Analysis Of Audiology And Related Pathogenic Genes In Enlarged Vestibular Aqueduct Patients

1.ObjectiveTo investigate the characteristics of audiology in patients with enlarged vestibular aqueduct and mutation site of SLC26A4.2.MethodsDiagnosis of EVA in 24 cases of Deafness by CT Imaging of temporal Bone.Using Conera Pure tone audiometer to detect Pure tone audiometry,Acoustic Impedance is detected by ZODIAC901 Middle ear Analyzer,to detect auditory brainstem evoked potential and 40Hz related potential threshold by HIS Smart EP tester,to detection of distortion product otoacoustic emission by HIS Smart DPOAE otoacoustic emission instrument,to detection of speech recognition rate.All patients' hearing results were graded according to the degree of hearing loss.According to the nature of deafness,it is divided into conductive,sensorineural and mixed deafness.The ratio of different types of deafness is calculated and compared.A panel?including 127 deafness genes?was used to detect the mutation sites of FOXI1 and KCNJ10 genes in deafness with non-allelic mutations.The results were grouped according to SLC26A4 allele mutation and non-allelic mutation,and the location of all the detected mutation sites in the gene was identified by consulting the NCBI database.Audiological examination in strict accordance with the operating procedures,including personnel preparation?persons who cannot cooperate are not included in the study?and the environment?the hearing tests were carried out in a standard soundproof room and indoor electrical shielding insulation?.3.ResultHearing results:one mild deafness case?4.17%?,five moderate deafness cases?20.83%?,6 cases with moderate and severe deafness?25%?,6 cases with severe deafness?25%?,6 cases with profound deafness?25%?.Type of deafness:16 cases of sensorineural deafness?n = 16?and 8 cases of mixed deafness?n = 8?with deafness of 33.33%.5 cases passed DPOAE?20.83%?,all of them were mild or moderate hearing loss patients,9 cases induced ABR?37.5%?.Gene results:the detection rate of high frequency gene loci is c.919-2A>G in SLC26A4 mutant alleles were detected in patients with the rate of 59.09%,of which a homozygous mutation in 8 patients.Followed by the site is c.2168A>G?p.His723Arg?,the detection rate of c.1707 6.82%.22 and c.1336C 5G>A in patients with>T?p.Gln446Ter?were found in two patients carrying.Pathogenic sites:c.387delC,c.230A>T?p.Lys77Ile?,c.1229C>T?p.Thr410Met?,c.235C>T?p.Arg79Ter?,c.1226G>A?p.Arg409His?,c.1595G>T?p.Ser532Ile?,c.1174A>T?p.Asn392Tyr?,c.1339delA.clinical significance of unknown sites:c.915₉16insG,c.692T>A?p.Val231Glu?.4.Conclusion1.The auditory manifestations of patients with enlarged vestibular aqueduct were diverse.The degree of deafness is more than moderate,and the characteristic of deafness is sensorineural hearing loss and mixed deafness.DPOAE and ABR in EVA patients with severe hearing loss and above cannot be elicited.2.c.919-2A>G has the highest rate of carrying.SLC26A4 gene mutation can cause deaf-mute and does not show that the vestibular aqueduct enlargement.3.SLC26A4 gene is not the only pathogenic gene of EVA.