Parasympathetic Dominant Autonomic Dysfunction in Charcot-Marie-Tooth Disease Type 2J with the MPZ Thr124Met Mutation

We herein report the case of a 69-year-old woman with Charcot-Marie-Tooth Disease type 2J (CMT2J) who presented with Adie's pupil, deafness, and urinary disturbance in addition to motor symptoms. On autonomic investigation, the coefficient of variation of the R-R intervals was decreased, and a urodynamic analysis showed a hypotonic bladder. A heart rate variability analysis revealed a decreased high frequency component and low frequency/high frequency ratio. Orthostatic hypotension was not present, and the sympathetic skin response and cardiac scintigraphy using (123)I-metaiodobenzylguanidine were normal. A gene analysis showed a known heterozygous mutation associated with CMT2J in myelin protein zero exon 3, resulting in the substitution of threonine to methionine at position 124. Our case suggests that mainly the parasympathetic autonomic function is disturbed in CMT2J.