Among 336 children with prelingual deafness who underwent implantation in our department between 1997 and 2007, 85 with GJB2 gene-related (Cx) deafness and 30 patients with Waardenburg syndrome (WaardS) were included.
Mutations in the genes GJB2 and GJB6 encoding human connnexin26 (hCx26) and connexin30 (hCx30), respectively, are the leading cause of non-syndromic prelingual deafness in several human populations.
Determine the prevalence of 35delG mutation in GJB2 gene in patients with prelingual deafness of no defined etiology whose underwent cochlear implant in the Otolaryngology Department at the Hospital de Clínicas de Porto Alegre and compare the speech recognition index using an open-set of sentences according to the presence or absence of the 35delG mutation.
Mutations in Gjb2 and Gjb6 genes, coding for connexin26 (Cx26) and Cx30 proteins, respectively, are linked to about half of all cases of human autosomal non-syndromic prelingual deafness.
Mutations in the genes GJB2 and GJB6, which encode the proteins Connexin 26 (Cx26) and Connexin 30 (Cx30), have been linked to nonsyndromic prelingual deafness in humans.
DFNB1 is the most common identifiable etiology of nonsyndromic prelingual deafness both in sporadic and familial cases in this cohort with ethnic diversity.
Mutations in genes coding for connexin26 (Cx26) and/or Cx30 are linked to approximately half of all cases of human autosomal nonsyndromic prelingual deafness.
Mutations in the GJB2 gene are the most common cause of autosomal recessive nonsyndromic hearing loss and occur in approximately 20% of all cases of prelingual deafness.
This is the first reported Czech case, and probably also the first central European case, of prelingual deafness due to mutations involving both the GJB2 and GJB6 genes.
The most significant clinical finding to date has been the discovery that mutations of GJB2 at the DFNB1 locus are the major cause of profound prelingual deafness in many countries.
Mutations in the connexin 26 gene (GJB2) are responsible for the major part of nonsyndromic autosomal recessive or apparently sporadic prelingual deafness in Caucasians (DFNB1).
Some of the 25 families with multiple cases of inherited prelingual deafness and wildtype GJB2 sequences may represent as-yet-unknown genes for inherited hearing loss.
(1) The prevalence and types of connexin 26 mutations in a cohort of children with prelingual deafness; (2) the carrier frequency of the common connexin 26 mutation, 35delG, in the general population.