A new pathogenic variant in the TRIOBP associated with profound deafness is remediable with cochlear implantation
AuthorTekin, Ahmet Mahmut
de Ceulaer, Geert
van de Heyning, Paul
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CitationTekin, A. M., de Ceulaer, G., Govaerts, P., Bayazıt, Y., Wuyts, W., van de Heyning, P. ... Topsakal, V. (2021). A new pathogenic variant in the TRIOBP associated with profound deafness is remediable with cochlear implantation. Audiology and Neurotology, 26(2), 76-84. https://dx.doi.org/10.1159/000508434
Background and Objectives: A rare type of nonsyndromic autosomal recessive hereditary hearing loss is caused by pathogenic mutations in the TRIOBP gene mostly involving exons 6 and 7. These mutations cause hearing loss originating from dysfunction of sensory inner ear hair cells. Of all the affected siblings, 2 brothers and 1 sister, part of an Afghan family, were referred to our clinic for diagnostic workup and candidacy selection for cochlear implantation (CI). Methods: Molecular analysis showed a homozygous c.1342C > T p. (Arg448*) pathogenic variant in exon 7 of the TRIOBP gene (reference sequence NM_001039141.2) in all 3 affected siblings. Clinical audiometry demonstrated profound sensorineural hearing loss in all 3 affected siblings (2 males and 1 female), and they were implanted unilaterally. Results: One month after activation, the pure-tone averages with the CI processor were between 30 and 23 dBHL. Ten months after the first activation of the implant, open-set speech audiometry test could be performed for the first time in the 2 younger CI recipients (S5 and S9), and they could identify up to a maximum 77% phonemes correctly. The oldest brother (S12) could not yet perform open-set speech audiometry at that moment. Conclusions: Implant outcomes are better with normal inner ear anatomy in general. The earlier congenital patients are implanted, the better their outcomes. Here, we demonstrate both statements are true in a homozygous c.1342C > T p. (Arg448*) pathogenic variant in the TRIOBP gene in all 3 affected siblings.