Abstract: Abstract：Objective To explore the genetic pathogen of patients with non-syndromic hearing impairment and to provide prenatal diagnosis for the families of hereditary deafness. Methods DNA was extracted from peripheral blood of 208 patients. Gene chip and direct sequencing were performed to find mutations. And prenatal diagnosis was carried out in two families by direct sequencing. Results Forty patients were detected two mutations and 46 patients were detected one by gene chip. And 12 cases were found the second mutation through sequencing. The most frequent mutation is 235delC. Fetus 1carried compound mutations of 299-300delAT and 235delC. And fetus 2 carried heterozygous mutation of IVS7-2A＞G. Conclusion Patients with non-syndromic hearing impairment can be accurate diagnosed by gene chip and Sanger sequencing. And prenatal diagnosis is primary means for affected families.

Key words: non-syndromic hearing impairment(NSHI), GJB2gene, SLC26A4　gene, prenatal diagnosis, sequencing