Newborn screening of genetic mutations in common deafness genes with bloodspot-based gene chip array

Purpose: This study screens for deafness gene mutations in newborns in the Northwest China population. Method: The 9 sites of 4 common deafness genes (GJB2, GJB3, SLC26A4, and mt 12S rRNA) were detected by bloodspot-based gene chip array in 2,500 newborns. Results: We detected mutations of the 4 genes in 101 (4.04%) newborns; particularly, 0.20% detected the double mutations. In the Hui population, 4.58% of the newborns tested positive for mutations, whereas 4.01% of Han newborns tested positive for mutations. The detective rates are as follows: 1.44% for GJB2 235delC, 1.08% for SLC26A4 IVS7-2A>G, 0.48% for GJB2 299_300delAT, 0.28% for SLC26A4 2168A>G, 0.2% for mt 12S rRNA 1555A>G, and 0.16% for GJB3 538C>T. The 31.25% (5/16) of infants with GJB2 235delC, 50% (3/6) with GJB2 299_300delAT, and 25% (3/12) with SLC26A4 IVS7-2A>G showed abnormal hearing when tested; only 1 double mutation case received the hearing test, and this infant showed abnormality in both ears on the hearing test. Conclusions: High mutation rates in the common deafness genes were detected in newborns in Northwest China. Our study is helpful in understanding the deafness genomic epidemiology and also provides evidence for prenatal and postnatal care as well as policy making on population health in the region.