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Martínez-Cruz CF, Ramírez-Vargas MN, García-Alonso Themann P. Results of the Universal Neonatal Hearing Screening in a Tertiary Care Hospital in Mexico city. Int J Pediatr Otorhinolaryngol 2020; 139:110412. [PMID: 33022555 DOI: 10.1016/j.ijporl.2020.110412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Universal Neonatal Hearing Screening (UNHS) includes as its main objective, that all Newborns (NB) receive an audiological evaluation during their first month of life. OBJECTIVE To determine the prevalence of hearing loss in a population of healthy NB in a tertiary care hospital in Mexico City. MATERIAL AND METHODS A prospective cross-sectional study was designed. The period was from October 1, 2011 to May 15, 2019. UNHS was performed with a flowchart in three phases using Transient Evoked Otoacoustic Emissions and Brainstem auditory evoked potentials. Data were analyzed using descriptive statistics. RESULTS 14,000 NB were evaluated, 28,000 ears. Gender was distributed in n = 7038 (50.3%) males and n = 6962 (49.7%) females. The mean age at the time of the first UNHS study was 48.3 ± 22.2 days. Hearing loss was confirmed in n = 31 (0.22%) NB, in 20 (64%) of the cases with hearing loss there were no documented audiological risk factors. CONCLUSIONS The prevalence of hearing loss was 2.2 per 1000 NB in a tertiary care hospital in Mexico City. Diagnosis and early habilitation of hearing loss in NB constitute quality indicators in health care and guarantee the best prognosis for NB with hearing loss.
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Affiliation(s)
- Carlos Fabián Martínez-Cruz
- Department of Pediatric Follow-up, National Institute of Perinatology, "Dr. Isidro Espinosa de los Reyes" Montes Urales 800, Col. Lomas de Virreyes, c.p.11000, Mexico City, Mexico.
| | - Mayra Norma Ramírez-Vargas
- Department of Pediatric Follow-up, National Institute of Perinatology, "Dr. Isidro Espinosa de los Reyes" Montes Urales 800, Col. Lomas de Virreyes, c.p.11000, Mexico City, Mexico
| | - Patricia García-Alonso Themann
- Department of Pediatric Follow-up, National Institute of Perinatology, "Dr. Isidro Espinosa de los Reyes" Montes Urales 800, Col. Lomas de Virreyes, c.p.11000, Mexico City, Mexico
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Large scale newborn deafness genetic screening of 142,417 neonates in Wuhan, China. PLoS One 2018; 13:e0195740. [PMID: 29634755 PMCID: PMC5892933 DOI: 10.1371/journal.pone.0195740] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/28/2018] [Indexed: 11/19/2022] Open
Abstract
Almost one third of the three million people in China suffering severe deafness are children, and 50% of these cases are believed to have genetic components to their etiology. Newborn hearing genetic screening can complement Universal Neonatal Hearing Screening for the diagnosis of congenital hearing loss as well as identifying children at risk for late-onset and progressive hearing impairment. The aim of this joint academic and Ministry of Health project was to prototype a cost effective newborn genetic screen in a community health setting on a city-wide level, and to ascertain the prevalence of variation at loci that have been associated with non-syndromic hearing loss. With the participation of 143 local hospitals in the city of Wuhan, China we screened 142,417 neonates born between May 2014 and Dec. 2015. The variants GJB2 c.235delC, SLC26A4 c.919-2A>G, and mitochondrial variants m.1555A>G and m.1494C>T were assayed using real time PCR. Newborns found to carry a variant were re-assayed by sequencing in duplicate. Within a subset of 707 newborns we assayed using real-time PCR and ARMS-PCR to compare cost, sensitivity and operating procedure. The most frequent hearing loss associated allele detected in this population was the 235delC variant in GJB2 gene. In total, 4289 (3.01%) newborns were found to carry at least one allele of either GJB2 c.235delC, SLC26A4 c.919-2A>G or two assayed MT-RNR1 variants. There was complete accordance between the real-time PCR and the ARMS PCR, though the real-time PCR had a much lower failure rate. Real-time PCR had a lower cost and operating time than ARMS PCR. Ongoing collaboration with the participating hospitals will determine the specificity and sensitivity of the association of the variants with hearing loss at birth and arising in early childhood, allowing an estimation of the benefits of newborn hearing genetic screening in a large-scale community setting.
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Auditory outcome after cochlear implantation in patients with congenital nonsyndromic hearing loss: influence of the GJB2 status. Otol Neurotol 2015; 35:1361-5. [PMID: 24691507 DOI: 10.1097/mao.0000000000000348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the audiologic outcome after cochlear implantation between 2 groups of patients with congenital nonsyndromic sensorineural hearing loss. STUDY DESIGN Retrospective cohort study. SETTING Department of Otorhinolaryngology, University hospital (tertiary referral center). PATIENTS From a bigger pool of implanted patients, 2 groups, each numbering 30 were enrolled. The patients from the first group were diagnosed with a Connexin 26 mutation (GJB2), whereas all of the patients from the second cohort were with a wild type genotype. Both groups were age matched, 1 to 7 years old at the age of implantation, with diagnosed congenital nonsyndromic sensorineural hearing loss. MAIN OUTCOME MEASURES Both groups were evaluated with the help evaluation of auditory responses to speech/EARS/test battery - LiP test (Listening Progress Profile), MTP tests 3,6,12 (Monosyllabic-Trochee-Polysyllabic Test), GASP test (Glendonald Auditory Screening Procedure), and others. Follow-up period was at least 36 months. RESULTS Mean test scores were compared at the 1st, 6th, 12th, 24th, and 36th month. LiP outcome was significantly better (p < 0.05) for the GJB2-related cohort for the whole follow-up period except at the first month. MTP3, 6, and 12 tests displayed the same statistically significant outcome in favor of the first group. In the open-set test GASP, the difference was apparent: 1.22, 2.40, 5.59, and 7.40 mean scores at the 6th, 12th, 24, and 36th months for the first cohort versus 0.00, 0.07, 0.81, and 1.74 for the GJB2-unrelated patients. CONCLUSION The results from our study suggest that children with GJB2-related deafness show better auditory performance after cochlear implantation than age-matched children with GJB2-nonrelated sensorineural hearing loss.
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Cordblood-Based High-Throughput Screening for Deafness Gene of 646 Newborns in Jinan Area of China. Clin Exp Otorhinolaryngol 2015; 8:211-7. [PMID: 26330914 PMCID: PMC4553350 DOI: 10.3342/ceo.2015.8.3.211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 06/18/2014] [Accepted: 07/03/2014] [Indexed: 12/03/2022] Open
Abstract
Objectives Infants with slight/mild or late-onset hearing impairment might be missed in universal newborn hearing screening (UNHS). We identified the mutation hot spot of common deaf gene in the newborns in Jinan area population by screening the mutation spot with neonate cord blood, in order to make clear whether the neonate cord blood for screening is feasible. Methods Six hundred and forty-six newborns were subjected to both UNHS and genetic screening for deafness by using neonate cord blood. The newborn genetic screening targeted four deafness-associated genes, which were commonly found in the Chinese population including gap junction beta-2 protein (GJB2), gap junction beta-3 protein (GJB3), solute carrier family 26 member 4 (SLC26A4), and mtDNA 12S rRNA. The most common 20 spot mutations in 4 deaf genes were detected by MassARRAY iPLEX platform and mitochondrial 12S rRNA A1555G and C1494T mutations were sequenced using Sanger sequencing. Results Among the 646 newborns, 635 cases passed the UNHS and the other 11 cases (1.7%) did not. Of the 11 failures, two cases were found to carry homozygous GJB2 p.R143W pathogenic mutation, one case was found to have heterozygous GJB2 235delC mutation, and another one case carried heterozygous GJB3 p.R180X pathogenic mutation. Six hundred and thirty-five babies passed the newborn hearing screening, in which 25 babies were identified to carry pathogenic mutations, including 12 heterozygotes (1.9%) for GJB2 235delC, eight heterozygotes (1.3%) for SLC26A4 IVS7-2A>G, one heterozygote (0.2%) for p.R409H, two homozygotes (0.3%) for m.1494C>T, and two homozygotes (0.3%) for m.1555A>G. Conclusion Newborn genetic screening through the umbilical cord blood for common deafness-associated mutations may identify carriers sensitive to aminoglycoside antibiotic, and can effectively prevent or delay hearing loss occurs.
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Zheng J, Ying Z, Cai Z, Sun D, He Z, Gao Y, Zhang T, Zhu Y, Chen Y, Guan MX. GJB2 Mutation Spectrum and Genotype-Phenotype Correlation in 1067 Han Chinese Subjects with Non-Syndromic Hearing Loss. PLoS One 2015; 10:e0128691. [PMID: 26043044 PMCID: PMC4456361 DOI: 10.1371/journal.pone.0128691] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 04/29/2015] [Indexed: 11/17/2022] Open
Abstract
Mutations in Gap Junction Beta 2 (GJB2) have been reported to be a major cause of non-syndromic hearing loss in many populations worldwide. The spectrums and frequencies of GJB2 variants vary substantially among different ethnic groups, and the genotypes among these populations remain poorly understood. In the present study, we carried out a systematic and extended mutational screening of GJB2 gene in 1067 Han Chinese subjects with non-syndromic hearing loss, and the resultant GJB2 variants were evaluated by phylogenetic, structural and bioinformatic analysis. A total of 25 (23 known and 2 novel) GJB2 variants were identified, including 6 frameshift mutations, 1 nonsense mutation, 16 missense mutations and 2 silent mutations. In this cohort, c.235delC is the most frequently observed pathogenic mutation. The phylogenetic, structural and bioinformatic analysis showed that 2 novel variants c.127G>T (p.V43L), c.293G>C (p.R98P) and 2 known variants c. 107T>C (p.L36P) and c.187G>T (p.V63L) are localized at highly conserved amino acids. In addition, these 4 mutations are absent in 203 healthy individuals, therefore, they are probably the most likely candidate pathogenic mutations. In addition, 66 (24 novel and 42 known) genotypes were identified, including 6 homozygotes, 20 compound heterozygotes, 18 single heterozygotes, 21 genotypes harboring only polymorphism(s) and the wild type genotype. Among these, 153 (14.34%) subjects were homozygous for pathogenic mutations, 63 (5.91%) were compound heterozygotes, and 157 (14.71%) carried single heterozygous mutation. Furthermore, 65.28% (141/216) of these cases with two pathogenic mutations exhibited profound hearing loss. These data suggested that mutations in GJB2 gene are responsible for approximately 34.96% of non-syndromic hearing loss in Han Chinese population from Zhejiang Province in eastern China. In addition, our results also strongly supported the idea that other factors such as alterations in regulatory regions, additional genes, and environmental factors may contribute to the clinical manifestation of deafness.
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Affiliation(s)
- Jing Zheng
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhengbiao Ying
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Zhaoyang Cai
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Dongmei Sun
- Department of Laboratory Medicine, Jinhua Municipal Central Hospital, Jinhua, China
| | - Zheyun He
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yinglong Gao
- Attardi Institute of Mitochondrial Biomedicine, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Ting Zhang
- Department of Otolaryngology, Wenling People’s Hospital, Wenzhou Medical University, Taizhou, China
| | - Yi Zhu
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ye Chen
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Min-Xin Guan
- Institute of Genetics, School of Medicine, Zhejiang University, Hangzhou, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
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Park JH, Kim NKD, Kim AR, Rhee J, Oh SH, Koo JW, Nam JY, Park WY, Choi BY. Exploration of molecular genetic etiology for Korean cochlear implantees with severe to profound hearing loss and its implication. Orphanet J Rare Dis 2014; 9:167. [PMID: 25373420 PMCID: PMC4243193 DOI: 10.1186/s13023-014-0167-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 10/17/2014] [Indexed: 02/01/2023] Open
Abstract
Background Severe to profound sensorineural hearing loss (SNHL) requires cochlear implantation (CI) for auditory rehabilitation. Etiologic diagnoses can contribute to candidacy selection and decision-making regarding the timing of successful CI. However, few studies have been performed to address the etiologic spectrum of severe SNHL in the population where there is no consanguineous marriage and the majority of SNHL cases are sporadic in small sized families. The authors sought to comprehensively understand the etiologies of Korean cochlear implantees by incorporating the targeted resequencing of 204 candidate deafness genes (TRS-204) and a phenotype-driven candidate gene approach. Methods Ninety-three that consented to molecular genetic testing and underwent at least one molecular genetic test were included. Patients with a characteristic Phenotypic marker were subject to Sanger sequencing to detect variants in corresponding candidate genes. The rest of patients without any prominent phenotype were tested on GJB2. Next, TRS-204 was applied in GJB2-negative cases without any phenotypic marker. In addition, the sibling recurrence-risk of SNHL among families with non-diagnostic genotypes after TRS-204 was performed to gain insight of etiologies in non-diagnostic cases. Results Overall, we could find causative variants in 51 (54.8%) of the 93 cochlear implantees. Thirty (32.3%) probands could be diagnosed by direct Sanger sequencing of candidate genes selected by their phenotypes. GJB2 sequencing added 10 subjects to the group with a diagnostic genotype. TRS-204 could detect a causative variant from additional 11 cases (11.8%). We could not detect any pathogenic deletion or duplication on 204 target genes. The sibling recurrence-risk of SNHL among 42 genetically undiagnosed families with 0.03 (1/38) was significantly lower than among genetically diagnosed recessive families with 0.19 (7/37). Conclusion Despite that the majority of severe or more degree of SNHL occurs sporadically in Koreans, at least 54.8% of such cases that were willing to join the genetic study in the Korean population are monogenic Mendelian disorders with convincing causative variants. This study also indicates that a substantial portion of unsolved cases after applying our current protocol are predicted to have non-genetic or complex etiology rather than a Mendelian genetic disorder involving new genes beyond the 204 target genes. Electronic supplementary material The online version of this article (doi:10.1186/s13023-014-0167-8) contains supplementary material, which is available to authorized users.
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Javidnia H, Carson N, Awubwa M, Byaruhanga R, Mack D, Vaccani JP. Connexin gene mutations among Ugandan patients with nonsyndromic sensorineural hearing loss. Laryngoscope 2014; 124:E373-6. [PMID: 24706568 DOI: 10.1002/lary.24697] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/31/2014] [Accepted: 04/02/2014] [Indexed: 11/06/2022]
Abstract
OBJECTIVES/HYPOTHESIS Congenital deafness occurs in approximately 1 in 1,000 live births, and 50% of these cases are hereditary. Connexin mutations have been identified as the most common cause of hereditary hearing loss in many populations. The prevalence of this mutation in African patients has not been adequately studied. The objective of this study was to determine the prevalence of connexin 26 and 30 mutations in a population of hearing-impaired patients from Uganda. STUDY DESIGN This is an observational study. METHODS Coding regions of both GJB2 and GJB6, noncoding exon 1 of GJB2, and 30 nucleotides of intronic sequence bordering the exons were analyzed in 126 subjects from Uganda with confirmed bilateral, severe-to-profound sensorineural hearing loss. All variants were analyzed for possible clinical significance using a combination of database searches and in silico tools. RESULTS Complete sequence data were obtained on 115/126 individuals; 11 had only partial or no results. Only one reported pathogenic variant was found in GJB2 (c.208C>G; p.Pro70Ala) and none in GJB6. Three reported variants and two novel variants within intron 1 of GJB2 and two variants within exon 3 of GJB6 were also found. CONCLUSIONS None of the most common types of deletions in the GJB2 gene (c.35delG, c.167delT or c.235delC) were found in this large cohort of deaf children from Uganda. This prompts a search for genetic causes of deafness among this and other previously studied African populations.
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Affiliation(s)
- Hedyeh Javidnia
- Department of Otolaryngology, Head and Neck Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada
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Chan DK, Chang KW. GJB2-associated hearing loss: Systematic review of worldwide prevalence, genotype, and auditory phenotype. Laryngoscope 2013; 124:E34-53. [DOI: 10.1002/lary.24332] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2013] [Indexed: 12/17/2022]
Affiliation(s)
- Dylan K. Chan
- Department of Otolaryngology-Head and Neck Surgery; University of California; San Francisco U.S.A
| | - Kay W. Chang
- Department of Otolaryngology-Head and Neck Surgery; Stanford University School of Medicine; Stanford California U.S.A
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Yao G, Chen D, Wang H, Li S, Zhang J, Feng Z, Guo L, Yang Z, Yang S, Sun C, Zhang X, Ma D. Novel mutations of SLC26A4 in Chinese patients with nonsyndromic hearing loss. Acta Otolaryngol 2013; 133:833-41. [PMID: 23638949 DOI: 10.3109/00016489.2013.777160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSIONS This study demonstrated high prevalence of GJB2, SLC26A4, and mtDNA A1555G mutations in Chinese patients with nonsyndromic hearing loss and discovered eight novel mutations in SLC26A4. Most of these novel mutations were predicted pathogenic variants. OBJECTIVES Nonsyndromic hearing loss is the most common neurosensory deafness where the majority of patients have highly diversified genetic defects. This study aimed to define the genetic profile of deafness in a Chinese population with potential to discover novel mutations. METHODS A total of 227 segregating deaf students and 200 individuals with normal hearing were enrolled. With the Sanger sequencing chemistry, direct sequencing was performed on entire coding regions of GJB2, GJB3, SLC26A4, and mtDNA m.C1494T and m.A1555G. RESULTS Direct sequencing analysis revealed that 53 (23.35%) of 227 patients carried at least 1 mutant allele in GJB2, 40 (17.62%) patients in SLC26A4, 5 (2.20%) patients in mtDNA A1555G, and 1 (0.44%) patient in mtDNA C1494T mutations. Four patients carried three unclassified mutations in GJB3 genes. Overall 38 mutant variants were detected in this cohort of patients, including 8 novel mutations in SLC26A4. The eight novel variants were six missense substitutions (p.V163L, p.G222S, p.A456D, p.N457I, p.C466Y, p.F667L), one nonsense mutation (p.W472X), and one frameshift (p.Asn612Ilefs×23).
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Affiliation(s)
- Gendong Yao
- Department of Laboratory Medicine, Central Hospital of Handan City, Hebei, China.
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Gallant E, Francey L, Tsai EA, Berman M, Zhao Y, Fetting H, Kaur M, Deardorff MA, Wilkens A, Clark D, Hakonarson H, Rehm HL, Krantz ID. Homozygosity for the V37I GJB2 mutation in fifteen probands with mild to moderate sensorineural hearing impairment: further confirmation of pathogenicity and haplotype analysis in Asian populations. Am J Med Genet A 2013; 161A:2148-57. [PMID: 23873582 DOI: 10.1002/ajmg.a.36042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 04/12/2013] [Indexed: 11/11/2022]
Abstract
Hearing impairment affects 1 in 650 newborns, making it the most common congenital sensory impairment. Autosomal recessive nonsyndromic sensorineural hearing impairment (ARNSHI) comprises 80% of familial hearing impairment cases. Mutations in GJB2 account for a significant number of ARNSHI (and up to 50% of documented recessive (e.g., more than 1 affected sibling) hearing impairment in some populations). Mutations in the GJB2 gene are amongst the most common causes of hearing impairment in populations of various ethnic backgrounds. Two mutations of this gene, 35delG and 167delT, account for the majority of reported mutations in Caucasian populations, especially those of Mediterranean and Ashkenazi Jewish background. The 235delC mutation is most prevalent in East Asian populations. Some mutations are of less well-characterized significance. The V37I missense mutation, common in Asian populations, was initially described as a polymorphism and later as a potentially pathogenic mutation. We report here on 15 unrelated individuals with ARNSHI and homozygosity for the V37I GJB2 missense mutation. Nine individuals are of Chinese ancestry, two are of unspecified Asian descent, one is of Japanese descent, one individual is of Vietnamese ancestry, one of Philippine background and one of Italian and Cuban/Caucasian background. Homozygosity for the V37I GJB2 mutation may be a more common pathogenic missense mutation in Asian populations, resulting in mild to moderate sensorineural hearing impairment. We report a presumed haplotype block specific to East Asian individuals with the V37I mutation encompassing the GJB2 gene that may account for the high prevalence in East Asian populations.
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Affiliation(s)
- Emily Gallant
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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Prevalence of DFNB1 mutations among cochlear implant users in Slovakia and its clinical implications. Eur Arch Otorhinolaryngol 2013; 271:1401-7. [PMID: 23700267 DOI: 10.1007/s00405-013-2559-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 05/04/2013] [Indexed: 10/26/2022]
Abstract
Hereditary etiology plays an important role in bilateral profound deafness as a main indication for cochlear implantation. Mutations in DFNB1 locus account for most of the inherited deafness cases in Caucasians. To provide actual data on mutation prevalence among implanted deaf subpopulation, we performed DNA analysis of GJB2 and GJB6 genes in 131 unrelated Slovak cochlear implant users. Eight previously described causal mutations and one probably pathogenic missense variant (c.127G>A) were detected in the GJB2 gene in 58 (44.28%) subjects. The most common mutation found was c.35delG with frequency 83.02% of all disease alleles, followed by c.71G>A, c.1-3201G>A, c.313_326del14, c.109G>A, 167delT, c.269T>C, and c.333_334delAA. GJB6 deletion delD13S1830 was identified in only one subject, in double heterozygosity with a GJB6 mutation. Thus, the deafness cause could be clearly attributable to DFNB1 mutations in 36.64% of the patients examined. In summary, the mutation profile found in our cohort was similar to the mutation spectrum reported for Central European deaf populations. The mutation prevalence in cochlear implant users was, however, almost by 25% higher than previously established for non-implanted hearing-impaired population in Slovakia. Finally, we also demonstrate a certain variability in deafness onset in patients with causal genotype and coincidence with other risk factors for deafness. Our results underline the importance of genetic tests in all cochlear implant candidates.
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Connexin 26 and 30 mutations in paediatric patients with congenital, non-syndromic hearing loss treated with cochlear implantation in Mediterranean Turkey. The Journal of Laryngology & Otology 2012; 127:33-7. [PMID: 23171692 DOI: 10.1017/s0022215112002587] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractObjective:Mutations in the genes for connexin 26 (GJB2) and connexin 30 (GJB6) play an important role in autosomal recessive, non-syndromic hearing loss. This study aimed to detect the 35delG and 167delT mutations of theGJB2gene and the del(GJB6-D13S1830) mutation of theGJB6gene in paediatric patients diagnosed with congenital, non-syndromic hearing loss and treated with cochlear implantation in Mediterranean Turkey.Materials and method:We included 94 children diagnosed with congenital, non-syndromic hearing loss and treated with cochlear implantation. Blood samples were collected, DNA extracted and an enzyme-linked immunosorbent assay performed to enable molecular diagnosis of mutations.Results:Of the 94 children analysed, the 35delG mutation was detected in 12 (12.7 per cent): 10 (83.3 per cent) were homozygous and 2 (16.7 per cent) heterozygous mutant. The 167delT and del(GJB6-D13S1830) mutations were not detected.Conclusion:The GJB2-35delG mutation is a major cause of congenital, non-syndromic hearing loss in this study population.
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Prevalence of GBJ2 mutations in patients with severe to profound congenital nonsyndromic sensorineural hearing loss in Bulgarian population. Eur Arch Otorhinolaryngol 2011; 269:1589-92. [DOI: 10.1007/s00405-011-1817-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 10/17/2011] [Indexed: 10/15/2022]
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Detection of the GJB2 Mutation in Iranian Children with Hearing Loss Treated with Cochlear Implantation. Balkan J Med Genet 2011; 14:19-24. [PMID: 24052698 PMCID: PMC3776689 DOI: 10.2478/v10034-011-0013-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 35delG mutation in the gap junction protein, β2, 26kDa (GJB2) gene is the most common mutation that has been found in children with non syndromic hearing loss. Testing for the GJB2 gene mutation is simple and can directly answer the concerns of the parents about cause of the disorder and prognosis for their children. Cochlear implantation (CI) is one of the methods of hearing rehabilitation in patients with complete hearing loss. The present study was designed for genetic assessment of children who were referred for CI. Connexin 26 (Cx26) gene analyses were performed on 42 children with non syndromic hearing loss who were referred to the Baqiyatallah Hospital, Tehran, Iran for genetic consultation and CI. Clinical history was obtained and an examination conducted on each individual. Genomic DNA was extracted from peripheral blood and mutation identification of the Cx26 gene was performed by polymerase chain reaction (PCR) amplification and direct sequencing of the coding sequence of the gene. Cochlear implantation was performed for all patients and treatment response was assessed for all of them based on speech intelligibility rating (SIR) before and after CI. We found six patients (14.3%) with the 35delG mutation on the Cx26 gene, two homozygotes and four heterozygotes. No other mutation was detected. Treatment response in children with the homozygous 35delG mutation was better than in heterozygous patients, and treatment response in children with the mutation was better than in children with no mutation. Mutation screening for finding deafness causing mutations in the GJB2 gene is a useful predictor of post-implantation speech perception. We suggest microarray or other advanced mutation detection methods for assessment of other genes that might be responsible for non syndromic deafness.
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Gordon KA, Wong DDE, Valero J, Jewell SF, Yoo P, Papsin BC. Use it or lose it? Lessons learned from the developing brains of children who are deaf and use cochlear implants to hear. Brain Topogr 2011; 24:204-19. [PMID: 21479928 DOI: 10.1007/s10548-011-0181-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 03/26/2011] [Indexed: 11/24/2022]
Abstract
In the present paper, we review what is currently known about the effects of deafness on the developing human auditory system and ask: Without use, does the immature auditory system lose the ability to normally function and mature? Any change to the structure or function of the auditory pathways resulting from a lack of activity will have important implications for future use through an auditory prosthesis such as a cochlear implant. Data to date show that deafness in children arrests and disrupts normal auditory development. Multiple changes to the auditory pathways occur during the period of deafness with the extent and type of change being dependent upon the age and stage of auditory development at onset of deafness, the cause or type of deafness, and the length of time the immature auditory pathways are left without significant input. Structural changes to the auditory nerve, brainstem, and cortex have been described in animal models of deafness as well in humans who are deaf. Functional changes in deaf auditory pathways have been evaluated by using a cochlear implant to stimulate the auditory nerve with electrical pulses. Studies of electrically evoked activity in the immature deaf auditory system have demonstrated that auditory brainstem development is arrested and that thalamo-cortical areas are vulnerable to being taken over by other competitive inputs (cross-modal plasticity). Indeed, enhanced peripheral sight and detection of visual movement in congenitally deaf cats and adults have been linked to activity in specific areas of what would normally be auditory cortex. Cochlear implants can stimulate developmental plasticity in the auditory brainstem even after many years of deafness in childhood but changes in the auditory cortex are limited, at least in part, by the degree of reorganization which occurred during the period of deafness. Consequently, we must identify hearing loss rapidly (i.e., at birth for congenital deficits) and provide cochlear implants to appropriate candidates as soon as possible. Doing so has facilitated auditory development in the thalamo-cortex and allowed children who are deaf to perceive and use spoken language.
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Affiliation(s)
- K A Gordon
- Archie's Cochlear Implant Laboratory, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada.
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Multiple effects of childhood deafness on cortical activity in children receiving bilateral cochlear implants simultaneously. Clin Neurophysiol 2011; 122:823-33. [DOI: 10.1016/j.clinph.2010.10.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 10/21/2010] [Accepted: 10/26/2010] [Indexed: 11/22/2022]
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James AL, Chadha NK, Papsin BC, Stockley TL. Pediatric cholesteatoma and variants in the gene encoding connexin 26. Laryngoscope 2010; 120:183-7. [PMID: 19877196 DOI: 10.1002/lary.20649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVES/HYPOTHESIS Connexin 26 is a gap junction protein encoded by the GJB2 gene. It is expressed in cholesteatoma, and mutations cause proliferative skin disorders and sensorineural hearing loss (SNHL). Deletions of GJB6, which encodes connexin 30, cause SNHL in a digenic manner with a heterozygous GJB2 mutation. We hypothesize that GJB2 and GJB6 mutations might influence the development of cholesteatoma. STUDY DESIGN Prospective observational study to identify GJB mutations in pediatric cholesteatoma. METHODS Peripheral blood samples from 98 children with cholesteatoma were screened for mutations in the GJB2 gene by direct sequencing of the coding region (exon 2 and the intron/exon boundary). Deletions of the GJB6 gene were tested using multiple ligation probe amplification methods. GJB status was compared with other populations and patient age and extent of cholesteatoma at presentation. RESULTS Fourteen children had at least one GJB2 variant (14%). Of these, three had two variants. Two of the variants were neutral polymorphisms. One child with the GJB2 genotype 35delG/35delG also had SNHL. No correlation was found between GJB2 status and patient age or cholesteatoma severity at presentation. No GJB6 deletions were found. CONCLUSIONS GJB2 gene variants are present in a minority of children with cholesteatoma, but may be more common than in normal populations. It is conceivable that alterations of connexin 26 expression could contribute to the multifactorial disease process in cholesteatoma by modifying the cell-to-cell communication that is important in proliferation and migration of keratinocytes.
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Affiliation(s)
- Adrian L James
- Department of Otolaryngology, The Hospital for Sick Children, Ontario, Canada.
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Abidi O, Boulouiz R, Nahili H, Bakhouch K, Wakrim L, Rouba H, Chafik A, Hassar M, Barakat A. Carrier frequencies of mutations/polymorphisms in the connexin 26 gene (GJB2) in the Moroccan population. ACTA ACUST UNITED AC 2009; 12:569-74. [PMID: 19072567 DOI: 10.1089/gte.2008.0063] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mutations in the Connexin 26 gene (GJB2/Cx26) are responsible for more than half of all cases of prelingual nonsyndromic recessive deafness in Caucasians. The carrier frequency of the 35delG-GJB2 mutation was found to be as high as 2-4% in the Mediterranean populations. Different GJB2 mutations were reported in the Moroccan patients with autosomal recessive nonsyndromic hearing loss; however, rare studies were carried out on the carrier frequencies of these mutations in the healthy populations. The aim of this study was to estimate the carrier frequencies of the GJB2 mutations in the Moroccan population. The molecular analysis of the 35delG mutation and other GJB2 sequence variations was performed in 386 healthy unrelated Moroccan individuals with no known hearing loss. Five GJB2 sequence variations at heterozygous state were found: two mutations, 35delG and 109G > A (V37I), and three polymorphisms, 79G > A (V27I), 341G > A (E114G), and 457G > A (V153I). The carrier frequency of the 35delG mutation was the highest with 2.07% [95% confidence interval (0.90-4.04%)], followed by that of the V37I mutation with 1.43% (0.06-5.39). The carrier frequency of V27I, E114G, and V153I changes was estimated to be 0.71% (0.01-4.34). This finding shows that the 35delG carrier frequency found here is similar to the one observed in Mediterranean populations. It provides new information about GJB2 carrier rates facilitating the diagnosis and the genetic counseling in the Moroccan population.
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Affiliation(s)
- Omar Abidi
- Laboratory of Human Genetics, Department of Scientific Research, Pasteur Institute, Casablanca, Morocco
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Fischer TC, Samanich J, Morrow BE, Chobot-Rodd J, Shanske A, Parikh SR. Genetic evaluation of American minority pediatric cochlear implant recipients. Int J Pediatr Otorhinolaryngol 2009; 73:195-203. [PMID: 19081147 DOI: 10.1016/j.ijporl.2008.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 10/07/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To review the results of genetic evaluation of American minority pediatric cochlear implant recipients over a 5-year period. METHODS Case series review of pediatric cochlear implant recipients of Caribbean Hispanic and African American admixture descent with severe to profound sensorineural hearing loss at a tertiary care children's hospital. RESULTS Out of 28 patients receiving cochlear implants, 14 were of Caribbean Hispanic or African American admixture ancestry. Six (43%) had environmental risk factors for sensorineural hearing loss. Eight (57%) patients had presumed genetic sensorineural hearing loss; two of whom were syndromic and six non-syndromic. Patients with no clear etiology for hearing loss were tested for Gap Junction Beta 2 (GJB2) mutations. Within this admixture group, we found no biallelic mutations in GJB2, while two patients, both with environmental risk factors for sensorineural hearing loss, had monoallelic GJB2 variants. One patient of mixed ethnicity (Caribbean Hispanic, Turkish, Macedonian), not included as part of the 14, had the common Caucasian founder mutation, 35delG, along with a heterozygous polymorphism in the GJB2 gene. This extends previous data showing a paucity of GJB2 mutations in these admixture populations. CONCLUSIONS We found no biallelic GJB2 mutations in our admixture cochlear implant population, and two sequence variants of the gene, only one of which was disease causing. This suggests that the incidence of GJB2 mutations in these admixture populations is low. Hence, there may be low cost-benefit of GJB2 mutation analysis in these admixture populations with severe to profound non-syndromic sensorineural hearing loss.
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Affiliation(s)
- Tova C Fischer
- Division of Pediatric Otorhinolaryngology-Head and Neck Surgery, Children's Hospital at Montefiore, Bronx, NY 10467, USA
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Abstract
Hearing impairment (HI) is the most frequent sensory disorder, with a genetic etiology in >50% of all cases, due to mutations in >44 identified genes. Autosomal recessive inheritance explains the majority, with GJB2 (connexin 26) mutations accounting for 15-50% of paediatric HI. Delayed presentation of HI to 11-60 months in cases of biallelic GJB2 mutations is a concern, necessitating a good audiological follow-up in addition to neonatal hearing screening. Providing a genetic diagnosis in congenital HI has implications for the prognosis, the possible risk of associated medical manifestations, and precise genetic counseling of the family, and should be integrated into the medical examinations done in order to diagnose syndromic features. Large-scale mutation detection methods, such as micro arrays, are promising for wider genetic testing, but few studies on their clinical utility have been published, so far. Limitations of interpretation of genetic test results, combined with significant ethical issues, currently do not justify to institute genetic screening for GJB2 mutations in neonates before a diagnosis of HI is established.
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Cushing SL, MacDonald L, Propst EJ, Sharma A, Stockley T, Blaser SL, James AL, Papsin BC. Successful cochlear implantation in a child with Keratosis, Icthiosis and Deafness (KID) Syndrome and Dandy-Walker malformation. Int J Pediatr Otorhinolaryngol 2008; 72:693-8. [PMID: 18313767 DOI: 10.1016/j.ijporl.2008.01.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 12/29/2007] [Accepted: 01/05/2008] [Indexed: 10/22/2022]
Abstract
Keratosis, Icthiosis, and Deafness (KID) Syndrome is a rare congenital disorder associated with dominant connexin 26 mutations, affecting epidermis, corneal epithelium, and inner ear. Given eventual visual impairment, cochlear implantation is an important consideration despite an increased risk of wound complications. We present a child with KID Syndrome and bilateral profound sensorineural hearing loss associated with a novel heterozygous missense D50A connexin 26 mutation (c.149A > C). Imaging revealed mild cochlear malformation and Dandy-Walker malformation. She received a cochlear implant at the age of 12 months, using a small incision approach. Following an immediate minor wound infection, implantation has been successful without further complication over 4 years.
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Affiliation(s)
- Sharon L Cushing
- Department of Otolaryngology Head and Neck Surgery, University of Toronto, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8.
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Affiliation(s)
- Blake C Papsin
- Department of Otolaryngology, Hospital for Sick Children, Toronto, Canada
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Utrera R, Ridaura V, Rodríguez Y, Rojas MJ, Mago L, Angeli S, Henríquez O. Detection of the 35delG/GJB2 and del(GJB6-D13S1830) Mutations in Venezuelan Patients with Autosomal Recessive Nonsyndromic Hearing Loss. ACTA ACUST UNITED AC 2007; 11:347-52. [DOI: 10.1089/gte.2006.0526] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- René Utrera
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela 1081-A
| | - Vanessa Ridaura
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela 1081-A
| | - Yuryanni Rodríguez
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela 1081-A
| | - Maria J. Rojas
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela 1081-A
| | - Leomig Mago
- Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, Venezuela 1081-A
| | - Simón Angeli
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33101
| | - Oswaldo Henríquez
- Departamento de Otorinolaringología, Hospital San Juan de Dios, Caracas, Venezuela 1081-A
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Hernández-Rojas ML, Quiroz-Mercado H, Dalma-Weiszhausz J, Fromow-Guerra J, Amaya-Espinosa A, Solís-Vivanco A, Reyna-Castelán E, Abraham-Marín M, Martínez-Castellanos MA, Aiello LP. Short-term effects of intravitreal bevacizumab for subfoveal choroidal neovascularization in pathologic myopia. Genet Med 2007; 27:707-12. [PMID: 17621179 DOI: 10.1097/gim.0b013e3180a03276] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To determine short-term effects of intravitreal bevacizumab for subfoveal choroidal neovascularization (CNV) in pathologic myopia. METHODS In this prospective interventional case series, patients were treated with 2.5 mg of intravitreal bevacizumab and followed for 3 months. Best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and fluorescein angiography (FA) were recorded. Indications for retreatment were active leaking CNV shown by FA and presence of subretinal fluid by OCT in combination with visual disturbances. RESULTS Fourteen patients were included, with a mean age of 53.86 +/- 16.26 years (range 29-85). Mean spherical equivalent was -13.87 +/- 3.68 diopters (-7.25 to -20.50). Minimum follow-up was 3 months. There were no adverse events. The mean initial visual acuity was 20/200 improving to 20/100 at 2 weeks, 20/80 at 4 weeks, and 20/60 at 8 and 12 weeks (P=0.007; P=0.001; P=0.005; P=0.001, respectively). Initial foveal thickness improved from 385.43 microm +/- 125.83 microm to 257.64 +/- 76.6 microm and 194.54 +/- 54.35 microm after the first and third month, respectively (P=0.001). CONCLUSIONS Initial treatment results of patients with CNV due to pathologic myopia did not reveal any short-term safety concerns. Intravitreal bevacizumab resulted in a significant decrease in foveal thickness and improvement in visual acuity. These favorable initial results support further larger and long-term studies.
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Affiliation(s)
- Myriam L Hernández-Rojas
- Hospital Luis Sánchez Bulnes, Asociación Para Evitar la Ceguera en México I.A.P., México City, México.
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Gordon KA, Papsin BC, Harrison RV. Auditory brainstem activity and development evoked by apical versus basal cochlear implant electrode stimulation in children. Clin Neurophysiol 2007; 118:1671-84. [PMID: 17588811 DOI: 10.1016/j.clinph.2007.04.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 04/17/2007] [Accepted: 04/30/2007] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The role of apical versus basal cochlear implant electrode stimulation on central auditory development was examined. We hypothesized that, in children with early onset deafness, auditory development evoked by basal electrode stimulation would differ from that evoked more apically. METHODS Responses of the auditory nerve and brainstem, evoked by an apical and a basal implant electrode, were measured over the first year of cochlear implant use in 50 children with early onset severe to profound deafness who used hearing aids prior to implantation. RESULTS Responses at initial stimulation were of larger amplitude and shorter latency when evoked by the apical electrode. No significant effects of residual hearing or age were found on initial response amplitudes or latencies. With implant use, responses evoked by both electrodes showed decreases in wave and interwave latencies reflecting decreased neural conduction time through the brainstem. Apical versus basal differences persisted with implant experience with one exception; eIII-eV interlatency differences decreased with implant use. CONCLUSIONS Acute stimulation shows prolongation of basally versus apically evoked auditory nerve and brainstem responses in children with severe to profound deafness. Interwave latencies reflecting neural conduction along the caudal and rostral portions of the brainstem decreased over the first year of implant use. Differences in neural conduction times evoked by apical versus basal electrode stimulation persisted in the caudal but not rostral brainstem. SIGNIFICANCE Activity-dependent changes of the auditory brainstem occur in response to both apical and basal cochlear implant electrode stimulation.
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Affiliation(s)
- K A Gordon
- Cochlear Implant Laboratory, the Hospital for Sick Children, and Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Ontario, Canada.
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Li Y, Steinberg AG, Bain L, Yaeger D, Bieler A, Ewing R, Kaimal G, Krantz I. Assessing parental attitudes toward genetic testing for childhood hearing loss: Before and after genetic consultation. Am J Med Genet A 2007; 143A:1546-53. [PMID: 17542006 DOI: 10.1002/ajmg.a.31730] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We report on the development of a Genetic Attitude Assessment Tool (GAAT) to measure parental attitudes in contemplating genetic testing for childhood hearing loss, and to examine the differences in assessments made before and after genetic counseling. The GAAT tool was administered to a convenient sample of 119 parents of children with bilateral sensorineural hearing loss. The respondents completed the survey either before (n = 77) or after (n = 42) genetic counseling. Exploratory Factor Analysis was applied to identify and quantify the underlying psychosocial structure. Our results showed the validated 54-item GAAT instrument contains six subscales: (1) "test intention," (2) "beliefs in non-genetic causes of hearing loss," (3) "deferral of decision to undergo genetic testing," (4) "appropriate use of genetic testing results," (5) "beliefs in the benefits," and (6) "concerns about stigma." The respondents who answered the survey after genetic counseling had higher "test intention" (P = 0.017) and endorsed to a greater extent "beliefs in the benefits" (P < 0.001). They believed to a lesser extent that childhood hearing loss was due to "non-genetic causes" (P < 0.001) and were less inclined to prefer "decision deferral" (P = 0.031). Respondents who themselves had a hearing loss expressed a significantly weaker belief in "non-genetic causes" of hearing loss (P < 0.0001). In conclusion the validated GAAT instrument is responsive to changes in parental attitudes after genetic counseling. The GAAT may be used to monitor parental attitudes serially, to further understand how parental attitudes change from pre genetic counseling, post genetic counseling, to post test result disclosure.
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Affiliation(s)
- Yuelin Li
- Department of Psychiatry and Behavioral Sciences, Memorial Sloan-Kettering Cancer Center, New York, NY 10022, USA.
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Propst EJ, Blaser S, Stockley TL, Harrison RV, Gordon KA, Papsin BC. Temporal bone imaging in GJB2 deafness. Laryngoscope 2007; 116:2178-86. [PMID: 17146393 DOI: 10.1097/01.mlg.0000244389.68568.a7] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To describe temporal bone findings on computed tomography (CT) imaging in GJB2-related hearing loss (HL). We asked whether evaluation of the temporal bone is required in individuals with biallelic GJB2 mutations. STUDY DESIGN Randomized, blinded, controlled, prospective measurement. METHODS Blood from 264 pediatric cochlear implant users was analyzed for mutations in the GJB2 gene. Thirty-six aspects of the temporal bone on CT imaging were evaluated in 53 individuals (106 ears) with biallelic disease causing GJB2 mutations. A subset of patients was age matched and compared with normally hearing individuals. Subjects with biallelic GJB2 mutations were tested for mutations in the SLC26A4 gene to rule out Pendred syndrome as a confounding cause of large vestibular aqueduct syndrome. RESULTS Approximately 53% of ears of subjects (72% of subjects) with biallelic GJB2 mutations had at least one temporal bone anomaly. The most common findings were 1) dilated endolymphatic fossa (28%); 2) hypoplastic modiolus (25%); 3) large vestibular aqueduct (8%); 4) hypoplastic horizontal semicircular canal (8%); 5) hypoplastic cochlea (4%). Compared with normally hearing individuals, the GJB2 group had hypoplasia of the cochlear nerve canal, lateral semicircular canal vestibule, internal auditory canal (t tests, P < .001), and were 11 times more likely to have a hypoplastic modiolus. Dilated endolymphatic fossae were 1.4 times more common in the GJB2 group, and large vestibular aqueducts were 3 times more common in the GJB2 group, as compared with normally hearing controls. CONCLUSIONS Temporal bone anomalies are common in GJB2-related HL, and imaging of the temporal bone should be included in routine evaluation of these individuals.
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Affiliation(s)
- Evan J Propst
- Cochlear Implant Program, Department of Otolaryngology-Head and Neck Surgery, Molecular Genetics Laboratory, The Hospital for Sick Children, Toronto, Canada.
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