The rigid spine syndrome and Emery-Dreifuss muscular dystrophy.

We present five patients, three of whom suffered from a rigid spine syndrome and two from Emery-Dreifuss muscular dystrophy. One patient with rigid spine syndrome showed a nonprogressive course, normal cardiac rhythm and mild myopathic changes in muscle histology, while in the other two patients there was a rapidly progressive course, sinus tachycardia without cardiac conduction defects and marked fiber necrosis in muscle histology. The two patients suffering from Emery-Dreifuss muscular dystrophy showed a very mildly progressing course, myopathic changes in muscle histology, cardiac conduction defects and deviations in electrocardiograms. These findings show that rigid spine syndrome can be distinguished from Emery-Dreifuss muscular dystrophy.