Novel Variants and Clinical Features of Hearing Loss in a Large Japanese Cohort.

Background/objectives: The gene is responsible for autosomal recessive non-syndromic sensorineural hearing loss and is assigned as DFNB18B. To date, 44 causative variants have been reported to cause non-syndromic hearing loss. However, the detailed clinical features for -associated hearing loss remain unclear.

Methods: In this study, we analyzed 7065 patients with non-syndromic hearing loss (mean age 26.4 ± 22.9 years, 2988 male, 3855 female, and 222 without gender information) using massively parallel DNA sequencing for 158 target deafness genes. We identified the patients with biallelic variants and summarized the clinical characteristics.

Results: Among the 7065 patients, we identified 14 possibly disease-causing variants in 26 probands, with 13 of the 14 variants regarded as novel. Patients with -associated hearing loss mostly showed congenital or childhood-onset hearing loss. They were considered to show non-progressive, mild-to-moderate hearing loss. There were no symptoms that accompanied the hearing loss in -associated hearing loss patients.

Conclusions: We confirmed non-progressive, mild-to-moderate hearing loss as the clinical characteristics of -associated hearing loss. These findings will contribute to a better understanding of the clinical features of -associated HL and will be useful in clinical practice.