[automatically translated] About 60% of congenital hearing loss are associated with genetic causes in developed countries. Genetic deafness is classified into syndromic (30%) and non-syndromic (70%), the latter due in more than 50% of the cases by mutations in the GJB2 gene. This gene, expressed in the cochlea, encodes the gap junction protein "Connexin 26", the function of which is crucial for intercellular communication. The goal of our work was to estimate the frequency of GJB2 mutations and their correlation with the phenotype of audiology in 102 Sicilian patients with congenital sensorineural deafness, non-syndromic (NSHL) bilateral and carriers of at least one of the GJB2 gene mutation. All subjects underwent genetic testing (to detect the presence of mutations in GJB2 and GJB6 genes) and audio-impedenzometrico exam. In the studied cohort we were identified 15 different mutations and 17 genotypes. In 64.72% of patients showed a hearing loss of profound degree (average PTA0.25-4kHz = 88.82 ± 26.52 dB HL). The 81.37% of subjects was a carrier of at least one allele c.35delG; the c.167delT mutations and c.-23 + 1G> A were identified in 10.78% and in 9.8% of patients respectively. The homozygous genotype for c.35delG mutation was associated with a more severe hearing loss and higher average PTA0.25-4kHz values (96.79 ± 21.11 dB HL) than genotypes c.35delG / non-c.35delG and c .35delG / Wt (P <0.05) our study highlights the role of c.35delG, c.167delT and c.-23 + 1G> a as a major cause of NSHL in Sicily.
|Number of pages||0|
|Publication status||Published - 2014|