title: A novel 9-bp insertion in the GJB1 gene causing a mild form of X-linked CMT with late onset.
abstract: X-linked Charcot-Marie-Tooth disease is the second most common variant of CMT. CMTX1 is caused by mutations in the GJB1 gene encoding for connexin 32. We describe an Italian family with an intermediate CMTX phenotype with late onset. Mutation screening of the GJB1 gene revealed a 9-bp duplication leading to the insertion of three aminoacids (Thr-Val-Phe) between the end of the second extracellular domain and the beginning of the fourth transmembrane domain. This is the third in-frame insertion in the GJB1 gene identified so far and, like the previous ones, it consists in the duplication of the flanking sequence which is repeated in tandem in the wild-type gene.
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Vazza
authors.forename: L
authors.initials: L
authors.lastname: Merlini
authors.forename: C
authors.initials: C
authors.lastname: Bertolin
authors.forename: M
authors.initials: M
authors.lastname: Zortea
authors.forename: M L
authors.initials: ML
authors.lastname: Mostacciuolo
mesh_terms: D000328:Adult; D017668:Age of Onset; D000595:Amino Acid Sequence / Q000235:genetics; D019943:Amino Acid Substitution / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D002607:Charcot-Marie-Tooth Disease / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D040181:Genetic Diseases, X-Linked / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D007558:Italy; D008297:Male; D009133:Muscular Atrophy / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D009154:Mutation / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D000097002:Gap Junction beta-1 Protein
chemical_list: D017630:Connexins; D000097002:Gap Junction beta-1 Protein