Hearing progression of children with enlarged vestibular aqueduct (EVA) according to SLC26A4 genetic mutation status

Enlarged vestibular aqueduct (EVA) is a malformation associated with sensorineural hearing loss in children. Mutations in the SLC26A4 gene are also associated with EVA and may contribute to more severe hearing losses that progress, but the timescale of this progression remains unknown. Given that children undergo significant speech and language development, a better understanding of the timing and extent of hearing loss is needed for individuals who have EVA. Through a retrospective review of records in a local database, we aimed to 1) estimate the prevalence of a SLC26A4 mutation in this pediatric EVA cohort; and 2) compare hearing threshold severity and timing of progression across children who have EVA and different SLC26A4 statuses. Of 62 children with EVA, 39 had available genetic results and of these, 15 had at least one mutation of the SLC26A4 gene (38%). The children with a SLC26A4 mutation had a more severe onset of hearing loss and a more rapid progression of hearing loss over time, especially for higher frequencies, than children without a mutation in this gene. This longitudinal information may facilitate prognostic counseling to pediatric patients and better inform the audiology follow-up appointments for these families.