Etiologic and diagnostic evaluation: algorithm for severe to profound sensorineural hearing loss in Brazil.

Objective: Evaluation of the effectiveness of imaging and genetic testing, and establishment of a cost-effective diagnostic protocol for the etiologic diagnosis of sensorineural hearing loss (SNHL) in Brazil.

Design: Prospective cohort study.

Study Sample: Analysis of 100 unrelated Brazilian patients with severe to profound bilateral SNHL submitted to cochlear implant (CI) between 2002 and 2010 at the University of Campinas hospital.

Molecular analysis of SLC26A4 gene in patients with nonsyndromic hearing loss and EVA: identification of two novel mutations in Brazilian patients.

Unlabelled: The SLC26A4 gene has been described as the second gene involved in most cases of sensorineural non-syndromic hearing loss, since the first is the GJB2 gene. Recessive mutations in the SLC26A4 gene encoding pendrin, an anion transporter, are responsible for non-syndromic hearing loss associated with an enlarged vestibular aqueduct (EVA) and Pendred syndrome, which causes early hearing loss and affects the thyroid gland. Typically, the hearing loss is profound and prelingual.

Study of modifiers factors associated to mitochondrial mutations in individuals with hearing impairment.

Hearing impairment is the most prevalent sensorial deficit in the general population. Congenital deafness occurs in about 1 in 1000 live births, of which approximately 50% has hereditary cause in development countries. Non-syndromic deafness can be caused by mutations in both nuclear and mitochondrial genes.

Interaction between audiology and genetics in the study of a family: the complexity of molecular diagnosis and genetic counseling.

Unlabelled: Hearing loss is a multifaceted condition with many etiologies, among which genetic mutation is. Therefore, it is important to connect audiological investigation to etiological diagnosis.

Aim: this study aims to establish the audiological and genetic profiles of three non-syndromic children with sensorineural hearing loss.