Abstract:

Objective To investigate the distribution characteristics of common genetic variations of deafness in newborns in Tongzhou District of Jiangsu Province，and to evaluate the effectiveness of deafness gene screening. Methods A total of 11 256 newborns who underwent deafness gene screening in Tongzhou District of Jiangsu Province from June 2018 to December 2022 were enrolled. All the newborns' heel blood was collected and prepared into dried blood spots. The 15 variation sites of 4 deafness genes（GJB2，GJB3，SLC26A4，mtDNA12SrRNA） were determined using microarray chips. The samples with determined variation sites were verified by Sanger sequencing. The parents of newborns with determined genetic variations were followed up by phone. Results Among the 11 256 newborns，514 cases were determined as carriers of genetic variations（including 9 cases of double gene variations），with a total variation rate of 4.57%. Among them，253 cases had GJB2 gene variations（2.25%），27 cases had GJB3 gene variations（0.23%），209 cases had SLC26A4 gene variations（1.86%），and 34 cases had mtDNA 12SrRNA variations（0.30%）（P<0.001）. The top 3 variation sites determined were GJB2 gene c.235delC（1.67%），SLC26A4 gene c.IVS7-2A>G（1.45%） and GJB2 gene c.299delG（0.39%）. There were 261 cases of male newborns（261/5 711，4.57%） and 253 cases of female newborns（253/5 545，4.56%） as carriers of genetic variations. Among the follow-up patients of the genetic variation newborns，2 cases had hearing loss（GJB2 gene c.235delC homozygous variation and SLC26A4 gene c.IVS7-2A>G+c.1226G>A heterozygous variation）. Conclusions The common types of deafness genes in newborns in Tongzhou District of Jiangsu Province are SLC26A4 gene c.IVS7-2A>G，GJB2 gene c.235delC and GJB2 gene c.299delG. Conducting deafness susceptibility gene screening can help improve the determination rate of hearing impairment in newborns.

Key words: Deafness gene, Microarray chip, Gene sequencing, Hearing impairment