Centronuclear Myopathy With Type I Fiber Atrophy and "Myotubes"

RECENTLY patients have been described with muscle fibers that resembled the myotubes seen in early fetal life.1-11In some of these cases, there were many fibers of small diameter, predominantly or exclusively of type I.5,6,9,11 In this paper, a patient is found to have a neuromuscular disease that differs histopathologically from cases described hitherto. Report of a Case The patient was a 38-year-old woman. Motor development appeared normal until age 5 years. From that time, there was a slowly progressing paresis of the legs. During pregnancies at age 25 and 27, the weakness increased. There was no diplopia or weakness of the arms. In the family, no other siblings were known to be suffering from a neuromuscular disease. Examination revealed a well-developed woman of average intelligence. There was no ptosis and no weakness of the facial, extraocular, and neck muscles. The strength of the deltoid and biceps