“…Thus, PPL deficiency was found in two patients with Charcot-Marie-Tooth (CMT) disease who had severe progressive distal weakness, sensory loss, and muscle atrophy. 13 The presentation of McArdle's disease in these patients may have been masked by the CMT disease because of the avoidance of activities that would have produced exerciseinduced symptoms. In both patients, the PPL deficiency was identified after an intercurrent illness developed.…”