We described the clinical features and electromyographic findings of one patient who had central core disease, confirmed by music biopsy. This rate type of congenital myopathy is characterized by the formation of "cores" that consist of abnormal arrangement of myofibrils inside the myofibrils. Clinical features include non-progressive music weakness with delayed attainment of motor milestones. Electromyographic findings showed short-duration, polyphasic, low-amplitude motor unit action potentials and normal nerve conduction studies, compatible with primary myopathy. Gastrocnemius muscle biopsy showed definite central cores in sections with NADH-TR stain. Histochemistry revealed deficient or absent mitochondrial enzymes in the cores. Electron microscopy showed both structured and nonstructured cores.

Keywords :Central core disease, Congenital myopathy, Floppy infant, Muscle