Centronuclear ("Myotubular") Myopathy

IN 1966 Spiro and co-workers1reported a 12-year-old boy with slowly progressive weakness from infancy who had unusual muscle fibers with centrally placed nuclei. Histochemical alterations in the central portions of the muscle fibers were noted. Because of similarities between these muscle fibers and the stage of embryogenesis, the authors designated the disorder myotubular myopathy and suggested an arrested state of development persisting into adolescence. Two sisters and an additional female with similar histochemical, clinical, and structural findings have been more recently reported.2,3The present paper describes the fifth reported case. However, certain differing structural and histochemical findings suggest a less specific pathogenesis. Methods Muscle biopsy was obtained with an isometric clamp. Part of the specimen was fixed in 10% formol alcohol for paraffin embedding. Hematoxylin and eosin (H & E), periodic acid-Schiff (PAS), Masson's trichrome, phosphotungstic acid hematoxylin (PTAH), and oil red O stains were done