Genetic Screening for 35delG Mutation in Egyptian Patients with Profound Sensorineural Hearing Loss Scheduled for Cochlear Implantation: A Population-Based Study

ORL ◽  
2021 ◽  
Vol 83 (3) ◽  
pp. 181-186
Author(s):  
Badr Eldin Mostafa ◽  
Mohammed Abdel El Sawi ◽  
Sabry Magdi Sabry ◽  
Dalia Mohammed Hassan ◽  
Michael Rezk Shafik
Keyword(s):  
Hearing Loss ◽  
Cochlear Implantation ◽  
Genetic Screening ◽  
Population Based ◽  
Clinical Severity ◽  
Speech Discrimination ◽  
Exon 2 ◽  
Gjb2 Mutation ◽  
Egyptian Patients ◽  
35Delg Mutation

<b><i>Objectives:</i></b> The aim of this work was to assess the type and site of the 35delG gene mutation in patients presenting with profound SNHL and scheduled for cochlear implantation. The secondary objectives were to determine their geographical distribution throughout Egypt, screening of the parents for the mutation, and to correlate the type of mutation with clinical severity and outcomes after surgery. <b><i>Methods:</i></b> The study was carried out on 100 consecutive patients scheduled for cochlear implantation. Patients with syndromic hearing loss or noncongenital hearing loss (trauma, infections, and ototoxicity) were excluded. All patients were subjected to detailed history taking including geographic tagging for their origins in Egypt, imaging (CT and MRI cochlear implantation protocols), full audiological evaluation (PTA, ABR, and TEOAE), and genetic screening for GJB2 mutation using Invitrogen PCR mix and ApaI restriction enzyme (North America, CA, 10572-014). The parents of mutation-positive patients were also subjected to audiological and genetic analysis. All patients were subjected to postimplantation evaluation of hearing after 6 and 12 months. <b><i>Results:</i></b> There were 64 males and 36 females from 98 families. Ages ranged between 1.9 and 7 years (mean 3.72 years). They originated from all over Egypt but the majority came from the Giza and Cairo areas. The 35delG mutations were found in exon 2 in 31% of the cases and all were heterozygous. In the parents, 18 mothers and 13 fathers were positive but only 8 had mild to moderate SNHL. Hearing evaluation by pure tone and speech discrimination scores at 6 and 12 months showed that the 35delG children had a statistically better result compared to the children without this mutation. <b><i>Conclusion:</i></b> The prevalence of the 35delG mutation in nonsyndromic children in this sample was 31% which is different from previous studies in the Egyptian population but close to the values found in other populations in the Mediterranean basin.

scholarly journals Detailed Clinical Features of Deafness Caused by a Claudin-14 Variant

2019 ◽  
Vol 20 (18) ◽  
pp. 4579 ◽  
Author(s):  
Kitano ◽  
Kitajiri ◽  
Nishio ◽  
Usami
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Cochlear Implantation ◽  
Vestibular Function ◽  
Sound Field ◽  
Speech Discrimination ◽  
Epithelial Barrier Function ◽  
Pathogenic Variants ◽  
Novel Variant ◽  
Claudin 14

Tight junctions are cellular junctions that play a major role in the epithelial barrier function. In the inner ear, claudins, occludin, tricellulin, and angulins form the bicellular or tricellular binding of membrane proteins. In these, one type of claudin gene, CLDN14, was reported to be responsible for human hereditary hearing loss, DFNB29. Until now, nine pathogenic variants have been reported, and most phenotypic features remain unclear. In the present study, genetic screening for 68 previously reported deafness causative genes was carried out to identify CLDN14 variants in a large series of Japanese hearing loss patients, and to clarify the prevalence and clinical characteristics of DFNB29 in the Japanese population. One patient had a homozygous novel variant (c.241C>T: p.Arg81Cys) (0.04%: 1/2549). The patient showed progressive bilateral hearing loss, with post-lingual onset. Pure-tone audiograms indicated a high-frequency hearing loss type, and the deterioration gradually spread to other frequencies. The patient showed normal vestibular function. Cochlear implantation improved the patient’s sound field threshold levels, but not speech discrimination scores. This report indicated that claudin-14 is essential for maintaining the inner ear environment and suggested the possible phenotypic expansion of DFNB29. This is the first report of a patient with a tight junction variant receiving a cochlear implantation.

scholarly journals Spectrum and Frequency of the GJB2 Gene Mutations Among Latvian Patients with Prelingual Nonsyndromic Hearing Loss

2009 ◽  
Vol 63 (4-5) ◽  
pp. 198-203
Author(s):  
Olga Šterna ◽  
Natālija Proņina ◽  
Ieva Grīnfelde ◽  
Sandra Kušķe ◽  
Astrīda Krūmiņa ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Gjb2 Gene ◽  
Connexin 26 ◽  
Compound Heterozygous ◽  
Nonsyndromic Hearing Loss ◽  
Profound Hearing Loss ◽  
Common Cause ◽  
Gjb2 Mutation ◽  
35Delg Mutation

Spectrum and Frequency of the GJB2 Gene Mutations Among Latvian Patients with Prelingual Nonsyndromic Hearing Loss Mutations in the GJB2 gene (connexin 26) are the most common cause of congenital nonsyndromic severe-to-profound hearing loss. Sixty-five hearing impaired probands from Latvia were tested for mutations in the GJB2 gene to determine the percentage of hearing loss attributed to connexin 26 and the types of mutations in this population. A total of 62% of patients tested had GJB2 mutations. Four different mutations in the GJB2 gene were identified in Latvian patients with nonsyndromic sensorineural hearing loss: 35delG, 311-324del14, 235delC and M34T. The most prevalent mutation is 35delG (47% of all probands were homozygous and 8% compound heterozygous). Our findings support the conclusion that the 35delG mutation is the most prevalent GJB2 mutation and that it is the common cause of hereditary nonsyndromic hearing loss in populations of European descent.

scholarly journals Investigating GJB2 Mutation in 31 Individuals With Non-syndromic Hearing Loss

2021 ◽  
Vol 24 (1) ◽  
pp. 50-61
Author(s):  
Pedram Pouryari Biyachal ◽  
◽  
Najmeh Ranji ◽  
Ali Nazemi ◽  
◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cross Sectional Study ◽  
Gjb2 Gene ◽  
Common Mutation ◽  
Cross Sectional ◽  
Gjb2 Mutation ◽  
Syndromic Hearing Loss ◽  
Pcr Method ◽  
Gilan Province ◽  
35Delg Mutation

Background and Aim: Non-syndromic hearing loss is a genetically heterogeneous disorder. Mutation in the GJB2 gene is a major cause of non-syndromic hearing loss in numerous countries. This study aimed to evaluate GJB2 mutations in 31 individuals with non-syndromic hearing loss Methods & Materials: In this descriptive cross-sectional study, the required blood samples were collected from 31 individuals with non-syndromic hearing loss in Rasht and Bandar Anzali Cities, Gilan Province, Iran. After DNA isolation, the GJB2 gene was amplified by the PCR method and underwent sequencing. Ethical Considerations:This study was approved by the Ethics Committee of the Islamic Azad University, Mashhad Branch (Code: IR.IAU.MSHD.REC.1398.027). Results: In this study, 3 mutations were determined in 18 individuals with hearing loss. Accordingly, 35delG mutation had the highest frequency (48.38%) in individuals with hearing loss as homozygote (n=14) and heterozygote (n=2). A patient with heterozygosity in V153I mutation and a patient with compound heterozygosity in 35delG/G200R mutation was determined. Conclusion: It appears that 35delG mutation is a common mutation in the GJB2 gene in individuals with non-syndromic hearing loss in Guilan Province.

Connexin 26 and 30 mutations in paediatric patients with congenital, non-syndromic hearing loss treated with cochlear implantation in Mediterranean Turkey

2012 ◽  
Vol 127 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Ö Tarkan ◽  
P Sari ◽  
O Demirhan ◽  
M Kiroğlu ◽  
Ü Tuncer ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cochlear Implantation ◽  
Autosomal Recessive ◽  
Connexin 26 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Paediatric Patients ◽  
Study Population ◽  
Connexin 30 ◽  
Syndromic Hearing Loss ◽  
35Delg Mutation

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.

scholarly journals Detection of the GJB2 Mutation in Iranian Children with Hearing Loss Treated with Cochlear Implantation

2011 ◽  
Vol 14 (1) ◽  
Author(s):  
A Peyvandi ◽  
S Morovvati ◽  
H Rabiee ◽  
R Ranjbar ◽  
M Ajalloueyan ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cochlear Implantation ◽  
Gjb2 Mutation ◽  
Children With Hearing Loss ◽  
Iranian Children

scholarly journals Management of advanced otosclerosis: experience in a tertiary care centre

2018 ◽  
Vol 4 (2) ◽  
pp. 376
Author(s):  
Mohammed Iftekharul Alam ◽  
Kiran Natarajan ◽  
Takhellambam Biram Singh ◽  
Abha Kumari ◽  
Mohan Kameswaran
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Cochlear Implantation ◽  
Selection Criteria ◽  
Tertiary Care ◽  
Speech Discrimination ◽  
Tertiary Care Centre ◽  
Management Options ◽  
Profound Hearing Loss ◽  
Mixed Hearing Loss

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">Advanced otosclerosis affects approximately 10% of patients with otosclerosis. Ossification of the cochlea increases with the course of the disease and may cause sensori-neural or mixed hearing loss. Hearing aids, stapedotomy and cochlear implants are management options for hearing loss associated with advanced otosclerosis. </span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">A retrospective study of 153 patients with advanced otosclerosis was done in a tertiary ENT centre. 110 patients with advanced otosclerosis underwent stapedotomy and 43 patients with advanced otosclerosis underwent cochlear implantation (CI) from 1997 till date. Exclusion criteria included patients with profound hearing loss from causes other than otosclerosis. The aim was to study the indications, selection criteria, as well as surgical issues of stapedotomy and cochlear implantation in patients with advanced otosclerosis.  </span></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">Stapedotomy followed by use of hearing aid was found to give good outcomes in advanced otosclerosis. Patients with advanced otosclerosis who had poor pre-operative speech discrimination underwent CI. Complete insertion was possible in 39 patients and partial insertion was done in 4 patients. The outcomes of cochlear implantation were found to be satisfactory. Facial nerve stimulation was seen in 5 patients who underwent CI; however this was successfully managed by reprogramming or switching off the concerned electrodes. </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">In our experience, stapedotomy or CI in advanced otosclerosis has proven successful, with a low complication rate. The selection criteria for stapedotomy versus CI have to be stringent for optimal outcomes.</span></p>

Cochlear Implantation in Autoimmune Inner Ear Disease

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P53-P53 ◽  
Author(s):  
Katrina R Stidham ◽  
Joseph B Roberson
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Immunosuppressive Therapy ◽  
Cochlear Implantation ◽  
Hearing Aid ◽  
Speech Discrimination ◽  
Inner Ear Disease ◽  
Potential Risks ◽  
The Impact ◽  
Autoimmune Inner Ear Disease

Objective 1) Evaluate the success of cochlear implantation (CI) in patients with autoimmune inner ear disease (AIED). 2) Discuss the impact of CI on consideration of immunosuppressive therapy for patients with fluctuating hearing loss due to AIED. Methods Retrospective chart review was conducted of patients undergoing CI with diagnosis of AIED between 6/02 and 6/07. Patients’ autoimmune and immunotherapy treatment history was explored. Non-operative ear hearing thresholds and speech discrimination scores (SDS) were documented pre- and postoperatively. Objective and subjective implant success in setting of fluctuating hearing in non-implant ear was evaluated. Results Four patients with AIED, aged 5–55, underwent CI. Two had isolated otologic symptoms and 2 had other systemic autoimmune diagnoses. All had been previously treated with steroids. Three had received other immunosuppressive therapy. One declined other treatment due to potential risks. At the time of implantation, 3 patients had functional hearing in the non-implant ear and received benefit from a hearing aid. Each continued to have usable hearing, with fluctuating improvements post-implant at times to much better SDS than would normally meet candidacy requirements for CI. All patients found the implant provided better hearing than the hearing-aid ear. Conclusions CI is a viable option for patients with AIED. Implanting a profoundly deafened ear where opposite ear has fluctuating but usable hearing does not negatively impact outcomes. With the success of CI for AIED, the potential risks of long-term immunosuppressive therapy may not warrant its use in patients with isolated hearing loss symptoms.

Partial Deafness Cochlear Implantation at the University of Kansas: Techniques and Outcomes

2010 ◽  
Vol 21 (03) ◽  
pp. 197-203 ◽  
Author(s):  
Sandra Prentiss ◽  
Kevin Sykes ◽  
Hinrich Staecker
Keyword(s):  
Hearing Loss ◽  
Cochlear Implantation ◽  
Signal To Noise Ratio ◽  
Hearing Preservation ◽  
Residual Hearing ◽  
Speech Discrimination ◽  
Insertion Depth ◽  
Low Frequencies ◽  
Hearing In Noise ◽  
Electrode Insertion

Background: One of the most significant recent advances in cochlear implantation is the implantation of patients with residual hearing. These patients have a downsloping sensorineural hearing loss with poor speech discrimination and perform poorly with standard amplification. Studies using a variety of different electrode designs have demonstrated that it is possible to implant an inner ear and preserve residual hearing. Initial studies have demonstrated that a combination of residual acoustic hearing in the low frequencies with electrical stimulation in the mid- to high frequencies resulted in superior hearing performance in background noise. Purpose: The objective of this study was to determine the effect of electrode insertion depth on hearing preservation. Study Sample: Eighteen patients with mild to severe hearing loss in the low frequencies combined with poor word recognition were recruited for the study. Intervention: Cochlear implantation. Data Collection and Analysis: Pre- and postoperative hearing test, Hearing in Noise Test, and consonant–nucleus–consonant testing. Data analysis was performed with Kruskal Wallis and Mann-Whitney testing. Results: In our study of 18 patients implanted with a Med-El PulsarCI100 we demonstrated the ability to preserve residual hearing with implant insertion depths ranging from 20 to 28 mm, giving us the possibility of near complete cochlear frequency coverage with an implant array while preserving residual hearing. These patients performed well both in quiet and in 10 dB signal-to-noise ratio conditions. Conclusion: Hearing preservation was achievable even with deep implant insertion. Patients performed well in combined acoustic and electric conditions.

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