The Clinical Characteristics Of Common Gene-related Deafness And The Effect Analysis Of Cochlear Implantation

Normal hearing is the basis for language formation and development,so listening speech disorder will directly affect the communication and learning in daily life.Deafness is one of the most troublesome diseases of mankind.In 2006,China’s second national sample survey of disabled persons showed that the total number of disabled persons was 82.96 million,including 27.8 million people with hearing disabilities,which occupying the first position on the list of disabilities,and the growth rate of newborns with deafness in each year is 20000 to 30000.The causes of deafness include hereditary,drug,noise,trauma,aging or a combination of a variety of factors.Among them,the genetic mutation as a major cause of hearing impairment in children is accounted for the proportion of up to 50%-60%.In China,the deafness related with GJB2 and SLC26A4 mutation is about 35.5% in the proportion of hereditary deafness,and the two genes has become two responsible and major genes with the highest detection rate for deafness.The two kinds of genetic mutation have different pathogenesis,so their clinical manifestations may be different.Therefore,to study the clinical and imaging characteristics of deaf people with GJB2 and SLC26A4 mutations from the aspects of age of onset,degree of hearing loss,CT manifestation and so on,is of great significance to help to accurately diagnose and to guide the clinical intervention measures.The emergence of Cochlear implantation(CI)technology provides a chance for bilateral patients with severe sensorineural hearing loss to return to the sound world.The CI implantation technology has been improved,and the number of patients with cochlear implantation increases year by year.The abilities of CI population in the auditory perception,speech recognition and language output and other aspects have been improved;however,the postoperative rehabilitation effect still indicates a large individual difference.With the widespread application of genetic testing and diagnostic techniques,deaf children caused by genetic mutation have occupied a large part of the CI population.Whether different gene mutations,as the cause of sensorineural hearing loss,have an impact on the rehabilitation effect of hearing and language after CI,there is still no definite conclusion.Objectives:1.To study and analyze the children with sensorineural hearing loss who are diagnosed as GJB2 and SLC26A4 gene mutations from the age of onset,the degree of hearing loss and the characteristics of the inner ear imaging.2.To explore and evaluate the hearing and language rehabilitation effect of children with sensorineutral hearing loss who are related with GJB2 and SLC26A4 mutations after CI.Section one:The Clinical Characteristics of Common Gene Related Deafness Objective:To study and analyze the children with sensorineural hearing loss who are diagnosed as GJB2 and SLC26A4 gene mutations from the age of onset,the degree of hearing loss and the characteristics of the inner ear imaging.Methods:The study objects are a total of 218 cases of children of 0-12 years old with sensorineutral hearing loss,who have been treated by our hospital otological clinic,and diagnosed as GJB2 and SLC26A4 gene mutation or compound heterozygous mutations by deafness gene chip and DNA sequencing,and of which,123 cases are patients with homozygous GJB2 gene mutation or heterozygous GJB2 gene mutation,and 95 cases are patients with omozygous SLC26A4 gene mutation or heterozygous SLC26A4 gene mutation.According to the age of onset,the patients are divided into infancy group,early childhood group,preschool groupand school age group.Then,this paper will try to explore the children with homozygous or heterzygous GJB2 and SLC26A4 gene mutations from the aspects of age composition,age of hearing loss and characteristics of temporal bone CT scan.Results:1.The proportions of children with GJB2 gene mutation and children with SLC26A4 gene mutation in the periods of infancy,early childhood,preschool and school age respectively were 43.09%,37.40%,14.63%,4.88% and 24.2%,44.21%,18.95%,12.63%,and the difference between the two groups was statistically significant(P = 0.014).2.The hearing loss was classified into moderate,severe and extremely severe,and the proportions of hearing loss extent of children with GJB2 gene mutation and SLC26A4 gene mutation respectively were 8.94%,17.89%,73.17% and 9.47%,34.74% and 55.79%.The GJB2 group was mainly extremely severe hearing,and when comparing with the hearing loss extent in SLC26A4 group,the difference is statistically significant(P = 0.014).3.The proportions of hearing loss of patients with GJB2 gene mutation in different age groups had differences,which were statisticly significant(P = 0.000)By comparing with two groups,the results showed that the degree of hearing loss in the infancy group and early childhood group was mainly extremely severe,and the younger the age of onset was,the higher the proportion of severe hearing loss;the proportion of extremely severe hearing loss in preschool group and school age group was declining.The hearing loss of patients with SLC26A4 gene mutation in all age groups was mainly severe and extremely severe,and the proportion of hearing loss has no significant difference(P = 0.686).4.In GJB2 gene mutation group,99.19%(122/123)patients have normal inner ear structure,and only one case has shown bilateral internal auditory canal stenosis by CT;while in SLC26A4 gene mutation group,95.79%(91/95)patients were accompanied with vestibular expansion by temporal bone CT scan.Conclusions:1.For deaf children with GJB2 gene mutation,the age of onset are centered in the periods of infant and early childhood(0 to 3 years old),and they are mainly extremely severe sensorineural hearing loss,mostly without the ear deformity.2.For deaf children with SLC26A4 gene mutation,the age of onset are centered in early childhood period(1.1 to 3 years old),and they are mainly severe and extremely sensorineural hearing loss,closely related with the inner ear deformity accompanied by the vestibular esophageal expansion.Section Two:The Effect Analysis of Artificial Cochlear Implantation in Common Gene Related Deafness Objective:To explore and evaluate the hearing and language rehabilitation effect of children of sensorineutral hearing loss who are related with GJB2 and SLC26A4 gene mutations after CI.Methods:198 cases of patients collected from January in 2015 to February in 2016,have been undergone the unilateral CI implantation in our department,and of which,102 cases were males and 96 females.The age of implantation was ranged from ten months to 6 years old,with an average age of 3.14 years old.Based on the results of genetic test,patients were divided into GJB2 group,SLC26A4 group and control group without gene mutation.The three groups were evaluated on their abilities of hearing and language respectively before the operation,3 months,6 months,and 12 months after the operation,The evaluation includes: sound field aided hearing threshold test,categories of auditory performance(CAP)and speech intelligibility rate(SIR)scores,and the verbal recognition ability test adopted The Assessment Standard and Method of Hearing and Language Proficiency for Deaf Children.Results:1.The auditory speech ability of GJB2 group,SLC26A4 group and control group all gradually increased with the prolongation of rehabilitation time.The CAP and SIR scores,speech recognition rate and language age of each group at the adjacent time points were statistically significant(P <0.05).2.There was no significant difference in CAP and SIR scores,speech recognition rate and language age between the GJB2 group and the control group at the same time points(P> 0.05).3.The CAP and SIR scores and speech recognition rate in SLC26A4 group were higher than those in GJB2 group and control group before operation,at 3 months,and at 6 months after operation,and the differences were statisticly significant(P <0.05).While,the CAP and SIR scores and speech recognition rate in SLC26A4 group at 12 months after operation,comparing with GJB2 group and control group at 12 months after operation,were of no significant difference(P> 0.05).And there was no significant difference in language age between SLC26A4 group and the other two groups at each time point(P> 0.05).Conclusions:1.After artificial cochlear implantation,the rehabilitation effect of SNHL children with SLC26A4 gene mutation in a short term is significantly better than those with GJB2 gene mutation and those without gene mutations.2.SNHL children with GJB2 gene mutations after surgery can get a better auditory speech rehabilitation effect,and those patients without gene mutation have the equal rehabilitation effect.Conclusions of paper1.The auditory speech ability of GJB2 group,SLC26A4 group and control group all gradually increased with the prolongation of rehabilitation time.The CAP and SIR scores,speech recognition rate and language age of each group at the adjacent time points were statistically significant(P<0.05).2.There was no significant difference in CAP and SIR scores,speech recognition rate and language age between the GJB2 group and the control group at the same time points(P>0.05).3.After artificial cochlear implantation,the rehabilitation effect of SNHL children with SLC26A4 gene mutation in a short term is significantly better than those with GJB2 gene mutation and those without gene mutations.4.SNHL children with GJB2 gene mutations after surgery can get a better auditory speech rehabilitation effect,and those patients without gene mutation have the equal rehabilitation effect.