Objective      To screen the hereditary deafness genes by DNA microarray in newborns

evaluate the mutation types and frequencies of 9 mutation spots

and identify the relationship between these mutations and deafness.       Methods      A total of 756 umbilical cord blood samples of newborns without hereditary deafness history were collected after informed consent was signed by their parents. Genomic DNA was extracted and then 9 hot mutation spots in 4 deafness genes were detected by microarray

which included GJB2 (35 del G，176 del 16，235 del C and 299 del AT)

GJB3 (538  CT)

SLC26A4 (IVS 7-2 AG

2168  AG)

and mitochondial 12S rRNA (1555 AG ，1494  CT). Positive microarray results were verified by DNA sequencing.       Results      Fifteen cases had GJB2 mutation (235 del C)

13 cases SLC26A4 mutation (IVS 7-2 AG)

4 cases GJB2 mutation (299 del AT)

1 case GJB2 mutation (176 del 16)

1 case SLC26A4 mutation (2168  AG)， and 1 case 12S rRNA mutation (1555  AG). The sequencing results were consistent with the microarray results.       Conclusion      Among those newborns without family history of deafness

the mutation frequency of GJB2 is higher than SLC26A4 in this study

and mutation of GJB3 is rare. Mutation screening for hereditary deafness related genes play an important role in the early detection and proper treatment for neonatal deafness

and in the instruction for marriage and breeding.