treatments.
Collapse
|
11
|
Laitila JM, McNamara EL, Wingate CD, Goullee H, Ross JA, Taylor RL, van der Pijl R, Griffiths LM, Harries R, Ravenscroft G, Clayton JS, Sewry C, Lawlor MW, Ottenheijm CAC, Bakker AJ, Ochala J, Laing NG, Wallgren-Pettersson C, Pelin K, Nowak KJ. Nebulin nemaline myopathy recapitulated in a compound heterozygous mouse model with both a missense and a nonsense mutation in Neb. Acta Neuropathol Commun 2020; 8:18. [PMID: 32066503 PMCID: PMC7027239 DOI: 10.1186/s40478-020-0893-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 02/05/2020] [Indexed: 12/31/2022] Open
Abstract
Nemaline myopathy (NM) caused by mutations in the gene encoding nebulin (NEB) accounts for at least 50% of all NM cases worldwide, representing a significant disease burden. Most NEB-NM patients have autosomal recessive disease due to a compound heterozygous genotype. Of the few murine models developed for NEB-NM, most are Neb knockout models rather than harbouring Neb mutations. Additionally, some models have a very severe phenotype that limits their application for evaluating disease progression and potential therapies. No existing murine models possess compound heterozygous Neb mutations that reflect the genotype and resulting phenotype present in most patients. We aimed to develop a murine model that more closely matched the underlying genetics of NEB-NM, which could assist elucidation of the pathogenetic mechanisms underlying the disease. Here, we have characterised a mouse strain with compound heterozygous Neb mutations; one missense (p.Tyr2303His), affecting a conserved actin-binding site and one nonsense mutation (p.Tyr935*), introducing a premature stop codon early in the protein. Our studies reveal that this compound heterozygous model, NebY2303H, Y935X, has striking skeletal muscle pathology including nemaline bodies. In vitro whole muscle and single myofibre physiology studies also demonstrate functional perturbations. However, no reduction in lifespan was noted. Therefore, NebY2303H,Y935X mice recapitulate human NEB-NM and are a much needed addition to the NEB-NM mouse model collection. The moderate phenotype also makes this an appropriate model for studying NEB-NM pathogenesis, and could potentially be suitable for testing therapeutic applications.
Collapse
|
12
|
Abstract
Nebulin, encoded by NEB, is a giant skeletal muscle protein of about 6669 amino acids which forms an integral part of the sarcomeric thin filament. In recent years, the nebula around this protein has been largely lifted resulting in the discovery that nebulin is critical for a number of tasks in skeletal muscle. In this review, we firstly discussed nebulin’s role as a structural component of the thin filament and the Z-disk, regulating the length and the mechanical properties of the thin filament as well as providing stability to myofibrils by interacting with structural proteins within the Z-disk. Secondly, we reviewed nebulin’s involvement in the regulation of muscle contraction, cross-bridge cycling kinetics, Ca2+-homeostasis and excitation contraction (EC) coupling. While its role in Ca2+-homeostasis and EC coupling is still poorly understood, a large number of studies have helped to improve our knowledge on how nebulin affects skeletal muscle contractile mechanics. These studies suggest that nebulin affects the number of force generating actin-myosin cross-bridges and may also affect the force that each cross-bridge produces. It may exert this effect by interacting directly with actin and myosin and/or indirectly by potentially changing the localisation and function of the regulatory complex (troponin and tropomyosin). Besides unravelling the biology of nebulin, these studies are particularly helpful in understanding the patho-mechanism of myopathies caused by NEB mutations, providing knowledge which constitutes the critical first step towards the development of therapeutic interventions. Currently, effective treatments are not available, although a number of therapeutic strategies are being investigated.
Collapse
|
13
|
Qiu B, Ruston J, Granzier H, Justice MJ, Dowling JJ. Failure to identify modifiers of NEBULIN-related nemaline myopathy in two pre-clinical models of the disease. Biol Open 2019; 8:bio.044867. [PMID: 31530540 PMCID: PMC6777365 DOI: 10.1242/bio.044867] [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] [Indexed: 01/17/2023] Open
Abstract
Nemaline myopathy is a rare neuromuscular disorder that affects 1 in 50,000 live births, with prevalence as high as 1 in 20,000 in certain populations. 13 genes have been linked to nemaline myopathy (NM), all of which are associated with the thin filament of the muscle sarcomere. Of the 13 associated genes, mutations in NEBULIN (NEB) accounts for up to 50% of all cases. Currently, the disease is incompletely understood and there are no available therapeutics for patients. To address this urgent need for effective treatments for patients affected by NM, we conducted a large scale chemical screen in a zebrafish model of NEB-related NM and an N-ethyl-N-nitrosourea (ENU)-based genetic screen in a mouse model of NEB exon 55 deletion, the most common NEB mutation in NM patients. Neither screen was able to identify a candidate for therapy development, highlighting the need to transition from conventional chemical therapeutics to gene-based therapies for the treatment of NM. Summary: NEBULIN-related nemaline myopathy currently has no treatment. We attempted to uncover new avenues for therapy by performing modifier screens, which unfortunately failed to identify modifiers that improved disease relevant phenotypes.
Collapse
Affiliation(s)
- Boyang Qiu
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - Julie Ruston
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Henk Granzier
- Department of Physiology, University of Arizona, Tuscon, Arizona 85724, USA
| | - Monica J Justice
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada .,Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
14
|
Marttila M, Win W, Al-Ghamdi F, Abdel-Hamid HZ, Lacomis D, Beggs AH. MYL2-associated congenital fiber-type disproportion and cardiomyopathy with variants in additional neuromuscular disease genes; the dilemma of panel testing. Cold Spring Harb Mol Case Stud 2019; 5:mcs.a004184. [PMID: 31127036 PMCID: PMC6672024 DOI: 10.1101/mcs.a004184] [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: 03/11/2019] [Accepted: 05/16/2019] [Indexed: 12/13/2022] Open
Abstract
Next-generation sequencing has led to transformative advances in our ability to diagnose rare diseases by simultaneously sequencing dozens, hundreds, or even entire genomes worth of genes to efficiently identify pathogenic mutations. These studies amount to multiple hypothesis testing on a massive scale and not infrequently lead to discovery of multiple genetic variants whose relative contributions to a patient's disease are unclear. Panel testing, in particular, can be problematic because each of the many genes being sequenced might represent a plausible explanation for a given case. We performed targeted gene panel analysis of 43 established neuromuscular disease genes in a patient with congenital fiber-type disproportion (CFTD) and fatal infantile cardiomyopathy. Initial review of variants identified changes in four genes that could be considered relevant candidates to cause this child's disease. Further analysis revealed that two of these are likely benign, but a homozygous frameshift variant in the myosin light chain 2 gene, MYL2, and a heterozygous nonsense mutation in the nebulin gene, NEB, met criteria to be classified as likely pathogenic or pathogenic. Recessive MYL2 mutations are a rare cause of CFTD associated with both skeletal and cardiomyopathy, whereas recessive NEB mutations cause nemaline myopathy. Although the proband's phenotype is likely largely explained by the MYL2 variant, the heterozygous pathogenic NEB variant cannot be ruled out as a contributing factor. This case illustrates the complexity when analyzing large numbers of variants from targeted gene panels in which each of the genes might plausibly contribute to the patient's clinical presentation.
Collapse
Affiliation(s)
- Minttu Marttila
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Wathone Win
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Fouad Al-Ghamdi
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.,King Fahad Specialist Hospital, Dammam 32253, Saudi Arabia
| | - Hoda Z Abdel-Hamid
- Department of Pediatrics, Child Neurology Division, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.,Pediatric MDA Clinic, Division of Child Neurology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania 15224, USA
| | - David Lacomis
- Neuromuscular Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
15
|
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
|
16
|
Dominantly inherited distal nemaline/cap myopathy caused by a large deletion in the nebulin gene. Neuromuscul Disord 2018; 29:97-107. [PMID: 30679003 DOI: 10.1016/j.nmd.2018.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/29/2018] [Accepted: 12/16/2018] [Indexed: 11/20/2022]
Abstract
We report the first family with a dominantly inherited mutation of the nebulin gene (NEB). This ∼100 kb in-frame deletion encompasses NEB exons 14-89, causing distal nemaline/cap myopathy in a three-generation family. It is the largest deletion characterized in NEB hitherto. The mutated allele was shown to be expressed at the mRNA level and furthermore, for the first time, a deletion was shown to cause the production of a smaller mutant nebulin protein. Thus, we suggest that this novel mutant nebulin protein has a dominant-negative effect, explaining the first documented dominant inheritance of nebulin-caused myopathy. The index patient, a young man, was more severely affected than his mother and grandmother. His first symptom was foot drop at the age of three, followed by distal muscle atrophy, slight hypomimia, high-arched palate, and weakness of the neck and elbow flexors, hands, tibialis anterior and toe extensors. Muscle biopsies showed myopathic features with type 1 fibre predominance in the index patient and nemaline bodies and cap-like structures in biopsies from his mother and grandmother. The muscle biopsy findings constitute a further example of nemaline bodies and cap-like structures being part of the same spectrum of pathological changes.
Collapse
|
17
|
Laitila J, Lehtonen J, Lehtokari VL, Sagath L, Wallgren-Pettersson C, Grönholm M, Pelin K. A nebulin super-repeat panel reveals stronger actin binding toward the ends of the super-repeat region. Muscle Nerve 2018; 59:116-121. [PMID: 30265400 DOI: 10.1002/mus.26350] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 08/27/2018] [Accepted: 09/23/2018] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Nebulin is a giant actin-binding protein in the thin filament of the skeletal muscle sarcomere. Studies of nebulin interactions are limited by the size, complexity, and poor solubility of the protein. We divided the nebulin super-repeat region into a super-repeat panel, and studied nebulin/actin interactions. METHODS Actin binding was studied using a co-sedimentation assay with filamentous actin and 26 different nebulin super-repeats. RESULTS The panel revealed notable differences in actin binding between the super-repeats. Both ends of the super-repeat region bound actin significantly more strongly, whereas the central part of the protein bound actin weakly. Thus, the binding between nebulin and actin formed a location-dependent pattern of strong vs. weak binding. DISCUSSION The nebulin super-repeat panel allowed us to study the actin binding of each super-repeat individually. The panel will be a powerful tool in elucidating nebulin function in health and disease. Muscle Nerve 59:116-121, 2019.
Collapse
Affiliation(s)
- Jenni Laitila
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland
| | - Johanna Lehtonen
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland
| | - Vilma-Lotta Lehtokari
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland
| | - Lydia Sagath
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland
| | - Mikaela Grönholm
- Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Katarina Pelin
- The Folkhälsan Institute of Genetics and Department of Medical and Clinical Genetics, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014, Helsinki, Finland.,Faculty of Biological and Environmental Sciences, Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| |
Collapse
|
18
|
Kawai M, Karam TS, Kolb J, Wang L, Granzier HL. Nebulin increases thin filament stiffness and force per cross-bridge in slow-twitch soleus muscle fibers. J Gen Physiol 2018; 150:1510-1522. [PMID: 30301869 PMCID: PMC6219688 DOI: 10.1085/jgp.201812104] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/19/2018] [Indexed: 01/15/2023] Open
Abstract
Nebulin stabilizes the thin filament and regulates force generation in skeletal muscle, but its precise role is not understood. Using conditional knockout mice, Kawai et al. demonstrate that nebulin functions to increase the force per cross-bridge in skinned slow-twitch soleus muscle fibers. Nebulin (Neb) is associated with the thin filament in skeletal muscle cells, but its functions are not well understood. For this goal, we study skinned slow-twitch soleus muscle fibers from wild-type (Neb+) and conditional Neb knockout (Neb−) mice. We characterize cross-bridge (CB) kinetics and the elementary steps of the CB cycle by sinusoidal analysis during full Ca2+ activation and observe that Neb increases active tension 1.9-fold, active stiffness 2.7-fold, and rigor stiffness 3.0-fold. The ratio of stiffness during activation and rigor states is 62% in Neb+ fibers and 68% in Neb− fibers. These are approximately proportionate to the number of strongly attached CBs during activation. Because the thin filament length is 15% shorter in Neb− fibers than in Neb+ fibers, the increase in force per CB in the presence of Neb is ∼1.5 fold. The equilibrium constant of the CB detachment step (K2), its rate (k2), and the rate of the reverse force generation step (k−4) are larger in Neb+ fibers than in Neb− fibers. The rates of the force generation step (k4) and the reversal detachment step (k−2) change in the opposite direction. These effects can be explained by Le Chatelier’s principle: Increased CB strain promotes less force-generating state(s) and/or detached state(s). Further, when CB distributions among the six states are calculated, there is no significant difference in the number of strongly attached CBs between fibers with and without Neb. These results demonstrate that Neb increases force per CB. We also confirm that force is generated by isomerization of actomyosin (AM) from the AM.ADP.Pi state (ADP, adenosine diphophate; Pi, phosphate) to the AM*ADP.Pi state, where the same force is maintained after Pi release to result in the AM*ADP state. We propose that Neb changes the actin (and myosin) conformation for better ionic and hydrophobic/stereospecific AM interaction, and that the effect of Neb is similar to that of tropomyosin.
Collapse
Affiliation(s)
- Masataka Kawai
- Departments of Anatomy and Cell Biology, and Internal Medicine, College of Medicine, University of Iowa, Iowa City, IA
| | - Tarek S Karam
- Departments of Anatomy and Cell Biology, and Internal Medicine, College of Medicine, University of Iowa, Iowa City, IA
| | - Justin Kolb
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ
| | - Li Wang
- Departments of Anatomy and Cell Biology, and Internal Medicine, College of Medicine, University of Iowa, Iowa City, IA.,School of Nursing, Soochow University, Suzhou, China
| | - Henk L Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ
| |
Collapse
|
19
|
Nebulin stiffens the thin filament and augments cross-bridge interaction in skeletal muscle. Proc Natl Acad Sci U S A 2018; 115:10369-10374. [PMID: 30249654 PMCID: PMC6187167 DOI: 10.1073/pnas.1804726115] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nebulin is a giant sarcomeric protein that spans along the actin filament in skeletal muscle, from the Z-disk to near the thin filament pointed end. Mutations in nebulin cause muscle weakness in nemaline myopathy patients, suggesting that nebulin plays important roles in force generation, yet little is known about nebulin's influence on thin filament structure and function. Here, we used small-angle X-ray diffraction and compared intact muscle deficient in nebulin (using a conditional nebulin-knockout, Neb cKO) with control (Ctrl) muscle. When muscles were activated, the spacing of the actin subunit repeat (27 Å) increased in both genotypes; when converted to thin filament stiffness, the obtained value was 30 pN/nm in Ctrl muscle and 10 pN/nm in Neb cKO muscle; that is, the thin filament was approximately threefold stiffer when nebulin was present. In contrast, the thick filament stiffness was not different between the genotypes. A significantly shorter left-handed (59 Å) thin filament helical pitch was found in passive and contracting Neb cKO muscles, as well as impaired tropomyosin and troponin movement. Additionally, a reduced myosin mass transfer toward the thin filament in contracting Neb cKO muscle was found, suggesting reduced cross-bridge interaction. We conclude that nebulin is critically important for physiological force levels, as it greatly stiffens the skeletal muscle thin filament and contributes to thin filament activation and cross-bridge recruitment.
Collapse
|
20
|
Abstract
PURPOSE OF REVIEW This article uses a case-based approach to highlight the clinical features as well as recent advances in molecular genetics, muscle imaging, and pathophysiology of the congenital myopathies. RECENT FINDINGS Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by early-onset muscle weakness, hypotonia, and developmental delay. Congenital myopathies are further classified into core myopathies, centronuclear myopathies, nemaline myopathies, and congenital fiber-type disproportion based on the key pathologic features found in muscle biopsies. Genotype and phenotype correlations are hampered by the diverse clinical variability of the genes responsible for congenital myopathies, ranging from a severe neonatal course with early death to mildly affected adults with late-onset disease. An increasing number of genes have been identified, which, in turn, are associated with overlapping morphologic changes in the myofibers. Precise genetic diagnosis has important implications for disease management, including family counseling; avoidance of anesthetic-related muscle injury for at-risk individuals; monitoring for potential cardiac, respiratory, or orthopedic complications; as well as for participation in clinical trials or potential genetic therapies. SUMMARY Collaboration with neuromuscular experts, geneticists, neuroradiologists, neuropathologists, and other specialists is needed to ensure accurate and timely diagnosis based on clinical and pathologic features. An integrated multidisciplinary model of care based on expert-guided standards will improve quality of care and optimize outcomes for patients and families with congenital myopathies.
Collapse
MESH Headings
- Adult
- Child
- Child, Preschool
- Female
- Genetic Therapy/trends
- Humans
- Infant
- Infant, Newborn
- Male
- Mutation/genetics
- Myopathies, Nemaline/genetics
- Myopathies, Nemaline/pathology
- Myopathies, Nemaline/therapy
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/pathology
- Myopathies, Structural, Congenital/therapy
Collapse
|
21
|
Abstract
PURPOSE OF REVIEW This article reviews adult presentations of the major congenital myopathies - central core disease, multiminicore disease, centronuclear myopathy and nemaline myopathy - with an emphasis on common genetic backgrounds, typical clinicopathological features and differential diagnosis. RECENT FINDINGS The congenital myopathies are a genetically heterogeneous group of conditions with characteristic histopathological features. Although essentially considered paediatric conditions, some forms - in particular those due to dominant mutations in the skeletal muscle ryanodine receptor (RYR1), the dynamin 2 (DNM2), the amphiphysin 2 (BIN1) and the Kelch repeat-and BTB/POZ domain-containing protein 13 (KBTBD13) gene - may present late into adulthood. Moreover, dominant RYR1 mutations associated with the malignant hyperthermia susceptibility trait have been recently identified as a common cause of (exertional) rhabdomyolysis presenting throughout life. In addition, improved standards of care and development of new therapies will result in an increasing number of patients with early-onset presentations transitioning to the adult neuromuscular clinic. Lastly, if nemaline rods are the predominant histopathological feature, acquired treatable conditions have to be considered in the differential diagnosis. SUMMARY Recently identified genotypes and phenotypes indicate a spectrum of the congenital myopathies extending into late adulthood, with important implications for clinical practice.
Collapse
|
22
|
Bugiardini E, Morrow JM, Shah S, Wood CL, Lynch DS, Pitmann AM, Reilly MM, Houlden H, Matthews E, Parton M, Hanna MG, Straub V, Yousry TA. The Diagnostic Value of MRI Pattern Recognition in Distal Myopathies. Front Neurol 2018; 9:456. [PMID: 29997562 PMCID: PMC6028608 DOI: 10.3389/fneur.2018.00456] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 05/29/2018] [Indexed: 12/14/2022] Open
Abstract
Objective: Distal myopathies are a diagnostically challenging group of diseases. We wanted to understand the value of MRI in the current clinical setting and explore the potential for optimizing its clinical application. Methods: We retrospectively audited the diagnostic workup in a distal myopathy patient cohort, reassessing the diagnosis, whilst documenting the usage of MRI. We established a literature based distal myopathies MRI pattern template and assessed its diagnostic utility in terms of sensitivity, specificity, and potential impact on the diagnostic workup. Results: Fifty-five patients were included; in 38 with a comprehensive set of data the diagnostic work-up was audited. The median time from symptoms onset to diagnosis was 12.1 years. The initial genetic diagnostic rate was 39%; 18% were misdiagnosed as neuropathies and 13% as inclusion body myositis (IBM). Based on 21 publications we established a MRI pattern template. Its overall sensitivity (50%) and specificity (32%) were low. However in some diseases (e.g., MYOT-related myopathy, TTN-HMERF) MRI correctly identified the causative gene. The number of genes suggested by MRI pattern analysis was smaller compared to clinical work up (median 1 vs. 9, p < 0.0001) but fewer genes were correctly predicted (5/10 vs. 7/10). MRI analysis ruled out IBM in all cases. Conclusion: In the diagnostic work-up of distal myopathies, MRI is useful in assisting genetic testing and avoiding misdiagnosis (IBM). The overall low sensitivity and specificity limits its generalized use when traditional single gene test methods are applied. However, in the context of next generation sequencing MRI may represent a valuable tool for interpreting complex genetic results.
Collapse
Affiliation(s)
- Enrico Bugiardini
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Jasper M. Morrow
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Sachit Shah
- Neuroradiological Academic Unit, UCL Institute of Neurology, London, United Kingdom
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Claire L. Wood
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle upon Tyne, United Kingdom
| | - David S. Lynch
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Alan M. Pitmann
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Mary M. Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Emma Matthews
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Matt Parton
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Michael G. Hanna
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle upon Tyne, United Kingdom
| | - Tarek A. Yousry
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom
- Neuroradiological Academic Unit, UCL Institute of Neurology, London, United Kingdom
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom
- *Correspondence: Tarek A. Yousry
| |
Collapse
|
23
|
Mizuno Y, Mori-Yoshimura M, Oya Y, Nishikawa A, Nishino I, Takahashi Y. [Two cases of nemaline myopathy presenting with hypertrophy of distal limbs with prominent asymmetry]. Rinsho Shinkeigaku 2017; 57:691-697. [PMID: 29070751 DOI: 10.5692/clinicalneurol.cn-001024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nemaline myopathy commonly presents with symmetrical proximal weakness. Here we report two cases of nemaline myopathy presenting with distal dominant involvement with prominent asymmetry. Case 1 was a 37-year-old man who recalled frequently falling down and had right calf atrophy since he was 3-years-old. He had right calf muscle atrophy and weakness and steppage gait; his cardiopulmonary function was normal. Case 2 was a 35-year-old man with right calf muscle atrophy and weakness since childhood. He had right dominant distal leg weakness and atrophy together with respiratory failure and started noninvasive positive pressure ventilation. He also developed cardiomyopathy and died from acute respiratory failure due to pneumonia at age 39. Both cases harbored compound heterozygous nebulin (NEB) mutations with c.20131 C>T:p.Arg6711Trp and a nonsense mutation. Nemaline myopathy associated with NEB mutations can present as distal dominant myopathy with prominent asymmetry.
Collapse
Affiliation(s)
- Yukio Mizuno
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry.,Department of Neurology, Yokohama Asahi Chuo General Hospital
| | - Madoka Mori-Yoshimura
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| | - Yasushi Oya
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| | - Atsuko Nishikawa
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry.,Department of Genome Medicine Development, Medical Genome Center, National Center of Neurology and Psychiatry
| | - Yuji Takahashi
- Department of Neurology, National Center Hospital, National Center of Neurology and Psychiatry
| |
Collapse
|
24
|
Lee JM, Lim JG, Shin JH, Park YE, Kim DS. Clinical and genetic diversity of nemaline myopathy from a single neuromuscular center in Korea. J Neurol Sci 2017; 383:61-68. [PMID: 29246625 DOI: 10.1016/j.jns.2017.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/19/2017] [Accepted: 10/09/2017] [Indexed: 11/17/2022]
Abstract
Nemaline myopathy (NM), the most common of the congenital myopathies, is caused by various genetic mutations. In this study, we attempted to identify the causative mutations of NM and to reveal any specific genotype-phenotype relationship in Korean patients with this disease. We investigated the clinical features and genotypes in 15 pathologically diagnosed NM patients, using whole exome sequencing (WES) combined with targeted sequencing and array-based comparative genomic hybridization. This strategy revealed pathogenic causative mutations in seven patients (46.7%), among whom mutations in the nebulin gene (NEB) were the most frequent (5 patients, 33.3%). Copy number variation (CNV) abnormality in NEB was not observed in any of our patients. In those with NEB-associated NM, the clinical spectrum was highly variable regardless of the mutation type. However, the majority of patients showing anterior lower leg weakness were associated with mutations located between NEB exons 166 and 177. We concluded that the combination of WES and targeted Sanger sequencing is an effective strategy for analyzing genotypes in patients with NM, and that CNV in NEB may not be a frequent cause of this disease among Koreans.
Collapse
Affiliation(s)
- Jong-Mok Lee
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea
| | - Jeong Geun Lim
- Department of Neurology, Keimyung University School of Medicine, Republic of Korea
| | - Jin-Hong Shin
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea
| | - Young-Eun Park
- Department of Neurology, Pusan National University School of Medicine, Republic of Korea
| | - Dae-Seong Kim
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Republic of Korea; Department of Neurology, Pusan National University School of Medicine, Republic of Korea.
| |
Collapse
|
25
|
Abdalla E, Ravenscroft G, Zayed L, Beecroft SJ, Laing NG. Lethal multiple pterygium syndrome: A severe phenotype associated with a novel mutation in the nebulin gene. Neuromuscul Disord 2017; 27:537-541. [DOI: 10.1016/j.nmd.2017.01.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 11/21/2016] [Accepted: 01/15/2017] [Indexed: 11/27/2022]
|
26
|
Park YE, Shin JH, Kang B, Lee CH, Kim DS. NEB-related core-rod myopathy with distinct clinical and pathological features. Muscle Nerve 2016; 53:479-84. [PMID: 26562614 DOI: 10.1002/mus.24966] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2015] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Mutations in the gene encoding nebulin (NEB) are known to cause several types of congenital myopathy including recessive nemaline myopathy and distal nebulin myopathy. Core-rod myopathy has recently been reported to be another type of NEB-related myopathy, and is pathologically characterized by the coexistence of cores and nemaline rods within muscle fibers. METHODS We describe 2 patients with core-rod myopathy who were analyzed genetically by whole exome sequencing and evaluated clinically and pathologically. Findings were compared with those of patients with the disease of other genetic causes. RESULTS Three NEB mutations were identified, 2 of which were novel. Mild clinical features, unusual patterns of muscle involvement, and atypical pathological findings were observed. CONCLUSIONS We propose that the clinical and pathological spectrum of core-rod myopathy should be widened. A significant amount of residual nebulin expression is believed to contribute to the much milder phenotype exhibited by the patients we describe here.
Collapse
Affiliation(s)
- Young-Eun Park
- Department of Neurology, Pusan National University Yangsan Hospital, Beomo-ri, Mulgeum-eup, Yangsan, 626-770, Gyeongnam, South Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea
| | - Jin-Hong Shin
- Department of Neurology, Pusan National University Yangsan Hospital, Beomo-ri, Mulgeum-eup, Yangsan, 626-770, Gyeongnam, South Korea.,Research Institute for Convergence of Biomedical Research and Technology, Pusan National University Yangsan Hospital, Gyeongnam, South Korea
| | - Boram Kang
- Research Institute for Convergence of Biomedical Research and Technology, Pusan National University Yangsan Hospital, Gyeongnam, South Korea
| | - Chang-Hoon Lee
- Biomedical Research Institute, Pusan National University Hospital, Busan, South Korea.,Department of Pathology, Pusan National University, Busan, South Korea
| | - Dae-Seong Kim
- Department of Neurology, Pusan National University Yangsan Hospital, Beomo-ri, Mulgeum-eup, Yangsan, 626-770, Gyeongnam, South Korea.,Research Institute for Convergence of Biomedical Research and Technology, Pusan National University Yangsan Hospital, Gyeongnam, South Korea
| |
Collapse
|
27
|
Park HJ, Hong YB, Choi YC, Lee J, Kim EJ, Lee JS, Mo WM, Ki SM, Kim HI, Kim HJ, Hyun YS, Hong HD, Nam K, Jung SC, Kim SB, Kim SH, Kim DH, Oh KW, Kim SH, Yoo JH, Lee JE, Chung KW, Choi BO. ADSSL1 mutation relevant to autosomal recessive adolescent onset distal myopathy. Ann Neurol 2015; 79:231-43. [PMID: 26506222 DOI: 10.1002/ana.24550] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/07/2015] [Accepted: 10/18/2015] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Distal myopathy is a heterogeneous group of muscle diseases characterized by predominant distal muscle weakness. A study was done to identify the underlying cause of autosomal recessive adolescent onset distal myopathy. METHODS Four patients from 2 unrelated Korean families were evaluated. To isolate the genetic cause, exome sequencing was performed. In vitro and in vivo assays using myoblast cells and zebrafish models were performed to examine the ADSSL1 mutation causing myopathy pathogenesis. RESULTS Patients had an adolescent onset distal myopathy phenotype that included distal dominant weakness, facial muscle weakness, rimmed vacuoles, and mild elevation of serum creatine kinase. Exome sequencing identified completely cosegregating compound heterozygous mutations (p.D304N and p.I350fs) in ADSSL1, which encodes a muscle-specific adenylosuccinate synthase in both families. None of the controls had both mutations, and the mutation sites were located in well-conserved regions. Both the D304N and I350fs mutations in ADSSL1 led to decreased enzymatic activity. The knockdown of the Adssl1 gene significantly inhibited the proliferation of mouse myoblast cells, and the addition of human wild-type ADSSL1 reversed the reduced viability. In an adssl1 knockdown zebrafish model, muscle fibers were severely disrupted, which was evaluated by myosin expression and birefringence. In these conditions, supplementing wild-type ADSSL1 protein reversed the muscle defect. INTERPRETATION We suggest that mutations in ADSSL1 are the novel genetic cause of the autosomal recessive adolescent onset distal myopathy. This study broadens the genetic and clinical spectrum of distal myopathy and will be useful for exact molecular diagnostics.
Collapse
Affiliation(s)
- Hyung Jun Park
- Department of Neurology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, South Korea.,Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Young Bin Hong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Young-Chul Choi
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Jinho Lee
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Eun Ja Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Ji-Su Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea
| | - Won Min Mo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Soo Mi Ki
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea
| | - Hyo In Kim
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea
| | - Hye Jin Kim
- Department of Biological Science, Kongju National University, Gongju, South Korea
| | - Young Se Hyun
- Department of Biological Science, Kongju National University, Gongju, South Korea
| | - Hyun Dae Hong
- Department of Biological Science, Kongju National University, Gongju, South Korea
| | - Kisoo Nam
- Department of Chemistry, New York University, New York, NY
| | - Sung Chul Jung
- Department of Biochemistry, Ewha Womans University School of Medicine, Seoul, South Korea
| | - Sang-Beom Kim
- Department of Neurology, Kyung Hee University College of Medicine, Kangdong Hospital, Seoul, South Korea
| | - Se Hoon Kim
- Department of Pathology, Yonsei University College of Medicine, Seoul, South Korea
| | - Deok-Ho Kim
- Department of Bioengineering, University of Washington, Seattle, WA
| | - Ki-Wook Oh
- Department of Neurology, College of Medicine, Hanyang University, Seoul, South Korea
| | - Seung Hyun Kim
- Department of Neurology, College of Medicine, Hanyang University, Seoul, South Korea
| | - Jeong Hyun Yoo
- Department of Radiology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, South Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea.,Samsung Genome Institute, Samsung Medical Center, Seoul, South Korea
| | - Ki Wha Chung
- Department of Biological Science, Kongju National University, Gongju, South Korea
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.,Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, South Korea.,Neuroscience Center, Samsung Medical Center, Seoul, South Korea
| |
Collapse
|
28
|
Malfatti E, Monges S, Lehtokari VL, Schaeffer U, Abath Neto O, Kiiski K, Lubieniecki F, Taratuto AL, Wallgren-Pettersson C, Laporte J, Romero NB. Bilateral foot-drop as predominant symptom in nebulin (NEB) gene related “core-rod” congenital myopathy. Eur J Med Genet 2015; 58:556-61. [DOI: 10.1016/j.ejmg.2015.09.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/10/2015] [Accepted: 09/21/2015] [Indexed: 12/11/2022]
|
29
|
Lehtokari VL, Kiiski K, Sandaradura SA, Laporte J, Repo P, Frey JA, Donner K, Marttila M, Saunders C, Barth PG, den Dunnen JT, Beggs AH, Clarke NF, North KN, Laing NG, Romero NB, Winder TL, Pelin K, Wallgren-Pettersson C. Mutation update: the spectra of nebulin variants and associated myopathies. Hum Mutat 2015; 35:1418-26. [PMID: 25205138 DOI: 10.1002/humu.22693] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 08/29/2014] [Indexed: 12/23/2022]
Abstract
A mutation update on the nebulin gene (NEB) is necessary because of recent developments in analysis methodology, the identification of increasing numbers and novel types of variants, and a widening in the spectrum of clinical and histological phenotypes associated with this gigantic, 183 exons containing gene. Recessive pathogenic variants in NEB are the major cause of nemaline myopathy (NM), one of the most common congenital myopathies. Moreover, pathogenic NEB variants have been identified in core-rod myopathy and in distal myopathies. In this update, we present the disease-causing variants in NEB in 159 families, 143 families with NM, and 16 families with NM-related myopathies. Eighty-eight families are presented here for the first time. We summarize 86 previously published and 126 unpublished variants identified in NEB. Furthermore, we have analyzed the NEB variants deposited in the Exome Variant Server (http://evs.gs.washington.edu/EVS/), identifying that pathogenic variants are a minor fraction of all coding variants (∼7%). This indicates that nebulin tolerates substantial changes in its amino acid sequence, providing an explanation as to why variants in such a large gene result in relatively rare disorders. Lastly, we discuss the difficulties of drawing reliable genotype-phenotype correlations in NEB-associated disease.
Collapse
Affiliation(s)
- Vilma-Lotta Lehtokari
- The Folkhälsan Institute of Genetics and the Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Güttsches AK, Dekomien G, Claeys KG, von der Hagen M, Huebner A, Kley RA, Kirschner J, Vorgerd M. Two novel nebulin variants in an adult patient with congenital nemaline myopathy. Neuromuscul Disord 2015; 25:392-6. [PMID: 25740301 DOI: 10.1016/j.nmd.2015.01.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/21/2015] [Accepted: 01/30/2015] [Indexed: 12/13/2022]
Abstract
Congenital myopathies are clinically and genetically heterogeneous disorders, which often remain genetically undiagnosed for many years. Here we present a 40-year old patient with an almost lifelong history of a congenital myopathy of unknown cause. Muscle biopsy in childhood revealed mild myopathic features and rods. Clinical examination on presentation at the age of 40 revealed a facial weakness, atrophy and weakness of the arm muscles and distal leg muscles with mild contractures of the foot flexors and the right elbow. Subsequently, the nebulin gene was identified as a putative candidate gene by linkage analyses, but sequence analysis only revealed one heterozygous splice site mutation in intron 73 (c.10872+1G>T). Therefore, "Next Generation Sequencing" was performed, which revealed a second pathogenic variant in exon 145 (c.21622A>C). Compound-heterozygous carrier status was confirmed via sequence analysis of the index patient's parents. Whole body muscle MRI showed a muscle involvement as previously described in nebulin-associated myopathies. Based on biopsy material, genetic analyses and muscle MRI, we identified two novel, compound-heterozygous variants in the nebulin gene after a 30 year clinical history, which cause a classical childhood type of nemaline myopathy.
Collapse
Affiliation(s)
- Anne K Güttsches
- Neurologische Klinik, Heimer-Institut am Bergmannsheil, Ruhr-Universität Bochum, Bochum, Germany.
| | - Gabriele Dekomien
- Abteilung für Humangenetik, Ruhr-Universität Bochum, Bochum, Germany
| | - Kristl G Claeys
- Neurologische Klinik, RWTH Aachen University, Aachen, Germany; Institut für Neuropathologie, RWTH Aachen University, Aachen, Germany
| | - Maja von der Hagen
- Abteilung Neuropädiatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Angela Huebner
- Klinik für Kinder- und Jugendmedizin, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Rudolf A Kley
- Neurologische Klinik, Heimer-Institut am Bergmannsheil, Ruhr-Universität Bochum, Bochum, Germany
| | - Janbernd Kirschner
- Klinik für Neuropädiatrie und Muskelerkrankungen, Universitätskinderklinik Freiburg, Freiburg, Germany
| | - Matthias Vorgerd
- Neurologische Klinik, Heimer-Institut am Bergmannsheil, Ruhr-Universität Bochum, Bochum, Germany
| |
Collapse
|
31
|
Nowak KJ, Davis MR, Wallgren-Pettersson C, Lamont PJ, Laing NG. Clinical utility gene card for: Nemaline myopathy - update 2015. Eur J Hum Genet 2015; 23:ejhg201512. [PMID: 25712079 DOI: 10.1038/ejhg.2015.12] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 12/16/2014] [Accepted: 01/13/2015] [Indexed: 11/09/2022] Open
Affiliation(s)
- Kristen J Nowak
- Centre for Medical Research, The University of Western Australia and the Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Mark R Davis
- Department of Diagnostic Genomics, Neurogenetics Laboratory, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Carina Wallgren-Pettersson
- Department of Medical Genetics, The Folkhälsan Institute of Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Phillipa J Lamont
- Department of Diagnostic Genomics, Neurogenetics Laboratory, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Nigel G Laing
- Centre for Medical Research, The University of Western Australia and the Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
| |
Collapse
|
32
|
Marttila M, Hanif M, Lemola E, Nowak KJ, Laitila J, Grönholm M, Wallgren-Pettersson C, Pelin K. Nebulin interactions with actin and tropomyosin are altered by disease-causing mutations. Skelet Muscle 2014; 4:15. [PMID: 25110572 PMCID: PMC4126377 DOI: 10.1186/2044-5040-4-15] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/09/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Nemaline myopathy (NM) is a rare genetic muscle disorder, but one of the most common among the congenital myopathies. NM is caused by mutations in at least nine genes: Nebulin (NEB), α-actin (ACTA1), α-tropomyosin (TPM3), β-tropomyosin (TPM2), troponin T (TNNT1), cofilin-2 (CFL2), Kelch repeat and BTB (POZ) domain-containing 13 (KBTBD13), and Kelch-like family members 40 and 41 (KLHL40 and KLHL41). Nebulin is a giant (600 to 900 kDa) filamentous protein constituting part of the skeletal muscle thin filament. Around 90% of the primary structure of nebulin is composed of approximately 35-residue α-helical domains, which form super repeats that bind actin with high affinity. Each super repeat has been proposed to harbor one tropomyosin-binding site. METHODS We produced four wild-type (WT) nebulin super repeats (S9, S14, S18, and S22), 283 to 347 amino acids long, and five corresponding repeats with a patient mutation included: three missense mutations (p.Glu2431Lys, p.Ser6366Ile, and p.Thr7382Pro) and two in-frame deletions (p.Arg2478_Asp2512del and p.Val3924_Asn3929del). We performed F-actin and tropomyosin-binding experiments for the nebulin super repeats, using co-sedimentation and GST (glutathione-S-transferase) pull-down assays. We also used the GST pull-down assay to test the affinity of WT nebulin super repeats for WT α- and β-tropomyosin, and for β-tropomyosin with six patient mutations: p.Lys7del, p.Glu41Lys, p.Lys49del, p.Glu117Lys, p.Glu139del and p.Gln147Pro. RESULTS WT nebulin was shown to interact with actin and tropomyosin. Both the nebulin super repeats containing the p.Glu2431Lys mutation and nebulin super repeats lacking exon 55 (p.Arg2478_Asp2512del) showed weak affinity for F-actin compared with WT fragments. Super repeats containing the p.Ser6366Ile mutation showed strong affinity for actin. When tested for tropomyosin affinity, super repeats containing the p.Glu2431Lys mutation showed stronger binding than WT proteins to tropomyosin, and the super repeat containing the p.Thr7382Pro mutation showed weaker binding than WT proteins to tropomyosin. Super repeats containing the deletion p.Val3924_Asn3929del showed similar affinity for actin and tropomyosin as that seen with WT super repeats. Of the tropomyosin mutations, only p.Glu41Lys showed weaker affinity for nebulin (super repeat 18). CONCLUSIONS We demonstrate for the first time the existence of direct tropomyosin-nebulin interactions in vitro, and show that nebulin interactions with actin and tropomyosin are altered by disease-causing mutations in nebulin and tropomyosin.
Collapse
Affiliation(s)
- Minttu Marttila
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.,Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Mubashir Hanif
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.,Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Elina Lemola
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.,Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Kristen J Nowak
- Molecular Neurogenetics Laboratory, Centre for Medical Research, University of Western Australia, Nedlands, Australia
| | - Jenni Laitila
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.,Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Mikaela Grönholm
- Department of Biosciences, Division of Biochemistry and Biotechnology, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics, Biomedicum Helsinki, Helsinki, Finland.,Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Katarina Pelin
- Department of Biosciences, Division of Genetics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
33
|
Abstract
PURPOSE OF REVIEW This article reviews recent advances in the understanding of nemaline myopathy, with a focus on the genetic basis of the disorder, histology, and pathogenesis. RECENT FINDINGS Pathogenic mutations have been identified in eight genes and there is evidence of further genetic heterogeneity in nemaline myopathy. Clinical presentation, histological features on skeletal muscle biopsy, and pattern of changes on muscle MRI may guide prioritization of molecular genetic testing. It is anticipated that use of new technologies such as whole exome sequencing and comparative genomic hybridization will increase the number of genes associated with nemaline myopathy and the proportion of patients in whom the genetic basis of the disorder is identified. Single fiber studies and animal models continue to add to understanding of the pathogenesis of this disorder. Current management focuses on supportive treatment; however, encouraging advances are emerging for the future. SUMMARY Recent advances in understanding of nemaline myopathy have important implications for clinical practice and for genetic diagnosis of patients with nemaline myopathy.
Collapse
|
34
|
|
35
|
Scoto M, Cullup T, Cirak S, Yau S, Manzur AY, Feng L, Jacques TS, Anderson G, Abbs S, Sewry C, Jungbluth H, Muntoni F. Nebulin (NEB) mutations in a childhood onset distal myopathy with rods and cores uncovered by next generation sequencing. Eur J Hum Genet 2013; 21:1249-52. [PMID: 23443021 PMCID: PMC3798838 DOI: 10.1038/ejhg.2013.31] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 01/16/2013] [Accepted: 01/24/2013] [Indexed: 11/09/2022] Open
Abstract
Recessive nebulin (NEB) mutations are a common cause of nemaline myopathy (NM), typically characterized by generalized weakness of early-onset and nemaline rods on muscle biopsy. Exceptional adult cases with additional cores and an isolated distal weakness have been reported. The large NEB gene with 183 exons has been an obstacle for the genetic work-up. Here we report a childhood-onset case with distal weakness and a core-rod myopathy, associated with recessive NEB mutations identified by next generation sequencing (NGS). This 6-year-old boy presented with a history of gross-motor difficulties following a normal early development. He had distal leg weakness with bilateral foot drop, as well as axial muscle weakness, scoliosis and spinal rigidity; additionally he required nocturnal respiratory support. Muscle magnetic resonance (MR) imaging showed distal involvement in the medial and anterior compartment of the lower leg. A muscle biopsy featured both rods and cores. Initial targeted testing identified a heterozygous Nebulin exon 55 deletion. Further analysis using NGS revealed a frameshifting 4 bp duplication, c.24372_24375dup (P.Val8126fs), on the opposite allele. This case illustrates that NEB mutations can cause childhood onset distal NM, with additional cores on muscle biopsy and proves the diagnostic utility of NGS for myopathies, particularly when large genes are implicated.
Collapse
Affiliation(s)
| | - Thomas Cullup
- DNA Laboratory, GSTS Pathology, Guy's Hospital, London, UK
| | - Sebahattin Cirak
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health, London, UK
| | - Shu Yau
- DNA Laboratory, GSTS Pathology, Guy's Hospital, London, UK
| | - Adnan Y Manzur
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health, London, UK
| | - Lucy Feng
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health, London, UK
| | - Thomas S Jacques
- Neural Development Unit, UCL Institute of Child Health, London, UK
- Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Glenn Anderson
- Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Stephen Abbs
- DNA Laboratory, GSTS Pathology, Guy's Hospital, London, UK
| | - Caroline Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health, London, UK
- Centre for Inherited Neuromuscular Diseases, RJAH Orthopaedic NHS Foundation Trust, Oswestry, UK
| | - Heinz Jungbluth
- Clinical Neuroscience Division, IOP, King's College London, London, UK
- Department of Paediatric Neurology – Neuromuscular Service, Evelina Children's Hospital, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health, London, UK
| |
Collapse
|
36
|
Abstract
The distal myopathies are a heterogeneous group of genetic disorders defined by a predominant distal weakness at onset or throughout the evolution of the disease and by pathological data supporting a myopathic process. The number of genes associated with distal myopathies continues to increase. Fourteen distinct distal myopathies are currently defined by their gene and causative mutations, compared to just five entities delineated on clinical grounds two decades ago. The known proteins affected in the distal myopathies are of many types and include a significant number of sarcomeric proteins. The useful indicators for clinicians to direct towards a correct molecular diagnosis are the mode of inheritance, the age at onset, the pattern of muscle involvement, the serum creatine kinase level and the muscle pathology findings. This review gives an overview of the clinical and genetic characteristics of the currently identified distal myopathies with emphasis on some recent findings.
Collapse
|
37
|
Myopathies associated with β-tropomyosin mutations. Neuromuscul Disord 2012; 22:923-33. [DOI: 10.1016/j.nmd.2012.05.018] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 05/09/2012] [Accepted: 05/31/2012] [Indexed: 12/29/2022]
|
38
|
Kiiski K, Laari L, Lehtokari VL, Lunkka-Hytönen M, Angelini C, Petty R, Hackman P, Wallgren-Pettersson C, Pelin K. Targeted array comparative genomic hybridization--a new diagnostic tool for the detection of large copy number variations in nemaline myopathy-causing genes. Neuromuscul Disord 2012; 23:56-65. [PMID: 23010307 DOI: 10.1016/j.nmd.2012.07.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/16/2012] [Indexed: 11/28/2022]
Abstract
Nemaline myopathy (NM) constitutes a heterogeneous group of congenital myopathies. Mutations in the nebulin gene (NEB) are the main cause of recessively inherited NM. NEB is one of the most largest genes in human. To date, 68 NEB mutations, mainly small deletions or point mutations have been published. The only large mutation characterized is the 2.5 kb deletion of exon 55 in the Ashkenazi Jewish population. To investigate any copy number variations in this enormous gene, we designed a novel custom comparative genomic hybridization microarray, NM-CGH, targeted towards the seven known genes causative for NM. During the validation of the NM-CGH array we identified two novel deletions in two different families. The first is the largest deletion characterized in NEB to date, (∼53 kb) encompassing 24 exons. The second deletion (1 kb) covers two exons. In both families, the copy number change was the second mutation to be characterized and shown to have been inherited from one of the healthy carrier parents. In addition to these novel mutations, copy number variation was identified in four samples in three families in the triplicate region of NEB. We conclude that this method appears promising for the detection of copy number variations in NEB.
Collapse
Affiliation(s)
- K Kiiski
- The Folkhälsan Institute of Genetics and the Department of Medical Genetics, University of Helsinki, Haartman Institute, Helsinki, Finland.
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Laitila J, Hanif M, Paetau A, Hujanen S, Keto J, Somervuo P, Huovinen S, Udd B, Wallgren-Pettersson C, Auvinen P, Hackman P, Pelin K. Expression of multiple nebulin isoforms in human skeletal muscle and brain. Muscle Nerve 2012; 46:730-7. [PMID: 22941678 DOI: 10.1002/mus.23380] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2012] [Indexed: 11/11/2022]
Abstract
INTRODUCTION Nebulin is a large actin-binding protein of the skeletal muscle sarcomere. Multiple isoforms of nebulin are produced from the 183-exon-containing nebulin gene (NEB). Mutations in NEB cause nemaline myopathy, distal myopathy, and core-rod myopathy. METHODS Nebulin mRNA expression was assessed by microarrays and RT-PCR in 21 human leg muscle and 2 brain samples. Protein expression was assessed by immunohistochemistry in 5 regions of 1 brain sample. RESULTS Nebulin isoform diversity is as high in brain as in skeletal muscle. Isoforms with more than 22 super repeats seem to be more common than previously anticipated. Immunohistochemistry showed nebulin expression predominantly in the cytoplasm of pyramidal neurons but also in the cytoplasm of mainly subcortical endothelial cells. CONCLUSIONS Nebulin, as in skeletal muscle, may have a role as an actin filament stabilizer or length regulator in neurons of the human brain, although patients with NEB mutations usually have normal cognition.
Collapse
Affiliation(s)
- Jenni Laitila
- Department of Biosciences, Division of Genetics, PO Box 56, University of Helsinki, Helsinki FI-00014, Finland
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
|
41
|
Abstract
Nemaline myopathy constitutes a continuous spectrum of primary skeletal muscle disorders named after the Greek word for thread, nema. The diagnosis is based on muscle weakness, combined with visualization of nemaline bodies on muscle biopsy. The patients' muscle weakness is usually generalized, but there may be a selective pattern of more pronounced weakness, and, most importantly, respiratory muscles may be especially weak. Histologically, additional features may coexist with the nemaline bodies. There are 7 known causative genes. The function of the most recently identified gene is unknown, but the other 6 encoded proteins are associated with the muscle thin filament. The 2 most common causes of nemaline myopathy are recessive mutations in nebulin and de novo dominant mutations in skeletal muscle α-actin. At least 1 further gene remains to be identified. Patient care is based on managing the clinical symptoms. Animal models are helping to gain insight into pathogenesis, and a variety of therapeutic approaches are being investigated.
Collapse
Affiliation(s)
- Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
| | | | | | | |
Collapse
|
42
|
Abstract
Congenital myopathies are a genetically heterogeneous group of early-onset myopathies classified according to the predominant histopathological findings in skeletal muscle. During the past years, considerable overlap between different pathological and genetic forms of congenital myopathies has been discovered. In contrast, the pattern of involved muscles seen on muscle imaging is often more specific, providing useful additional information in the differential diagnosis of these diseases. Therefore, muscle imaging can help to target the most appropriate genetic investigations. The aim of this review is to give a comprehensive up-to-date overview of the muscle imaging findings that have recently been described in different genetic congenital myopathies.
Collapse
Affiliation(s)
- Susana Quijano-Roy
- APHP, Service de Pédiatrie, Hôpital Universitaire R. Poincaré, Garches, France
| | | | | |
Collapse
|