Genetic Testing And Mutation Analysis For The Cochlear Implantation Children And Their Normal Auditory Phenotype Parents

Objective:To investigate the characteristics and significants of prevalence about the mutations of GJB2gene, SLC26A4gene and mitochondrial12S rRNA in deafness children who received cochlear implantation (CI) in Yunnan province. Provide the patients and their families an accurate genetic counseling for early diagnosis and treatment. The research also offers scientific genetic instructions, procedures and epidemiology data of prenatal care and guidance for the families of hereditary deafness.Method:Genomic DNA was extracted from the peripheral blood samples collected from46CI children and their parents (110cases). All the children received the CI and similar rehabilitation training. Their parents have normal auditory phenotype. PCR was performed and the products were sequenced by automated DNA sequencer. Detect the hot spots of mutations and analyzed the data with Statistics means.Results:The detection rates of GJB2235delC (13.0%) and109G>A (24.0%) mutations were significantly higher than other mutations. SLC26A is the secondary major mutation (13.0%), the frequence of IVS7-2A>G (6.5%) is higher than other mutions of SLC26A. There is no difference between Han and other racial minorities (P=0.225). We find out there is no patient who carried the mitochondrial12SrRNA mutations. Leukoencephalopathy, hyperbilirubinemia and hypoxic-ischemic injure were disclosed in7patients (15.2%).Conclusion:The children who received cochlear implantation in Yunnan have a high frequency of235delC and109G>A mutation, IVS7-2A>G is also a common mutation which related to the CI children's hearing loss; Aminoglycoside antibiotics may not be the main reason which induced congenital deaf in CI children; Environment facts was suggested to contribute another important cause. The hot-spots gene screening for the CI children can offer an accurate genetic counseling and epidemiology data for early diagnosis, prenatal care and treatment, it also provide evidences for the clinical analysis between mutations and curative effect.