title: Prevalence of Deafness-Associated Connexin-26 (GJB2) and Connexin-30 (GJB6) Pathogenic Alleles in a Large Patient Cohort from Eastern Sicily.
abstract: Mutations in the gene encoding the gap junction protein connexin 26 (GJB2) and connexin 30 (GJB6) have been shown to be a major contributor to prelingual, sensorineural, nonsyndromic deafness. The aim of this study was to characterize and establish the prevalence of GJB2 and GJB6 gene alterations in 196 patients affected by sensorineural, nonsyndromic hearing loss, from Eastern Sicily. We performed sequence analysis of GJB2 and identified sequence variants in 68 out of 196 patients (34.7%); (28 homozygous for c.35delG, 22 compound heterozygous and 11 with only one variant allele). We found 12 different allelic variants, the most prevalent being c.35delG, which was found on 89 chromosomes (65.5%), followed by other alleles with different frequencies (p.E47X, c.-23+1G>A, p.L90P, p.R184W, p.M34T, c.167delT, p.R127H, p.M163V, p.V153I, p.W24X, and p.T8M). Importantly, for the first time we present the frequency and spectrum of GJB2 mutations in NSHL patients from Eastern Sicily. No alterations were found in the GJB6 gene, confirming that alterations in this gene are uncommon in our geographic area. Note that 65.3% and 23.5% of our patients, respectively were found to be negative or carriers by GJB2 molecular screening. This emphasizes the need to broaden the genetic analysis to other genes involved in hearing loss.
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Amorini
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Petronilla
authors.initials: P
authors.lastname: Romeo
authors.affiliation: Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy.
authors.forename: Rocco
authors.initials: R
authors.lastname: Bruno
authors.affiliation: Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Galletti
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Di Bella
authors.affiliation: Department of Experimental Medical-Surgery, Specialist and Odontostomatological Science, Otorhinolaringology and Auditory Microsurgery Unit, University of Messina, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Longo
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Silvana
authors.initials: S
authors.lastname: Briuglia
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Salpietro
authors.affiliation: Department of Paediatrics, University of Messina, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Rigoli
keywords: Eastern Sicily population; Prevalance of connexin-26 (GJB2) and connexin-30 (GJB6) allelic variants; nonsyndromic hearing loss