Abstract

Myhre syndrome is a rare disorder characterised by short stature, skeletal anomalies, facial dysmorphism and hearing loss (HL), resulting from heterozygous mutations of the SMAD4 gene. We describe the benefits of cochlear implant (CI) in a patient with sensorineural HL carrying a mutation (NM_005359.6: c.1498A>G; p.lle500Val) within the SMAD4 gene, detected by whole-exome sequencing. The CI was inserted through the round window despite otospongiotic abnormalities. Pure-tone audiometry improved up to 20 dBHL. Speech perception in noise (Simplified Noise Reduction - SNR +10) increased from 0% pre implantation with hearing aids to 50% post implantation. The postoperative setting of the electrical stimulation limits yielded an asymmetric map, with lower levels for central electrodes and higher levels for lateral ones. Action potential could not be evoked via medial electrodes, suggesting a cochlear nerve dysfunction. Outcomes related to quality of life and cognitive impairment improved. CI was shown to be an effective auditory rehabilitation strategy.