Study Of Screening The Deafness Gene Of Yangzhou Children Who Are Moderate To Severe Hearing-impaired,Then Make Genetic Counseling To The Deafness Couples

Deafness, known as hearing impairment, also means that the ability people feel the size of the voice and distinguish the voice is below normal. Hearing loss has a high proportion in the physical disabilities, which has serious impact on people’s normal life.And deafness often causes dumb, the patient is undoubtedly worse. The study found that the cause of deafness is maily by genetic factors （60%）. Deafness is divided into non-syndromic deafness （nonsyndromic hearing impairment, NSHI） and syndromic hearing loss （syndromic hearing impairment, SHI）. Syndromic hearing impairment’s clinical manifestation is variety, non-syndrome deafness is only in a single nerve damage. Non-syndromic deafness （NSHI） is as the hearing loss for a single symptom. NSHI has a high degree of genetic heterogeneity. The experts of Medical Genetics estimate that there may be more than100loci related NSHI. Hereditary deafness can be divided into the mode of inheritance:autosomal recessive inheritance, which accounts for about70%, about22%of autosomal dominant and X-chains account for about1%, mitochondrial mutations in maternally inherited about1%.With the project of human genome being completed, there has been remarkable progress being made on hereditary hearing loss. Since the majority of Chinese hereditary deaf people have been confirmed to be caused by GJB2gene,GJB3gene, SLC26A4gene, and mtDNA mutations, genetic testing of these four genes can assist us with making clear about cause of deafness and providing theoretical evidences for genetic counseling which make genetic information and instruction more scientific and accurate. Furthermore, it makes prenatal diagnosis possible for deaf families. It’s significant to the deaf couples who has the requirements of give birth again to a normal hearing children.Genetic counseling of deafness is therefore of great significance. It gives the deaf couples scientific and rational guidance for their marriage and childbearing. It also reduced the birth rate of deaf children and the economic burden of the countries and deafness families. Based on the above, our study screening the deafness gene of the Yangzhou children who are patient of moderate to severe hearing impairment.Then we put the genetic screening results into the clinical study. Genetic counseling provides scientific protection to the deafness family who want to give birth again for a hearing normal children. Parti Study of screening the deafness gene on deafness children of Yangzhou who have moderate to severe hearing impairedObjective:Application of deafness gene microarray technology for screening the children of Yangzhou Special school who of moderate to severe hearing-impaired, research the hereditary deafness genes types of Yangzhou.Methods:In the voluntary principle, by questionnaire and signed informed consent,65non-syndrome deafness students from the Special school in Yangzhou City （45of them called the proband, the remaining20had no significant hereditary）, general physical examination and ENT examination, audiological tests confirmed the non-syndrome deafness （hearing loss as the only clinical symptoms）, extraction of peripheral venous blood3ml, low dose of whole blood genomic DNA extraction kit to extract DNA, detection of gene by gene Polymerase chain reaction （PCR） amplification and hybridization, washing, etc, after the application of crystal core nine hereditary deafness gene detection kit which have subjects4deafness9hot spots in the genes, including GJB2（35delG,176del16bp,235delC,299₃00del AT）, GJB3（538C>T,547G> A）, SLC26A4（IVS7-2A> G,2168A> G） and mitochondrial DNA12s rRNA （The A1555G）. Lux, ScanTM of the crystal core chip scan10KB microarray scanner90laser scanning intensity and532nm laser wave length and the corresponding genetic deafness gene microarray discrimination system for signal read and judge.Results:The results is the positive rate （at least carry one mutant allele） in the children who parts in this study is61.54%（40/65）:there are14cases of GJB2235delC gene pure mutations, three cases of235delC miscellaneous mutations, two cases of235delC/299delAT compound heterozygous mutations,1case176del16pure mutant,2cases of299delAT homozygous,1case of299delAT heterozygous mutation,1case of176dell6/235delC heterozygous mutations.The total mutation positive rate of GJB2mutations is60.00%（24/40）;2cases of SLC26A4IVS7-2A> G pure mutation, seven cases of SLC26A4IVS7-2A> G heterozygous mutation, four cases of SLC26A4IVS7-2A>G/SLC26A42168A>G compound heterozygous, two cases of SLC26A42168A> G heterozygous mutations, the positive rate of SLC26A4mutations accounted37.50%（15/40）; one case of mitochondrial DNA12SrRNA The A1555G homogeneous, mutation of the total mutation positive rate is2.50%（1/40）; GJB3mutation-positive rate is0;20cases of the control Group didn’t detect any mutant genes.Conclusions:The genetic deafness of Yangzhou has a higher incidence, and GJB2is a major deafness gene.The rate of SLC26A4gene mutations rate is higher than the national average. Normal people don’t carry any deafness gene. Part2Genetic counseling for deafness based on genetic testingObjective:Based on the results of genetic testing, our study aim is to predict the fertility of the risk of deafness combined the results of genetic screening to whom want to give birth again.Methods:Following the informed consent and confidentiality principle, we test the couple’s deafness gene who want to give birth again to a normal child by deafness gene chips technology. Combined the questionnaire and their first child’s genetic test results, we can help the deaf couples to detect and counsel the genetic types of their second children who will be give birth to.Results:Six families from the outpatient’s deafness genes were detected, we discovered that two couples of them need pregnancy counseling during the prenatal diagnosis:a couple during pregnancy didn’t need prenatal diagnosis:and three pairs of the couples need pregnancy counseling during their prenatal diagnosis.Conclusion:The deaf family has a high rate of re-fertility a deaf child. The deafness genetic testing can predict their second fetal’s risk of hearing loss.