Role of Genetic Factors in the Causation of Non-Syndromic Hearing Loss (NSHL) in Indian Population

2020 ◽  
Vol 04 (06) ◽  
Author(s):  
Shehnaz Sultana ◽  
Pratibha Nallari ◽  
Venkateshwari Ananthapur
Keyword(s):  
Hearing Loss ◽  
Indian Population ◽  
Genetic Factors ◽  
Syndromic Hearing Loss

scholarly journals Lights and Shadows in the Genetics of Syndromic and Non-Syndromic Hearing Loss in the Italian Population

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1237
Author(s):  
Anna Morgan ◽  
Stefania Lenarduzzi ◽  
Beatrice Spedicati ◽  
Elisabetta Cattaruzzi ◽  
Flora Maria Murru ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Disease Genes ◽  
Italian Population ◽  
Essential Information ◽  
Whole Exome ◽  
Relevant Role ◽  
Multiplex Ligation Probe Amplification ◽  
Syndromic Hearing Loss

Hearing loss (HL), both syndromic (SHL) and non-syndromic (NSHL), is the most common sensory disorder, affecting ~460 million people worldwide. More than 50% of the congenital/childhood cases are attributable to genetic causes, highlighting the importance of genetic testing in this class of disorders. Here we applied a multi-step strategy for the molecular diagnosis of HL in 125 patients, which included: (1) an accurate clinical evaluation, (2) the analysis of GJB2, GJB6, and MT-RNR1 genes, (3) the evaluation STRC-CATSPER2 and OTOA deletions via Multiplex Ligation Probe Amplification (MLPA), (4) Whole Exome Sequencing (WES) in patients negative to steps 2 and 3. Our approach led to the characterization of 50% of the NSHL cases, confirming both the relevant role of the GJB2 (20% of cases) and STRC deletions (6% of cases), and the high genetic heterogeneity of NSHL. Moreover, due to the genetic findings, 4% of apparent NSHL patients have been re-diagnosed as SHL. Finally, WES characterized 86% of SHL patients, supporting the role of already know disease-genes. Overall, our approach proved to be efficient in identifying the molecular cause of HL, providing essential information for the patients’ future management.

scholarly journals Identification of Main Genetic Causes Responsible for Non-Syndromic Hearing Loss in a Peruvian Population

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 581 ◽  
Author(s):  
Figueroa-Ildefonso ◽  
Bademci ◽  
Rajabli ◽  
Cornejo-Olivas ◽  
Villanueva ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Genetic Factors ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Gjb2 Gene ◽  
Pathogenic Variants ◽  
Novel Variants ◽  
Syndromic Hearing Loss ◽  
Different Populations ◽  
Global Population

: Hearing loss (HL) is a common sensory disorder affecting over 5% of the global population. The etiology underlying HL includes congenital and acquired causes; genetic factors are the main cause in over 50% of congenital cases. Pathogenic variants in the GJB2 gene are a major cause of congenital non-syndromic hearing loss (NSHL), while their distribution is highly heterogeneous in different populations. To the best of our knowledge, there is no data regarding the genetic etiologies of HL in Peru. In this study, we screened 133 Peruvian families with NSHL living in Lima. We sequenced both exons of the GJB2 gene for all probands. Seven probands with familial NSHL that remained negative for GJB2 variants underwent whole genome sequencing (WGS). We identified biallelic pathogenic variants in GJB2 in 43 probands; seven were heterozygous for only one allele. The c.427C>T variant was the most common pathogenic variant followed by the c.35delG variant. WGS revealed three novel variants in MYO15A in two probands, one of them was predicted to affect splicing and the others produce a premature stop codon. The Peruvian population showed a complex profile for genetic variants in the GJB2 gene, this particular profile might be a consequence of the admixture history in Peru.

scholarly journals Potential role for lipopolysaccharide in congenital sensorineural hearingloss

2010 ◽  
Vol 59 (4) ◽  
pp. 377-383 ◽  
Author(s):  
A. L. Smit ◽  
R. J. Stokroos ◽  
S. G. H. Litjens ◽  
B. Kremer ◽  
B. W. Kramer
Keyword(s):  
Hearing Loss ◽  
Comparative Analysis ◽  
Sensorineural Hearing Loss ◽  
Genetic Factors ◽  
Potential Role ◽  
Experimental Studies ◽  
Intrauterine Infection ◽  
Live Births ◽  
Inner Ear Damage

Congenital sensorineural hearing loss (SNHL) is common. In theWestern world, the incidence is 1–3 per 1000 live births. The aetiologyencompasses genetic and non-genetic factors accounting for 55 %and 45 % of cases, respectively. Reports that describe the contributionof intrauterine infection to the occurrence of congenital SNHL are limited,and comparative analysis of the different pathogens is lacking. Lipopolysaccharide (LPS),a product of bacteriolysis, has been demonstrated to be associated with innerear damage in experimental studies. To elucidate the potential role of thistoxin in congenital SNHL and to identify the pathogenesis and transmissionroutes, we reviewed the literature. We speculate that different routes ofexposure to LPS in utero may result in congenital inner ear damage.

High frequency of heterozygosity in GJB2 mutations among patients with non-syndromic hearing loss

2008 ◽  
Vol 123 (3) ◽  
pp. 273-277 ◽  
Author(s):  
G Khandelwal ◽  
S Bhalla ◽  
M Khullar ◽  
N K Panda
Keyword(s):  
Hearing Loss ◽  
Indian Population ◽  
Gjb2 Gene ◽  
Coding Region ◽  
Syndromic Hearing Loss ◽  
Polymerase Chain ◽  
35Delg Mutation ◽  
Control Study ◽  
Gjb2 Mutations ◽  
Prevalent Mutation

AbstractObjective:To determine the prevalence of GJB2 mutations among subjects with congenital, non-syndromic, sensorineural hearing loss, within a north Indian population.Materials and methods:This was a case–control study in which the frequencies of the three most prevalent GJB2 mutations (35delG, W24X and 167delT) were studied. Polymerase chain reaction restriction fragment length polymorphism assays were performed to detect these mutations. The entire coding region of the GJB2 gene was sequenced in all patients, and also in any of their family members who showed GJB2 mutations.Results:The 35delG mutation was found to be the most prevalent mutation (21 per cent), followed by the W24X mutation (7 per cent). This is the first report of the 35delG mutation in an Indian population. One patient was a compound heterozygote for 35delG/W24X. The 167delT mutation was not observed in any patient.Conclusions:These findings challenge the classical view that the W24X variant of the GJB2 gene represents a single ‘founder’ mutation.

Screening of 10 DFNB Loci Causing Autosomal Recessive Non-Syndromic Hearing Loss in Two Iranian Populations Negative for GJB2 Mutations

2020 ◽  
Author(s):  
Mahbobeh KOOHIYAN ◽  
Somayeh REIISI ◽  
Fatemeh AZADEGAN-DEHKORDI ◽  
Mansoor SALEHI ◽  
Hamidreza ABTAHI ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Autosomal Recessive ◽  
Homozygosity Mapping ◽  
Gjb2 Gene ◽  
Global Public Health ◽  
Relative Contribution ◽  
Syndromic Hearing Loss ◽  
High Degree ◽  
Gjb2 Mutations

Background: Autosomal recessive non-syndromic hearing loss (ARNSHL), one of the global public health concerns, is marked by a high degree of genetic heterogeneity. The role of GJB2, as the most common cause of ARNSHL, is only <20% in the Iranian population. Here, we aimed to determine the relative contribution of several apparently most common loci in a cohort of ARNSHL Iranian families that were negative for the GJB2 mutations. Methods: Totally, 80 Iranian ARNSHL families with 3 or more affected individuals from Isfahan and Hamedan provinces, Iran were enrolled in 2017. After excluding mutations in the GJB2 gene via Sanger sequencing, 60 negative samples (30 families from each province) were analyzed using homozygosity mapping for 10 ARNSHL loci. Results: Fourteen families were found to be linked to five different known loci, including DFNB4 (5 families), DFNB2 (3 families), DFNB7/11 (1 family), DFNB9 (2 families) and DFNB3 (3 families). Conclusion: Despite the high heterogeneity of ARNSHL, the genetic causes were determined in 23.5% of the studied families using homozygosity mapping. This data gives an overview of the ARNSHL etiology in the center and west of Iran, used to establish a diagnostic gene panel including most common loci for hearing loss diagnostics.

scholarly journals Genetic linkage analysis of DFNB22 in families with autosomal recessive non-syndromic hearing loss in Khuzestan province

2019 ◽  
Vol 21 (5) ◽  
pp. 200-203
Author(s):  
Ladan Sadeghian ◽  
Mohammad Amin Tabatabaiefar ◽  
Morteza Hashemzadeh Chaleshtori
Keyword(s):  
Hearing Loss ◽  
Linkage Analysis ◽  
Autosomal Recessive ◽  
Polyacrylamide Gel Electrophoresis ◽  
Genetic Linkage Analysis ◽  
Haplotype Reconstruction ◽  
Limited Information ◽  
Khuzestan Province ◽  
Syndromic Hearing Loss

Background and aims: Hearing loss (HL) is the most common sensorineural disorder affecting 1 in 1000 newborns. Autosomal recessive non-syndromic hearing loss (ARNSHL), which is the most common cause of severe HL, is caused by mutations in more than 80 loci. The OTOA gene located on DFNB22 is a rare cause of the disease and the gene studied less in Iranian ARNSHL families. Hence, limited information is available on the frequency and type of OTOA mutations in different populations. In this study, we investigated the role of DFNB22 locus in ARNSHL patients in Khuzestan province, Iran. Materials and Methods: In this descriptive-experimental study, 23 large families with pre-lingual ARNSHL from Khuzestan province were enrolled. Mutations in GJB2 were excluded by DNA sequencing followed by linkage analysis. Homozygosity mapping of DFNB22 was conducted using 6 short tandem repeat polymorphic markers via touch-down PCR and polyacrylamide gel electrophoresis. Homozygosityby-descent was identified by calculating two-point and multi-point LOD score and haplotype reconstruction. Results: Families were negative for GJB2 mutations. Genotyping the STRP markers, haplotype reconstruction, and two-point and multiplepoint LOD scores did not show homozygosity-by-descent in any of the pedigrees. Conclusion: Our findings suggest that OTOA mutations might not contribute significantly to the molecular pathophysiology of ARNSHL in Khuzestan province. However, extending the sample size can illuminate the role of this gene in Khuzestan province.

Occurrence of del( GIB6 -D13S1830) mutation in italian non-syndromic hearing loss patients carrying a single GJB2 mutated allele

2004 ◽  
Vol 124 (0) ◽  
pp. 29-34 ◽  
Author(s):  
F. Gualandi ◽  
A. Ravani ◽  
A. Berto ◽  
S. Burdo ◽  
P. Trevisi ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Syndromic Hearing Loss

Moderating Role of Stress, Anxiety, and Depression in the Relationship Between Tinnitus and Hearing Loss Among Patients

2020 ◽  
Vol 34 (4) ◽  
pp. 753-772
Author(s):  
Ammar Ahmed ◽  
Muhammad Aqeel ◽  
Tanvir Akhtar ◽  
Sammeen Salim ◽  
Bashir Ahmed
Keyword(s):  
Hearing Loss ◽  
Psychological Problems ◽  
Anxiety And Depression ◽  
Adaptation Level ◽  
Depression Anxiety Stress Scale ◽  
Neuropsychological Theory ◽  
Anxiety Depression ◽  
The Relationship ◽  
Moderating Role

Adaptation level theory of tinnitus and neuropsychological theory of tinnitus are extensively used frameworks for understanding emotional and psychological distress among tinnitus sufferers. Objective of the present study was to investigate potential associations between hearing loss, tinnitus, anxiety, depression, and stress. The Tinnitus Handicap Inventory (Newman, Jacobson, & Spitzer, 1996) and the Depression, Anxiety, Stress Scale (Lovibond & Lovibond, 1995)scales were administered to a sample of 110 tinnitus outpatients recruited from Audiology departments of Lahore and Rawalpindi hospitals. Results revealed tinnitus was positively linked with psychological problems. Additionally, it was established that tinnitus is a positive significant predictor for anxiety, stress and depression. The moderation models related to the interactions between psychological problems and hearing loss were negative significant predictors for tinnitus symptoms. Moreover, the comparative analysis between gender differences revealed a significant diversity in the levels of stress, anxiety, and depression. Results also elucidated that patients at initial stages of hearing loss were more prone towards reporting tinnitus symptoms along with emerging psychological problems.

Epigenetic factors and molecular markers of the risk of early pregnancy losses

GYNECOLOGY ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 9-16
Author(s):  
Nataly I Frolova ◽  
Tatiana E Belokrinitskaya
Keyword(s):  
Early Pregnancy ◽  
Genetic Factors ◽  
Molecular Genetic ◽  
Pregnancy Complication ◽  
Common Complication ◽  
Epigenetic Factors ◽  
Genetic Determination ◽  
Periconceptional Period ◽  
Combined Impact

Background. Miscarriage is a common complication in early pregnancy. Current studies have shown a higher prevalence of miscarriage, ranging from 10 to 20%. The review is devoted to modern concepts of etiology and pathogenesis of early pregnancy losses. Aim. Assess the role of epigenetic factors and molecular-genetic markers in the pathogenesis and prediction of early pregnancy losses Materials and methods. In order to write this review domestic and foreign publications were searched in Russian and international search systems (PubMed, eLibrary, etc.) for the last 10-15 years. Relevant articles from the peer-reviewed literature and clinical practice guidelines were included. Results. Many recent studies have proved the contribution of various epigenetic factors to the pathogenesis of spontaneous miscarriages, and the molecular-genetic determination such kinds of pregnancy complication has been confirmed. Conclusion. The miscarriage in early gestation is driven by combined impact of epigenetic and molecular-genetic factors, as well as the presence of intergenic interactions. It is may lead to deterioration of physiological functions, and maternal pathologenic pathways could be changed as during her periconceptional period as so during the pregnancy.

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