A case of congenital myopathy with myonuclear changes consistent with apoptotic degeneration in a 4-year-old girl is reported from the National Institute of Neuroscience, Tokyo, Japan. She was hypotonic at birth and psychomotor development was markedly delayed. Brain MRI was normal. DNA fragmentation in myonuclei was demonstrated by the TUNEL method and supported by ultrastuctural characteristics and immunochemistry. 
COMMENT. The authors add a new type of structural abnormality associated with congenital myopathy. Other types include central core disease, nemaline myopathy, myotubular myopathy, and congenital fiber-type disproportion.