Genetic screening of common genetic deafness in 60,391 women of childbearing age and intervention of birth defects.

INTRODUCTION: At least 60% of cases of severe hearing loss result from genetic factors. In this study genetic screening was carried out for common genetic deafness in women of childbearing age to prevent deafness and birth defects via providing genetic counseling and follow-up services for high-risk families.

MATERIAL AND METHODS: In total 60,391 pre-pregnancy/early-gestation women who received treatment in second-level or above hospitals in Weihai from February 2017 to December 2019 were selected. Venous or peripheral blood was collected to make dried blood slices on filter paper to extract genomic DNA, and high-throughput sequencing was applied to detect 20 variant sites in 4 common deafness genes ( GJB2, GJB3, SLC26A4 and mitochondrial 12S rRNA ) in the Chinese population. The spouses of women with deafness gene variants were sequenced.

RESULTS: In total 3,761 carriers with deafness gene variants were detected in 60,391 women of childbearing age, with a carrier rate of 6.2%. Among them, 1,739 women (2.88%) only carried GJB2 pathogenic variants. The carrying rate of c.235delC in GJB2 pathogenic variants was the highest at 2.08%. 1,553 women (2.58%) only carried SLC26A4 pathogenic variants. The carrying rate of c.919-2A>G in SLC26A4 pathogenic variants was the highest at 1.63%. 300 women (0.5%) only carried GJB3 variants, and 125 women (0.2%) carried the mitochondrial drug-sensitive gene variant.

CONCLUSIONS: This screening model will greatly reduce the birth rate of children with hearing disabilities and is an effective way to prevent newborn deafness. In addition, genetic screening provided the related knowledge of hereditary deafness, especially strengthening genetic counseling and the clinical decision making from the genetic screening.