• Neonatal Medicine
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• v.28 no.2
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• pp.89-93
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• 2021

Nemaline myopathy is a genetically heterogeneous neuromuscular disorder and one of the most common congenital myopathies. The clinical manifestations usually vary depending on the age of onset. Neonatal nemaline myopathy has the worst prognosis, primarily due to respiratory failure. Several genes associated with nemaline myopathy have been identified, including NEB, ACTA1, TPM3, TPM2, TNNT1, CFL2, KBTBD13, KLHL40, KLHL41, LMOD3, and KBTBD13. Here, we report a neonatal Korean female patient with nemaline myopathy carrying compound heterozygous mutations in the gene KLHL40 as revealed using next generation sequencing (NGS). The patient presented with postnatal cyanosis, respiratory failure, dysphagia, and hypotonia just after birth. To identify the genetic cause underlying the neonatal myopathy, NGS-based gene panel sequencing was performed. Compound heterozygous pathogenic variants were detected in KLHL40: c.[1405G>T];[1582G>A] (p. [Gly469cys];[Glu528Lys]). NGS allows quick and accurate diagnosis at a lower cost compared to traditional serial single gene sequencing, which is greatly advantageous in genetically heterogeneous disorders such as myopathies. Rapid diagnosis will facilitate efficient and timely genetic counseling, prediction of disease prognosis, and establishment of treatments.

• Annals of Clinical Neurophysiology
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• v.16 no.2
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• pp.81-85
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• 2014

Primary metabolic myopathy as a type of congenital myopathies was first described by McArdle in 1951. Glycogen storage disease is a disease caused by genetic mutations involved in glycogen synthesis, glycogenolysis or glycolysis. Several types of glycogen storage disease are known to cause metabolic myopathies. We report a case of adult onset metabolic myopathy with glycogen storage.

• Annals of Clinical Neurophysiology
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• v.22 no.2
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• pp.51-60
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• 2020

Muscle pathology findings may guide the diagnosis of neuromuscular disorders since they are helpful for understanding the pathological processes causing muscle weakness and also provide significant clues for the diagnosis of muscle diseases. Recent advances in molecular genetics mean that a muscle biopsy can be omitted when diagnosing inherited muscle diseases. However, the muscle pathology can still play a role in those cases and its findings are also required when diagnosing inflammatory myopathies.

• Annals of Clinical Neurophysiology
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• v.8 no.1
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• pp.23-28
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• 2006

Background: central core disease is one of the non-progressive benign congenital myopathies characterized by the presence of cores in muscle fibers, which was originally described by Shy and Magee (1956). We describe clinical charcteristics of central core disease in a Korean family manifested by autosomal dominant pattern through three generations. Methods: Clinical, serologic, and electrophysiologic profiles were evaluated in eleven members among 22 family members through three generations. Results: Six family members were symptomatic and five were non-symptomatic. Instead of proximal muscle weakness, musculoskeletal manifestations including non-specific joint pain and stiff sense were the most frequent symptoms. Muscle biopsy performed in two symptomatic patients revealed that type I fiber showed central halo, which is charactreristics of central core disease. No remarkable findings were present in serologic study including CPK level and electromyographic findings suggesting myopathic pattern were only present in two patients among 11 symptomatic group. Conclusions: In evaluating non-specific musculoskeletal complaints from the familial members showing genetic trait, central core disease should be considered to one of the possible diagnosis.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.139-142
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• 2013

X-linked recessive myotubular myopathy (XLMTM) is a severe congenital muscle disorder caused by mutations in the MTM1 gene and characterized by severe hypotonia and generalized muscle weakness in affected males. It is generally a fatal disorder during the neonatal period and early infancy. The diagnosis is based on typical histopathological findings on muscle biopsy, combined with suggestive clinical features. We experienced a case of a newborn who required intubation and ventilator care because of profound hypotonia and respiratory difficulty. The preliminary diagnosis at the time of request for retrieval was hypoxic ischemic encephalopathy, but the infant was clinically reevaluated for generalized weakness and muscle atrophy. Muscle biopsies showed variability in fiber size and centrally located nuclei in nearly all the fibers. We detected an MTM1 gene mutation of c.1261-1C>A in the intron 10 region, and diagnosed the neonate with myotubular myopathy. The same mutation was detected in his mother.