Unraveling the Genetic Landscape of Hearing Loss: A Comprehensive Study of Azeri Families in Ardabil, Iran.

Background: Hereditary hearing loss (HHL) is a clinically and genetically heterogeneous sensorineural disorder that presents challenges for diagnosis. Next-generation sequencing (NGS) approaches have facilitated a more cost-effective, streamlined diagnostic process. This study aimed to identify HHL variants using NGS in Iranian Azeri families in Ardabil Province, establishing a suitable framework for screening programs tailored to the local population.

Methods: Seventy-four GJB2-negative Azeri families with HHL from Ardabil Province of Iran were studied using the OtoSCOPE panel and/or exome sequencing over 15-years from 2008 to 2023.

Results: Data analysis revealed 53 HHL variants in 52 of the 74 most consanguineous families (70%), including 34 pathogenic/likely pathogenic variants and 19 variants of uncertain significance. Seventeen of the detected variants were novel. SLC26A4, MYO7A, USH2A, and TMPRSS3 were the most prevalent mutated genes for non-syndromic hearing loss (NSHL) and syndromic hearing loss (SHL) in this study.

Conclusion: Our results are comparable to those of previous studies, indicating that SLC26A4 is the second most common cause of HHL, after GJB2. Moreover, our study emphasizes the significance of understanding the genetic basis of HL for early diagnosis and the implementation of suitable screening programs for various ethnicities in Iran.