(A808) Cochlear Implantation in Siblings with ANSD – a Case Series and Review of the Literature

Introduction: Cochlear implantation (CI) has become the standard of care for patients with severe-to-profound hearing loss, however, its use in auditory neuropathy spectrum disorder (ANSD) is controversial due to variable outcomes. Here, we present a case series and literature review to investigate whether first sibling CI outcome could predict performance for subsequently implanted siblings with ANSD.

Methods: Medical records at our institution from 2000 to 2024 were searched for siblings with ANSD treated with CI. Demographic, genetic, and audiometric data were recorded when available. Extensive literature review was performed, selecting for the same. Quantitative and qualitative analysis was performed to determine relationships between sibling outcomes.

Results: Three families with seven siblings were identified at our institution. Family 1A/B, two half-brothers with ANSD of unknown etiology underwent bilateral CI at 9 and 3 years old, resulting in widely disparate functional outcomes. Family 2A/B/C, three siblings with MYO15A mutations underwent unilateral CI at 2-3 years old, also resulting in disparate functional outcomes. Family 3A/B, two sisters with several pathogenic variants (GJB2, DFNB31, DIAPH1, EYA4, and MYO1A) underwent bilateral CI at 12 months old, resulting in improved hearing thresholds and excellent speech recognition at 10 years post-CI. Review of nine case reports of CI in siblings with ANSD similarly demonstrated variable speech perception outcomes in syndromic (Brown-Vialetto-Van Laere, Charcot-Marie-Tooth, and Perrault) and non-syndromic (Otoferlin, DFNB77, and unknown etiology) cases of ANSD.

Conclusions: Genetic etiology and older sibling performance was generally not a strong predictor of CI performance in families with syndromic or non-syndromic ANSD.