Clinical, audiometric, radiologic, and genetic profiles of Southeast Asian children with hearing loss due to enlarged vestibular aqueduct.

Objective: Analysis of the clinical, audiometric, radiologic, and genotypic characteristics of a cohort of Southeast Asian patients with hearing loss (HL) associated with enlarged vestibular aqueduct (EVA).

Patients: Ten consecutive children with sensorineural HL and EVA detected on computed tomographic scanning of the temporal bone.

Interventions: Audiometric, radiologic, and genetic analysis of the patient cohort of 10 children.

Main Outcome Measures: Audiometric, radiologic analysis.Genetic analysis to assess for the presence of Connexin 26, Connexin 30, A1555G, and Pendrin gene variants.

Results: The novel 1693insA and 1521delT variants were identified in our study group. When both loci were considered simultaneously, 8 (80%) of 10 patients studied carried variants in either the pendrin (n = 5) or connexin 26 (n = 6) genes. When analyzing (using the Mann-Whitney U test) for a correlation between an increased probability of either a larger VA, bilateral EVA, or higher rate of progression of HL in the presence of pendrin or connexin 26 gene variants (as opposed to the absence of these variants), there was no statistically significant difference found. This differs from other studies where there was a significantly wider VA and a wider vestibule in subjects with pendrin mutations.

Conclusion: There is a significant delay in the diagnosis of EVA in children with HL in our Southeast Asian population. An increased awareness of EVA as a differential diagnosis among professionals managing these children is important to reduce this delay.