The Yield of Multigene Testing in the Management of Pediatric Unilateral Sensorineural Hearing Loss

Objective: To explore the role and yield of multigene evaluation in children recently diagnosed with unilateral sensori-neural hearing loss (SNHL). Study Design: Retrospective cohort study. Setting: Tertiary level pediatric institution. Patients: Sixty children diagnosed with unilateral SNHL between January 2005 and December 2015. Intervention: Targeted mutation analysis was performed in 51 children using DNA microarray for genotyping 11 different genes known to be correlated with nonsyndromic SNHL. Main Outcome Measure: Multigene testing results. Results: Average age at diagnosis was 4.3 years. All children appeared to have nonsyndromic hearing loss (HL). HL was categorized as mild (17 children), moderate (17 children), severe (7 children), or profound (19 children). Genetic testing was performed in 51 (85%) children. Sixteen children (31.3%) were tested positive to connexin 26 (GJB2). One patient (2%) from this subgroup was homozygous and 15 were heterozygous. The average age of GJB2 positive children was 6 years and their average pure tone audiometry (PTA) was 75 dB. Computed tomography (CT) and/or magnetic resonance imaging (MRI) scans were performed in 43 children (71.66%). Out of the children who had a scan, 27 patients (62.8%) had negative findings on either CT or MRI scans. Sixteen (37.2%) patients had positive scan finding/s. Conclusions: Significant proportion of children with unilateral SNHL may have positive genetic testing while the vast majority of these children present with heterozygous mutations of connexin 26 (GJB2). Findings suggest that genetic evaluation has a role as a complementary modality in HL evaluation for pediatric unilateral SNHL although it may not be necessary to analyze for various abnormalities other than connexin 26 when practising in a limited resources environment.