[Analysis of OTOGL gene variants in a child with moderate non-syndromic hearing loss]

To explore the genetic basis for a child with moderate non-syndromic hearing loss.

Next generation sequencing was carried out for the child. Co-segregation of the phenotype and candidate variants was verified among his family members by Sanger sequencing.

The child was found to harbor biallelic variants of the OTOGL gene, namely c.2773C>T (p.Arg925Ter) and c.2826C>G (p.Tyr942Ter), which were respectively inherited from his phenotypically normal father and mother. Both variants were predicted to cause premature termination of protein synthesis and be disease causing by MutationTaster software. The c.2826C>G (p.Tyr942Ter) variant has not been recorded in the Human Gene Mutation Database. Based on the guidelines of the American College of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+PM2+PM4+PP3+PP5 and PVS1+PM2+PM4+PP3, respectively).

The c.2773C>T (p.Arg925Ter) and c.2826C>G (p.Tyr942Ter) variants of the OTOGL gene probably underlay the hearing loss in this child.