Audiological characteristics following gene therapy in patients with autosomal recessive deafness 9

BACKGROUND: Gene therapy shows promising potential for patients with autosomal recessive deafness 9 (DFNB9), with ongoing clinical trials (ChiCTR2200063181). A deeper understanding of changes in audiological characteristics is crucial for optimizing the monitoring and evaluation of patients' recovery post-treatment. METHODS: Audiological data were collected from 10 DFNB9 patients who underwent gene therapy, including auditory brain stem response (ABR), auditory steady-state response (ASSR), distortion product otoacoustic emission (DPOAE), and pure-tone audiometry (PTA) tests. FINDINGS: A clear ABR wave V was observed in all participants by 13 weeks. By 52 weeks, distinct ABR waves I and III were visible in some participants. The 1-kHz ABR wave V latency at 85 dB decreased significantly from 9.220 (range 9.015-9.810) ms at 4 weeks to 8.190 (range 7.780-8.530) ms at 52 weeks (p = 0.004), with a trend toward increased wave V amplitude (p = 0.055). Significant correlations were observed between PTA, ABR, and ASSR thresholds at 0.5-4 kHz. The DPOAE signal-to-noise ratio (SNR) at 26 weeks post-treatment showed no significant difference compared with pre-treatment SNR values, nor were there significant correlations between the pre-treatment SNR values and the post-treatment ABR thresholds. CONCLUSIONS: The study demonstrates that ABR and ASSR are reliable objective tools for assessing hearing recovery in DFNB9 patients after gene therapy. ABR reveals positive changes in the auditory pathway over time after gene therapy, enhancing our understanding of the impact of gene therapy on auditory pathway recovery. FUNDING: This work was funded by the National Natural Science Foundation of China.