Detailed characterization of auditory neuropathy in Perrault syndrome with TWNK variants

Perrault syndrome is an autosomal recessive condition characterized by hearing loss and ovarian failure. Hearing loss in Perrault syndrome has been reported as sensorineural; however, only two cases in a single report have comprehensively investigated hearing in Perrault syndrome with TWNK variant, and the association between this variant and auditory neuropathy has not been established. The proband presented with hearing difficulties and primary amenorrhea. Hearing tests revealed mild hearing loss. Maximum speech intelligibility score was 95 % with normal otoacoustic emission. However, no auditory brainstem responses were observed, leading to the diagnosis of auditory neuropathy. Genetic tests identified compound heterozygous variants of TWNK (p.Ile253Met and p.Arg391His), which lead to the genetic diagnosis of Perrault syndrome. Electrocochleography suggests a decreased cochlear nerve function. The patient's sister was also subsequently genetically diagnosed with Perrault syndrome upon identification of the same TWNK variant and had auditory neuropathy with low-tone hearing loss on pure-tone audiometry. These cases highlight the importance of detailed hearing tests, including auditory brainstem response and genetic tests in patients with Perrault syndrome, even in cases of mild hearing loss, for accurate diagnosis and appropriate management.