Title: | Phenotypic spectrum of dynamin 2 mutations in Charcot-Marie-Tooth neuropathy. |
Author(s): | Claeys, K.G.; Zuchner, S.; Kennerson, M.; Berciano, J.; Garcia, A.; Verhoeven, K.; Storey, E.; Merory, J.R.; Bienfait, H.M.; Lammens, M.M.Y. ; Nelis, E.; Baets, J.; Vriendt, E. De; Berneman, Z.N.; Veuster, I. De; Vance, J.M.; Nicholson, G.; Timmerman, V.; Jonghe, P. de |
Publication year: | 2009 |
Source: | Brain, vol. 132, iss. Pt 7, (2009), pp. 1741-1752 |
ISSN: | 0006-8950 |
DOI: | https://doi.org/10.1093/brain/awp115 |
Publication type: | Article / Letter to editor |
Please use this identifier to cite or link to this item : https://hdl.handle.net/2066/81938 ![]() |
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Subject: | DCN 1: Perception and Action |
Organization: | Neurology Pathology |
Journal title: |
Brain
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Volume: | vol. 132 |
Issue: | iss. Pt 7 |
Page start: | p. 1741 |
Page end: | p. 1752 |
Abstract: |
Dominant intermediate Charcot-Marie-Tooth neuropathy type B is caused by mutations in dynamin 2. We studied the clinical, haematological, electrophysiological and sural nerve biopsy findings in 34 patients belonging to six unrelated dominant intermediate Charcot-Marie-Tooth neuropathy type B families in whom a dynamin 2 mutation had been identified: Gly358Arg (Spain); Asp551_Glu553del; Lys550fs (North America); Lys558del (Belgium); Lys558Glu (Australia, the Netherlands) and Thr855_Ile856del (Belgium). The Gly358Arg and Thr855_Ile856del mutations were novel, and in contrast to the other Charcot-Marie-Tooth-related mutations in dynamin 2, which are all located in the pleckstrin homology domain, they were situated in the middle domain and proline-rich domain of dynamin 2, respectively. We report the first disease-causing mutation in the proline-rich domain of dynamin 2. Patients with a dynamin 2 mutation presented with a classical Charcot-Marie-Tooth phenotype, which was mild to moderately severe since only 3% of the patients were wheelchair-bound. The mean age at onset was 16 years with a large variability ranging from 2 to 50 years. Interestingly, in the Australian and Belgian families, which carry two different mutations affecting the same amino acid (Lys558), Charcot-Marie-Tooth cosegregated with neutropaenia. In addition, early onset cataracts were observed in one of the Charcot-Marie-Tooth families. Our electrophysiological data indicate intermediate or axonal motor median nerve conduction velocities (NCV) ranging from 26 m/s to normal values in four families, and less pronounced reduction of motor median NCV (41-46 m/s) with normal amplitudes in two families. Sural nerve biopsy in a Dutch patient with Lys558Glu mutation showed diffuse loss of large myelinated fibres, presence of many clusters of regenerating myelinated axons and fibres with focal myelin thickenings--findings very similar to those previously reported in the Australian family. We conclude that dynamin 2 mutations should be screened in the autosomal dominant Charcot-Marie-Tooth neuropathy families with intermediate or axonal NCV, and in patients with a classical mild to moderately severe Charcot-Marie-Tooth phenotype, especially when Charcot-Marie-Tooth is associated with neutropaenia or cataracts.
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