[The analysis of gene screening results for common hereditary hearing loss in 2 102 pregnant women in Dali area].

<b>Objective:</b>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. <b>Methods:</b>Twenty-one mutation sites of 4 hearing loss genes, including <i>GJB2</i>, <i>GJB3</i>, <i>SLC26A4</i> and <i>mtDNA</i>, were detected by PCR amplification technology. The positive ratio, mutation ratio and ethnic distribution of positive samples were statistically described. <b>Results:</b>The positive ratios of <i>GJB2</i> and <i>SLC26A4</i> 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 <i>GJB3</i>gene was 0.19%, and <i>mtDNA</i> mutation genes accounted for 0.14%, and all of them were <i>mtDNA</i>（Heterozygous）. There was only one case of <i>GJB2</i>/<i>SLC26A4</i> double positive multi-gene mutation, with a positive ratio of 0.05%. The frequency of <i>GJB2</i> c. 235delC site was the highest, accounting for 65.38% of GJB2 mutation genes and 26.56% of mutation gene samples. <b>Conclusion:</b><i>GJB2</i> and <i>SLC26A4</i> are the most common genes of hearing loss, and <i>GJB2</i> 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.