Objective: To explore the molecular basis for an individual with postnatal deafness and provide genetic counseling for her family.
Methods: Following extraction of genomic DNA from peripheral blood samples, 127 genes associated with deafness were subjected to targeted capturing and next generation sequencing. Suspected mutation was verified by Sanger sequencing.
Results: The proband was found to carry a homozygous c.1893C>A mutation in the TECTA gene, which is located in the tectorial membrane of inner ear and may cause premature termination of translation of TECTA protein. In addition, two heterozygous mutations, c.13010C>T and c.12790G>A, were found in the USH2A gene. Whilst the former is likely to be pathogenic, the latter has unknown clinical significance. Further analysis suggested that all three mutations have derived from the parents of the proband.
Conclusion: The homozygous c.1893C>A mutation of the TECTA gene probably underlies the proband's hearing loss which conformed to an autosomal recessive inheritance.