Bernardes R, Bortoncello S, Christiani TV, Sartorato EL, Silva RCE, Porto PRC. Molecular investigation in children candidates and submitted to cochlear implantation.
Braz J Otorhinolaryngol 2006;
72:333-6. [PMID:
17119768 PMCID:
PMC9443549 DOI:
10.1016/s1808-8694(15)30965-4]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Accepted: 09/19/2005] [Indexed: 11/30/2022] Open
Abstract
Aim
recent progresses in molecular biology have been made in the diagnosis of sensorineural hearing loss. The high prevalence of a connexin 26 gene mutation, and its easy identification have made the diagnosis possible. The most frequent gene mutation is called 35delG. The purpose of this study was to evaluate the prevalence of 35delG mutation in children submitted to cochlear implantation who had severe and profound hearing loss previously diagnosed as idiopathic.
Method
The study was done at the Cochlear Implantation Clinic of the Otolaryngology Department and at the Laboratório Genética Humana-CBMEG, UNICAMP-SP. 32 children with severe to profound sensorineural hearing loss were evaluated. The detection of the 35delG mutation was made by a allele - specific PCR, using primers and polymerase chain reaction.
Results
69% had a normal exam, 12% were homozygous for the mutation, 19% of the cases were heterozygous. The 35delG mutation in heterozygousity is not a cause of hearing loss.
Conclusion
The data confirm the high prevalence of the 35delG mutation in nonsyndromic bilateral profound sensorineural hearing loss. It was also possible to diagnose the cause of hearing loss as genetic in a significant percentage of patients. That stresses the importance of the molecular investigation in those cases formerly classified as idiopathic.
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