Association Of Sensorineural Hearing Loss Research Articles

<i>TWNK</i> Gene Associated Perrault Syndrome Patient with Neurological Features

Perrault syndrome 5 is a rare autosomal recessive disorder that is characterized by the association of sensorineural hearing loss and ovarian dysgenesis in females with diversity of neurologic deficits due to variants of twinkle mtDNA helicase (<i>TWNK</i>) gene. Since neurologic deficits develop gradually, patient is often misdiagnosed with other neurological disease during early age. Herein, we report a case of genetically diagnosed Perrault syndrome 5.

Association of sensorineural hearing loss and pseudoexfoliation syndrome: a meta-analysis

Association of sensorineural hearing loss and pseudoexfoliation syndrome: a meta-analysis

Study of incidence of sensorineural hearing loss in allergic rhinitis

<p><strong>Background:</strong> The aim was assessment of sensorineural hearing loss incidence in allergic rhinitis. Anatomical and physiological relation of nose with ear increases the possibility of conductive hearing loss in allergic rhinitis, but association of sensorineural hearing loss is least studied.</p><p><strong>Methods: </strong>60 patients with clinically diagnosed allergic rhinitis were compared with age and gender matched controls. All participants were subjected for pure tone audiometry; distortion product otoacoustic emission and tympanometry. Facts and statistics were analysed by chi-square and t- test with significance at p<0.05.</p><p><strong>Results:</strong> Study population had sensorineural hearing loss which was in high frequencies, distortion product otoacoustic emissions revealed low distortion product and mostly “A” type tympanogram when compared with the controls.</p><p><strong>Conclusions:</strong> We found patients having allergic rhinitis are prone to sensorineural hearing loss.</p><p class="abstract"> </p><p> </p>

Diabetic-Mellitus as an Etiological Factor in Hearing Loss

Background: The association of sensorineural hearing loss (SNHL) in diabetes mellitus patients is known since decades, yet there is no clear consensus among previous studies, with respect to the prevalence of SNHL in type 2 diabetes patients and the effect of duration and control of diabetes on hearing acuity. Hence the objectives of this study are to find the prevalence of SNHL in type 2 diabetes patients and to find the effect of duration and control of diabetes on hearing loss. Methods: The present study was conducted on 100 type 2 diabetes patients and age and gender matched 100 non- diabetic controls in the age group of < 50 yrs, selected based on inclusion and exclusion criteria. After detailed history taking and clinical examination, all subjects underwent FBS, PPBS estimation and HbA1c evaluation was done for diabetic patients. All underwent pure tone audiometry, DPOAE and BERA and the findings were recorded and analyzed. Results: Diabetes patients had insidious onset, gradually progressive, bilaterally symmetrical SNHL. SNHL is prevalent in 73% of type 2 diabetes patients compared to 16% of controls. It is aggravated with the increasing age and duration of diabetes. Poor control of diabetes showed increased prevalence of SNHL compared to good control of diabetes. Conclusions: There is increased prevalence of SNHL in type 2 diabetes patients and it is more evident in patients with long duration of diabetes and more pronounced in patients with poor diabetic control.

Association of sensorineural hearing loss in type 2 diabetes mellitus patients: an analytical cross sectional study

&lt;p class="Normal1"&gt;&lt;strong&gt;Background: &lt;/strong&gt;The association of sensorineural hearing loss in diabetes mellitus patients is known since decades, yet there is no clear consensus among previous studies, with respect to the prevalence of SNHL in type 2 diabetes patients and the effect of duration and control of diabetes on hearing acuity. Hence the objectives of this study are to find the prevalence of SNHL in type 2 diabetes patients and to find the effect of duration and control of diabetes on hearing loss.&lt;/p&gt;&lt;p class="Normal1"&gt;&lt;strong&gt;Methods: &lt;/strong&gt;The present study was conducted on 100 type 2 diabetes patients and age and gender matched 100 non- diabetic controls in the age group of &amp;lt;50 years, selected based on inclusion and exclusion criteria. After detailed history taking and clinical examination, all subjects underwent FBS, PPBS estimation and HbA1c evaluation was done for diabetic patients. All underwent pure tone audiometry, DPOAE and BERA and the findings were recorded and analyzed.&lt;/p&gt;&lt;p class="Normal1"&gt;&lt;strong&gt;Results: &lt;/strong&gt;Diabetes patients had insidious onset, gradually progressive, bilaterally symmetrical SNHL. SNHL is prevalent in 73% of type 2 diabetes patients compared to 16% of controls. It is aggravated with the increasing age and duration of diabetes. Poor control of diabetes showed increased prevalence of SNHL compared to good control of diabetes.&lt;/p&gt;&lt;p class="Normal1"&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;There is increased prevalence of SNHL in type 2 diabetes patients and it is more evident in patients with long duration of diabetes and more pronounced in patients with poor diabetic control.&lt;/p&gt;

Association of Sensorineural Hearing Loss in Patients With Alopecia Areata

This nationwide population-based cohort study investigates the risk of hearing loss in patients with alopecia areata using claims data from the National Health Insurance Research Database in Taiwan.

Genotypes and estimated prevalence of phosphomannomutase 2 deficiency in Turkey differ significantly from those in Europe.

Phosphomannomutase 2 deficiency (PMM2-CDG) is an autosomal recessive congenital disorder of glycosylation, characterized by multisystem phenotypes, mostly including neurological involvement. In Turkey, due to high rates of consanguinity, many patients with autosomal recessive disorders have homozygous variants and these diseases are more common, compared to Europe. However, published reports of PMM2-CDG from Turkey are scarce. Here, we describe clinical and molecular characteristics of PMM2-CDG patients diagnosed in three centers in Turkey, using data obtained retrospectively from hospital records. We also analyzed an in-house exome database of 1,313 individuals for PMM2 variants and estimated allele, carrier and disease frequencies, using the Hardy-Weinberg law. Eleven patients were identified from 10 families, displaying similar characteristics to previous publications, with the exception of the first report of epilepsia partialis continua and increased prevalence of sensorineural hearing loss. p.Val231Met was the most common variant, and was homozygous in four patients. This novel genotype results in a neurological phenotype with subclinical visceral involvement. Exome database analysis showed an estimated prevalence of 1:286,726 for PMM2-CDG, which is much lower than expected (1:20,000 in Europe) because of the lack of predominance of the common European p.Asp141His allele, associated with a severe phenotype (allele frequency of 1:2,622 compared to 1:252 in gnomAD). These data suggest that prevalence, phenotypes and genotypes of PMM2-CDG in Turkey differ significantly from those in Europe: Milder phenotypes may be more common, but the disease itself rarer, requiring a higher clinical suspicion for diagnosis. The association of sensorineural hearing loss with PMM2-CDG warrants further study.

Prevalence of sensorineural hearing loss in type 2 diabetes mellitus

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The association of sensorineural hearing loss (SNHL) in diabetes mellitus patients is known since decades, yet there is no clear consensus among previous studies, with respect to the prevalence of SNHL in type 2 diabetes patients and the effect of duration and control of diabetes on hearing acuity. Hence the objectives of this study are to find the prevalence of SNHL in type 2 diabetes patients and to find the effect of duration and control of diabetes on hearing loss.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The present study was conducted on 86 type 2 diabetes patients attending Navodaya Medical College Hospital, Raichur and age and gender matched 86 non- diabetic controls in the age group of 30-65 years, selected based on inclusion and exclusion criteria. After detailed history taking and clinical examination, all subjects underwent FBS, PPBS estimation and HbA1c evaluation was done for diabetic patients. All underwent pure tone audiometry and the findings were recorded and analyzed. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Diabetes patients had insidious onset, gradually progressive, bilaterally symmetrical SNHL. SNHL is prevalent in 67.44% of type 2 diabetes patients compared to 23.26% of controls. It is aggravated with the increasing age and duration of diabetes. Poor control of diabetes showed increased prevalence of SNHL compared to good control of diabetes.&lt;/p&gt;&lt;p align="left"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; There is increased prevalence of SNHL in type 2 diabetes patients and it is more evident in patients with long duration of diabetes and more pronounced in patients with poor diabetic control.&lt;/p&gt;

An association of sensorineural hearing loss in mucosal type of chronic suppurative otitis media

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Chronic suppurative otitis media of mucosal variety is one of the most common cause of conductive hearing loss worldwide. Sensorinueral hearing loss is rare but well established complication of chronic suppurative otitis media of squamosal variety. We made an attempt to view the sensorineural hearing loss in mucosal type of chronic otitis media and keeping objectives and aims as follows occurrence of sensorinueral hearing loss in mucosal type of chronic suppurative otitis media; relation of sensorinueral component with age, gender and duration in mucosal type of chronic suppurative otitis media.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A total of 105 cases of mucosal type of CSOM were studied retrospectively for the pattern of hearing impairement on the basis of pure tone audiogram in a Tertiary care hospital. Relation 0f sensorinueral hearing loss with with age, gender and duration in mucosal type of CSOM is compared and tabulated with various studies. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Out of total 105 cases of CSOM of mucosal variety 30 (28.57%) had sensorinueral hearing loss affecting 13 males and 17 females with males to females ratio of 1:1.3.Mean bone conduction thresholds in males at 1 kh, 2 kh and 4 kh is 30.38%, 38.46% and 46.15% respectively and Mean bone conduction thresholds in females at 1 kh, 2 kh and 4 kh is 30.88%, 35% and 44.41% respectively.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Significant sensorinueral hearing loss was seen in our study. Age, gender and duration didn’t have any impact on degree of sensorinueral hearing loss.&lt;/p&gt;

Identification of a de novo mutation of SOX10 in a Chinese patient with Waardenburg syndrome type IV

ObjectivesWaardenburg syndrome is a rare genetic disorder, characterized by the association of sensorineural hearing loss and pigmentation abnormalities. Four subtypes have been classified. The present study aimed to analyze the clinical feature and investigate the genetic cause for a Chinese case of Waardenburg type IV (WS4). MethodsThe patient and his family members were subjected to mutation detection in the candidate gene SOX10 by Sanger sequencing. ResultsThe patient has the clinical features of WS4, including sensorineural hearing loss, bright blue irides, premature graying of the hair and Hirschsprung disease. A novel heterozygous frameshift mutation, c.752_753ins7 (p.Gly252Alafs*31) in the exon 5 of SOX10 was detected in the patient, but not found in the unaffected family members and 100 normal controls. This mutation results in a premature stop codon 31 amino acid downstream. ConclusionsThe novel mutation c.752_753ins7 (p.Gly252Alafs*31) arose de novo and was considered as the cause of WS4 in the proband. This study further characterized the molecular complexity of WS4 and provided a clinical case for genotype-phenotype correlation studies of different phenotypes caused by SOX10 mutations.

Prevalence of Otological Disorders in Diabetic Cases with Hearing Loss

Objective: Diabetes mellitus is a systemic metabolic disease, characterized by fluctuating levels of glucose which affects multiple organs. Hearing loss is one of the most common otological disorders in adults with diabetes. This study aims to evaluate the prevalence of otological diseases and hearing loss patterns in adults suffering from diabetes. Methods: A total of 174 diabetic cases with hearing loss visiting MAA ENT Hospitals, Hyderabad, India along with 420 age and sex matched subjects with hearing loss constituted the study subjects. The age group of the cases above 40 years and the diagnosis was confirmed by otological examinations. Hearing loss was evaluated using pure tone audiometry and average for the frequencies at 0.5,1,2,4 and 8 kHz was recorded. Statistical analysis was performed using PASW STATISTICS 18.0 for determining the association of various demographic and otological parameters with hearing loss of diabetes subjects compared with non-diabetics. Results: In the present study, chronic suppurative otitis media (47.1%) and presbycusis (27%) were the common otological disorders prevalent in diabetic patients with hearing loss at elderly age (>60 years). 44.3% of the study subjects showed prevalence of conductive hearing loss followed by sensorineural(38.5%) and mixed hearing loss(17.2%). It was also observed that there was a significant association of sensorineural hearing loss (OR=4.85; 95% CI=2.37-9.96; p 60 years). Conclusion: Therefore, the present study has revealed hearing loss in otological disorders is as an important consequence of diabetes.

Prevalence of epileptiform discharges in children with sensori-neural hearing loss and behavioral problems compared to their normal hearing peers.

Overactivity and behavioral problems are common problems in children with prelingually profound sensorineural hearing loss (SNHL). Data on epileptiform electroencephalography (EEG) discharges in deaf children with psychological disorders are so limited. The primary focus of this study was to determine the prevalence of epileptiform discharges (EDs) in children with SNHL and overactivity or behavioral problems. A total of 262 patients with prelingually profound SNHL who were referred to our cochlear implantation center between 2008 and 2010 were enrolled in this study. Children with SNHL who had diagnosis of overactivity and/or behavioral problems by a pediatric psychiatrist, underwent electroencephalography (EEG). EEG analysis was carried out by a board-certified pediatric neurologist. The control group consisted of 45 cases with overactivity or behavioral problems and normal hearing. One hundred thirty-eight children with mean age of 3.5±1.23 year were enrolled in the case group, of whom 88 cases (63.7%) were boy. The control group consisted of 45 cases with mean age of 3.2±1.53 years, of whom 30 (66.6%) cases were male. EDs were detected in 28 (20.02%) children of the case group (with SNHL) in comparison with 4 (8.88%) in the control group (without SNHL), which was statistically significantly different. In this study, we obtained higher frequency of EDs in deaf children with overactivity and/or behavioral problem compared to the children without SNHL. Further studies are required to evaluate the possible association of SNHL with EDs in overactive children.

Ear diseases among secondary school students in Xi'an, China: The role of portable audio device use, insomnia and academic stress

BackgroundHearing impairment negatively impacts students' development of academic, language and social skills. Even minimal unilateral hearing loss can hinder educational performance. We investigated the prevalence of ear diseases among secondary school students in the city of Xi'an, China in order to provide a foundation for evidence-based hearing healthcare.MethodsA stratified random sampling survey was conducted in 29 secondary schools. Demographics and medical histories were collected, and otologic examinations were performed. Questionnaires were administered to assess insomnia, academic stress and use of portable audio devices. Logistic regression analysis was used to identify factors associated with hearing impairment, and the association of sensorineural hearing loss with insomnia, academic stress and the use of portable audio devices was analyzed with the chi-square test.ResultsThe percentage of students with some form of ear disease was 3.32%. External ear disease, middle ear disease and sensorineural hearing loss occurred in 1.21%, 0.64% and 1.47% of the students, respectively. Boys had a relatively higher prevalence of ear disease than girls. According to our survey, the prevalence of sensorineural hearing loss increased significantly among the students with insomnia and extended use of portable audio devices, but not among those with elevated levels of academic stress. Hearing aids and surgical treatment were needed in 1.47% and 0.89% of the students, respectively.ConclusionsThere is a high prevalence of ear disease among secondary school students, and this should be given more attention. Insomnia and the excessive use of portable audio devices may be related to adolescent sensorineural hearing loss. It is important to establish and comply with an evidence-based preventive strategy.

Functional analysis of splicing mutations in MYO7A and USH2A genes

Usher syndrome is defined by the association of sensorineural hearing loss, retinitis pigmentosa and variable vestibular dysfunction. Many disease-causative mutations have been identified in MYO7A and USH2A genes, which play a major role in Usher syndrome type I and type II, respectively. The pathogenic nature of mutations that lead to premature stop codons is not questioned; nevertheless, additional studies are needed to verify the pathogenicity of some changes such as those putatively involved in the splice process. Five putative splice-site variants were detected in our cohort of patients: c.2283-1G>T and c.5856G>A in MYO7A and c.1841-2A>G, c.2167+5G>A and c.5298+1G>C in the USH2A gene. In this study, we analyze these changes with bioinformatic tools and investigate the expression of MYO7A and USH2A transcripts through hybrid minigene assays. Our study showed that all five mutations abolished the consensus splice site producing the skipping of involved exons. In addition, for variant c.2167+5G>A, a new donor splice site was observed. Our data reveal the pathogenic nature of the analyzed variants. The fact that splicing mutations led to in-frame or out-of-frame alterations cannot explain phenotypic differences, thus, genotype-phenotype correlations cannot be inferred.

MENIERE’S DISEASE: UPDATE OF ETIOPATHOGENETIC THEORIES AND PROPOSAL OF A POSSIBLE MODEL OF EXPLANATION

Meniere’s Disease (MD) is an affection consisting of an association of sensorineural hearing loss, tinnitus and vertigo initially presenting by crises. A review of the most considered possible causative factors and pathophysiologic interpretations allows us to underline the uncertainties which still exist about the genesis of this illness. We propose a mechanistic model based on the effect of a haemodynamic imbalance leading to transient ischaemia which could have an effect on the pH of the inner ear as well as on the work of the inner ear proton pumps. It is hypothesized that under ischaemic conditions and consequent metabolic acidity a preserved proton pump activity can generate an overload of anions in the endolymphatic partition, which is a closed system, thus resulting in an enhancement of osmolarity and consequently in the formation of a hydrops resulting in the development of fluctuating hearing loss, tinnitus and vertigo which characterize Meniere’s Disease.

High phenotypic intrafamilial variability in patients with Pendred syndrome and a novel duplication in the SLC26A4 gene: clinical characterization and functional studies of the mutated SLC26A4 protein

Pendred syndrome (PS) is characterized by the association of sensorineural hearing loss (SNHL) and a partial iodide organification defect at the thyroid level. It is caused by mutations in the SLC26A4 gene. The encoded transmembrane protein, called pendrin, has been found to be able to transport chloride and other anions. The aim of the present study was to characterize a family with PS, which shows a strong intrafamilial phenotypic variability, including kidney atrophy in one member. The age of disease-onset was significantly different in all three affected siblings, ranging from 2 to 21 years for thyroid alterations and from 1.5 to 11 years for SNHL. Clinical and genetic studies were carried out in affected siblings. The functional activity of the novel duplication found was studied by a fluorimetric method in a human renal cell line (HEK293 Phoenix) in which the protein was overexpressed. All three siblings were found to be compound heterozygotes for the missense mutation (1226G>A, R409H) and for a novel 11 bp duplication (1561_1571CTTGGAATGGC, S523fsX548). The latter mutation creates a frame shift leading to the loss of the entire carboxy-terminus domain. Functional studies of this mutant demonstrated impaired transport of chloride and iodide when expressed in HEK 293 Phoenix cells, when compared with wild type pendrin. A novel 11 bp duplication was found in a family with Pendred syndrome, showing a high intrafamilial phenotypic variability. An impaired transmembrane anionic transport of the mutated SLC26A4 protein was demonstrated in functional studies using a heterologous cell system.

Genotype-phenotype correlations for SLC26A4-related deafness.

Pendred syndrome (PS) and non-syndromic enlarged vestibular aqueduct (EVA) are two recessive disorders characterized by the association of sensorineural hearing loss (SNHL) with inner ear malformations that range from isolated EVA to Mondini Dysplasia, a complex malformation that includes a cochlear dysplasia and EVA. Mutations in the SLC26A4 gene, coding for the protein pendrin, have been implicated in the pathophysiology of both disorders. In order to determine whether SLC26A4 genotypes can be correlated to the complexity and severity of the phenotypes, we ascertained 1,506 deaf patients. Inner ear abnormalities were present in 474 patients (32%). Mutation screening of SLC26A4 detected two mutations in 16% of patients, one mutation in 19% of patients and zero mutation in 65% of patients. When the distribution of SLC26A4 genotypes was compared across phenotypes, a statistically significant difference was found between PS patients and non-syndromic EVA-Mondini patients (P = 0.005), as well as between EVA patients and Mondini patients (P = 0.0003). There was a correlation between phenotypic complexity of inner ear malformations and genetic heterogeneity--PS patients have the most severe phenotype and the most homogeneous etiology while EVA patients have the least severe phenotype and the most heterogeneous etiology. For all patients, variability in the degree of hearing loss is seen across genotypes implicating other genetic and/or environmental factors in the pathogenesis of the PS-Mondini-EVA disease spectrum.

Screening of the USH1G Gene among Spanish Patients with Usher Syndrome. Lack of Mutations and Evidence of a Minor Role in the Pathogenesis of the Syndrome

The Usher syndrome (USH) is an autosomal recessive hereditary disorder characterized by the association of sensorineural hearing loss, retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. The USH1G gene, encoding SANS, has been found to cause both Usher syndrome type I and atypical Usher syndrome. 109 Spanish unrelated patients suffering from Usher syndrome type I, type II, type III and unclassified Usher syndrome were screened for mutations in this gene, but only eight different changes without a clear pathogenic effect have been detected. Based on these results as well as previous studies in other populations where mutational analysis of this gene has been carried out, one can conclude that USH1G has a minor involvement in Usher syndrome pathogenesis.

Données moléculaires du syndrome de Usher

Usher syndrome (USH) is an autosomal recessive disorder characterized by the association of sensorineural hearing loss and retinitis pigmentosa (RP). Usher syndrome is both clinically and genetically heterogeneous. Three clinical subtypes are defined with respect to vestibular dysfunction and the degree of hearing loss. Type I (USH1) patients have profound hearing loss and vestibular dysfunction from birth. Type II (USH2) is the most frequent and patients tend to have less severe hearing impairment and normal vestibular response. Type III (USH3) is characterized by a progressive loss of hearing and is found more frequently among Finnish patients. Recently, major breakthroughs have been made in the molecular genetics of Usher syndrome as a number of chromosomal loci and causative genes have been identified in each clinical subtype. Twelve loci are known and the corresponding genes have been cloned for six of them. Although their functions are not always clearly established, a common role is emerging for the proteins identified within each subtype. As a result, each subtype could emanate from defects affecting distinct cellular mechanisms.

Potassium ion recycling pathway via gap junction systems in the mammalian cochlea and its interruption in hereditary nonsyndromic deafness.

In the mammalian cochlea, there are two independent gap junction systems, the epithelial cell gap junction system and the connective tissue cell gap junction system. Thus far, four different connexin molecules, including connexin 26, 30, 31, and 43, have been reported in the cochlea. The two networks of gap junctions form the route by which K+ ions that pass through the sensory cells during mechanosensory transduction can be recycled back to the endolymphatic space, from which they reenter the sensory cells. Activation of hair cells by acoustic stimuli induces influx of K+ ions from the endolymph to sensory hair cells. These K+ ions are released basolaterally to the extracellular space of the organ of Corti, from which they enter the cochlear supporting cells. Once inside the supporting cells they move via the epithelial cell gap junction system laterally to the lower part of the spiral ligament. The K+ ions are released into the extracellular space of the spiral ligament by root cells and taken up by type II fibrocytes. This uptake incorporates K+ into the connective tissue gap junction system. Within this system, the K+ ions pass through the tight junctional barrier of the stria vascularis and are released within the intrastrial extracellular space. The marginal cells of the stria vascularis then take up K+ and return it to the endolymphatic space, where it can be used again in sensory transduction. It is highly probable that mutations of connexin genes that result in human nonsyndromic deafness cause dysfunction of cochlear gap junctions and thereby interrupt K+ ion recirculation pathways. In addition to connexin mutations, other conditions may disrupt gap junctions within the ear. For example, mice with a functionally significant mutation of Brain-4, which is expressed in the connective tissue cells within the cochlea, show marked depression of the endolymphatic potential and profound sensorineural hearing loss. It seems likely that disruption of connective tissue cells by this mutation disrupts K+ ion entry into the stria vascularis and thereby results in loss of endolymphatic potential. The association of sensorineural hearing loss with these genetic disorders provides strong evidence for the necessity of gap junction systems for the normal functioning of the cochlea.