Objective: Based on the clinical manifestations of a hearing loss patient, the POU3F4 gene was tested for diagnosis of etiology.Methods: A comprehensive physical examination was performed on the proband to exclude abnormalities of other organs, and detailed audiological testing and temporal bone CT scan were also performed. Genomic DNA was extracted using the proband's peripheral blood leukocytes.Polymerase chain reactions(PCR) were performed in the coding sequence of the POU3F4 gene. Direct DNA sequencing was subsequently applied to screen the entire coding region of the POU3F4 gene.Results: The proband had severe sensorineural hearing loss. Temporal CT showed bilateral cochlear incomplete partition, vestibule dysplasia,internal auditory canal fundus expansion, and cochlear interlink with the internal auditory canal fundus. A novel mutation(c.530 C > A(p.S177X)) in the POU3F4 gene was found in this patient, creating an new stop codon and was predicted to result in a truncated protein lacking normal POU3F4 transcription factor function.Conclusion: Through analysis of the POU3F4 gene and clinical manifestations in the patient, we conclude that a novel mutation may have resulted in a premature stop codon, contributing to the mutation of POU3F4 gene.
