autonomic and respiratory dysfunction MPZ gene research from France

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Abstract from Clin Neurophysiol. 2003 Sep;114(9):1609-1614.

Autonomic and respiratory dysfunction in Charcot-Marie-Tooth disease due

to Thr124Met mutation in the myelin protein zero gene.

Stojkovic T, de Seze J, Dubourg O, Arne-Bes MC, Tardieu S, Hache JC,

Vermersch P.

Department of Neurology, University of Lille, 59037 Cedex, Lille, France

OBJECTIVE: To report the clinical and electrophysiological

characteristics of a family presenting Charcot-Marie-Tooth disease (CMT)

associated with autonomic nervous system

disturbances.

METHODS: We studied nerve conduction values, postural adaptation,

sympathetic skin reflex, the variation in heart rate by the Valsalva

ratio and pupillometry in 7 members of a French family in which CMT due

to a Thr124Met mutation in the myelin protein zero (MPZ) gene was

diagnosed.

RESULTS: Clinical and laboratory evidence of autonomic nervous system

disturbances were found in the affected individuals. The clinical

phenotype was characterized by sensorimotor peripheral neuropathy,

defined as axonal type by electrophysiological studies, and was

associated with severe pain, bladder dysfunction, sudorimotor

disturbances and abolished pupillary reflex to light. Moreover, two

patients had severe restrictive respiratory insufficiency requiring

noninvasive mechanical ventilation.

CONCLUSIONS: Our study demonstrates that autonomic disturbances may be

one of the major clinical signs associated with CMT secondary to MPZ

gene mutation in codon 124. Testing of pupillary reflex allows the

discrimination of affected and unaffected subjects in our family.

However, involvement of the autonomic nervous system in this type of

neuropathy is unclear and further studies are required to elucidate the

role of the MPZ gene in the autonomic nervous system.