CMT families in Japan with MPZ Thr124Met mutation

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Abstract from J Neurol Neurosurg Psychiatry. 2004 Oct;75(10):1492-4.

Charcot-Marie-Tooth families in Japan with MPZ Thr124Met mutation.

Kurihara S, Adachi Y, Imai C, Araki H, Hattori N, Numakura C, Lin Y,

Hayasaka K, Sobue G, Nakashima K.

Department of Neurology, Institute of Neurological Sciences, Faculty of

Medicine, Tottori University, 36-1 Nishimachi, Yonago, Tottori 683-8504

Japan.

BACKGROUND: The MPZ Thr124Met mutation is characterised by a late onset,

pupillary abnormality, deafness, normal or moderate decreased motor

nerve conduction velocity, and axonal damage in sural nerve biopsy.

OBJECTIVE: To investigate the clinical manifestations of the axonal or

demyelinating forms of the Japanese MPZ Thr124Met mutation originating

in four different areas: Tottori, Nara, Aichi, and Ibaragi.

RESULTS: Genotyping with DNA microsatellite markers linked to the MPZ

gene on chromosome 1q22-q23 showed shared allelic characteristics

between 12.65 cM and revealed a common haplotype in all Tottori

families. Aichi and Ibaragi families shared parts of the haplotype

around the MPZ gene. However, there was no consistency with a Nara

family.

CONCLUSIONS: The high frequency of this peculiar genotype in the Tottori

CMT population is presumably due to a founder effect, but in Thr124 it

might constitute a mutation hotspot in the MPZ gene.