[Molecular etiology analysis among students with profound hearing loss in a special education school in Yangzhou]

To study molecular epidemiological basis of non-syndromic hearing loss in Yangzhou area.

The selected objects were 90 severe non-syndrome deafness students in special education schools in Yangzhou city, Jiangsu province. The deafness gene chip diagnostic kit was used for screening the nine hot spots mutations in four common deafness-related genes in Medical Testing Center of Northern Jiangsu People's Hospital. These nine hot spots gene mutations included GJB2 (35 delG, 176 del16, 235 delC and 299 delAT) GJB3 (538C > T), SLC26A4 (IVS7-2A > G, 2168A > G) and mtDNA 12S rRNA (A > G,1494C > T) mutation detection by line.

In 90 patients, 64 patients were found to carry deafness mutations by using gene chip diagnostic kit (the rate of mutation was 71.7%) GJB2 gene mutation in 40 cases (44.4%)which included 235 delC homozygous in 20 (22.2%) cases, 235 delC single heterozygous mutation in 4 cases (4.4%)and 235 delC and 299 delAT compound heterozygous mutations in 2 case (2.2%) separately. 299 delAT single heterozygous mutation in 2 case (2.2%), 299 delAT simple mutation in 2 case (2.2%). 176 del16 heterozygous mutations in 2 case, 176 del16 homozygous mutation in 2 case (2.2%). 176 del16 heterozygous mutations, and 235 del C heterozygous mutation in 6 cases (6.7%). SLC26A4 gene mutations in 22 cases (24.4%),which included IVS7-2A > G homozygous in 2 (2.22%) cases, IVS7-2A > G and 2168A > G compound heterozygous mutations in 2 cases (2.2%), IVS7-2A > G single heterozygous mutation in 18 cases (20.2%), and mtDNA 12S rRNA A > G mutation in 2 cases (2.2%), GJB3 mutations were not detected.

The deafness gene diagnostic techniques is worth applying for screening and diagnosis.