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

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.

Two novel compound heterozygous families with a trimutation in the GJB2 gene causing sensorineural hearing loss

2015 ◽  
Vol 79 (12) ◽  
pp. 2295-2299 ◽  
Author(s):  
M. Martínez-Saucedo ◽  
M.R. Rivera-Vega ◽  
L. Gonzalez-Huerta ◽  
H. Urueta-Cuellar ◽  
J. Toral-López ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
Gjb2 Gene ◽  
Compound Heterozygous

scholarly journals Audit of the Aetiological Investigations Performed in Children with Sensorineural Hearing Loss At Salford

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Saud K AlHajeri ◽  
Dr Mohammed Iqbal
Keyword(s):  
Hearing Loss ◽  
Genetic Testing ◽  
Sensorineural Hearing Loss ◽  
Genetic Counselling ◽  
Gold Standard ◽  
Sensorineural Hearing ◽  
British Association ◽  
Hearing Tests ◽  
Work Up

Objective: This project aims to look at the Audiovestibular Physician’s practice at Salford and how closely it aligns with the gold standard guidelines set in the protocol lately published by the British Association of Audiological Physicians. Method: An audit was done retrospectively on 20 patients suffering from sensorineural hearing loss. As such, patient notes were utilised to ascertain which aetiological investigations have been completed and which were not. Any inadequacy in the aetiological work up has been dissected to help know the underlying reasons. Results: All patients had a thorough history taken and were comprehensively physically examined. 95% of patients underwent imaging in the form of MRI/CT. 80% received CMV testing. 75% underwent ECG testing. 60% received family hearing tests. Only 35% had ophthalmology examinations and 25% underwent urine and genetic testing. Conclusion: In some cases, the low compliance rates were due to the Audiovestibular Physician not ordering the investigation as part of the aetiological work up. This could be improved with the use of a dedicated checklist to act as an aid to the physician. Moreover, genetic counselling has been proposed to attempt to boost the compliance rates with genetic testing and similarly, leaflets briefing patients’ families about the importance of undergoing hearing tests themselves is another promising proposition to help improve the adherence

scholarly journals Autosomal Recessive Congenital Sensorineural Hearing Loss due to a Novel Compound Heterozygous PTPRQ Mutation in a Chinese Family

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Xia Wu ◽  
Shan Wang ◽  
Sen Chen ◽  
Ying-ying Wen ◽  
Bo Liu ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Tyrosine Phosphatase ◽  
Sensorineural Hearing ◽  
Paternal Allele ◽  
Chinese Family ◽  
Compound Heterozygous ◽  
Gene Encoding ◽  
Sequencing Method ◽  
And Function

PTPRQ gene, encoding protein tyrosine phosphatase receptor Q, is essential for the normal maturation and function of hair bundle in the cochlea. Its mutations can cause the defects of stereocilia in hair cell, which lead to nonsyndromic sensorineural hearing loss. Using next-generation sequencing and Sanger sequencing method, we identified a novel compound heterozygous missense mutation, c.4472C>T p.T1491M (maternal allele) and c.1973T>C p.V658A (paternal allele), in PTPRQ gene. The two mutations are the first reported to be the cause of recessively inherited sensorineural hearing loss. Hearing loss levels and progression involved by PTPRQ mutations among the existing cases seem to be varied, and the relationship between genotypes and phenotypes is unclear. Our data here further prove the important role of PTPRQ in auditory function and provide more information for the further mechanism research of PTPRQ-related hearing loss.

Etiologic diagnosis of sensorineural hearing loss in adults

2005 ◽  
Vol 132 (6) ◽  
pp. 890-895 ◽  
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.

scholarly journals Molecular Investigation of Pediatric Portuguese Patients with Sensorineural Hearing Loss

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Célia Nogueira ◽  
Miguel Coutinho ◽  
Cristina Pereira ◽  
Alessandra Tessa ◽  
Filippo M. Santorelli ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Genetic Testing ◽  
Mitochondrial Genome ◽  
Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
Novel Mutations ◽  
Portuguese Population ◽  
Molecular Investigation ◽  
Molecular Etiology ◽  
Testing And Counseling

The understanding of the molecular genetics in sensorineural hearing loss (SNHL) has advanced rapidly during the last decade, but the molecular etiology of hearing impairment in the Portuguese population has not been investigated thoroughly. To provide appropriate genetic testing and counseling to families, we analyzed the whole mitochondrial genome in 95 unrelated children with SNHL (53 nonsyndromic and 42 syndromic) and searched for variations in two frequent genes, GJB2 and GJB6, in the non-syndromic patients. Mutations in mtDNA were detected in 4.2% of the cases, including a hitherto undescribed change in the mtDNA-tRNATrp gene (namely, m.5558A>G). We also identified mono- or biallelic GJB2 mutations in 20 of 53 non-syndromic cases and also detected two novel mutations (p.P70R and p.R127QfsX84). Our data further reinforce the notion that genetic heterogeneity is paramount in children with SNHL.

scholarly journals Genetic background in late-onset sensorineural hearing loss patients

2021 ◽  
Author(s):  
Natsumi Uehara ◽  
Takeshi Fujita ◽  
Daisuke Yamashita ◽  
Jun Yokoi ◽  
Sayaka Katsunuma ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Genetic Testing ◽  
Sensorineural Hearing Loss ◽  
Late Onset ◽  
Japanese Patients ◽  
Sensorineural Hearing ◽  
The Other ◽  
Mild Phenotype ◽  
Appropriate Treatment ◽  
Bilateral Sensorineural Hearing Loss

AbstractGenetic testing for congenital or early-onset hearing loss patients has become a common diagnostic option in many countries. On the other hand, there are few late-onset hearing loss patients receiving genetic testing, as late-onset hearing loss is believed to be a complex disorder and the diagnostic rate for genetic testing in late-onset patients is lower than that for the congenital cases. To date, the etiology of late-onset hearing loss is largely unknown. In the present study, we recruited 48 unrelated Japanese patients with late-onset bilateral sensorineural hearing loss, and performed genetic analysis of 63 known deafness gene using massively parallel DNA sequencing. As a result, we identified 25 possibly causative variants in 29 patients (60.4%). The present results clearly indicated that various genes are involved in late-onset hearing loss and a significant portion of cases of late-onset hearing loss is due to genetic causes. In addition, we identified two interesting cases for whom we could expand the phenotypic description. One case with a novel MYO7A variant showed a milder phenotype with progressive hearing loss and late-onset retinitis pigmentosa. The other case presented with Stickler syndrome with a mild phenotype caused by a homozygous frameshift COL9A3 variant. In conclusion, comprehensive genetic testing for late-onset hearing loss patients is necessary to obtain accurate diagnosis and to provide more appropriate treatment for these patients.

scholarly journals GJB2 Gene Mutations in Syndromic Skin Diseases with Sensorineural Hearing Loss.

2011 ◽  
Vol 12 (7) ◽  
pp. 475-485 ◽  
Author(s):  
Sandra Iossa ◽  
Elio Marciano ◽  
Annamaria Franze
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Skin Diseases ◽  
Gene Mutations ◽  
Sensorineural Hearing ◽  
Gjb2 Gene
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