Etiologic Diagnosis of Genetic Hearing Loss in an Ethnically Diverse Deafness Cohort

Introduction: Hearing loss is a common sensory disorder that impacts patients across the lifespan. Many genetic variants have been identified that contribute to non-syndromic hearing loss. Yet, genetic testing is not routinely administered when hearing loss is diagnosed, particularly in adults. In this study, genetic testing was completed in patients with known hearing loss. Methods: A total of 104 patients who were evaluated for hearing loss were enrolled and received genetic testing. Results: Of those 104 patients, 39 had available genetic testing, 20 had one missing allele, and 45 yielded no genetic diagnosis. Of the 39 cases with genetic testing data, 24 were simplex cases, and 15 were multiplex cases. A majority of patients presented with an autosomal recessive inheritance pattern (n = 32), 26 of whom presented with congenital hearing loss. 38% of cases were positive for GJB2 mutation with c.35delG being the most common pathogenic variant. These findings are consistent with previous literature suggesting GJB2 mutations are the most common causes of non-syndromic hearing loss. Conclusion: Given the frequency of genetic variants in patients with hearing loss, genetic testing should be considered a routine part of the hearing loss work-up, particularly as gene therapies are studied and become more widely available. Lay Summary: Many genetic variants have been identified that contribute to non-syndromic hearing loss. Given the frequency of genetic variants in patients with hearing loss, genetic testing should be considered a routine part of the hearing loss work-up.