A novel missense mutation in the SLC26A4 gene in a chinese family with enlarged vestibular aqueducts

Abstract Background: SLC26A4 gene is closely related to enlarged vestibular aqueducts. Its homozygous mutation or compound heterozygous mutation may cause deafness and seriously affect the patient's life. As far as we know, this is the first reported pathogenic or probable pathogenic for the missense mutation. Our studies expand the mutation site of SLC26A4 gene and provide genetic counseling for the patient's family.Methods: The patients who came to our hospital for hearing test and accompanied by bilateral hearing abnormalities were collected for 15 genetic tests for hereditary deafness. Those who are positive on chip screening will be verified by first-generation sequencing, combined with family history, hearing test, and computerized tomography (CT) of the temporal bone to diagnose the enlarged vestibular aqueducts. If necessary, perform second-generation sequencing.Results: The patient failed the two hearing screenings on both sides, computerized tomography diagnosed enlarged vestibular aqueduct (>1.5 mm). Two pathogenic mutations, c.1174A>T and c.2069T>A were detected in SLC26A4. The heterozygous c.2069T>A mutation of SLC26A4 gene is a novel missense mutation that has been submitted to the clinvar website, Variation ID：1048780.Conclusion: Our findings enriched SLC26A4 gene spectrum and support previous studies that the enlarged vestibular aqueducts can be caused by a compound heterozygous mutation in SLC26A4.