Objective: To investigate the roles of connexin genes in Chinese population.
Methods: Peripheral blood samples were collected from 214 patients with hearing loss, 160 with sensorineural hearing loss (66 with prelingual hearing loss and 94 with postlingual hearing loss), 32 with auditory neuropathy, and 22 with enlarged vestibular aqueduct syndrome (EVAS), 110 males and 104 females, all from 14 provinces north of the Yangtze River, all of Han nationality, and 86 normal controls. PCR and sequencing of the PCR products were used to screen 3 connexin genes: GJB2, GJB3, and GJB6.
Results: The frequency of connexin gene sequence variant was 73.36% (157/214), higher than that of the controls (60.05%, 42/86). 34 of the 157 patients carried pathogenic mutations (15.89%). The frequency of 235delC deletion was 16.67% among patients with prelingual hearing loss (11/66). Six known polymorphisms and six new mutations were found in these patients.
Conclusion: The pathogenic mutations of the patients with hearing loss are distributed quite differently between the patients and normal persons. The genetic variants GJB2 235delG and GJB6-Delta (GJB6/D13S1830) were not common. Relevant information is helpful in early diagnosis of hearing loss in Chinese population.