Central core disease is a rare congenital myopathy characterized by the formation of cores that consist of abnormal arrangement of myofibrils inside the myofibers. We report a 5-year-old Korean girl who showed a fairly typical clinical course of non-progressive muscle weakness. Electrodiagnostic studies showed low-amplitude polyphasic electromyograph and normal nerve conduction velocity. Gastrocnemius muscle biopsy showed central cores in over 80% of the fibers on H&E section. Histochemistry revealed deficient or absent mitochondrial enzyme in the cores and type I predominance. Ultrastructurally both structured and non-structured cores were found separately or simultaneously in one fiber. This case is the first report in the Korean literature.
Child, Preschool ; Female ; Humans ; Microscopy, Electron ; Muscles/pathology/ultrastructure ; Muscular Diseases/*congenital/*pathology

Centronuclear myopathy is a rare congenital myopathy, which is characterized by centrally located nuclei and hypotrophy or predominance of type 1 fibers in muscle pathology. It is classified into three forms according to the clinical features and inheritance pattern: the X-linked recessive, the autosomal recessive, and the autosomal dominant forms. We report a case of a patient with generalized muscle weakness, poor muscle bulk, and dysmorphic features who was diagnosed as centronuclear myopathy.
Humans ; Inheritance Patterns ; Muscle Weakness ; Muscular Diseases ; Myopathies, Structural, Congenital* ; Pathology

Congenital fiber type disproportion (CFTD) is a form of congenital myopathy characterized by histologic findings of the smallness of type 1 fiber and type 1 fiber predominance. It is usually associated with hypotonia and motor weakness of the limb muscles at birth or the neonatal period. We report a 6-year-old girl with limb weakness and ophthalmoplegia, whose muscle pathology showed the classic pattern of CFTD without any other abnormality.
Child ; Extremities ; Female ; Humans ; Muscle Hypotonia ; Muscles ; Muscular Diseases ; Myopathies, Structural, Congenital* ; Ophthalmoplegia* ; Parturition ; Pathology

Myotubular or centronuclear myopathy(MTM) is a rare congenital myopathy, which is characterized by predominance and atrophy of type 1 fibers and centrally located nuclei in muscle pathology. The clinical features and severity are quite variable. MTM is classified as three forms according to the inheritance pattern : autosomal dominant, autosomal recessive and X-linked recessive. The authors present familial myotubular myopathy, suggestive of X linked, occurred in a sibling with intrafamilial clinical variability.
Atrophy ; Humans ; Inheritance Patterns ; Muscular Diseases ; Myopathies, Structural, Congenital* ; Pathology ; Siblings*

All the diagnostic muscle biopsy cases were collected from the file of Department of Pathology, Seoul National University Hospital during June 1976 to December 1978. Slides were reviewed and correlated with clinical informations. Two hundred seventy four cases showed pathological changes, which were classified into six large groups (Table 1). Neurogenic atrophy was most common, 97 cases (35%), including 71 cases of motor neuron disease and 22 cases of peripheral neuropathy. Muscular dystrophy was seen in 92 cases (34%), and Duchenne type was the commonest among them (51 cases). Fifty seven cases showed inflammatory myopathy, making 20% of all cases. There were four cases of congenital myopathy and 13 cases showed various muscle diseases.
Adult ; Aged ; Child, Preschool ; Female ; Humans ; Infant ; Korea ; Male ; Middle Aged ; Motor Neurons/*pathology ; Muscular Diseases/congenital/*epidemiology/immunology ; Muscular Dystrophies/*epidemiology ; Neuromuscular Diseases/*epidemiology

Congenital myopathies are clinical and genetic heterogeneous disorders characterized by skeletal muscle weakness and specific structural changes in muscle fiber. Congenital myopathy with fiber type disproportion (CFTD) is an established disorder of congenital myopathy. CFTD is characterized by non-progressive childhood neuromuscular disorders with a relatively good prognosis and type 1 fiber predominance and smallness. Congenital myopathy with type 1 fiber predominance (CMT1P) is also a distinct entity of congenital myopathy characterized by non-progressive childhood neuromuscular disorders and type 1 fiber predominance without smallness. Little is known about CMT1P. Clinical characteristics, including dysmorphic features such as hip dislocation, kyphoscoliosis, contracture, and high arch palate, were analyzed along with laboratory and muscle pathologies in six patients with CMT1P and three patients with CFTD. The clinical manifestations of CFTD and CMT1P were similar. However, the frequency of dysmorphic features is less in CMT1P than in CFTD. Long term observational studies of CMT1P are needed to determine if it will change to another form of congenital myopathy or if CMT1P is a distinct clinical entity.
Myopathies, Structural, Congenital/*diagnosis ; Muscular Diseases/*pathology ; Muscles/pathology ; Male ; Infant ; Humans ; Female ; Child, Preschool ; Child ; Biopsy ; Adult