Outcomes of cochlear implants in patients with PCDH15 mutations: a clinical study.

Objectives: To explore molecular diagnoses in cochlear implantation (CI) recipients and evaluate CI outcomes in patients with PCDH15 mutations.

Methods: Whole-exome sequencing and biomedical informatics were used to identify potential genetic causes in 467 individuals with congenital sensorineural hearing loss. We reviewed six CI recipients with PCDH15 mutations, assessing their CI outcomes and clinical features.

Results: Nine PCDH15 variants and a heterozygous variant in CDH23 were identified in members of five families who underwent CI. Six of these were novel variants: exon 14-21 del, exon two del, exon 19 del, two splicing variants (c.2869-2A>C, c.1918-1G>A) in PCDH15, and c.209C>T in CDH23. All but one of the individuals with PCDH15 mutations exhibited autosomal recessive inheritance; one showed both digenic and autosomal recessive inheritance. Variants in PCDH15 contributed to Usher syndrome type 1F in patients 1 and 5, whereas the remaining four had isolated deafness (DFNB23). All six patients expressed satisfaction with their CI outcomes.

Conclusion: CI significantly improved auditory and communication abilities in individuals with PCDH15 mutations. Early intervention is critical for achieving favorable outcomes. Preoperative genetic testing in individuals with hearing loss provides valuable insights for predicting CI success, offering potential treatments for retinal degeneration in Usher syndrome and facilitating personalized genetic counseling.