| Objective:Hearing loss is most common sensory disorder in the human population.In our country, two in 1000 children are affected with congenital hearing loss of a lesser degree in more than 30 million babies every year, which is about half of hereditary deafness. And in a large number delayed patients with hearing loss, there are many patients because of its genetic defects and disease. Even in the normal population also has more than 6% of the carriers of genes that cause deafness, which means that there is a certain risk of normal birth to deaf children.In the past, clinicians for the prevention of deafness could be taken to small and ineffective. However, with the development of genetic science, detecting deafness gene turns into reality, and genetic testing of deafness can be able to do "early discovery, early prevention, early treatment" ,which is the most effective high-tech means . According to a related report, we already know the common cause deafness genes including GJB2 gene, mitochondrial DNA A1555G genes, the PDS gene,and so on. These genes are the focus of deafness gene or gene mutation. GJB2 gene have close relations to congenital deafness. Congenital deafness patients carrying the GJB2 gene mutation accounts for about 20 percent in China. Mitochondrial DNA A1555G mutation has close relations to streptomycin, gentamicin,and kanamycin aminoglycoside drugs so on,which can lead to drug-induced deafness. PDS gene mutation can lead to large vestibular aqueduct syndrome,of which clinical performance is congenital or acquired deafness. Injury and the flu can lead to deaf or heavier. These three genes of hereditary deafness caused by the hereditary deafness about 50 percent. On this basis, there has been suitable for Chinese conditions of deafness gene detection chip. In this paper,we have used gene chip technology to diagnose 153 cases of patients with common hereditary deafness gene, for the future of the family, marriage and child rearing molecular biology guidance.Methods: A questionnaire survey has been done for153 cases deafness patients about the basic information related to deaf. We have aquired these deafness patients'fresh blood, which were anticoagulated by the sodium citrate, and we extracted DNA from the blood by the NucleoSpin Blood DNA Extraction Kit.Then we finishied the extraction of DNA for GJB2 35delG, 176del16, 235delC, 299delAT, GJB3 538C→T, 547G→A, PDS 2168 A→G, IVS7-2 A→G, MtDNA 1494 C→T, 1555 A→G mutation ten point detection with the use of crystal core ? Genetic deafness gene chip testing kit.Results: 1, All of the 153 patients with deafness, deaf ears before a clear history of drug toxicity, 53 cases (34.64%), 57 cases of congenital deafness (37.25%), unknown causes acquired deafness 43 cases (28.01%); there were 19 cases of family history.2, there are 53 cases children with drug poison before deaf , of which the largest single drug to see gentamicin, were 22 cases, single streptomycin, small Daunomycin were 6 cases, 2 cases, streptomycin and gentamicin combined two cases, gentamicin combination with small Daunomycin one cases, gentamicin and kanamycin one case of combined application of salicylic acid drugs two cases, with History of unknown drugs in 17 cases.3, in the dissemination of the 134 deaf patients, 53 patients (39.55%) have been detected common deafness genes, which exist GJB2 gene mutation in 30 cases (22.39%): homozygous mutations in 10 cases, including: 235delC homozygous mutation nine cases, 299 delAT one case of homozygous mutation; heterozygous mutation 7 cases, including: 35 delG heterozygous mutation in 1, 176del16 heterozygous mutation in 1, 235 delC heterozygous mutation 4 cases, 299 delAT heterozygous mutations 1 cases of mutations in 13 cases, including: 176 del16 heterozygous mutations with 235 delC heterozygous mutation 3 cases, 235delC heterozygous mutations with 299 delAT heterozygous mutations in 10 cases. Another one case of 235 delC heterozygous mutations with 299 delAT heterozygous mutations with MtDNA 1494 C→T mutation. there are PDS gene mutation in 21 (14.58%), which IVS7-2A→G homozygous mutation 7 cases, 10 cases of heterozygous mutations, 2168 A→G heterozygous mutations 1 case ,of the two mutations of 3 cases. There are GJB3 538C→T heterozygous mutation in 1 case. In the 16 hereditary deafness families, 10 (62.50%) of common family deafness gene abnormalities, including GJB2 176del16 homozygous mutant one, 235 delC a homozygous mutation, PDS IVS7-2A→G a homozygous mutation; 235 delC heterozygous mutations with 299 delAT heterozygous mutations 2, the PDS IVS7-2A→G heterozygous mutations associated with 2168 A→G mutation of a hybrid; GJB2 235delC heterozygous mutations 3, PDS IVS7-2A→G mutation of a hybrid.Conclusion: 1 ,In 153 cases of deaf patients, the existence of common deafness genes accounted for 42.48% abnormal, GJB2 gene accounted for 24.84%, 16.34% of the PDS gene, and GJB3,MtDNA gene mutation frequency <1%. 2, all participants in the detection of deaf patients, can clear the molecular diagnosis of the overall 14.37%, GJB2 gene accounted for 7.84%, 5.23% of the PDS gene, MtDNA and GJB3 <1%.3, a family history of hereditary deafness in patients with common deafness gene detection rate and molecular diagnosis were significantly higher than those in patients with disseminated.
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