Background Genetic mutations in GJB2 and GJB3 are primarily associated with non-syndromic sensorineural congenital hearing loss (HL), whereas mutations in SLC26A4 and MT-RNR1 are linked to syndromic or mixed forms of sensorineural HL and are among the most commonly investigated hearing loss-associated genes. However, the clinical significance of these mutations, particularly in congenital HL, remains underexplored. Methodology In this study, 30 children with HL were evaluated for clinical features and tested for the expression of GJB2, GJB3, SLC26A4, and MT-RNR1 using reverse transcription-polymerase chain reaction, with genetic analyses performed before cochlear implantation. Additionally, MT-RNR1 was sequenced in all patients to detect potential mutations. Results Relative to 18S rRNA, the expression levels of GJB2, GJB3, SLC26A4, and MT-RNR1 were approximately 40%, 43.3%, 40%, and 46.67%, respectively. Six MT-RNR1 variants were identified, including c.1438A>G, c.1119T>C, c.1048C>T, c.1107T>C, c.1541T>C, and c.1005T>C. While the m.1105T>C variant has been implicated in aminoglycoside-induced ototoxicity, no significant association was observed in this cohort. Conclusions These findings provide preliminary insights into the potential utility of gene expression and mutation screening for early diagnosis and risk assessment of congenital HL in Vietnam.
Hoang et al. (Mon,) studied this question.