Mutation Detection Of SLC26A4,FOXI1 And KCNJ10 In Cochlear Implant Recipients With Enlarged Vestibular Aqueduct Syndrome

Objective:To analyze the molecular epidemiology of SLC26A4 mutations in 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.Methods:Genomic DNA samples were extracted from peripheral blood of 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.The SLC26A4 mutations were analyzed by direct sequencing.Results:There were 27 cases with SLC26A4 compound heterozygous mutations,15 cases with SLC26A4 homozygous mutations,8 cases with one SLC26A4 mutation and 2 cases with no SLC26A4 mutations.Of the 52 cases,the percentage of cases carrying IVS7-2A>G mutation,2168A>G mutation and 1226G>A mutation was 80.8%(42/52),17.3%(9/52)and 5.8%(3/52)respectively.Conclusion:This study showed that the occurrence of SLC26A4 mutations was very high and the IVS7-2A>G was the most common mutation in the cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.Objective:To analyze the molecular epidemiology of FOXI1 mutations in 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.Methods:Genomic DNA samples were extracted from peripheral blood of 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.The FOXI1 mutations were analyzed by direct sequencing.Results:There were 30 cases with FOXI1 compound heterozygous mutations,21 cases with FOXI1 homozygous mutations and 1 case with one FOXI1 mutation,which accounted for 57.7%(30/52),40.4%(21/52)and 1.9%(1/52)respectively.Three synonymous mutations(279G>A,651G>A and 759T>C)and one missense mutation(800A>G)were detected,and the percentage of cases carrying 279G>A mutation,651G>A mutation,759T>C mutation and 800A>G mutation was 76.9%(40/52),1.9%(1/52),100%(52/52)and 1.9%(1/52)respectively.Conclusion:This study showed that in the cochlear implant recipients with enlarged vestibular aqueduct syndrome the occurrence of FOXI1 mutations was high and the 759T>C and 279G>A were the common FOXI1 mutations.However,the 759T>C and 279G>A were synonymous mutations and cannot lead to the enlarged vestibular aqueduct syndrome.Objective:To analyze the molecular epidemiology of KCNJ10 mutations in 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.Methods:Genomic DNA samples were extracted from peripheral blood of 52 cochlear implant recipients associated with enlarged vestibular aqueduct syndrome.The KCNJ10 mutations were analyzed by direct sequencing.Results:There were 49 cases with no KCNJ10 mutations and 3 cases with one KCNJ10 mutation,which accounted for 94.2%(49/52)and 5.8%(3/52)respectively.All three KCNJ10 mutations were 812G>A,which is missense mutation and cannot lead to the enlarged vestibular aqueduct syndrome.Conclusion:This study showed that there was a certain amount of KCNJ 10 single heterozygous mutation in cochlear implant recipients with enlarged vestibular aqueduct syndrome.The 812G>A was the relatively common mutation and there was no direct correlation between KCNJ 10 single heterozygous mutation and enlarged vestibular aqueduct syndrome.