Abstract：Objective To identify the diagnostic variations in 4 families with congenital deafness through genetic testing and to provide the corresponding counseling advice.Methods Four families with congenital deafness who visited our center from May 2020 to Jan 2022 were included. The experimental methods of deafness gene chip and whole exome sequencing (WES) were used to identify genetic pathogenic mutations.Results GJB2 gene was associated with all the four cases of hereditary deafness, but there were different conditions. Case 1 was with autosomal dominant pattern, whose de novo pathogenic variation was C.167T>C, a novelly reported variant. In case 2, both wife and husband had congenital deafness, yet caused by MYO7A and GJB2 compound heterozygous variations respectively; and the wife carried two newly reported pathogenic variants, namely MYO7A: C.1214G>A and MYO7A: c.3545A>G. Case 3 was autosomal recessive deafness caused by GJB2 compound heterozygous variation. Case 4 was late on-set deafness caused by GJB2 compound heterozygous variation.Conclusions GJB2 gene-related congenital deafness has strong clinical heterogeneity, and comprehensive genetic testing is necessary for its differential diagnosis.
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