Heterogeneous Group of Genetically Determined Auditory Neuropathy Spectrum Disorders

Abstract

Auditory neuropathy spectrum disorder (ANSD) is often missed by standard hearing tests, accounting for up to 10% of hearing impairments (HI) and commonly linked to variants in 23 genes. We assessed 122 children with HI, including 102 with sensorineural hearing loss (SNHL) and 20 with ANSD. SNHL patients were genotyped for common GJB2 variants using qPCR, while ANSD patients underwent whole exome sequencing, with variants analyzed across 249 genes. Homozygous GJB2 variants were found in 54.9% of SNHL patients. In 60% of ANSD patients, variants were detected in OTOF (25%), CDH23, TMC1, COL11A1, PRPS1, TWNK, and HOMER2 genes, including eight novel variants. Transient evoked otoacoustic emissions testing revealed differences at 4000 Hz (p = 0.0084) between the ANSD and SNHL groups. The auditory steady-state response (ASSR) test showed significant differences at 500 Hz (p = 2.69 × 10−4) and 1000 Hz (p = 0.0255) compared to pure-tone audiometry (PTA) in ANSD patients. Our questionnaire shows that the parents of children with SNHL often report an improved quality of life with hearing aids or cochlear implants, while parents of children with ANSD frequently experience uncertainty about outcomes (p = 0.0026), leading to lower satisfaction.