The invention provides a CDH23 gene mutant, which is characterized in that compared with a wild type CDH23 gene sequence, the nucleotides of the CDH23 gene mutant have c.3890G > T and/or c.6649A > G mutation; the polypeptide of the CDH23 gene mutant has the mutation of p.Cys1297Phe and/or the mutation of p.Lys2217Glu. The invention further provides a kit for detecting the CDH23 gene mutant and application of the kit, and the kit is used for screening susceptible sensorineural deafness diseases. The CDH23 gene mutant disclosed by the invention can be used for screening autosomal recessive deafness pathogenic mutation carriers, can also be used for molecular diagnosis of autosomal recessive deafness patients and differential diagnosis of related diseases, and is rapid, accurate, efficient, simple and convenient and high in early diagnosis rate, and detection results can provide scientific basis for early diagnosis, differential diagnosis and drug therapy of autosomal recessive deafness.
CDH23 gene mutant, kit for detecting CDH23 gene mutant and application of kit