The aim was to investigate the progress of hearing loss over time in a cohort of pendred syndrome and non-syndromic enlarged vestibular aqueduct (PS/NSEVA) with one or two confirmed pathogenic variations in SLC26A4.
Retrospective cohort study.
At our tertiary referral center, a retrospective search of all patients with enlarged vestibular aqueduct, hearing loss and SLC26A4 mutations yielded 103 individuals by March 2017, 96 of whom had records of hearing levels; both an early audiometry and the latest between 3 and 668 months follow-up. Pure-tone average (PTA; average of thresholds at 0.5, 1, 2 and 4 kHz) was calculated for both ears at time 1 and time 2. Neonatal screening results were retrieved.
Eighty-seven (87) individuals had biallelic (M2) and 16 had monoallelic alterations (M1) in their SLC26A4. On average, the PTA progressed to 80 dB HL by the age of 6 years for the entire cohort, and 3.2 years for the biallelic (M2) affected individuals. 25% of the cohort was screened in the neonatal screening program; of these 42% had “passed” at least monaurally. Audiometric profiles related to age show faster deterioration in high frequencies than in low frequencies.
In patients with PS/NSEVA and SLC26A4 mutations, the average hearing loss progresses to 80 dB HL by the age of 6 years. For biallelic (M2) affected individuals it was 3.2 years. Although hearing levels reached severe to profound during childhood, almost 1/2 had passed neonatal hearing screening, at least monaurally, emphasizing the need for close follow-up.
*Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet/Gentofte, Hellerup
†Big Data Team, Municipality of Copenhagen
‡Department of Clinical Genetics, Rigshospitalet/The Kennedy Centre
§Faculty of Health Sciences and Medicine, University of Copenhagen
||Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
Address correspondence and reprint requests to Kristianna Mey, M.D., Department of Otorhinolaryngology, Head & Neck Surgery and Audiology, Rigshospitalet/Gentofte, Kildegaardsvej 28, 2900 Hellerup, Denmark; E-mail: Kristiannamey@gmail.com
The authors disclose no conflicts of interest.