Genotype-phenotype Correlation of SLC26A4 in CI Patients With EVA

A Genotype-phenotype Correlation of SLC26A4 Mutations in Cochlear-implanted Patients With Enlarged Vestibular Aqueduct

To explore the genotype-phenotype correlation of SLC26A4 mutations in cochlear-implanted patients with enlarged vestibular aqueduct.

Enlarged vestibular aqueduct (EVA) is one of the most common forms of inner ear malformation that cause sensorineural hearing loss (SNHL). Some patients with EVA present delayed, fluctuating, and progressive hearing loss, while the others are with congenital or sudden hearing loss. Cochlear implants (CI) have been widely used in patients with severe-profound SNHL. However, it is difficult to define the optimal timing of CI operations for patients with EVA. Mutations in SLC26A4 are known to be responsible for EVA. This study is to explore the genotype-phenotype correlation of SLC26A4 mutations in cochlear-implanted patients with EVA.

Inclusion Criteria:

1. Bilateral severe-to-profound sensorineural hearing loss who received cochlear implantation.
2. Bilateral or unilateral enlarged vestibular aqueduct (EVA) with or without Mondini malformation (IP-II) on temporal bone computed tomography (CT) and/or magnetic resonance imaging (MRI).

Exclusion Criteria:

1. Hearing loss that is associated with symptoms which meet the criteria of already known syndromes.
2. With other type of inner ear malformation.