Prevalence of GJB2 gene mutation in 330 cochlear implant patients in the Jiangsu province.

OBJECTIVE: GJB2 gene mutations are highly prevalent in pre-lingual hearing loss patients from China. Pre-lingual deafness is a sensorineural disorder that can only be treated with cochlear implantation.

METHOD: The prevalence of GJB2 gene mutations was examined in 330 randomly selected patients treated with cochlear implantation.

RESULTS: Overall, 276 patients (83.64 per cent) carried variations in the GJB2 gene. Seventeen different genotypes were identified, including 10 confirmed pathogenic mutations (c.235delC, c.299delAT, c.176del16, p.E47X, p.T123N, p.V167M, p.C218Y, p.T86R, p.V63L and p.R184Q), 3 polymorphisms (p.V27I, p.E114 G and p.I203 T) and 2 unidentified mutations (p.V37I and c.571 T > C).

CONCLUSION: A total of 103 patients (31.2 per cent) carried 2 confirmed pathogenic mutations. The frequency of c.235delC was higher than that reported previously in the Jiangsu province. The two novel mutations identified, 69C > G and 501G > A, are likely to be polymorphisms.