Molecular studies in patients with sensorineural deafness and enlarged vestibular aqueduct

• Grant number: 12/07901-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2012
• End date: July 31, 2013
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Edi Lúcia Sartorato
• Grantee: Edi Lúcia Sartorato
• Host Institution: Centro de Biologia Molecular e Engenharia Genética (CBMEG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Enlargement of the vestibular aqueduct (EVA) is a common radiological malformation of the inner ear in children with early onset of sensorineural hearing loss. It can be identified by CT or MRI. EVA can be unilateral or bilateral and is the main feature of Pendred syndrome (PDS), a genetic disease with autosomal recessive inheritance pattern in most cases caused by mutations in the SLC26A4 gene (OMIM 605646). In addition to EVA, goiter and iodide organification defect are other typical clinical signs of PDS. In turn, mutations in the SLC26A4 gene have also been observed in individuals with non-syndromic deafness.Recently FOXI1 and KCNJ10 genes have also been implicated in the PDS. FOXI1 The gene is a transcription factor gene SLC26A4. Electrophysiological measurements showed that changing the pendrin, SLC26A4 protein encoded by the gene in animal models deafness leading to lack of endocochler potential (PE) due to the loss of potassium. Being assigned to the gene KCNJ10 function maintenance of endocochlear potential. In fact, individuals were later observed with PDS compound heterozygous for mutations in genes SLC26A4/KCNJ10.Thus, this study intends to evaluate the occurrence of mutations in SLC26A4, and KCNJ10 FOXI1 in Brazilian patients with sensorineural hearing loss non-syndromic, with or without changes in the vestibular aqueduct, to clarify the prevalence of mutations of these genes in samples of Brazilian population and genotype-phenotype correlation in the subjects studied. (AU)