[Genetic analysis of children with nonsyndromic sensorineural hearing loss due to novel mutations/deletions of STRC bialleles].

Abstract

Objective: To investigate the clinical and genetic characteristics of nonsyndromic sensorineural hearing loss caused by STRC biallelic variation. Methods: A child with hearing impairment who was diagnosed at Gansu Provincial Maternal and Child Health Hospital on May 2022 and was selected as the research object. Peripheral blood of the child and her parents was collected, genomic DNA was extracted. IDT The xGen Exome Research Panel v2.0 whole exome capture chip was used to capture and sequence. Bioinformatics and clinical information analysis technology were used to analyze genetic data. The suspected pathogenic mutations were verified by quantitative polymerase chain reaction(QPCR)and Sanger sequencing. Results: The child had moderate hearing loss at about 1 year and 10 months, and now she is 3 years and 6 months, the hearing loss has not worsened. Whole exome sequencing(WES) testing revealed that the child carried the STRC gene with a deletion in EXON:1-29 and variants c.4561(exon24) _c.4562(exon24)insC, inherited from the mother and father, respectively. According to the relevant guidelines of the American Society for Medical Genetics and Genomics (ACMG), they were determined to be likely pathogenic variant and pathogenic variant. Conclusion: The discovery of c.4561(exon24) _c.4562(exon24)insC enriched the STRC variation spectrum, and provided a theoretical basis for the diagnosis and genetic counseling to the children.