A pedigree of CMT 4F (Periaxin mutation)

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Rinsho Shinkeigaku. 2005 Mar;45(3):221-5.

A pedigree of Charcot-Marie-Tooth disease type 4F (Periaxin mutation)

Shimohata M, Hirahara K, Igarashi S, Hara K, Kijima K, Onodera O,

Tanaka K, Nishizawa M, Tsuji S, Hayasaka K.

Department of Neurology, Brain Research Institute, Niigata University.

We report a 51-year-old man genetically diagnosed as Charcot-Marie-

Tooth disease type 4F. The patient was the first child of healthy,

consanguineous parents. He had two sisters and one of them showed

similar but milder symptoms.

He had gait disturbance since childhood. Then he noticed muscle

weakness of his hands at the age of early forties, and more

difficulties in gait at the age of late forties.

On examination at age 51, he showed absence of all deep tendon

reflexes, weakness of the hand and distal leg muscles, pes cavus and

decreased sensitivity to touch and vibration in the lower

extremities.

Electrophysiological studies of the median nerve showed delayed motor

nerve conduction velocity and undetectable sensory nerve action

potentials. The histology of his sural nerve revealed moderate loss

of large myelinated fibers and the diameters of residual fibers

shifted to small shown as size-frequency histogram. Many fibers are

thinly myelinated and some of the Schwann cells looked as wrapping

around the myelinate fibers with their processes.

On gene analyses, we identified an Arg 1070 Stop homozygous mutation

in the Periaxin, known to be a causative gene for CMT type 4F. Based

on these observations, we emphasized that broad genetic analyses are

necessary for diagnosis of CMT disease, including so far unidentified

mutations among the Japanese populations.