Natural History of Sensorineural Hearing Loss in Children With <scp> <i>STRC</i> </scp> Mutations

ABSTRACT Introduction The most common genes responsible for autosomal recessive nonsyndromic hearing loss (AR‐NSHL) are GJB2 and STRC . STRC mutations are associated with mild‐to‐moderate sensorineural (SNHL) hearing loss and a lack of progression. However, our institutional experience suggested otherwise, prompting this review. Methods A 10‐year retrospective chart review was performed at a tertiary children's hospital after the University of Iowa added STRC to its OtoSCOPE R panel in 2013. Subjects with positive OtoSCOPE R results underwent audiologic review. Hearing progression was defined based on pure‐tone average changes, and mutation subtypes were categorized. Results Of 354 subjects undergoing OtoSCOPE R testing, 181 (51.1%) carried a pathogenic mutation; GJB2 (28.7%) and STRC (16.6%) were most common. The STRC cohort included 30 subjects (21 males, 9 females) with hearing loss severity classifiable in 26 subjects and the highest proportion in the mild‐to‐moderate range ( n = 46 ears; 88.5%). Hearing progression was observed in 12/24 subjects (20 ears: 8 bilateral, 4 unilateral). Median annual progression was 1.1 dB (range −3.5 to 18.7 dB). Two STRC subjects had substantial progression requiring cochlear implantation (one performed, one recommended). Genetic subtyping revealed seven categories, including six males with STRC/CATSPER2 deletions (deafness‐infertility syndrome). No association between subtype and severity or progression was identified. Discussion STRC is the second most common cause of childhood NSHL and the leading contributor to mild‐to‐moderate SNHL. Unlike most published literature, 50% of our STRC cohort exhibited progression, and 17.6% of progressing subjects had substantial unilateral loss. We recommend long‐term audiometric monitoring and standardized genomic reporting for this population. Level of Evidence 4.