Median nerve motor conduction velocity is concordant with myelin protein zero gene mutation

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J Neurol. 2005 Feb;252(2):151-5.

Median nerve motor conduction velocity is concordant with myelin protein zero

gene mutation.

Lee YC, Soong BW, Liu YT, Lin KP, Kao KP, Wu ZA.

The Neurological Institute, Taipei Veterans General Hospital #201, Sec. 2,

Shih-Pai Road, Peitou District, Taipei, Taiwan 11217 (ROC).

BACKGROUND : Myelin protein zero gene (MPZ) mutations may account for a small

proportion of cases of Charcot-Marie-Tooth disease (CMT). Different MPZ

mutations may be associated with different clinical and electrophysiological

phenotypes.

OBJECTIVES : To expand our understanding of the characteristics of nerve

conduction velocity (NCV) in patients with different MPZ mutations, the authors

collected and analysed the NCV values from patients with MPZ mutations.

MATERIALS AND METHODS : The NCVs of fourteen patients from six families carrying

MPZ mutations of Val58Asp, Ser63Phe, Thr65Ile,Arg98Cys, Arg98His, and Ser233fs

were collected retrospectively. Five of them had received nerve conduction

studies (NCS) twice. The mutations were verified by polymerase chain reaction

(PCR) amplifications and nucleotide sequencing. Scatterplot analyses of median

motor NCV (MNCV) versus specific MPZ mutation were performed.

RESULTS : The median MNCV varied widely, with a mean of 16.3 m/s (SD=7.7 m/s)

and a range of 5.1-32.9 m/s. Median MNCVs of patients with particular MPZ

mutations were similar. Moreover, Median MNCV did not change significantly over

time.

CONCLUSIONS : There was concordance between median MNCV and specific MPZ

mutations. However, median MNCV is not an ideal measure with which to

distinguish CMT1B patients with MPZ mutations from CMT1A patients with PMP22

mutations.