Early deterioration of residual hearing in patients with SLC26A4 mutations

Objectives/hypothesis: To compare changes in hearing in patients with SLC26A4 during early and late childhood.

Study design: Retrospective chart review.

Methods: A total of 102 patients with biallelic SLC26A4 mutations visited the tertiary referral otolaryngology department between March 2005 and February 2015. Newborn hearing screening tests had been performed on 22 of these patients. We analyzed 26 patients who underwent hearing tests more than twice using the same method (auditory brainstem response/auditory steady state response/play audiometry) before and after 3 years of age. We analyzed changes in hearing levels according to age.

Results: Among 22 patients with SLC26A4 mutations who underwent newborn hearing screening tests, seven (31.8%) passed the newborn hearing screening test in both ears, and six (27.3%) passed in one ear. Among 16 patients with SLC26A4 mutations who underwent hearing tests more than twice before age 3 years, the hearing levels of 14 (87.5%) deteriorated rapidly during this time. Among 16 patients with SLC26A4 mutations who underwent hearing tests more than twice after the age of 3 years, two (12.5%) patients' hearing levels deteriorated; the hearing levels of most of the patients were relatively stable.

Conclusions: These data suggest that many patients with SLC26A4 mutations have significant residual hearing at birth, and that the hearing deterioration in these patients occurs before 3 years of age. After age 3 years, the residual hearing was relatively stable and did not tend to deteriorate. Therefore, in patients with a pendrin mutation, early intervention to preserve residual hearing should be a clinical focus.

Level of evidence: 4. Laryngoscope, 126:E286-E291, 2016.