Case report of a novel mutation in the TNC gene in Chinese patients with nonsyndromic hearing loss

Hereditary hearing loss is known to exhibit a significant degree of genetic heterogeneity. Herein, we present a case report of a novel mutation in the tenascin-C (TNC) gene in Chinese patients with nonsyndromic hearing loss (NSHL). This includes a young deaf couple and their 2-year-old baby. Based on the clinical information, hearing test, metagenomic next-generation sequencing (mNGS), Sanger sequencing, protein function and structure analysis, and model prediction, in our case, the study results revealed 2 heterozygous mutations in the TNC gene (c.2852C>T, p.Thr951Ile) and the TBC1 domain family member 24 (TBC1D24) gene (c.1570C>T, p.Arg524Trp). These mutations may be responsible for the hearing loss observed in this family. Notably, the heterozygous mutations in the TNC gene (c.2852C>T, p.Thr951Ile) have not been previously reported in the literature. Avoid taking drugs that can cause deafness, wearing hearing AIDS, and cochlear implants. Regular follow-up of family members is ongoing. The genetic diagnosis of NSHL holds significant importance as it helps in making informed treatment decisions, providing prognostic information, and offering genetic counseling for the patient's family.