Cochlear Implantation Outcomes in Children With CDH23 Mutations–Associated Hearing Loss

Abstract

Objective Mutations in the cadherin 23 gene ( CDH23) have been reported to cause cochlear damage, but few studies have investigated the auditory and speech outcome of patients after cochlear implantation. Here, we describe the genetic, auditory, and postoperative outcomes of patients with CDH23 mutations who received cochlear implants. Study Design Retrospective case review. Setting Tertiary referral center. Methods Targeted deafness-related gene panels were sequenced in Chinese families with profound sensorineural hearing loss. The clinical features of subjects carrying potentially pathogenic CDH23 mutations were analyzed. Results Between 2017 and 2019, we identified 5 children with prelinguistically profound hearing loss at our center who harbored 6 variants of CDH23 that segregated with the disease. Of these, 4 variants were novel (c.2591G>T, c.4785G>C, c.5765A>G, and c.9280_9281insTT). All affected individuals had a loss of outer hair cell function, with an average residual hearing level of 3 to 10 dB SPL. Cochlear implantations were arranged for the patients at 11 to 36 months of age. All children made gains in their hearing, language, and speech performances 14 to 120 months after surgery. Their auditory outcomes improved during follow-up intervals. Conclusion This study revealed that children with congenital cochlear defects caused by CDH23 variants can acquire an acceptable auditory and speech outcome after cochlear implantation. Early genetic detection and prenatal counseling for rare deafness genes such as CDH23 remain a priority for the future.

Identification of four novel variants in the CDH23 gene from four affected families with hearing loss

“…Lastly, affected individuals with hearing loss could benefit from the identification of their genetic causes by genomic sequencing, which may provide better preoperative evaluation and postoperative effect prediction for clinic and cochlear implant (CI). In fact, patients with CDH23 mutations were predicted to acquire an acceptable auditory and speech outcome after CI ( Liu et al, 2008 ; Yoshimura et al, 2020 ; Chen et al, 2022 ). In our study, two affected children in family three and family four underwent bilateral CI surgery at age of 2 years and indeed showed acceptable recovery.…”

A Short Overview on Hearing Loss and Related Auditory Defects

“…Missense variants with residual protein function are thought to cause DFNB12 while homozygous nonsense, frameshift, splice site, and a few missense variants with total loss of function cause USH1D [66]. Cochlear implants in children aged 11-36 months with CDH23 mutations improved their hearing, speech, and performance necessitating the need for early diagnosis and possible improvement in hearing following implants [67].…”