Genetic testing has the potential to impact hearing preservation following cochlear implantation

Abstract

<b>Background:</b> Recent advances in less-invasive surgery and electrode design allow for a high degree of hearing preservation (HP) after cochlear implantation (CI), although residual hearing still deteriorates in some patients. To date, the factors predictive of preserving residual hearing remain a controversial topic.<b>Objective:</b> The aim of this study was to investigate the predictive factors, including the etiology of hearing loss (HL) as a patient-related factor, influencing residual HP after CI.<b>Methods:</b> Forty-four patients (50 ears, 41 families) with residual acoustic hearing who underwent CI were included. Auditory thresholds before and at 6 months after initial activation were measured. Genetic testing was performed to identify the responsible genes for HL.<b>Results:</b> We identified the cause of HL in 21 families (51.2%). HP was marginally correlated with age at implantation, while it was independent of pre-operative low-frequency hearing thresholds, cochlear duct length, and electrode length. We found that patients who had pathogenic variants in the <i>CDH23</i>, <i>MYO7A</i>, or <i>MYO15A</i> gene showed statistically better HP scores compared with patients with HL due to other causes (<i>p</i> = .002).<b>Conclusions:</b> Identification of the etiology of HL using genetic testing is likely to facilitate the prediction of HP after implant surgery.