• Annals of Clinical Neurophysiology
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• v.21 no.2
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• pp.79-86
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• 2019

Background: Magnetic resonance (MR) images are useful for diagnosing myopathy. The purpose of this study was to determine the usefulness of lower-limb MR images in Korean patients with distal myopathy. Methods: We reviewed medical records in the myopathy database from January 2002 to October 2016. We selected 21 patients from 91 unrelated families with distal myopathy: four with GNE myopathy, 11 with dysferlinopathy, and six with ADSSL1 myopathy. Results: Ten (48%) of the 21 patients were men. The ages of the participants at symptom onset and imaging were $19.2{\pm}9.5$ and $30.4{\pm}9.0$ years (mean${\pm}$standard deviation), respectively. Their grade on the modified Gardner-Medwin and Walton grade was $3.3{\pm}1.7$. The strength grade of the knee extensors was not correlated with the Mercuri scale for the quadriceps (r = -0.247, p = 0.115). However, the Medical Research Council grades of the knee flexors, ankle dorsiflexors, and ankle plantar flexors were significantly correlated with the Mercuri scale ratings of the knee flexors (r = -0.497, p = 0.001), tibialis anterior (r = -0.727, p < 0.001), and ankle plantar flexors (r = -0.620, p < 0.001), respectively. T1-weighted MR images showed characteristic fatty replacement patterns that were consistent with the causative genes. Unsupervised hierarchical clustering of the Mercuri scale showed that the main factors contributing to the dichotomy were the causative gene and the clinical severity. Conclusions: This study is the first to reveal the usefulness of lower-limb MR images in the differential diagnosis of distal myopathy in Korea.

• Annals of Clinical Neurophysiology
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• v.3 no.1
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• pp.1-8
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• 2001

The distal myopathies(DM) are clinically defined as inherited or sporadic primary muscle disorders characterized by progressive muscular weakness and atrophy beginning in the hands or feet and pathologically by myopathic changes in skeletal muscles. The pathologic changes are somewhat similar to those seen in chronic muscular dystrophy, but necrotic and regenerative processes are less prominent and creatine kinase levels are either normal or only mildly elevated. The most representative diseases are dominantly inherited Welander distal myopathy and tibial muscular dystrophy, and the recessively inherited distal myopathy with rimmed vacuoles and distal muscular dystrophy(Miyoshi myopathy). At present, further study is necessary to determine why rimmed vacuoles are so common in the DM, and what role they play in the pathogenesis of muscle fiber atrophy and loss, predominantly in the distal portions of the extremities.

• Journal of Life Science
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• v.24 no.3
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• pp.311-317
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• 2014

Distal myopathy with rimmed vacuoles (DMRV) or hereditary inclusion body myopathy 2 is an autosomal recessive muscular disorder characterized by early adult-onset weakness of distal muscles and rimmed vacuoles in muscle biopsy. Mutations in the UDP-N-acetylglucosamine 2-epimerase/N-ace-tylmannosamine kinase (GNE) gene are associated with the development of DMRV. In this study, whole exome sequencing (WES) revealed compound heterozygous GNE mutations of p.Asp176Val and p.Val572Leu in a patient with distal limb weakness. Three hundred healthy controls did not show these mutations. All other variants found in distal myopathy-relevant genes were polymorphic. These findings confirmed that the patient had DMRV. This work underscores the usefulness of WES in improving the molecular diagnosis of myopathy.

• Annals of Clinical Neurophysiology
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• v.18 no.1
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• pp.31-33
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• 2016

• Journal of Genetic Medicine
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• v.13 no.1
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• pp.51-54
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• 2016

Centronuclear myopathy (CNM) is a rare congenital myopathy that is pathologically characterized by the centrally located nuclei in most of the muscle fibers. On clinical examination, dynamin 2 (DNM2)-related CNM typically shows distal dominant muscle atrophy, ptosis, ophthalmoplegia, and contracture. The reported cases of CNM in Caucasian studies show a high prevalence rate of early-onset ptosis and ophthalmoplegia and correlated with the severity of the disease. However, Asian reports show a low prevalence and late-onset ocular symptoms in DNM2-related CNM patients. p.R465W is one of the most commonly found mutations in Western countries, and all the cases showed ocular symptoms. The proband and his daughter had no ocular symptoms despite harboring the same p.R465W mutation. This family makes us speculate that ocular symptoms in DNM2-related CNM are influenced by ethnic background. In addition, this is the first familial case of DNM2-related CNM in Korea.

• Journal of Life Science
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• v.30 no.8
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• pp.672-679
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• 2020

Distal myopathy is a clinically and genetically heterogeneous group of degenerative diseases of the distal muscle. Glycogen storage disease type IXD (GSD9D) is a metabolic distal myopathy characterized by muscle deficiency of phosphorylase kinase, a key regulatory enzyme in glycogen metabolism. Affected individuals may develop muscle weakness, degeneration, and cramps, as well as abnormal muscle pain and stiffness after exercise. It has been reported that mutations in the PHKA1 gene which encodes the alpha subunit of muscle phosphorylase kinase cause GSD9D. In this study, we examined a Korean GSD9D family with a c.3314T>C (p.I1105T) mutation in the PHKA1 gene. This mutation has not been previously reported in any mutation database nor was it found in 500 healthy controls. The mutation region is well conserved in various other species, and in silico analysis predicts that it is likely to be pathogenic. To date, only seven mutations in the PHKA1 gene have been documented, and this is the first report of Korean GSD9D patients. This study also describes and compares the clinical symptoms and pathological conditions of previously reported cases and these Korean patients. We believe that our findings will be useful for the molecular diagnosis of GSD9D.

• Advances in pediatric surgery
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• v.8 no.1
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• pp.54-61
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• 2002

Hirschsprung's disease (HD) is usually diagnosed in the newborn period and early infancy. The common presentation of HD in newborns consists of a history of delayed passage of meconium within the first 48 hours of life. The differential diagnosis in newborns is one of the clinical challenges of this disorder. A number of medical conditions which cause functional obstruction of the intestines are easily excluded. Neonates with meconium ileus, meconium plug syndrome, distal ileal atresia and low imperforate anus often present in a manner similar to those with HD in the first few days of life. Abdominal radiographs may help to diagnose complete obstruction such as intestinal atresia. Microcolon on contrast enema can be shown in cases with total colonic aganglionosis, ileal atresia or meconium ileus. Suction rectal biopsy or frozen section biopsy at operation is essential for differential diagnosis in such cases. HD is also considered in any child who has a history of constipation regardless of age. Older children with functional constipation may have symptoms that resemble those of HD and contrast enema is usually diagnostic. However, children with other motility disorders generally referred to as chronic idiopathic intestinal pseudoobstruction present with very similar symptoms and radiographic findings. These disorders are classified according to their histologic characteristics.; visceral myopathy, visceral neuropathy, intestinal neuronal dysplasia (IND), hypoganglionosis, immature ganglia, internal sphincter achalasia. Therefore, the workup for motility disorders should include rectal biopsy not only to confirm the presence of ganglion cells but also evaluate the other pathologic conditions.

• Journal of Yeungnam Medical Science
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• v.25 no.2
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• pp.117-123
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• 2008

Dermatomyositis is characterized by progressive, symmetric, proximal muscle weakness and a nonsuppurative inflammatory myopathy of unknown etiology involving predominantly skeletal muscles. It is also characterized by typical skin lesions. Interstitial lung disease has a poor prognosis when it is associated with dermatomyositis. Organizing pneumonia is a disease in which granulation tissue fills the lumina of terminal and respiratory bronchioles and extends into the distal airspaces. The cryptogenic nature of the process is appreciated in that organizing pneumonia patterns of injury can be seen in secondary forms of the disease (secondary organizing pneumonia). Organizing pneumonia has been reported to occur in 5~10% in dermatomyositis-polymyositis patients. Anti-histidyl tRNA synthetase antibody (anti-Jo-1) is a predictive disease marker that is reported to occur in up to 70% of patients. We describe a 49-year-old male dermatomyositis patient who presented with organizing pneumonia and was found to have negative anti-Jo-1 antibody.