Revista de otorrinolaringología y cirugía de cabeza y cuello
version ISSN 0718-4816
ARANCIBIA S, Margarita et al. Frequency of the 35delG mutation of GJB2 (connexin 26) in a sample of deafschool children in Santiago. Rev. Otorrinolaringol. Cir. Cabeza Cuello [online]. 2012, vol.72, n.1, pp. 7-14. ISSN 0718-4816. doi: 10.4067/S0718-48162012000100002.
Introduction: Congenital hearing loss occurs in 1 in 1000 live births and 50 % of these cases are related with mutations in the connexin26 gene (GJB2). The 35delG variant is the most common of the known pathogenic alleles in Caucasian populations, reaching a frequency of 30 °% among the non syndromic congenital deaf people. The frequency of this variant has not been described in Chilean deaf children. Aim: To estimate the frequency of the 35delG GJB2 gene mutation in children with non syndromic congenital hearing loss of unknown etiology from deaf schools in Santiago, and to evaluate the association between clinical features of these children and the presence of the 35delG allele. Material and method: The presence of the 35delG mutation was studied by allele specific PCR and automatical sequencing in 81 children. The association between clinical issues and genotypes was explored by Fisher exact test. Results: We found the 35delG variant in 11,25 °% of the children, this mutation was more frequent in familial cases than sporadic cases of deafness. We also found the V27I non pathogenic variant in 8 cases. Conclusion: The frequency of the 35delG mutation was lower than the expected, probably due to the criterion used to select the school children to be studied.
Keywords : Genetic deafness; 26 connexine; GJB2; 35delG.