Prevalence and Characteristics of STRC Gene Mutations (DFNB16): A Systematic Review and Meta-Analysis.

Background: Mutations in the STRC (MIM 606440) gene, inducing DFNB16, are considered a major cause of mild-moderate autosomal recessive non-syndromic hearing loss (ARNSHL). We conducted a systematic review and meta-analysis to determine the global prevalence and characteristics of STRC variations, important information required for genetic counseling. Methods: PubMed, Google Scholar, Medline, Embase, and Web of Science were searched for relevant articles published before January 2021. Results: The pooled prevalence of DFNB16 in GJB2-negative patients with hearing loss was 4.08% (95% CI: 0.0289-0.0573), and the proportion of STRC variants in the mild-moderate hearing loss group was 14.36%. Monoallelic mutations of STRC were 4.84% (95% CI: 0.0343-0.0680) in patients with deafness (non-GJB2) and 1.36% (95% CI: 0.0025-0.0696) in people with normal hearing. The DFNB16 prevalence in genetically confirmed patients (non-GJB2) was 11.10% (95% CI: 0.0716-0.1682). Overall pooled prevalence of deafness-infertility syndrome (DIS) was 36.75% (95% CI: 0.2122-0.5563) in DFNB16. The prevalence of biallelic deletions in STRC gene mutations was 70.85% (95% CI: 0.5824-0.8213). Conclusion: Variants in the STRC gene significantly contribute to mild-moderate hearing impairment. Moreover, biallelic deletions are a main feature of STRC mutations. Copy number variations associated with infertility should be seriously considered when investigating DFNB16.