Background: The rate of genetic deafness in Chengdu is still underestimated.
Objective: To investigate patients' molecular etiology with profound hearing loss and facilitate genetic counseling for their families, we screened deafness-related genes of profound hearing loss in the population.
Methods: A total of 1427 unrelated patients with profound hearing loss containing all age groups in the administrative area of City Chengdu (Sichuan, China) were enrolled in this study, and the average examination rate is 81.13%. Nine loci of four deaf-associated genes (GJB2, GJB3, SLC26A4, and mitochondrial 12SrRNA gene) were analyzed. Then we examined all the deaf-associated mutations and compared them between groups.
Results: The average age of all subjects is 48.537 ± 19.077 years, peak range in 41-70 years (985/1427, 69.03%). The positive mutation rates of patients in GJB2, SLC26A4, and 12S rRNA are respectively 8.90%, 4.84%, and 5.96%, and GJB3 none. In group A the GJB2 and SLC26A4 mutation rate is 14.17% (36/254), which is remarkably higher than group B (6.14%, 72/1173). The frequency of 12SrRNA mutations is 3.15% (8/254) in group A, which is significantly different (χ2 = 4.34, p < .05) from that of group B (6.56%, 77/1173).
Conclusions and significance: The mutation rate of mtDNA 12SrRNA is higher than SLC26A4 gene in our study, which is different from other parts of China. And the deaf-related gene mutation spectrums have a distinct age difference.
Keywords: Gene mutation; molecular etiology; profound hearing loss.