Frequency of W24X Gene Polymorphism among the Students from Hearing Impaired Schools of Shimoga District

Introduction An important accompaniment of Non-syndromic sensorineural hearing loss is family history and consanguinity. One of the widely studied single nucleotide polymorphism is the gap junction protein beta-2 (GJB2) gene which encodes the protein connexin26. This study aims to detect the frequency of W24X mutation in a population with non-syndromic sensorineural hearing loss concerning the degree of consanguinity. Materials and Methods The study includes 76 subjects with Non-syndromic sensorineural hearing loss. These subjects had congenital sensorineural hearing loss and other causes for the same had been ruled out. The SNP rs 104894396 was identified by the PCR-RFLP method. Results The frequency of the wild allele was 0.84% and the mutant allele was 0.15%. The frequency of wild allele and mutant allele did not differ much between patients with and without consanguinity. The association between consanguineous marriage and allele frequency was not significant. Gene polymorphism was not present in 77 percent of our NSHL subjects, though 79 percent of our study population were a result of consanguineous marriage. Conclusion Though the role of consanguineous marriages in congenital sensorineural hearing loss is well established, the association between allele frequency and consanguineous marriage was not seen. We assume that other genes responsible for deafness may be involved in the population.

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Association of αENaC p. Ala663Thr Gene Polymorphism With Sudden Sensorineural Hearing Loss

Frontiers in Genetics ◽

10.3389/fgene.2021.659517 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jialei Chen ◽

Jing He ◽

Jing Luo ◽

Shixun Zhong

Keyword(s):

Hearing Loss ◽

Gene Polymorphism ◽

Sensorineural Hearing Loss ◽

Allele Frequency ◽

Low Frequency ◽

Sudden Sensorineural Hearing Loss ◽

Sensorineural Hearing ◽

Control Group ◽

Increased Risk ◽

Significant Difference

Objective: The etiology of sudden sensorineural hearing loss (SSNHL) is still unknown. It has been demonstrated that normal endolymph metabolism is essential for inner ear function and that epithelial sodium channels (ENaC) may play an important role in the regulation of endolymphatic Na+. This study aimed to explore the potential association between αENaC p. Ala663Thr gene polymorphism and SSNHL.Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine the genotype and allele frequency of the αENaC p. Ala663Thr polymorphism in 20 cases of low-frequency SSNHL (LF-SSNHL), 19 cases of high-frequency SSNHL (HF-SSNHL), 31 cases of all frequency SSNHL (AF-SSNHL), 42 cases of profound deafness SSNHL (PD-SSNHL), and 115 normal controls.Results: The T663 allele was found to be significantly associated with an increased risk of LF-SSNHL (p = 0.046, OR = 2.16, 95% CI = 1.01–4.62). The TT genotype and T663 allele, on the other hand, conferred a protective effect for PD-SSNHL (AA vs. TT: p = 0.012, OR = 0.25, 95% CI = 0.08–0.74; A vs. T: p = 0.001, OR = 0.36, 95% CI = 0.21–0.61). However, there was no statistically significant difference in genotype or allele frequency between the two groups (HF-SSNHL and AF-SSNHL) and the control group.Conclusion: The αENaC p. Ala663Thr gene polymorphism plays different roles in different types of SSNHL.

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Halláscsökkenést okozó etiológiai tényezők cochlearis implantáción átesett gyermekekben

Orvosi Hetilap ◽

10.1556/650.2019.31398 ◽

2019 ◽

Vol 160 (21) ◽

pp. 822-828

Author(s):

Nóra Kecskeméti ◽

Anita Gáborján ◽

Magdolna Szőnyi ◽

Marianna Küstel ◽

Ildikó Baranyi ◽

...

Keyword(s):

Hearing Loss ◽

Sensorineural Hearing Loss ◽

Cochlear Implantation ◽

Speech Development ◽

Sensorineural Hearing ◽

Diagnostic Process ◽

Sufficient Information ◽

Hearing Rehabilitation ◽

Junction Protein ◽

Newborn Hearing

Abstract: Introduction: Congenital sensorineural hearing loss is one of the most common sensory defects affecting 1–3 children per 1000 newborns. There are a lot of causes which result in congenital hearing loss, the most common is the genetic origin, but infection, cochlear malformation or other acquired causes can be reasons as well. Aim: The aim of this study was to establish the etiological factors of congenital profound sensorineural hearing loss in children who underwent cochlear implantation. Results: Our results show that the origin of the hearing loss was discovered in 62.9% of our patients. The most common etiological factor was the c.35delG mutation of the gap junction protein β-2 gene, the allele frequency was 38.7% in our cohort. Infection constituted to 10.1%, and meningitis and cytomegalovirus infection were the second most common cause. 79.9% of our patients received sufficient hearing rehabilitation before the end of the speech development’s period (6 years old), but 11.2% of our cases were still diagnosed late. Conclusions: Based on our data we can state that genetic evaluation is crucial in the diagnostic process of congenital profound sensorineural hearing loss. Sufficient hearing rehabilitation affects the whole life of the child, and by late cochlear implantation the speech development falls behind. We can decrease the ratio of the late implantation with the new protocol of newborn hearing screening, and with sufficient information provided to the colleagues, so the children may be referred to the proper center for rehabilitation without delay. Orv Hetil. 2019; 160(21): 822–828.

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Endothelin-1 gene polymorphism in sudden sensorineural hearing loss

The Laryngoscope ◽

10.1002/lary.24298 ◽

2013 ◽

Vol 123 (11) ◽

pp. E59-E65 ◽

Cited By ~ 3

Author(s):

Yasue Uchida ◽

Masaaki Teranishi ◽

Naoki Nishio ◽

Saiko Sugiura ◽

Mariko Hiramatsu ◽

...

Keyword(s):

Hearing Loss ◽

Gene Polymorphism ◽

Sensorineural Hearing Loss ◽

Sudden Sensorineural Hearing Loss ◽

Sensorineural Hearing ◽

Endothelin 1

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Erratum to “Two novel compound heterozygous families with a trimutation in the GJB2 gene causing sensorineural hearing loss” International Journal of Pediatric Otorhinolaryngology, Volume 79, Issue 12, December 2015, Pages 2295–2299

International Journal of Pediatric Otorhinolaryngology ◽

10.1016/j.ijporl.2016.02.001 ◽

2016 ◽

Vol 83 ◽

pp. 93

Author(s):

Mirna Martínez-Saucedo ◽

María del Refugio Rivera-Vega ◽

Luz María Gonzalez-Huerta ◽

Héctor Urueta-Cuellar ◽

Jaime Toral-López ◽

...

Keyword(s):

Hearing Loss ◽

Sensorineural Hearing Loss ◽

Sensorineural Hearing ◽

Gjb2 Gene ◽

Compound Heterozygous

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Efficacy of Connexin testing in detecting Non-syndromic Sensorineural Hearing Loss in an Indian cohort

10.1101/2020.07.30.20165530 ◽

2020 ◽

Author(s):

Jagannath Kurva ◽

Nalini Bhat ◽

Suresh K Shettigar ◽

Harshada Tawade ◽

Shagufta Shaikh ◽

...

Keyword(s):

Hearing Loss ◽

Genetic Testing ◽

Sensorineural Hearing Loss ◽

Indian Population ◽

Sensorineural Hearing ◽

Gjb2 Gene ◽

Compound Heterozygous ◽

Missense Mutations ◽

Pathogenic Mutations ◽

Chinese Studies

Hearing loss is one of the most common sensory disorder and approximately 466 million people have disabling hearing loss worldwide. This study was conducted to identify the mutations in the GJB2, GJB3, and GJB6 genes in an Indian cohort with non-syndromic sensorineural hearing loss and ascertain its use for genetic testing. 31 affected individuals with prelingual bilateral non-syndromic severe to profound sensorineural hearing loss were identified based on clinical evaluation and audiometric assessment. Sanger Sequencing method was used. Six out of 31 affected individuals showed pathogenic nonsense mutations in GJB2 gene, accounting to 19.3%. Of the 6 affected individuals, 5 were homozygous for c.71G>A(p.Trp24Ter) and one was compound heterozygous for c.71G>A and c.370C>T(p.Gln124Ter). Missense mutations [c.380G>A(p.Arg127His) and c.457G>A(p.Val153Ile)], and 3' UTR variations were also identified in GJB2 gene. GJB3 and GJB6 genes showed only silent mutations and 3' UTR variations. 19.3% of affected individuals showing pathogenic mutations in GJB2 gene in our cohort is comparable to other Indian studies (approximately 20%) and it is less as compared to Caucasian, Japanese, and Chinese studies (approximately 50%). Lower occurrence of pathogenic mutations in GJB2 gene in our cohort and other Indian studies as compared to other Caucasian, Japanese and Chinese studies, and absence of pathogenic mutations in GJB3 and GJB6 genes indicates that these genes may have a limited role in the Indian population. Hence there is a need to identify genes that play a major role in the Indian population so that they can be used for genetic testing for NHSL to aid in accurate and early diagnosis.

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Prevalence of Mutations in the GJB2, SLC26A4, GJB3, and MT-RNR1 Genes in 103 Children with Sensorineural Hearing Loss in Shaoxing, China

Ear Nose & Throat Journal ◽

10.1177/014556131809700603 ◽

2018 ◽

Vol 97 (6) ◽

pp. E33-E38 ◽

Cited By ~ 3

Author(s):

Hong Yu ◽

Dan Liu ◽

Jingqun Yang ◽

Zhiqiang Wu

Keyword(s):

Hearing Loss ◽

Sensorineural Hearing Loss ◽

Genetic Screening ◽

Mutant Allele ◽

Hot Spot ◽

Pathogenic Mutation ◽

Sensorineural Hearing ◽

Common Cause ◽

Vestibular Aqueduct ◽

Multiple Pcr

Mutations in the GJB2, SLC26A4, GJB3, and MT-RNR1 genes are known to be a common cause of hearing loss. However, the frequency of hot-spot mutations and genotype-phenotype correlations in patients with sensorineural hearing loss (SNHL) has been less frequently reported. We conducted a study of 103 children—56 boys and 47 girls, aged 5 months to 9 years (mean: 4.1 yr)—with SNHL who underwent genetic screening for 20 hot-spot mutations of the GJB2, SLC26A4, GJB3, and MT-RNR1 genes. Mutations were detected by multiple-PCR-based MALDI-TOF MS assay. At least one mutated allele was detected in 48 patients (46.6%), and 30 patients (29.1%) carried pathogenic mutations. Among all the detected mutations, the most common were GJB2 c.235delC and SLC26A4 c.919-2A>G, with allele frequencies of 23.8 and 6.8%, respectively. At least one mutant allele of SLC26A4 was detected in the 13 patients who had an enlarged vestibular aqueduct (EVA). Almost half of the children with SNHL carried a common deafness-related mutation, and nearly one-third carried a pathogenic mutation. The mutations in SLC26A4 were prevalent and correlated strongly with EVA.

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Etiologic diagnosis of sensorineural hearing loss in adults

Otolaryngology ◽

10.1016/j.otohns.2005.03.001 ◽

2005 ◽

Vol 132 (6) ◽

pp. 890-895 ◽

Cited By ~ 17

Author(s):

Simon I. Angeli ◽

Denise Yan ◽

Fred Telischi ◽

Thomas J. Balkany ◽

Xiao M. Ouyang ◽

...

Keyword(s):

Hearing Loss ◽

Mitochondrial Dna ◽

Sensorineural Hearing Loss ◽

Medical Center ◽

Academic Medical Center ◽

Sensorineural Hearing ◽

Gjb2 Gene ◽

High Resolution Computed Tomography ◽

Vestibular Aqueduct ◽

Etiologic Diagnosis

OBJECTIVE: To determine the etiology of adult-onset sensorineural hearing loss. STUDY DESIGN AND SETTING: This is a prospective cohort study of 60 adult subjects with bilateral sensorineural hearing loss of no obvious etiology by medical history and physical examination. These patients were evaluated at an academic medical center and underwent evaluation by high-resolution computed tomography of the temporal bone, autoimmune panel, and DNA testing for mutations of both the GJB2 gene and the mitochondrial DNA (1555A>G and 7445A>G). RESULTS: An etiologic diagnosis was achieved in 6 patients: cochlear otosclerosis, 1 case; dilated vestibular aqueduct, 1 case; a mitochondrial DNA 7445A>G mutation, 3 cases; and a mitochondrial DNA 1555A>G mutation, 1 case. CONCLUSION: This result underscores the importance of a search for the etiology of a hearing deficit in adult patients. There are specific interventions now available for the management of hearing-impaired patients with cochlear otosclerosis and mitochondrial DNA mutations.

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