Audiologic Phenotype and Progression in Pediatric STRC-Related Autosomal Recessive Hearing Loss

Sensorineural hearing loss (SNHL) is a common sensory deficit affecting pediatric populations. The majority of pediatric SNHL is genetic in etiology, with over 123 identified nonsyndromic causative genes. One such gene is STRC, which has been identified as the second most frequent autosomal recessive nonsyndromic gene associated with SNHL in multiple populations. The objective of this study was to investigate the phenotypic presentation and incidence of audiologic progression in pediatric patients with STRC-related hearing loss (HL).

Thirty-nine pediatric patients with confirmed HL and biallelic pathogenic STRC mutations were identified at two pediatric hospitals. A retrospective chart review was completed including demographics, medical history, genetic testing results, and audiologic data. HL progression was assessed using air conduction thresholds from pure-tone audiograms and auditory brain stem responses, and masked bone conduction thresholds from pure-tone audiograms.

Thirty-six patients had homozygous STRC deletions. Three were compound heterozygotes. All patients had bilateral, symmetric SNHL. Baseline HL was mild in 39% of ears, moderate in 52%, and moderate-severe in 3%. Of the 31 patients for which sufficient data were available to evaluate progression, 18 (58%) had some degree of progressive HL. Among these 31 patients assessed for progression, the mean hearing threshold declined by 0.6 dB per year (95% confidence interval: 0.5, 0.8; P < .001).

These biallelic STRC patients displayed HL ranging from mild to moderate-severe at baseline and progressing in 58%. The variability of the STRC phenotype and the possibility of audiologic progression should be considered in the clinical management of pediatric STRC-related SNHL.

3 Laryngoscope, 131:E2897-E2903, 2021.