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@#Abstract: Objective To explore the carrying status of four common deafness genes and mutations on 10 loci in newborns in Hainan, and to analyze the molecular epidemiological characteristics of deafness genes and their loci, so as to provide scientific basis for formulating neonatal deafness gene screening strategy and promoting children's hearing health in Hainan. Methods Newborns born in Hainan from January 2020 to December 2021 were selected as the research objects. The demographic characteristics of the research objects were collected. At the same time, the plantar blood of newborns was collected, and multiplex PCR amplification and directed hybridization combined with high-throughput sequencing technology were applied to detect 10 mutation loci on 4 common deafness genes. T-test or chi square test was used to process the data. Results A total of 7 124 newborns were included in the study through informed consent, 219 cases of deafness gene mutation were detected with the detection rate of deafness gene of 3.07%. The detection rates of GJB2, SLC26A4, MT-RNR1 and GJB3 were 1.56% (111/7 124), 1.18% (84/7 124), 0.21% (15/7 124) and 0.11% (8/7 124) respectively. Among the 10 loci of the four genes, the positive detection rate of c.235delC locus of GJB2 was the highest, which was 1.38% (98/7 124), followed by c.919-2A>G of SLC26A4 (0.87%, 62/7 124); 2.63% (113/4 289) of the newborns who passed the preliminary hearing screening still carried the deafness gene; in terms of gene type, the detection rate of GJB2 gene in newborns who failed the hearing screening was higher than that in newborns who passed the hearing screening [2.23% (63/7 124) vs 1.12% (48/7 124)，P<0.01]; in terms of gene loci, the detection rate of c.235delC locus in newborns who failed hearing screening was higher than that in newborns who passed hearing screening [2.09% (59/7 124) vs 0.91% (39/7 124)，P<0.01]. Conclusion The most common deafness genes types in Hainan were GJB2 and SLC26A4; The most common gene mutation sites were c.235delC and c.919-2A>G; 2.63% of the newborns who passed the preliminary hearing screening still carried the deafness gene, among which the high-risk newborns with MT-RNR1 and GJB3 genes were found. Therefore, hearing screening should be combined with deafness gene screening to improve the detection rate of children at high risk of hearing loss.
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Objective@#To learn the mutation types and hearing screening results in local newborns of Zhoushan,in order to provide evidence for prevention and early detection of deafness.@*Methods@#The newborns in Zhoushan Maternal and Child Health Hospital from August 2015 to May 2018 were recruited and detected by matrix-assisted laser desorption ionization time of flight mass spectrometry（MALDI-TOF-MS）for twenty-two mutation sites of GJB2,SLC26A,GJB3 and 12SrRNA genes. The results of genotyping and hearing screening were analyzed and the hearing condition of abnormal newborns was followed up. @*Results@# Among 4 029 newborns,180（4.47%）newborns were identified to carry mutations,including 94 males（4.66%）and 86 females （4.28%）. There was no statistically significant difference in the rate of carrying mutations between male and female infants （P>0.05）. Totally 135 （3.35%）newborns failed in primary hearing screening,13（9.63%）of whom carried the deafness genes;3 894（96.65%）newborns passed,167（4.29%）of whom carried the deafness gene. There was statistically significant difference in the the rate of carrying mutations between newborns who passed and failed in primary hearing screening （P<0.05）. Eleven newborns were diagnosed with hearing loss,with a rate of 2.73‰. Among 180 mutations identified,there were 91 GJB2 mutations（2.26%）,57 SLC26A4 mutations（1.41%）,14 GJB3 mutations （0.35%）,15 mtDNA 12SrRNA mutations （0.37%）and 3 with mutations of two genes （0.07%）. Sixteen mutation sites （184 cases）were found,and the detection rate was 4.57%. @*Conclusion@#The rate of carrying deafness genes in Zhoushan newborns was 4.47%. The deafness genes found were mainly GJB2 and SLC26A4,the carrying rate of mtDNA 12SrRNA gene mutation was also high.
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Objective To understand the carrying condition of the mutation gene of neonatal deafness in Huzhou City and explore the significance of the combination screening of hearing and deafness genes. Methods 2258 newborns who were born in Huzhou maternal and child health care hospital were screened for hearing and deafness and were followed up to the age of 3. Two kinds of complementarity and relativity of screening were analyzed. Early hearing screening was used by transient evoked otoacoustic emission (TEOAE) screening, hearing rescreening was used by TEOAE and autoauditory brainstem response (AABR) . Collected the neonatal umbilical cord blood and detected GJB2, SLC26A4, GJB3, mitochondrial 12SrRNA 4 genes 20 deafness mutations. Results Early hearing screening failed in 550 cases, with a failure rate of 24.36％. Detected in 118 cases of deafness gene carriers, total carrying rate was 5.23％. GJB2, SLC26A4, GJB3 and mitochondrial 12SrRNA gene mutation rate were 3.10％, 1.46％, 0.58％ and 0.09％ respectively. Initial failure rate of mother and child hearing screening was 16.30 ％ (300/1840) . The rate of gene transfer for deafness mutation was 5.65 ％ (104/1840) . Initial failure rate of NICU hearing screening was 59.81 ％ (250/418) . The rate of gene transfer for deafness mutation was 3.35％ (14/418) . The failure rate of initial hearing screening of NICU newborns was higher than that of mother and child (P<0.01) . There was no statistically significant difference in carrying rate between the two groups (P>0.05) . There was no statistical correlation between initial hearing screening andwhether or not to carry deaf mutation gene (P>0.05) . 52 infants were missed in this study. 12 patients were diagnosed with hearing impairment, and the hearing impairment rate was 0.54％. Among them, 9 cases were normal and 3 cases were abnormal. Conclusion Newborns hearing screening by whether or not had nothing to do with deafness gene.Hearing screening with deafness gene screening at the same time can reduce the delay in diagnosis of deafness and drug deafness can also be prevented early.
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Objective To investigate the prevalence and distribution of deafness gene mutations by the joint screening of deafness-related genes and hearing in Wuhan .Methods A total of 117930 newborns born in 2014 and 2015 volunteered to participate in this study .Besides traditional hearing screening ,heel blood of all subjects were collected to detect four sites of three common deafness genes GJB 2 (235delC ) ,SLC26A4 (919 -2A > G ) ,and DNA 12SrRNA(1555A>G ,1494C> T) .Results The total mutation rate of deafness gene was 3 .00％ in 117930 newborns .The highest spots were GJB2235delC and SLC26A4919-2 mutation .A total of 109036 newborns pas-sed the combined screenings ,and 5353 newborns passed the gene screening ,but failed hearing screening .A total of 32131 newborns passed the hearing screening with gene mutation ,while 310 newborns failed in both .Newborns with gene mutation were more likely to fail hearing screening .Conclusion This study indicates that neonatal deafness gene screening in combination with hearing screening not only can effectively improve the detection rate of hearing loss or high risk children ,but also can provide detailed genetic information to promote the popularization and application of such concurrent screenings .
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Objective The aim of this study was to find out the carrying rate and the type of mutation of children deafness gene and discuss the significance of combined screening of deafness gene and hearing screening.Methods From October 2015 to December 2016,a total of 505 children from primary screening institutions were done with AABR hearing re-screening and deafness gene through blood filter paper by heel for gene sequencing at the hearing screening clinic of Hefei Maternal and Child Health Hospital.The 9 mutation sites of deafness genes included GJB2 (235delC,299delAT,176del16,35delG),GJB3 (538C＞T),SLC26A4 (IVS7-2A＞G,2168A＞G) and mitochondrial 12SrRNA (1555A＞G,1494C＞T).Results There were 69 children with deafness susceptibility genes in 505 cases and its overall carrying rate was 13.7％.There were 56 cases (81.16％)with GJB2 gene mutations,10 cases (14.49％) with SLC26A4 gene mutations,and 3 patients (4.35％) with mitochondrial 12SrRNA gene mutations.GJB3 gene mutations wer not detected.There were 376 who failed AABR rescreening out of 505.The total failure rate for AABR rescreening was 74.46％.Thirty-seven cases were examined with ABR out of 69 cases with deafness gene abnormal.32 cases (86.49％) had different degrees of hearing impairment.Conclusion GJB2 gene mutation was the highest carrying rate of deafness genes in this region,followed by SLC26A4 gene,less mitochondrial 12SrRNA gene mutations while GJB3 gene mutations was not detected.Hereditary deafness gene screening was a valid supplement for physical screening,the combination of both methods was helpful for early detection and intervention of deaf children.
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Objective To investigate the characteristics of common deafness genes mutation from 222 sensori-neural hearing loss patients in Guangxi province.Methods A deafness-related gene mutations detection kit was used to detect 15 mutation sites in four deafness-associated genes.A total of 222 hearing impaired patients,who were selected from January 2015 to April 2016,were tested.The samples that could not be diagnosed with DNA mi-croarray were subjected to PCR and sequenced to detect other mutations.Results Among the 222 patients with sen-sorineural deafness,the total mutation rate was 10.36% (23/222),including GJB2 235delC homozygous in 3 cases (1.35%),235delC single heterozygous mutation in 8 cases (3.60%),35delG single heterozygous mutation in 2 cases (0.90%),GJB2 235delC and 109 A>G mutations in 2 cases (0.90%),SLC26A4 1229C>T homozygous in 2 case (0.90%),IVS7-2 A>G heterozygous mutation in 2 cases (0.90%);IVS7-2A>G,IVS11+47T>C and 1548 insC mutations in 2 cases (0.90%);GJB3 538C>T heterozygous mutation in 1 cases (0.45%);Mitochondrial 12S rRNA gene heterogeneous mutations in 1 case (0.45%).One of them carry both two mutations:GJB2 235 del C and SLC26A4 1226 G>A.Conclusion The results indicate that GJB2 and SLC26A4 were the main genes in this study,and in Guangxi province the mutation rate is significantly lower than the national average level.3 new muta-tions (SLC26A4 IVS11+47T ! C,1548insC and GJB2 109A>G)were found.There may be some rare mutations among sites or genes caused deafness in Guangxi.
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Objective To study the age, the degree of hearing loss and the characteristics of inner ear imaging in children with GJB2 and SLC26A4 gene mutation-related deafness.Methods A total of 218 children with GJB2 and SLC26A4 gene mutations were enrolled in this study.Among them, with the combined test of deafness gene chip and DNA sequencing, 123 patients were diagnosed with GJB2 homozygous or complex mutations, and 95 patients were diagnosed with SLC26A4 homozygous or complex mutations.The age of the onset, the degrees of hearing loss and CT features of the temporal bone in children with GJB2 and SLC26A4 mutations were studied.Results The incidence of GJB2 and SLC26A4 gene mutations was 43.09%, 37.40%, 14.63%, 4.88% and 24.2%, 44.21%, 18.95% and 12.63% in the periods of infancy,early childhood,preschool and shoolage,respectively.The age composition of onset in the two groups showed statistical significance(P=0.014).The constituent ratio of children with moderate, severe and extremely severe degrees of hearing loss in the two groups with GJB2 and SLC26A4 gene mutations were 8.94%, 17.89%, 73.17% and 9.47%, 34.74% and 55.79%, respectively.Most of the group with GJB2 gene mutation had profound hearing loss, and the composition ratio of hearing loss degree in SLC26A4 group was statistically significant(P=0.014).99.19% of the children with GJB2 gene mutation group had normal structures of the inner ears.Only one case of CT showed bilateral internal auditory canal stenosis.For 95.79% of the children with SLC26A4 gene mutation, the CT results of the temporal bone were associated with the vestibular aqueduct expansion.Conclusion The onset age of GJB2 gene mutation children is concentrated in the infancy.Most of them are with very severe sensorineural deafness, not associated with the inner ear malformation.The onset age of SLC26A4 gene deafness children is concentrated in the early childhood.Most of them are with severe and extremely sever sensorineural deafness, closely related to vestibular aqueduct expansion and inner ear malformations.
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Objective To learn the detection rate of deafness predisposing genes among newborns in order to provide suggestions for the prevention of hereditary hearing loss.Methods By means of MALDI -TOF,a total of 4 025 newborns were accepted for newborn hearing and deafness predisposing genetic screening.Four common deafness predisposing genes including GJB2,GJB3,12SrRNA and SLC26A4 were detected,which included 20 hot mutation sites.Results Of the 4 025 subjects,231 were detected with deafness predisposing genes and the positive rate was 5.71%.The total rate of pathogenic mutation was 1.74‰(7 /4 025),including 1 with GJB2 235delC homozygous mutation,1 with GJB2 235delC heterozygous mutation plus 299_300 del AT heterozygous mutation and 5 with 12SrRNA homozygous mutation.The positive rate of single heterozygous mutation was 5.54% (223 /4 025).Fourteen hot mutation sites were detected.GJB2 235delC was the most common one,followed by IVS7 -2A→G.There were 109 cases with GJB2 235delC and 50 cases with IVS7-2A→G.The positive rate was 2.71% and 1.24% respectively,which was 47.19% and 21.65% of the total detection rate respectively.Conclusion The detection rate of deafness predisposing genes is high among newborns.Expanding screening sites could facilitate the detection for the carrier of deafness gene.
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Objective To evaluate the effectiveness of newborn screening of hearing combined with deafness predisposing genes. Methods Through screening,514 newborns who may had the problem of hearing were classified as experimental group and the other 1 028 newborns were classified as control group by MALDI-TOF. Detecting the predisposing genes of GJB2,GJB3,12SrRNA,SLC26A4 including 20 hot spot mutations for these newborns. Results Among 514 subjects, 40 cases were found with deafness gene mutations,and the positive rate was 7. 47%. 7 cases were pathogenic mutation(1 was GJB2 235delC homozygous mutation,6 were GJB3 538C→T heterozygous mutation ),with the rate of 1. 36%,and 33 cases were heterozygous carrier,with the rate of 6. 62%. Among the control group,45 cases were found with deafness gene mutations,and the positive rate was 4. 38%. 3 cases were pathogenic mutation(1 was 12srRNA 1555A→G homozygous mutation,1 was GJB3 538C→T heterozygous mutation,1 was GJB3 547G→A heterozygous mutation),with the rate of 0. 29%,and 42 cases were carriers of heterozygous gene,with the rate of 4. 09%. The positive rate,the pathogenic mutation rate and the heterozygous carry rate of experimental group were higher than that of control group ,and the differences were significant(all p<0. 05). Conclusion The newborns who did not pass the hearing screening should be the target population for test of the deafness predisposing genes. Since the positive rate were still high,if condition permitted,the screening of hearing combined with deafness predisposing genes should be carried out in some areas.
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Objective To analyze the molecular epidemiology characteristic of neonatal deafness susceptibility genes .Methods Hearing screening and deafness susceptibility genes screening were performed in 1 674 cases of newborn to analyze the epidemiolog‐ical characteristics .Results Among 1 674 cases of neonatus ,37 cases were with deafness susceptibility gene abnormalities ,inclu‐ding 2 cases of 176 del 16 mutations ,5 cases of 299 del AT heterozygous mutation ,16 cases of 235 del C mutation ,9 cases of IVS7‐2A>G heterozygous mutations ,1 case of 2168A> G mutation ,2 cases of 538C> T heterozygous mutation ,2 cases of 1494C> T mutation ,and the positive rate was 2 .21% .Conclusion Hearing screening combined with deafness susceptibility gene screening could detect possible hearing loss children from molecular level ,providing favorable reference for the early detection ,predict and in‐terventions .