LETTER TO THE EDITOR Myopathic (not neuropathic) electrophysiological abnormalities in dynamin 2-related centronuclear myopathy

Sir, I read with great interest the recent article ‘Characteriza-tion of the muscle involvement in dynamin 2-related centro-nuclear myopathy ’ (DNM2-CNM) (Fischer et al., 2006). I commend the authors for their work in helping us under-stand how DNM2-CNM is manifested on physical examina-tion, muscle computerized tomography, and so forth. The article states that out of the nine DNM2-CNM patients who underwent electrodiagnostic testing all patients hadmyo-pathic changes on needle electrode examination (NEE) but that four patients had ‘additional neuropathic signs such as pathological spontaneous activity (fibrillations) on NEE and/ or a 15–30 % reduction of the compound motor action poten-tials (CMAPs) in some lower leg nerves on nerve conduction studies (NCSs). These results are consistent with features of the axonal Charcot–Marie–Tooth forms.