Objective:By conducting genetic testing of hereditary hearing loss in pregnant women within 17 weeks of gestation in Dali areas, the importance of genetic testing and genetic counseling during pregnancy was emphasized. Methods:Twenty-one mutation sites of 4 hearing loss genes, including GJB2, GJB3, SLC26A4 and mtDNA, were detected by PCR amplification technology. The positive ratio, mutation ratio and ethnic distribution of positive samples were statistically described. Results:The positive ratios of GJB2 and SLC26A4 genes were 1.24% and 1.43%, respectively, with mutation rates of 40.62% and 46.88% in the positive samples, respectively. The positive ratio of GJB3gene was 0.19%, and mtDNA mutation genes accounted for 0.14%, and all of them were mtDNA（Heterozygous）. There was only one case of GJB2/SLC26A4 double positive multi-gene mutation, with a positive ratio of 0.05%. The frequency of GJB2 c. 235delC site was the highest, accounting for 65.38% of GJB2 mutation genes and 26.56% of mutation gene samples. Conclusion:GJB2 and SLC26A4 are the most common genes of hearing loss, and GJB2 c. 235delC site is the most common mutation site. Identifying the hearing loss mutation site is of great importance to prevent the birth of hereditary hearing loss children, and genetic diagnosis, genetic counseling, and appropriate intervention are crucial to alleviate congenital problems.
Humans ; Female ; Pregnancy ; Sulfate Transporters/genetics* ; Connexin 26 ; Genetic Testing/methods* ; Connexins/genetics* ; Mutation ; Hearing Loss/diagnosis* ; DNA, Mitochondrial/genetics* ; Adult ; Membrane Transport Proteins/genetics* ; Genetic Counseling