EYA4 is a member of the vertebrate eya gene family of transcriptional activators and plays several roles in both embryonic and inner ear development. The majority of EYA4 gene mutations are associated with autosomal dominant non-syndromic hearing loss (DFNA10). In addition, some mutations in this gene cause autosomal dominant syndromic hearing loss with dilated cardiomyopathy. EYA4 is a rare cause of sensorineural hearing loss, and only a limited number of papers regarding mutations in this gene have been published. Thus, detailed clinical features remain unclear. We conducted next-generation sequencing of a Japanese individual with progressive sensorineural hearing loss and identified an EYA4 pathogenic variant. Pure-tone audiometry revealed bilateral, nearly symmetric, moderate sensorineural hearing loss in the low and middle frequencies. Minor abnormalities were observed on the patient's electrocardiogram and echocardiography without any apparent symptoms. Next-generation sequencing is effective in elucidating the etiology of hearing loss, and the present findings suggested the possible phenotypic expansion of deafness caused by EYA4 gene mutations.