CMT 2: Mutations in the mitofusin 2 gene are the most common cause of CMT 2

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Neurol Neurochir Pol. 2007 Jul-Aug;41(4):350-4.

Mutations in the mitofusin 2 gene are the most common cause of

Charcot-Marie-Tooth type 2 disease

So³tysiñska E, Kabziñska D, Kochañski A.

Zespó³ Badawczo-Leczniczy Chorób Nerwowo-Mieœniowych, Instytut

Medycyny Doœwiadczalnej i Klinicznej im. M. Mossakowskiego Polskiej

Akademii Nauk, ul. A. Pawiñskiego 5, 02-106 Warszawa, tel./faks +48

22 658 45 01

In contrast to Charcot-Marie-Tooth type 1 disease (CMT1), which is

most commonly caused by 17p11.2-p12 duplication (in 70% of CMT1

cases), the axonal form of hereditary motor and sensory neuropathy

(CMT2) seemed to be a genetically heterogeneous disease group, with

no single gene playing a major pathogenetic role.

In 2004, 10 mutations were identified in CMT2A families in the MFN2

gene coding for the mitochondrial protein mitofusin-2, previously

mapped to the 1p35-36 locus.

In the last two years, MFN2 gene mutations were shown to be the most

common cause of autosomal dominant hereditary axonopathy. In

addition, MFN2 gene mutations were also identified in CMT type 6

(axonal neuropathy with optic nerve atrophy).

Recent reports indicate that some MFN2 gene mutations may by

inherited as autosomal recessive traits. As MFN2 gene mutations are

the most common cause of autosomal dominant CMT2 disease (33% of

cases), MFN2 gene testing may be considered a diagnostic test for

CMT2.