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Mohtisham F, Al Thaqafi M, Shawli A, Sallam A. Congenital Nemaline Myopathy in Two Neonates With Different Mutations: A Case Series and Literature Review. Cureus 2023; 15:e45197. [PMID: 37720117 PMCID: PMC10503874 DOI: 10.7759/cureus.45197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2023] [Indexed: 09/19/2023] Open
Abstract
Nemaline myopathy is a skeletal muscle disorder characterized by a wide range of severity and variable presentation. While most cases present in the neonatal period with symptoms, such as hypotonia, muscle weakness, and respiratory insufficiency, delayed onset in childhood or adulthood is also observed. The pathogenesis of nemaline myopathy involves at least 12 genes, and the condition can arise from de novo mutations or be inherited in a dominant or recessive manner. In this study, we present two cases of neonates admitted to a neonatal intensive care unit (NICU) exhibiting hypotonia, muscle weakness, and respiratory insufficiency. Both cases were diagnosed with congenital nemaline myopathy, with each patient displaying distinct mutations. This report highlights the clinical and genetic heterogeneity of this condition, emphasizing the importance of early recognition and genetic evaluation for accurate diagnosis and appropriate management of affected individuals.
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Affiliation(s)
- Farzeen Mohtisham
- Neonatology, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, SAU
- Neonatology, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah, SAU
| | - Maram Al Thaqafi
- Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah, SAU
| | - Aiman Shawli
- Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah, SAU
| | - Adel Sallam
- Neonatology, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Jeddah, SAU
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Çap M, Akyüz A, Isik F, Türken A, Erdoğan E, Varsak S, Burak C, Süleymanoğlu M, Baysal E. Myocardial strain assessment by 2D speckle-tracking echocardiography in patients with congenital myopathy. J Cardiovasc Echogr 2021; 31:214-219. [PMID: 35284221 PMCID: PMC8893116 DOI: 10.4103/jcecho.jcecho_48_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 10/20/2021] [Accepted: 11/06/2021] [Indexed: 11/21/2022] Open
Abstract
Background: Congenital myopathies (CMs) are a group of rare genetic muscle disorders. Cardiac involvement can be seen in these patients. We aimed to evaluate the myocardial strain parameters by 2D speckle-tracking echocardiography (STE) in patients with CM. Materials and Methods: Twenty-four patients with CM whose diagnosis was confirmed by genetic analysis or muscle biopsy were included in the study, and 48 patients were involved as a control group. Left ventricular ejection fraction (LVEF%) was calculated by biplane Simpson method, and myocardial strain analysis was performed by 2D STE. Results: The median age of the study population was 26 (19–35 interquartile range [IQR]) and 43 (60%) were women. In the analysis performed after the exclusion of two patients with multiminicore disease (MMD) who developed heart failure, although mild, LVEF% (62 [60–65 IQR] vs. 64 [63–66 IQR], P = 0.008) and right ventricular global longitudinal strain (RVGLS) were significantly lower in the CM group (−21.8 [−19.7, −24.9 IQR] vs. −23.9 [−22.4, −25.6 IQR], P = 0.0017). Left ventricular global longitudinal strain (LVGLS) was observed similarly in both groups (−19.9 [−18.7, −20.7 IQR] vs. −20.5 [−19.3, −21.9 IQR], P = 0.069). LVEF% (33 and 46), LVGLS (−7.5 and −10.7), and RVGLS (−14.9 and −16.1) values were low in two siblings with MMD. Conclusion: Although LVEF% and RVGLS were significantly lower in the CM group, LVGLS was similar. The decrease in RVGLS and LVEF% was mild, and heart failure was not observed in any patient except MMD patients who were not included in the analysis.
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Maheshwari S, Pant I, Bala K, Paradasani V. Congenital myopathies: A clinicopathological study of 10 cases in a tertiary care hospital of North India. J Pediatr Neurosci 2021; 16:184-195. [PMID: 36160617 PMCID: PMC9496603 DOI: 10.4103/jpn.jpn_32_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 11/28/2022] Open
Abstract
Objective: Congenital myopathies (CMs) are rare neuromuscular disorders. Through this article, authors want to present a clinicopathological study of 10 cases of CM. Materials and Methods: The study included patients with histopathologically confirmed CM attending the neurology services at the Institute of Human Behavior and Allied Sciences for 2 years. After collecting the demographic data, all patients were subjected to comprehensive workup including a detailed neurological examination and investigations, including muscle biopsy from representative involved muscle. Results: Ten patients diagnosed with CM. The most common CM type was congenital fiber-type disproportion (CFTD) seen in four cases followed by centronuclear myopathy in two cases and one each in desmin-related myopathy, central core disease, nemaline myopathy, CM with type II fiber hypoplasia. Clinically, they have variable features. Conclusion: This study from India highlights the importance of specific clinical features to look for when suspecting a CM coupled with specific features in histopathology. However, studies with longer duration are needed to find out the true prevalence and various spectra of CMs.
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Abstract
Nemaline myopathy (NM) is a rare congenital muscular disease characterized by the presence of rod (nemaline) bodies visualized on muscle biopsy. The disease is genetically and clinically heterogeneous, and the age of onset can vary from neonate to adult. Patients typically present initially with diffuse muscle weakness and hypotonia. The disease also afflicts facial musculature and can cause anomalous facial growth and development. The authors report a patient of early onset NM with significant craniofacial abnormalities. The untreated facial growth is discussed and illustrated in this article. The authors reviewed the current knowledge in the literature regarding the molecular and genetic pathogenesis of NM. The roles of both surgical and supportive management are discussed in this particular patient.
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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.
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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
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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.
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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.
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Dhinakaran S, Kumar RS, Thakkar R, Narayanappa G. Coexistence of central nucleus, cores, and rods: Diagnostic relevance. Ann Indian Acad Neurol 2016; 19:201-4. [PMID: 27293330 PMCID: PMC4888682 DOI: 10.4103/0972-2327.176861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background: Congenital myopathies (CMs) though considered distinct disorders, simultaneous occurrence of central nucleus, nemaline rods, and cores in the same biopsy are scarcely reported. Objective: A retrospective reassessment of cases diagnosed as CMs to look for multiple pathologies missed, if any, during the initial diagnosis. Materials and Methods: Enzyme histochemical, and immunohistochemical-stained slides from 125 cases diagnosed as congenital myopathy were reassessed. Results: The study revealed 15 cases (12%) of congenital myopathy with more than one morphological feature. Central nucleus with cores (n = 11), central nucleus, nemaline rods and cores (n = 3), and nemaline rods with cores (n = 1). 4/11 cases were diagnosed as centronuclear myopathy (CNM) in the first instance; in addition, cores were revealed on reassessment. Discussion: The prevalence of CMs of all neuromuscular disorders is approximately 6 in 100,000 live births, with regional variations. Three main defined CMs include centro nuclear myopathy (CNM), nemaline rod myopathy (NRM), and central core disease (CCD). However, they are more diverse with overlapping clinical and histopathological features, thus broadening the spectra within each category of congenital myopathy. Conclusion: Identification of cases with overlap of pathological features has diagnostic relevance.
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Affiliation(s)
- Sathiyabama Dhinakaran
- Department of Neuropathology, National Institute of Mental Health and Neuroscience (NIMHANS), Bangalore, Karnataka, India
| | - Rashmi Santhosh Kumar
- Department of Neuropathology, National Institute of Mental Health and Neuroscience (NIMHANS), Bangalore, Karnataka, India
| | - Ravindra Thakkar
- Department of Neuropathology, National Institute of Mental Health and Neuroscience (NIMHANS), Bangalore, Karnataka, India
| | - Gayathri Narayanappa
- Department of Neuropathology, National Institute of Mental Health and Neuroscience (NIMHANS), Bangalore, Karnataka, India
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Fajardo VA, Smith IC, Bombardier E, Chambers PJ, Quadrilatero J, Tupling AR. Diaphragm assessment in mice overexpressing phospholamban in slow-twitch type I muscle fibers. Brain Behav 2016; 6:e00470. [PMID: 27134770 PMCID: PMC4842933 DOI: 10.1002/brb3.470] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 12/30/2022] Open
Abstract
AIMS Phospholamban (PLN) and sarcolipin (SLN) are small inhibitory proteins that regulate the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) pump. Previous work from our laboratory revealed that in the soleus and gluteus minimus muscles of mice overexpressing PLN (Pln (OE)), SERCA function was impaired, dynamin 2 (3-5 fold) and SLN (7-9 fold) were upregulated, and features of human centronuclear myopathy (CNM) were observed. Here, we performed structural and functional experiments to evaluate whether the diaphragm muscles of the Pln (OE) mouse would exhibit CNM pathology and muscle weakness. METHODS Diaphragm muscles from Pln (OE) and WT mice were subjected to histological/histochemical/immunofluorescent staining, Ca(2+)-ATPase and Ca(2+) uptake assays, Western blotting, and in vitro electrical stimulation. RESULTS Our results demonstrate that PLN overexpression reduced SERCA's apparent affinity for Ca(2+) but did not reduce maximal SERCA activity or rates of Ca(2+) uptake. SLN was upregulated 2.5-fold, whereas no changes in dynamin 2 expression were found. With respect to CNM, we did not observe type I fiber predominance, central nuclei, or central aggregation of oxidative activity in diaphragm, although type I fiber hypotrophy was present. Furthermore, in vitro contractility assessment of Pln (OE) diaphragm strips revealed no reductions in force-generating capacity, maximal rates of relaxation or force development, but did indicate that ½ relaxation time was prolonged. CONCLUSIONS Therefore, the effects of PLN overexpression on skeletal muscle phenotype differ between diaphragm and the postural soleus and gluteus minimus muscles. Our findings here point to differences in SLN expression and type I fiber distribution as potential contributing factors.
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Affiliation(s)
| | - Ian Curtis Smith
- Department of Kinesiology University of Waterloo Waterloo ON Canada
| | - Eric Bombardier
- Department of Kinesiology University of Waterloo Waterloo ON Canada
| | - Paige J Chambers
- Department of Kinesiology University of Waterloo Waterloo ON Canada
| | - Joe Quadrilatero
- Department of Kinesiology University of Waterloo Waterloo ON Canada
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Piga D, Magri F, Ronchi D, Corti S, Cassandrini D, Mercuri E, Tasca G, Bertini E, Fattori F, Toscano A, Messina S, Moroni I, Mora M, Moggio M, Colombo I, Giugliano T, Pane M, Fiorillo C, D’Amico A, Bruno C, Nigro V, Bresolin N, Comi GP. New Mutations in NEB Gene Discovered by Targeted Next-Generation Sequencing in Nemaline Myopathy Italian Patients. J Mol Neurosci 2016; 59:351-9. [DOI: 10.1007/s12031-016-0739-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/22/2016] [Indexed: 11/25/2022]
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Skeletal muscle microRNA and messenger RNA profiling in cofilin-2 deficient mice reveals cell cycle dysregulation hindering muscle regeneration. PLoS One 2015; 10:e0123829. [PMID: 25874796 PMCID: PMC4395318 DOI: 10.1371/journal.pone.0123829] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 03/07/2015] [Indexed: 12/19/2022] Open
Abstract
Congenital myopathies are rare skeletal muscle diseases presenting in early age with hypotonia and weakness often linked to a genetic defect. Mutations in the gene for cofilin-2 (CFL2) have been identified in several families as a cause of congenital myopathy with nemaline bodies and cores. Here we explore the global messenger and microRNA expression patterns in quadriceps muscle samples from cofillin-2-null mice and compare them with sibling-matched wild-type mice to determine the molecular pathways and mechanisms involved. Cell cycle processes are markedly dysregulated, with altered expression of genes involved in mitotic spindle formation, and evidence of loss of cell cycle checkpoint regulation. Importantly, alterations in cell cycle, apoptosis and proliferation pathways are present in both mRNA and miRNA expression patterns. Specifically, p21 transcript levels were increased, and the expression of p21 targets, such as cyclin D and cyclin E, was decreased. We therefore hypothesize that deficiency of cofilin-2 is associated with interruption of the cell cycle at several checkpoints, hindering muscle regeneration. Identification of these pathways is an important step towards developing appropriate therapies against various congenital myopathies.
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Smith BK, Goddard M, Childers MK. Respiratory assessment in centronuclear myopathies. Muscle Nerve 2014; 50:315-26. [PMID: 24668768 DOI: 10.1002/mus.24249] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2014] [Indexed: 12/23/2022]
Abstract
The centronuclear myopathies (CNMs) are a group of inherited neuromuscular disorders classified as congenital myopathies. While several causative genes have been identified, some patients do not harbor any of the currently known mutations. These diverse disorders have common histological features, which include a high proportion of centrally nucleated muscle fibers, and clinical attributes of muscle weakness and respiratory insufficiency. Respiratory problems in CNMs may manifest initially during sleep, but daytime symptoms, ineffective airway clearance, and hypoventilation predominate as more severe respiratory muscle dysfunction evolves. Respiratory muscle capacity can be evaluated using a variety of clinical tests selected with consideration for the age and baseline motor function of the patient. Similar clinical tests of respiratory function can also be incorporated into preclinical CNM canine models to offer insight for clinical trials. Because respiratory problems account for significant morbidity in patients, routine assessments of respiratory muscle function are discussed.
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Affiliation(s)
- Barbara K Smith
- Department of Physical Therapy, University of Florida, Gainesville, Florida, USA
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Abstract
Nemaline myopathy (NM) is a genetically and clinically heterogeneous muscle disorder, defined by the presence of characteristic nemaline bodies on muscle biopsy. The disease has a wide spectrum of phenotypes, ranging from forms with neonatal onset and fatal outcome to asymptomatic forms. The neonatal form is severe and usually fatal. The clinical variability, with differing age of onset and severity of symptoms makes the diagnosis difficult during infancy. There is no curative treatment. L-tyrosine may prevent aspiration by reducing pharyngeal secretions and drooling. Most of the patients die from respiratory and cardiac failure. This article discusses a newborn infant who presented with generalized weakness and respiratory failure. Partial response to L-tyrosine treatment was noted. The case is worth presenting to remind clinicians of congenital myopathies in the differential diagnosis of floppy infant during neonatal period and to emphasize the importance of muscle biopsy in diagnosis.
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Cuisset JM, Maurage CA, Carpentier A, Briand G, Thévenon A, Rouaix N, Vallée L. [Muscle biopsy in children: Usefulness in 2012]. Rev Neurol (Paris) 2013; 169:632-9. [PMID: 23993361 DOI: 10.1016/j.neurol.2012.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 11/10/2012] [Accepted: 11/27/2012] [Indexed: 12/14/2022]
Abstract
Muscle biopsy is a mainstay diagnostic tool for investigating neuromuscular disorders in children. We report the yield of pediatric muscle biopsy in a population of 415 children by a retrospective study of 419 biopsies performed between 1/01/2000 and 31/12/2009 in a neuropediatric department, including mitochondrial respiratory chain analysis for 87 children. Two hundred and fifty-five biopsies were from boys (61%) 164 from girls (39%). Their mean age at biopsy was 6.5years; 155 (37%) biopsies were obtained before the child was 5years old. Final histopathological diagnoses were: congenital myopathy (n=193, including 15 structural congenital myopathies); progressive muscular dystrophy (n=75 [18%] including 57 dystrophinopathies); congenital muscular dystrophy (n=17, including six primary merosinopathies); dermatomyositis (n=11); spinal muscular atrophy (n=9, including six atypical spinal muscular atrophies); metabolic myopathy (n=32, including 19 mitochondrial myopathies); encephalomyopathy (n=53 [13%], including 27 with a mitochondrial respiratory chain defect). Pathological diagnosis remained undetermined in 16 cases. In 184 patients (44%), the muscle biopsy revealed specific histopathological anomalies (dystrophic process; specific ultrastructural abnormalities; perifascicular atrophy; neurogenic atrophy; metabolic anomalies) enabling a precise etiological diagnosis. For 85% of progressive muscular dystrophies, the biopsy resulted in a genetic diagnosis after identification of the protein defect. In 15% of the congenital myopathies, histopathological anomalies focused attention on one or several genes. Concerning dystrophinopathies, quantification of dystrophin deficiency on the biopsy specimen contributed to the definition of the clinical phenotype: Duchenne, or Becker. In children with a myopathy, muscle biopsy is often indispensable to establish the etiological diagnosis. Based on the results from this series, muscle biopsy can provide a precise orientation in 45% of patients, leading to a genetic hypothesis.
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Affiliation(s)
- J-M Cuisset
- Service de neuropédiatrie, hôpital Roger-Salengro, CHRU, rue du Professeur-Émile-Laine, 59037 Lille cedex, France; Centre de référence des maladies neuromusculaires, CHRU, 2, rue André-Verhaeghe, 59037 Lille cedex, France.
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Kapoor S, Singh A, Lehtokari VL, Wallgren-Pettersson C, Batra VV. Mutations in the nebulin gene in a child with nemaline (rod) myopathy. Indian J Pediatr 2013; 80:691-3. [PMID: 22941215 DOI: 10.1007/s12098-012-0867-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 08/03/2012] [Indexed: 11/30/2022]
Abstract
Nemaline myopathy, also called rod myopathy, is a relatively common congenital myopathy and probably second in incidence only to central core disease. The mainstay of diagnosis is histopathology, but detection of the causative mutation is mandatory for determining the mode of inheritance and for prenatal diagnosis. The authors report two siblings with nemaline myopathy caused by mutations in the nebulin gene.
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Affiliation(s)
- Seema Kapoor
- Division of Genetics, Department of Pediatrics, Maulana Azad Medical College, New Delhi 110002, India.
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Tamblyn JA, Morris RK, Cox P, Hargitai B, Kilby MD. The role of ultrasound in fetal congenital myopathy detection: a novel case of fetal-onset cap myopathy. Prenat Diagn 2013; 33:1102-4. [DOI: 10.1002/pd.4184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/23/2013] [Accepted: 06/20/2013] [Indexed: 11/09/2022]
Affiliation(s)
- J. A. Tamblyn
- Division of Reproduction, Genes and Development, School of Clinical and Experimental Medicine; University of Birmingham; Birmingham UK
| | - R. K. Morris
- Division of Reproduction, Genes and Development, School of Clinical and Experimental Medicine; University of Birmingham; Birmingham UK
- Fetal Medicine Centre; Birmingham Women's NHS Foundation Trust; Birmingham UK
| | - P. Cox
- Department of Perinatal Pathology; Birmingham Women's NHS Foundation Trust; Birmingham UK
| | - B. Hargitai
- Department of Perinatal Pathology; Birmingham Women's NHS Foundation Trust; Birmingham UK
| | - M. D. Kilby
- Division of Reproduction, Genes and Development, School of Clinical and Experimental Medicine; University of Birmingham; Birmingham UK
- Fetal Medicine Centre; Birmingham Women's NHS Foundation Trust; Birmingham UK
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A Case Report of Congenital Fiber Type Disproportion with an Increased Level of Anti-ACh Receptor Antibodies. Case Rep Pediatr 2013; 2013:607678. [PMID: 23762716 PMCID: PMC3670572 DOI: 10.1155/2013/607678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/04/2013] [Indexed: 12/02/2022] Open
Abstract
Congenital fiber type disproportion (CFTD) is a form of congenital myopathy, which is defined by type 1 myofibers that are 12% smaller than type 2 myofibers, as well as a general predominance of type 1 myofibers. Conversely, myasthenia gravis (MG) is an acquired immune-mediated disease, in which the acetylcholine receptor (AChR) of the neuromuscular junction is blocked by antibodies. Thus, the anti-AChR antibody is nearly specific to MG. Herein, we report on a case of CFTD with increased anti-AChR antibody levels. A 23-month-old boy exhibited muscle hypotonia and weakness. Although he could walk by himself, he easily fell down and could not control his head for a long time. His blood test was positive for the anti-AChR antibody, while a muscle biopsy revealed characteristics of CFTD. We could not explain the relationship between MG and CFTD. However, we considered different diagnoses aside from MG, even when the patient's blood is positive for the anti-AChR antibody.
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Cuisset JM, Carpentier A. Myopathies constitutionnelles ou acquises chez l’enfant : les éléments d’orientation du diagnostic. Arch Pediatr 2012. [DOI: 10.1016/s0929-693x(12)71122-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Type 1 ryanodine receptor knock-in mutation causing central core disease of skeletal muscle also displays a neuronal phenotype. Proc Natl Acad Sci U S A 2011; 109:610-5. [PMID: 22203976 DOI: 10.1073/pnas.1115111108] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The type 1 ryanodine receptor (RyR1) is expressed widely in the brain, with high levels in the cerebellum, hippocampus, and hypothalamus. We have shown that L-type Ca(2+) channels in terminals of hypothalamic magnocellular neurons are coupled to RyRs, as they are in skeletal muscle, allowing voltage-induced Ca(2+) release (VICaR) from internal Ca(2+) stores without Ca(2+) influx. Here we demonstrate that RyR1 plays a role in VICaR in nerve terminals. Furthermore, in heterozygotes from the Ryr1(I4895T/WT) (IT/+) mouse line, carrying a knock-in mutation corresponding to one that causes a severe form of human central core disease, VICaR is absent, demonstrating that type 1 RyR mediates VICaR and that these mice have a neuronal phenotype. The absence of VICaR was shown in two ways: first, depolarization in the absence of Ca(2+) influx elicited Ca(2+)syntillas (scintilla, spark, in a nerve terminal, a SYNaptic structure) in WT, but not in mutant terminals; second, in the presence of extracellular Ca(2+), IT/+ terminals showed a twofold decrease in global Ca(2+) transients, with no change in plasmalemmal Ca(2+) current. From these studies we draw two conclusions: (i) RyR1 plays a role in VICaR in hypothalamic nerve terminals; and (ii) a neuronal alteration accompanies the myopathy in IT/+ mice, and, possibly in humans carrying the corresponding RyR1 mutation.
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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.
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Affiliation(s)
- Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
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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.
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Affiliation(s)
- Susana Quijano-Roy
- APHP, Service de Pédiatrie, Hôpital Universitaire R. Poincaré, Garches, France
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Nemaline myopathy and non-fatal hypertrophic cardiomyopathy caused by a novel ACTA1 E239K mutation. J Neurol Sci 2011; 307:171-3. [PMID: 21570694 DOI: 10.1016/j.jns.2011.04.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 04/13/2011] [Accepted: 04/22/2011] [Indexed: 11/22/2022]
Abstract
A twenty-year old male presented with diffuse limb muscle weakness and exertional dyspnea since childhood. The diagnosis of nemaline myopathy was given based on the muscle pathology findings that revealed nemaline rods on light and electron microscopy and discovery of a novel mutation, E239K, in ACTA1. Incidentally, the patient had hypertrophic cardiomyopathy (HCM) as shown by echocardiography. In nemaline myopathy, a few cases of HCM have been reported, albeit rarely and always fatal, but only one patient had ACTA1 mutation. This present report describes an infantile onset of nemaline myopathy with a milder clinical course and non-fatal HCM as compared with previous cases, showing clinical diversity in skeletal and cardiac manifestations of conditions associated with ACTA1 mutations.
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22
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MacLennan DH, Zvaritch E. Mechanistic models for muscle diseases and disorders originating in the sarcoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:948-64. [DOI: 10.1016/j.bbamcr.2010.11.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/11/2010] [Accepted: 11/18/2010] [Indexed: 11/29/2022]
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Tidyman WE, Lee HS, Rauen KA. Skeletal muscle pathology in Costello and cardio-facio-cutaneous syndromes: developmental consequences of germline Ras/MAPK activation on myogenesis. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:104-14. [PMID: 21495178 DOI: 10.1002/ajmg.c.30298] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cardio-facio-cutaneous syndrome (CFC) and Costello syndrome (CS) are two of the more rare RASopathies caused by altered signal transduction of the Ras/mitogen-activated protein kinase (MAPK) pathway. All of the RASopathies exhibit some degree of hypotonia, but CS and CFC are more severe. To determine if individuals with CS and CFC have an underlying skeletal myopathy, we systematically evaluated skeletal muscle pathology in both conditions. We reviewed pathology reports from six individuals who had undergone a skeletal muscle biopsy, and we reviewed histology slides on two cases with CS and one case with CFC. All patients in the cohort had histopathologic findings, and two consistent abnormalities were identified. The first was the presence of abnormal muscle fiber size and variability, and the second was the presence of type 2 fiber predominance. Given the degree of hypotonia typically present in these patients, the overall architecture of the muscle was relatively normal, without showing indications of severe structural histopathology or metabolic abnormalities. Because the Ras/MAPK pathway is vital for skeletal myogenesis, we evaluated the effects of CS and CFC mutations on myogenesis using C2C12 myoblasts. All CS/CFC mutations inhibited myoblast differentiation as indicated by fewer myosin heavy chain expressing cells and a decrease in the number of myotubes as compared to controls. These findings indicate that CS and CFC may have a true myopathy related to an inherent dysregulation of skeletal myogenesis, which further expands our understanding of the consequences of germline Ras/MAPK mutations.
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Affiliation(s)
- William E Tidyman
- Department of Orofacial Science at the University of California at San Francisco, USA
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24
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Quan D. Muscular dystrophies and neurologic diseases that present as myopathy. Rheum Dis Clin North Am 2011; 37:233-44, vi. [PMID: 21444022 DOI: 10.1016/j.rdc.2011.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Chronic muscle weakness is a common complaint among patients seen in rheumatology and neuromuscular specialty clinics. This article focuses on adult-onset muscular dystrophies, select hereditary myopathies, and other neuromuscular conditions that must be distinguished from acquired causes of inflammatory muscle disease such as polymyositis. A few organizing principles help to focus the evaluation and narrow the differential diagnosis.
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Affiliation(s)
- Dianna Quan
- Electromyography Laboratory, Department of Neurology, University of Colorado Denver, Academic office 1 - MS B-185, 12631 East 17th Avenue, Room 5121, Aurora, CO 80045, USA.
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Ca2+ dysregulation in Ryr1(I4895T/wt) mice causes congenital myopathy with progressive formation of minicores, cores, and nemaline rods. Proc Natl Acad Sci U S A 2009; 106:21813-8. [PMID: 19959667 DOI: 10.1073/pnas.0912126106] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ryr1(I4895T/wt) (IT/+) mice express a knockin mutation corresponding to the human I4898T EC-uncoupling mutation in the type 1 ryanodine receptor/Ca(2+) release channel (RyR1), which causes a severe form of central core disease (CCD). IT/+ mice exhibit a slowly progressive congenital myopathy, with neonatal respiratory stress, skeletal muscle weakness, impaired mobility, dorsal kyphosis, and hind limb paralysis. Lesions observed in myofibers from diseased mice undergo age-dependent transformation from minicores to cores and nemaline rods. Early ultrastructural abnormalities include sarcomeric misalignment, Z-line streaming, focal loss of cross-striations, and myofibrillar splitting and intermingling that may arise from defective myofibrillogenesis. However, manifestation of the disease phenotype is highly variable on a Sv129 genomic background. Quantitative RT-PCR shows an equimolar ratio of WT and mutant Ryr1 transcripts within IT/+ myofibers and total RyR1 protein expression levels are normal. We propose a unifying theory in which the cause of core formation lies in functional heterogeneity among RyR1 tetramers. Random combinations of normal and either leaky or EC-uncoupled RyR subunits would lead to spatial differences in Ca(2+) transients; the resulting heterogeneity of contraction among myofibrils would lead to focal, irreversible tearing and shearing, which would, over time, enlarge to form minicores, cores, and nemaline rods. The IT/+ mouse line is proposed to be a valid model of RyR1-related congenital myopathy, offering high potential for elucidation of the pathogenesis of skeletal muscle disorders arising from impaired EC coupling.
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Millichap JG. Update and Review of Congenital Myopathies. Pediatr Neurol Briefs 2009. [DOI: 10.15844/pedneurbriefs-23-6-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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