Gene mutation analysis and genetic counseling for patients with non-syndromic hearing loss in Linyi region

Through gene mutation analysis of patients with non-syndromic hearing loss (NSHL) correct genetic counseling for patients with NSHL and their family members were provided. A total of 116 patients suffering from NSHL were selected, and Sanger sequencing was applied to analyze 31 mutation sites in four deafness genes [gap junction β-2 (GJB2), solute carrier family 26, member 4 (SLC26A4), GJB3 and mitochondria 12S ribosomal ribonucleic acid (12SrRNA)]. Based on detection results, for the families with reproductive needs, amniotic fluid was extracted from pregnant women during proper gestational weeks to identify fetal genotypes and predict hearing state. Among 116 patients with NSHL, 51 patients carrying definite pathogenic mutation were found, including 35 patients with GJB2 mutations, 14 patients with SLC26A4 gene mutations and 2 patients with mitochondrial deoxyribonucleic acid 12SrRNA (mtDNA 12SrRNA) mutations. No GJB3 gene mutation site was detected. In addition, prenatal diagnosis to 17 pregnant women who had given birth to babies with deafness was performed, and results suggested that genotypes of 6 fetuses were consistent with those of probands, genotypes of 8 fetuses were consistent with those of their parents, and no mutation was found in the other 3 fetuses. Gene mutation analysis of patients with NSHL can identify the etiology and provide appropriate genetic counseling and birth guiding for patients with NSHL and their family members. In addition, prenatal diagnosis to the families who plan to give birth again can avoid the natality of fetuses with hearing loss.