Charcot-Marie-Tooth disease type I and related demyelinating neuropathies: Mutation analysis in a large cohort of Italian families

✍ Scribed by M.L. Mostacciuolo; E. Righetti; M. Zortea; V. Bosello; F. Schiavon; L. Vallo; L. Merlini; G. Siciliano; G.M. Fabrizi; N. Rizzuto; M. Milani; S. Baratta; F. Taroni

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 230 KB
• Volume: 18
• Category: Article
• ISSN: 1059-7794
• DOI: 10.1002/humu.1147

✦ Synopsis

Tooth neuropathy type 1 (CMT1), the most common hereditary neurological disorder in humans, is characterized by clinical and genetic heterogeneity. It is caused mainly by a 1.5 Mb duplication in 17p11.2, but also by mutations in the myelin genes PMP22 (peripheral myelin protein 22), MPZ (myelin protein zero), Cx32 (connexin 32; also called GJB1), and EGR2 (early growth response 2). In this study, we have screened 172 index cases of Italian families in which there was at least one subject with a CMT1 diagnosis for the duplication on 17p11.2 and mutations in these genes. Among 170 informative unrelated patients, the overall duplication frequency was 57.6%. A difference could be observed between the duplication frequency in familial cases (71.6%) and that observed in non-familial cases (36.8%). Among the non-duplicated patients, 12 were mutated in Cx32, four in MPZ, two in PMP22, and none in the EGR2. In the non-duplicated cases, the overall point mutation frequency for these genes was 25.0%. We describe the mutations identified, and consider possible genotype-phenotype correlation. Hum Mutat 18:32-41, 2001.