Muscle biopsy abnormalities differ between Charcot-Marie-Tooth type 1 and 2: reflect different pathophysiology?

: Muscle biopsy specimens have shown neuropathic findings in Charcot-Marie-Tooth (CMT) disease Type 1 (demyelinating form) and myopathic findings in CMT 2 (axonal form). Neurophysiological studies showed an active denervation-reinnervation process in CMT 1, whereas the CMT2 patients had a low reinnervation capacity and, thus, compensated for the loss of motor units by increasing the contractile tissue.