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Objective:To investigate the characteristics of clinical, muscle pathology and gene mutation in patients with nemaline myopathy caused by NEB gene mutation.Methods:The clinical and pathological data of patients with nemaline myopathy caused by NEB gene were collected from Neuromuscular Center of Jiaozuo People′s Hospital from January 1997 to January 2020. The next generation sequencing was preformed to detect NEB gene in all patients, and characteristics of gene mutation were analyzed.Results:Among the 11 patients, there were 8 males and 3 females, and 6 of them came from 2 families. The age of seeing a doctor ranged from 11 to 52 years, the age of onset was from 6 to 23 years, and the course of disease ranged from 5 to 35 years. Neurological examination showed that among the 11 patients, 8 patients had high palatal arch and long face. The muscle tone of both upperlimbs was normal, the tendon reflex was depressed, the proximal muscle strength was grade Ⅲ-Ⅴ, and the distal muscle strength was grade Ⅴ. The muscle tone of both lower extremities was reduced and the tendon reflex was absent. The proximal muscle strength was grade Ⅱ-Ⅳ and the distal muscle strength was grade Ⅲ-Ⅴ. No dysphagia or respiratory muscle involvement was found. Muscle biopsies were performed in 7 of the 11 patients, the pathological changes were muscle fibers of different sizes, circular atrophic muscle fibers and compensatory hypertrophic fibers, and occasionally denatured and necrotic muscle fibers were found. Different degrees of rod aggregation could be seen in all the 7 patients. Electron microscopic examination of 5 patients showed that there was rod aggregation between myofibrils, and most of them were located near the Z band, but no intranuclear rod was found. NEB gene was found in all 11 patients, and a total of 9 different mutation sites were detected, including 8 in exon region and 1 in intron region. Among them, c.21522+3A>G was found in 10 cases, c.1623delT was found in 3 cases and c.17611C>T was found in 3 cases. There was 1 case of c.4417C>T, c.2549delA, c.21065dupA, c.3520G>A, c.20943G>A, c.192G>A respectively.Conclusions:The clinical phenotype of nemaline myopathy caused by NEB gene has great heterogeneity. Muscle pathology shows that rod aggregation is an important basis for the diagnosis of this disease. Mutation c.21522+3A>G in intron is the most common mutation in this group of NEB gene. And the novel mutation sites of NEB gene are respectively c.17611C>T, c.2549delA, c.3520G>A, c.21065dupA, c.20943G>A and c.192G>A.
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Objective:To investigate the clinical, muscle biopsy and gene mutation characteristics of nemaline myopathy caused by the NEB gene variants.Methods:A retrospective analysis of the clinical manifestations, auxiliary examinations, muscle biopsies and genetic analysis of 3 nemaline myopathy patients carrying NEB gene mutations diagnosed in the Neuromuscular Pathology Laboratory of Qilu Hospital of Shandong University during 2019-2021 was done. And the related literature was reviewed.Results:All of the 3 patients were congenital onset. The onset symptoms of the 3 patients were weakness of bilateral lower limbs. Physical examinations showed high palatine arches and long narrow faces. Electromyography showed myogenic impairment. Muscle biopsies of the 3 patients revealed myodystrophic changes and nemaline bodies. The ATPase staining of patient 1 showed the predominance and grouping of type 1 muscle fibers. Genetic tests revealed patient 1 carried c.21522+3A>G and c.3471dupC (p.N1158Qfs *5) mutations in the NEB gene, patient 2 carried c.21522+3A>G and c.18991_18992delAG (p.Q6332Afs *8) compound heterozygous mutations and patient 3 carried c.21522+3A>G and c.3448A>T (p.K1150 *) compound heterozygous mutations. All the 3 patients carried the c.21522+3A>G mutation in the NEB gene, which had only been reported in Chinese population. The c.3471dupC (p.N1158Qfs *5), c.18991_18992delAG (p.Q6332Afs *8) and c.3448A>T (p.K1150 *) mutations have not been reported yet. According to American College of Medical Genetics and Genomics guideline, c.21522+3A>G, c.3471dupC (p.N1158Qfs *5), c.3448A>T (p.K1150 *) and c.18991_18992delAG (p.Q6332Afs *8) mutations were all rated pathogenic. Conclusions:The onset age and clinical symptoms of nemaline myopathy are heterogeneous. Muscle biopsy and genetic analysis are important for diagnosis of nemaline myopathy. The c.21522+3A>G mutation in the NEB gene may be more common in Chinese population.
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@#Nemaline myopathy (NM) is a primary muscle disorder presenting with proximal muscles weakness at birth or infancy and gross motor delay. This is a case report of a sixteen year old male who presented with proximal muscle weakness at 5 months of age. His gene testing revealed ACTA1 gene mutation, which is associated with nemaline myopathy. He presented with a relatively benign and slowly progressive course of weakness, not complicated by respiratory or cardiac symptoms.
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La miopatía nemalínica es un trastorno heterogéneo definido por la presencia de estructuras con forma de bastones, conocidas como cuerpos nemalínicos (o bastones de nemalina). El diagnóstico se funda en la debilidad muscular, además de la visualización de cuerpos nemalínicos en la biopsia muscular. La miopatía nemalínica no tiene cura. Las estrategias terapéuticas para este trastorno son sintomáticas y empíricas. En este artículo, presentamos el caso de una recién nacida con insuficiencia respiratoria grave y debilidad muscular generalizada, a la que se le diagnosticó miopatía nemalínica a través de la biopsia muscular. La paciente tuvo una notable disminución de la sialorrea y una mejora de los movimientos espontáneos después del tratamiento con L-tirosina. Este caso se presenta para destacar la importancia de la biopsia muscular en el diagnóstico diferencial de la hipotonía grave durante el período neonatal y el posible beneficio del aporte suplementario de L-tirosina para disminuir la sialorrea y restaurar la fuerza muscular.
Nemaline myopathy (NM) is a heterogeneous disorder defined by the presence of rod-shaped structures known as nemaline bodies or rods. The diagnosis is based on muscle weakness, combined with visualization of nemaline bodies on muscle biopsy. There is no curative treatment for nemaline myopathy. Therapeutic strategies for this condition are symptomatic and empirical. Herein, we present a newborn with severe respiratory failure and generalized muscle weakness, who was diagnosed as NM by muscle biopsy. The patient experienced remarkable decrease in sialorrhea and improvement of spontaneous movements after L-tyrosine treatment. This case is presented to emphasize the importance of muscle biopsy in the differential diagnosis of severe hypotonia during neonatal period and a possible benefit of L-tyrosine supplementation for decreasing sialorrhea and restoring muscle strength.
Subject(s)
Humans , Female , Infant, Newborn , Tyrosine/therapeutic use , Myopathies, Nemaline/diagnosis , Biopsy , Myopathies, Nemaline/therapy , Fatal Outcome , Muscle HypotoniaABSTRACT
PURPOSE: Nemaline myopathy (NM) is a clinical heterogeneous congenital myopathy characterized by the presence of subsarcolemmal or cytoplasmic rod-like structures that call nemaline bodies in the muscle fibers. The purpose of this study was to investigate the clinical diversity and pathological features of Korean patients with NM. MATERIALS AND METHODS: Eight patients underwent analyses of clinical manifestations by a structured protocol. Diagnoses were established by a muscle biopsy. RESULTS: Two patients had the typical congenital type, which exhibited neonatal hypotonia and delayed motor milestone, and five patients had the childhood onset type, which exhibited mild gait disturbance as a first symptom. One patient had the adult onset type, which showed acute respiratory failure. Limb weakness was proximal-dominant occurred in six patients. Hyporeflexia was observed in most patients. Elongated faces and high arched palates and feet were also observed. On light microscopy, the nemaline bodies were observed in type 1 and 2 fibers. All patients showed type 1 predominance and atrophy. In the two cases in which ultrastructural studies were performed, typical nemaline rods and disorganized myofibrillar apparatus were detected. CONCLUSION: In conclusion, the eight Korean patients in this study with NM shared common clinical expressions such as proximal limb weakness, reduced deep tendon reflex, and dysmorphic features. This study, however, showed that clinical heterogeneity ranged from typical congenital, mildly affected childhood to the adult onset form with acute respiratory failure. The pathological findings in this study were in accordance with those of other previous reports.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Young Adult , Asian People , Microscopy , Myopathies, Nemaline/pathology , Reflex, Abnormal/physiologyABSTRACT
Nemaline myopathy (NM) is a congenital disease that leads to hypotonia and feeding difficulties in neonates. Some cases have a more benign course, with skeletal abnormalities later in life. We analyzed a series of eight patients with NM obtained from a retrospective analysis of 4300 muscle biopsies. Patients were classified as having the typical form in five cases, intermediate form in two cases and severe form in one case. Histochemical analysis showed mixed rods distribution in all cases and predominance of type I fibers in five cases. Immunohistochemical analysis showed abnormal nebulin expression in all patients (four heterogeneous and four absent), homogeneous desmin expression in four cases, strongly positive in three and absent in one, fast myosin expression in a mosaic pattern in six cases and absent in two cases. There was no specific relation between these protein expression patterns and the clinical forms of NM.
Miopatia nemalínica (NM) é uma doença congênita que leva a hipotonia e dificuldade de sugar em neonatos. Alguns casos possuem uma evolução benigna, com deformidades ósseas tardias. Nós analisamos uma série de oito pacientes com NM obtidos da análise retrospectiva de 4300 biópsias musculares. Os pacientes foram classificados como forma típica em cinco casos, forma intermediária em dois casos e forma severa em um caso. Análise histoquímica mostrou distribuição mista dos rods em todos os casos e predominância de fibras tipo I em cinco casos. Análise imuno-histoquímica mostrou expressão anormal da nebulina em todos os pacientes (quatro heterogênea e quatro ausente), expressão homogenea da desmina em quatro casos, fortemente positiva em tres e ausente em um, expressão da miosina (rápida) com padrão em mosaico em seis casos e ausente em dois casos. Não há relação específica entre a expressão destas proteínas e as formas clínicas da NM.
Subject(s)
Child , Child, Preschool , Female , Humans , Infant , Male , Desmin/metabolism , Immunohistochemistry , Muscle Proteins/metabolism , Muscles/pathology , Myopathies, Nemaline/pathology , Myosins/metabolism , Biopsy , Electromyography , Myopathies, Nemaline/metabolism , Retrospective Studies , Severity of Illness IndexABSTRACT
Childhood onset nemaline myopathy, first described in 1963 by Shy, et al and Conen, et al, is rare congenital myopathy, characterized by nonprogressive or slowly progressive muscle weakness associated with rod-like structures in muscle fibers, often with dysmorphic features. This myopathy was confirmed by muscle biopsy. The light microscopic features noted generally small round fibers that showed variation in size and occasional internal nuclei and characteristic rod bodies that could be demonstrated in the longitudinal sections stained with modified Gomori trichrome stain. Electromicroscopically there were accumulations of numerous irregular electron dense materials scattered between the myofibrils, particularly under the sarcolemma and enlargement and streamimg of the Z disk. We report a case of childhood onset nemaline myopathy in Korea in a 7 year- old boy who had nonprogressive muscle weakness of the limbs with a waddling gait.
Subject(s)
Humans , Male , Biopsy , Extremities , Gait , Korea , Muscle Weakness , Muscular Diseases , Myofibrils , Myopathies, Nemaline , SarcolemmaABSTRACT
Nemaline rod myopathy is an autosomal dominant disease characterized by nonprogressive symmetric skeletal muscle weakness affecting principally proximal skeletal muscles. Anesthesia of the patient with this disease is known to present some problems:difficult intubation due to facial dysmorphism, delayed onset of succinilcholine, reduced vital capacity on pulmonary function test and skeletal deformity. We anesthetized 19 year old male patient with nemaline myopathy for the operation of cryptochidism. Because of the possibility of difficult intubation, we produced epidural anesthesia with 20 G Tuohy needle at L5-S1 intervertebral space successfully. There were no problems in the course of operation and recovery except transient airway obstruction due to sedative.