Mutation analysis of MFN2, GJB1, MPZ and PMP22 in Italian patients with axonal Charcot-Marie-Tooth disease

Giorgia Bergamin, Francesca Boaretto, Chiara Briani, Elena Pegoraro, Mario Cacciavillani, Andrea Martinuzzi, Maria Muglia, Andrea Vettori, Giovanni Vazza, Maria Luisa Mostacciuolo

Research output: Contribution to journalArticlepeer-review

Abstract

Charcot-Marie-Tooth (CMT) diseases include a group of clinically heterogeneous inherited neuropathies subdivided into demyelinating (CMT1), axonal (CMT2) and intermediate CMT forms. CMTs are associated with different genes, although mutations in some of these genes may cause both clinical pictures. To date, more than 50 CMT genes have been identified, but more than half of the cases are due to mutations in MFN2, MPZ, GJB1 and PMP22. The aim of this study was to estimate the frequency of disease mutations of these four genes in the axonal form of CMT in order to evaluate their effectiveness in the molecular diagnosis of CMT2 patients. A cohort of 38 CMT2 Italian subjects was screened for mutations in the MFN2, MPZ and GJB1 genes by direct sequencing and for PMP22 rearrangements using the MLPA technique. Overall, we identified 15 mutations, 8 of which were novel: 11 mutations (28.9 %) were in the MFN2 gene, 2 (5.3 %) in MPZ and 2 (5.3 %) in PMP22. No mutations were found in GJB1. Two patients showed rearrangements in the PMP22 gene, which is commonly associated with CMT1 or HNPP phenotypes thus usually not tested in CMT2 patients. By including this gene in the analysis, we reached a molecular diagnosis rate of 39.5 %, which is one of the highest reported in the literature. Our findings confirm the MFN2 gene as the most common cause of CMT2 and suggest that PMP22 rearrangements should be considered in the molecular diagnosis of CMT2 patients.

Original languageEnglish
Pages (from-to)540-550
Number of pages11
JournalNeuroMolecular Medicine
Volume16
Issue number3
DOIs
Publication statusPublished - 2014

Keywords

  • Axonal neuropathy
  • Charcot-Marie-Tooth disease
  • Molecular diagnosis
  • Mutation screening

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Molecular Medicine
  • Neurology
  • Medicine(all)

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