Introduction: GJB2 mutations are the most frequent reason of genetic congenital hearing loss. The aim of the study was to assess the prevalence of GJB2 mutations in the deaf and profound hearing loss children.
Material and methods: The material of the study was a group of 61 patients divided into two groups. Group I - 35 deaf or with profound sensorineural hearing loss children (the pupils of the deaf and hard of hearing school), aged 5-17 years (average 9.2 years), 14 males, 21 females, II - control group comprised 26 normal hearing patients, aged 5-16 years (average 10.4years), 14 males, 12 females (patients of Department of Pediatric Otolaryngology, Audiology and Phoniatrics, Medical University of Lodz). In both groups, exon 2 sequencing of GJB2 gene was performed.
Results: In group I in 6 patients (17%) 35delG in GJB2 gene was found. The patients were homozygotes, with negative family history of hearing loss. No other mutations in GJB2 gene were found. In group II no mutations in GJB2 were observed.
Conclusions: The most frequent cause of hearing impairment in the deaf and profound sensorineural hearing loss children was 35delG mutation in GJB2 gene. No other mutations in GJB2 gene were detected.