The Study Of Auditory And Speech Rehabilitation After Cochlear Implantation In Patients With SLC26A4 Gene Mutation

Objective:The aim of our study are as follows:First,study the mutation distribution of SLC26A4 gene in CI patients with bilateral severe hearing loss;Second,analyze the clinical manifestations of SLC26A4 gene mutation after cochlear implantation;the last one,explore the relationship between SLC26A4 mutation and speech rehabilitation after cochlear implantation.Method:In this study,350 patients who received cochlear implantation in the Second Hospital of Lanzhou university from 2012 to 2015 was received preoperative clinical data,including medical history,auditory results,imaging data.With the consent of the patients’guardian,peripheral blood was drawn to detected the mutation of common deafness genes.All this patients has evaluated their hearing and speech ability in our study,including hearing threshold,CAP and SIR scores,recognition ability words and short sentences in quiet and noise environments.350 patients were divided into SLC26A4 gene mutation group,other gene mutation group and negative group according to the gene detection results.Result:Gene test results:Among 350 patients,71 had SLC26A4 gene mutation,75 had GJB2 gene mutationm,10 had mitochondrial gene mutation,4 had GJB3 gene mutation and 190 hadn’t found gene mutation.The mutant carrier rate for SLC26A4was 20.29%,including 26 homozygous mutant carriers,18 single mutant carriers and29 complex heterozygous mutant carriers.33 genotypes were collected,among which the most common genotype was c.919-2A>G/c.919-2A>G,accounting for30.99%(22/71).In the 71 patients,a total of 21 different types of mutations were found.the two most common types(c.919-2A>G and c.2168)accounting for 52.12%(74/142)and 7.04%(10/142)mutant alleles identified,respectively.Clinical data:There were 190 male and 160 females among these 350 patients,with a male to female ratio of 1:0.84.There were 311 Han,24 Hui,5 Tibetan,8Dongxiang,1 Yugu and 1 Baoan.The auditory test for all these people were met the standard of cochlear implantation.HRCT of the temporal bone was performed in all these children,and the deformity rate was 26.29%,accounting for 55 EVA,20 EVA with IP-Ⅱ,3 IP-Ⅱand 14 other malformations,236 cases had normal inner ear structure.Among 73 patients with SLC26A4 mutation,the ratio of male to female was1:0.92.There was significant significant difference in ABR threshold distribution among three groups(χ~2=15.786,P=0.01).The distribution of ASSR threshold was significantly different in different frequencies(χ~2=64.784,P=0.000).The deformity rate was 91.55%,including 47 EVA,17 EVA with IP-Ⅱ,1 IP-Ⅱand 8 with normal structure.There was no significant difference in EVA,EVA with IP-Ⅱbetween SLC26A4 double allele mutation group and single allele mutation group(χ~2=0.347,P=0.556).Cochlear implant outcomes in children with SLC26A4 mutation:There was no significant difference of hearing aids threshold among the SLC26A4 gene mutation group(P<0.05).The CAP and SIR score of the SLC26A4 gene mutation group were better than those of the other gene mutation group(P<0.05).Compared with other gene mutation groups,SLC26A4 gene mutation group had significant difference(P<0.05)compared with negative groups in speech recognition rate of Chinese short sentences in quiet environment.Cochlear implant outcomes in children with different genotypes of SLC26A4:Patients with SLC26A4 gene mutation were divided into three groups:c.919-2A>G homozygous mutation group,c.919-2A>G single allele mutation group,other double allele mutation group and other single allele mutation group.Fisher’s accurate test was carried out for the distribution of malformations among the groups without statistical difference(χ~2=12.310,P=0.122).c.919-2A>G single allele mutation group had better hearing threshold than other single allele mutation group.There was no significant difference in CAP and SIR.c.919-2A>G homozygous mutation group had better words recognition rate than other single allele mutation group(P<0.05).Conclusion:The two most common types were c.919-2A>G and c.2168A>G and the most common genotype was c.919-2A>G/c.919-2A>G in people with SLC26A4 gene mutation.The most important molecular etiology of EVA and EVA combined with IP-Ⅱwas SLC26A4 gene mutation,isolated IP-Ⅱhad no clear relationship with SLC26A4 gene mutation,and SLC26A4 was not related to other common inner ear malformations.The hearing threshold and speech recognition rate in noise environment of patients with SLC26A4 mutation were similar to those of patients with other gene mutations,while speech recognition rate in quiet environment better than that of negative patients.Compared with other genotypes of SLC26A4,the patients with homozygous mutation of c.919-2A>G in SLC26A4 had better hearing reconstruction effect after cochlear implantation.SLC26A4 gene mutation and EVA deformity are good indications for CI.SLC26A4 related hearing loss and EVA patients can obtain good hearing and speech rehabilitation effects after CI operation.