Bilateral sequential cochlear implantation in a patient with the CAPOS syndrome – postsynaptic auditory neuropathy related toa missense mutation within the ATP1A3 gene

ntroduction: This paper presents a boy with CAPOS syndrome (Cerebellar ataxia, Areflexia, Pes calvus, Optic atrophy, Sensorineural hearing loss) and postsynaptic auditory neuropathy who underwent bilateral, sequential cochlear implantation. Aim: The aim of the study is to describe the development of communication skills after bilateral cochlear implantation in a child with multiple disabilities including profound hearing loss and vision impairment. Material and methods: The patient’s medical history, including the results of diagnostic tests is presented. Sequential, bilateral cochlear implantation was performed at the age of 7 (right ear) and 8 years (left ear). Results: The results of audiometric tests confirmed postsynaptic auditory neuropathy. Molecular testing revealed a diseasecausing heterozygous c.3007C>A variant in the ATP1A3 gene encoding the Na+/K+ ATPase. 14 months after surgery, the ability to speak had not been regained, but the patient was able to distinguish the environmental sounds. Conclusions: Cochlear implantation is recommended for patients with CAPOS syndrome. The development of communication skills improved the functioning of the child in the family and school environment. Meaning: The results observed in the presented patient differ from the results achieved by patients with cochlear hearing loss and presynaptic neuropathies, but indicate the validity of bilateral cochlear implantation in patients with postsynaptic neuropathy in the CAPOS syndrome.