CMT 2F: Distal hereditary motor neuropathy in Korean patients with a small heat

[Guest guest]

Exp Mol Med. 2008 Jun 30;40(3):304-12.

Distal hereditary motor neuropathy in Korean patients with a small

heat shock protein 27 mutation.

Chung KW, Kim SB, Cho SY, Hwang SJ, Park SW, Kang SH, Kim J, Yoo JH,

Choi BO.

Department of Biological Science, Kongju National University, Gongju

314-701, Korea.

Distal hereditary motor neuropathy (dHMN) is a heterogeneous disorder

characterized by degeneration of motor nerves in the absence of

sensory abnormalities. Recently, mutations in the small heat shock

protein 27 (HSP27) gene were found to cause dHMN type II or Charcot-

Marie-Tooth disease type 2F (CMT2F).

The authors studied 151 Korean axonal CMT or dHMN families, and found

a large Korean dHMN type II family with the Ser135Phe mutation in

HSP27. This mutation was inherited in an autosomal dominant manner,

and was well associated with familial members with the dHMN

phenotype. This mutation site is located in the ?-crystallin domain

and is highly conserved between different species.

The frequency of this HSP27 mutation in Koreans was 0.6%. Magnetic

resonance imaging analysis revealed that fatty infiltrations tended

to progressively extend distal to proximal muscles in lower

extremities. In addition, fatty infiltrations in thigh muscles

progressed to affect posterior and anterior compartments but to

lesser extents in medial compartment, which differs from CMT1A

patients presenting with severe involvements of posterior and medial

compartments but less involvement of anterior compartment.

The authors describe the clinical and neuroimaging findings of the

first Korean dHMN patients with the HSP27 Ser135Phe mutation. To our

knowledge, this is the first report of the neuroimaging findings of

dHMN type II.