Cause Of Deafness Research Articles

Severe retinal degeneration at an early age in Usher syndrome type 1B associated with homozygous splice site mutations in MYO7A gene

PurposeUsher syndrome is the most common cause of deafness associated with visual loss of a genetic origin. The purpose of this paper is to report very severe phenotypic features of type 1B Usher syndrome in a Saudi family affected by positive homozygous splice site mutation in MYO7A gene. MethodsAffected siblings went through detailed history. Complete ophthalmic examination was done. Imaging with colour fundus photography, fundus autofluorescence (AF), and optical coherence tomography (OCT) scans was performed. Full field electroretinogram (ffERG) was recorded. Molecular genetic testing was done using next-generation sequencing. ResultsVisual acuity was more reduced (range 20/300–20/40) in older siblings (age>30 years), than in younger (age <30 years) siblings (range 20/70–20/25). OCT scans showed macular atrophy in all but one case that has cystoid macular edema (CME). AF demonstrated atrophy outside a small foveal area showing high signal. FfERG was flat in all cases. The homozygous splice site mutation c.470+1G>A in intron 5 of the MYO7A gene was detected in all affected siblings. ConclusionsThis mutation manifested with advanced retinal degeneration at a young age. This may have implications regarding future gene therapy in Usher syndrome cases with this genotype.

Long-term Outcomes of Cochlear Implantation in Children With Congenital Cytomegalovirus Infection.

To investigate the role of the developmental delay often observed in children with congenital cytomegalovirus (CMV) infection on the improvement of language understanding after cochlear implantation (CI). Retrospective chart review. Sixteen children with severe and/or profound hearing loss due to congenital CMV infection (CMV group) and 107 congenitally deaf children (168 ears) without CMV infection as the cause of deafness (non-CMV group). Mean age at which patients underwent CI was 2.9 years in both groups. The mean follow-up period was 7.8 versus 8.2 years, respectively. The Enjoji Scale of Infant Analytical Development was used to evaluate/compare pre- and postoperative hearing level, word recognition score, speech discrimination score, and language production and perception skills. The Picture Vocabulary Test-Revised was used to assess vocabulary understanding skill. Correlation between the final vocabulary understanding skill assessment and several factors was also examined. Improvement in hearing thresholds (mean: 106.0 dB) was greater after the first CI, (27-45 dB; mean: 33.8 dB) compared with hearing aid (48-74 dB; mean: 63.1 dB). Similarly, language perception and production were better in the CMV group. However, in the long term, differences between good and poor cases became prominent, especially in children with motor or cognitive delay and brain abnormalities who performed poorly in the CMV group. Long-term language perception and production after CI were overall satisfactory in congenital CMV-deafened children. CI was effective, particularly in the absence of CMV-induced disorders. However, this effectiveness was limited in those with motor or cognitive delay.

Understanding Etiology of Hearing Loss as a Contributor to Language Dysfluency and its Impact on Assessment and Treatment of People who are Deaf in Mental Health Settings.

Working with individuals who are deaf in mental health settings can be complex work, necessitating consideration for the difference in language abilities. These differences include not only the language differences of American Sign Language (ASL) and English, but also the range of heterogeneity within the Deaf Community. Multiple influences such as mental illness, medical conditions, language deprivation and the etiology of deafness can impact how a person acquires and uses language. This article will discuss how various causes of deafness create the potential for specific language dysfluencies with individuals who are deaf in mental health settings. The article will also discuss the use of communication assessments to examine specific language dysfluency patterns and attempt to offer possible corresponding interventions.

GJB2 and GJB6 genes mutations in children with non-syndromic hearing loss

Abstract Introduction. At the moment there is not enough data in Romania about the incidence of the main genetic mutations which can cause hearing loss. Objective. The current research aims to determine on a representative sample the prevalence of two mutations of genes GJB2 -c.35delG and p.W24X- and two mutations of genes GJB6 -del(GJB6-D13S1830), del(GJB6-D13S1854) respectively - in patients with congenital nonsyndromic sensorineural hearing loss (CNSHL). Methods: The sample group included 179 children with CNSHL. The evaluation consist in: a.Clinical, laboratory and imagistic examination; b.ENT exam and audiological evaluation. c.Two methods (semi-nested PCR technique followed by RFLP, validated with ARMS-PCR analysis) for detection of c.35delG and pW24X mutations; d.PCR-multiplex technique for detecting del(GJB6-D13S1830) and del (GJB6-D13S1854). Results: The audiological diagnosis was: profound hearing loss in 116 patients (64.8%), severe hearing loss in 29 children (16.2%) and moderate hearing loss in 34 patients (representing 19% of the trial patients). The prevalence for the three mutations was: 27.3 % for c.35delG, 3.6 % for p.W24X and 0.28% for del(GJB6-D13S1830). The detection of the three mutations (two on GJB2 gene and one on GJB 6 gene) has allowed to establish the genetic cause for deafness in 45 patients, representing 25.14% of the sample group. Our study is reporting the first case in Romania with a mutation of gene GJB6. Mutation del(GJB6-D13S1854) lacked in all 179 patients. Conclusion: The prevalence data obtained in the current research are comparable to data communicated by studies from other European countries.

A novel missense mutation in the SLC26A4 gene causes nonsyndromic hearing loss and enlarged vestibular aqueduct

ObjectivesWe aimed to investigate the genetic causes of hearing loss in a Chinese proband with nonsyndromic hearing loss and enlarged vestibular aqueduct syndrome. MethodsWe conducted clinical and genetic evaluations in a deaf proband and his normal-hearing parents. Multiplex PCR technology combined with Ion Torrent™ next-generation sequencing technology was used to detect the pathogenic mutations. As a control, a group of 1500 previously studied healthy newborns from the same ethnic background were subjected to deafness gene screening using the same method as in our previous study. ResultsThe proband harbored two mutations in the SLC26A4 gene in the form of compound heterozygosity. He was found to be heterozygous for a novel mutation named c.1742 G > T (p.Arg581Met) in exon 13 and for the known mutation c.589 G > A (p.Gly197Arg). These variants were carried in the heterozygous state by the parents and therefore co-segregated with the genetic disease. The c.1742 G > T (p.Arg581Met) mutation was absent in 1500 healthy newborns. Protein alignment indicated high evolutionary conservation of the p.R581 residue, and this mutation was predicted by PolyPhen-2 and other online tools to be damaging. ConclusionThis study demonstrates that the novel mutation c.1742 G > T (p.Arg581Met) in compound heterozygosity with c.589 G > A in the SLC26A4 gene is the main cause of deafness in a family clinically diagnosed with enlarged vestibular aqueduct (EVA). Our study will provide a basic foundation for further investigations to elucidate the SLC26A4-related mechanisms of hearing loss.

Mutation Analysis of the Common Deafness Genes in Patients with Nonsyndromic Hearing Loss in Republic of Macedonia

Abstract Hearing impairment is the most common sensory disorder, which occurs in 1 of 1000 newborns. It is caused by heterogeneous conditions with more than a half due to genetic etiology. Although hundreds of genes are implicated in hearing process and have been found to be associated with nonsyndromic hearing loss, pathogenic variants in GJB2 gene have been considered as the main cause of deafness among nonsyndromic hearing loss (NSHL) population worldwide. Pathogenic variants in MT-RNR1 or mtDNA12SrRNA gene were also implicated predominantly in postlingual progresive deafness. The aim of this study was to analyze the implication of GJB2 and MT-RNR1 genes in the molecular etiology of deafness among 130 NSHL patients in the Republic of Macedonia. The presence of the del (GJB6-D13S1830) was also analysed. We performed SSCP and/or sequence analysis of GJB2 and identified sequence variants in 62 out of 130 patients (47.7%); (51 homozygous or compound heterozygous and 11 with only one variant allele). We found 8 different allelic variants, the most prevalent being c.35delG (65.49%), and p.W24*(23.01%), followed by other less frequent alleles (p.V27I, p.V37I, p. P175T and cd. delE120 or delGAG at 360). In addition, two polymorphic substitutions in the GJB2 gene with no clinical significance (p.V153I and p.R127H) were detected. No del(GJB6-D13S1830) was found. SNaPshot analysis was used to screen for the five most frequent allelic variants in the MT-RNR1 gene. Two MT-RNR1 mutations (A827G and T961G) were detected in three patients where only one GJB2 pathogenic variant was found. A new MT-RNR1 gene variant G1303A was also detected. In conclusion, MT-RNR1 mutations were not a significant contributor to the etiology of deafness in Macedonia, although could be considered as a modifier gene affecting the expression of deafness in patients carrying one GJB2 variant. On the other hand, the high percenttage of GJB2 pathogenic variants identified among NSHL cases indicates the necessity of molecular newborn screening for the two most common GJB2 variants (c.35delG and p.W24*) in the Republic of Macedonia.

The diagnostic impact generated by the presence of Cytomegalovirus IgM antibodies in pregnancy

Background: Cytomegalovirus (CMV) infection is one of the most common congenital infections and the most frequent cause of mental retardation and non-genetically cause of deafness. The risk of fetal transmission is above 40%. The objectives of this study were to review and improve the CMV diagnosis in pregnancy. Method: 50 pregnant women took part in the study. They were taken in evidence at the virology counseling office. The reason for the need of viral diagnosis came from the fact that the result of previous routine serological testing came out positive for CMV IgM antibodies (Ab). Based on the test result, the gynecologist may normally indicate the termination of the pregnancy. Results: In the virology counseling office the results for CMV IgM Ab test turn out negative in 48 of the 50 (96%) referred pregnant women. In two women CMV IgM Ab test turn out positive. These women also tested positive for CMV IgG Ab test. The pregnant women were also tested for pp65 antigenemia. They presented a four times raise in CMV IgG Ab titer. All the rest were negative for pp65 antigemenia. Conclusion: From the 50 women only two needed to terminate their pregnancies. It is important to test for CMV infection in pregnancy along with other viral, bacterial or parasitic infections, but the indication of pregnancy termination must be taken only after a thorough examination and testing. It would be helpful if CMV tests, as well as all the TORCH tests were supported by the health insurance system.

Establishing ancestry through pedigree of a village with high prevalence of hearing-impaired

Introduction: Population-based surveys into the cause of deafness have consistently shown that a high percentage (50%) of childhood deafness can be attributed to genetic causes. The flip side to genetic testing in population surveys is the operational difficulties associated with carrying it out. The present study was therefore planned with the aim of establishing ancestry through pedigree of a village with high prevalence of hearing-impaired. Materials and Methods: A two-stage study design was used to conduct this study. The first stage involved a house-to-house survey to identify hearing-impaired whereas the second stage involved clinical examination for hearing impairment. Results: Of a total of 2522 individuals studied, 80 were identified as hearing-impaired yielding a crude prevalence of 3.17%. The pedigree analysis of the whole village revealed a common ancestry. Discussion: In the late 20th century, deaf-mutism became a subject of debate and social isolation for Dadhkai villagers. A highlight of Dadhkai has been that its surroundings are not deaf-friendly as is expected. Consequently, as intermarriage flourished, the village community increasingly started resembling each other. This could have led to increase in autosomal recessive inheritance of deafness. Similar studies such as evaluation of six patients from two generations from a large sibship of Turkish ethnicity with double consanguinity in the family support the evidence. Conclusion: Flourishing of intermarriage and thereby consanguinity may be the reason behind high number of hearing impaired in this village. Therefore population based genetic counseling may be the key to prevent the same in future.

Aetiological Diagnosis of Child Deafness: CODEPEH Recommendations

Important progress in the fields of molecular genetics (principally) and diagnostic imaging, together with the lack of a consensus protocol for guiding the diagnostic process after confirming deafness by neonatal screening, have led to this new work document drafted by the Spanish Commission for the Early Detection of Child Deafness (Spanish acronym: CODEPEH). This 2015 Recommendations Document, which is based on the most recent scientific evidence, provides guidance to professionals to support them in making decisions regarding aetiological diagnosis. Such diagnosis should be performed without delay and without impeding early intervention. Early identification of the causes of deafness offers many advantages: it prevents unnecessary trouble for the families, reduces health system expenses caused by performing different tests, and provides prognostic information that may guide therapeutic actions.

Testing for Cytomegalovirus in Pregnancy.

Congenital cytomegalovirus (CMV) infection represents a relevant cause of deafness and neurological damage in newborns. Intrauterine CMV transmission might result after primary or nonprimary infections, though at different rates (30% versus 0.2%, respectively). At present, a prenatal diagnosis of CMV infection is based mainly on maternal serology, the detection of CMV-DNA in amniotic fluid and fetal blood, and ultrasound (US) and magnetic resonance imaging (MRI). Recent evidences suggest that congenital CMV infection may be an immune-mediated disease and that evaluation of humoral and especially T-cell immunities may improve the overall prenatal diagnosis. This review summarizes the most recent advancements in the diagnosis of maternal and prenatal CMV infections.

Molecular etiology and genotype-phenotype correlation of Chinese Han deaf patients with type I and type II Waardenburg Syndrome

Waardenburg syndrome (WS) characterized by sensorineural hearing loss and pigmentary abnormalities is genetically heterogeneous and phenotypically variable. This study investigated the molecular etiology and genotype-phenotype correlation of WS in 36 Chinese Han deaf probands and 16 additional family members that were clinically diagnosed with WS type I (WS1, n = 8) and type II (WS2, n = 42). Mutation screening of six WS-associated genes detected PAX3 mutations in 6 (86%) of the 7 WS1 probands. Among the 29 WS2 probands, 13 (45%) and 10 (34%) were identified with SOX10 and MITF mutations, respectively. Nineteen of the 26 detected mutations were novel. In WS2 probands whose parental DNA samples were available, de novo mutations were frequently seen for SOX10 mutations (7/8) but not for MITF mutations (0/5, P = 0.005). Excessive freckle, a common feature of WS2 in Chinese Hans, was frequent in WS2 probands with MITF mutations (7/10) but not in those with SOX10 mutations (0/13, P = 4.9 × 10−4). Our results showed that mutations in SOX10 and MITF are two major causes for deafness associated with WS2. These two subtypes of WS2 can be distinguished by the high de novo rate of the SOX10 mutations and the excessive freckle phenotype exclusively associated with the MITF mutations.

Diagnóstico etiológico de la sordera infantil: recomendaciones de la CODEPEH

Important progress in the fields of molecular genetics (principally) and diagnostic imaging, together with the lack of a consensus protocol for guiding the diagnostic process after confirming deafness by neonatal screening, have led to this new work document drafted by the Spanish Commission for the Early Detection of Child Deafness (Spanish acronym: CODEPEH). This 2015 Recommendations Document, which is based on the most recent scientific evidence, provides guidance to professionals to support them in making decisions regarding aetiological diagnosis. Such diagnosis should be performed without delay and without impeding early intervention. Early identification of the causes of deafness offers many advantages: it prevents unnecessary trouble for the families, reduces health system expenses caused by performing different tests, and provides prognostic information that may guide therapeutic actions.

Diphtheria Toxin-Induced Cell Death Triggers Wnt-Dependent Hair Cell Regeneration in Neonatal Mice.

Cochlear hair cells (HCs), the sensory cells that respond to sound, do not regenerate after damage in adult mammals, and their loss is a major cause of deafness. Here we show that HC regeneration in newborn mouse ears occurred spontaneously when the original cells were ablated by treatment with diphtheria toxin (DT) in ears that had been engineered to overexpress the DT receptor, but was not detectable when HCs were ablated in vivo by the aminoglycoside antibiotic neomycin. A variety of Wnts (Wnt1, Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt7b, Wnt9a, Wnt9b, and Wnt11) and Wnt pathway component Krm2 were upregulated after DT damage. Nuclear β-catenin was upregulated in HCs and supporting cells of the DT-damaged cochlea. Pharmacological inhibition of Wnt decreased spontaneous regeneration, confirming a role of Wnt signaling in HC regeneration. Inhibition of Notch signaling further potentiated supporting cell proliferation and HC differentiation that occurred spontaneously. The absence of new HCs in the neomycin ears was correlated to less robust Wnt pathway activation, but the ears subjected to neomycin treatment nonetheless showed increased cell division and HC differentiation after subsequent forced upregulation of β-catenin. These studies suggest, first, that Wnt signaling plays a key role in regeneration, and, second, that the outcome of a regenerative response to damage in the newborn cochlea is determined by reaching a threshold level of Wnt signaling rather than its complete absence or presence. Sensory HCs of the inner ear do not regenerate in the adult, and their loss is a major cause of deafness. We found that HCs regenerated spontaneously in the newborn mouse after diphtheria toxin (DT)-induced, but not neomycin-induced, HC death. Regeneration depended on activation of Wnt signaling, and regeneration in DT-treated ears correlated to a higher level of Wnt activation than occurred in nonregenerating neomycin-treated ears. This is significant because insufficient regeneration caused by a failure to reach a threshold level of signaling, if true in the adult, has the potential to be exploited for development of clinical approaches for the treatment of deafness caused by HC loss.

Effects of genetic correction on the differentiation of hair cell-like cells from iPSCs with MYO15A mutation.

Deafness or hearing loss is a major issue in human health. Inner ear hair cells are the main sensory receptors responsible for hearing. Defects in hair cells are one of the major causes of deafness. A combination of induced pluripotent stem cell (iPSC) technology with genome-editing technology may provide an attractive cell-based strategy to regenerate hair cells and treat hereditary deafness in humans. Here, we report the generation of iPSCs from members of a Chinese family carrying MYO15A c.4642G>A and c.8374G>A mutations and the induction of hair cell-like cells from those iPSCs. The compound heterozygous MYO15A mutations resulted in abnormal morphology and dysfunction of the derived hair cell-like cells. We used a CRISPR/Cas9 approach to genetically correct the MYO15A mutation in the iPSCs and rescued the morphology and function of the derived hair cell-like cells. Our data demonstrate the feasibility of generating inner ear hair cells from human iPSCs and the functional rescue of gene mutation-based deafness by using genetic correction.

Factors that influence outcomes in cochlear implantation in adults, based on patient-related characteristics - a retrospective study.

Outcomes in speech perception following cochlear implantation in adults vary widely. Many studies have been carried out to identify and quantify factors that influence outcomes. This study adds a new dimension to pre-existing literature. Single-centre retrospective cohort study. University Medical Center Utrecht, the Netherlands. A total of 428 adults with bilateral severe-to-profound sensorineural hearing loss, unilaterally implanted between February 1988 and March 2014. Univariable and multivariable linear regression analyses were carried out to identify factors that may influence outcome after cochlear implantation. Consonant-vowel-consonant word scores were recorded pre- and post-implant and were used as outcome measure in two groups of patients (prelingually and postlingually deafened adults). As an added dimension, multiple imputation was implemented and evaluated to tackle 4% (17/407) missing data. For postlinguals, pre-implant speech perception score and age at onset of deafness are positive predictors and meningitis and otosclerosis as cause of deafness are negative predictors of post-implant speech perception. This model accounted for 26% of variance. For prelinguals, pre-implant speech perception score is the only strong positive predictor (β 0.524; P < 0.001). This model accounted for 31% of variance. Age at implantation was not a significant predictor in either group. Speech perception is predicted by pre-implant speech perception, age at onset of deafness and aetiology (meningitis and otosclerosis) for postlinguals and solely pre-implant speech perception for prelinguals. Age at implantation is of lesser importance in predicting speech perception outcome post-implant. Multiple imputation is a useful statistical technique when analysing incomplete data sets.

A Twelve Months Follow-Up: Influence Of Origin and Duration of Hearing-Loss on Tnrts after Cochlear Implantation

Introduction: People with profound sensorineural hearing loss benefit from cochlear implantation. Nevertheless there are discrepancies as far as signal processing and hearing results are concerned. The large variety of patients in terms of age, cause and duration of deafness is one explanation. Neural response telemetry (tNRT) gives information about the function of the hearing nerve and the device. Previous studies couldn`t exactly show evident correlations between NRTs and cause or length of hearing-loss. Aim of the present study was the re-evaluation of tNRTs in a 12 months follow-up as a function of duration and reason of deafness. Patients and methods: 168 patients (82 female, 86 male) implanted at the department between 2008 and 2013 with an implant of Cochlear® were included into the study. 71 patients received a CI512 and 52 patients a CI24RE device, while 45 patients were supplied with the slim straight electrode array CI422. tNRTs were measured at each of the 22 electrodes intraoperatively, after 6 and after 12 months. Results: tNRT-values showed a reduction of tNRT-values over parts of the monitored period. Patients with Meniere`s disease showed slightly higher values but the differences regarding the cause of deafness weren`t significant. Implant recipients with a mean time of hearing loss or a mean time of hearing aid supply showed a tendency of lower tNRTs. However the results weren’t significant. Conclusion: Within the first six months after CI implantation tNRTs decreased significantly. Patients with Meniere's disease showed decent higher tNRTs. Patients with a period of deafness longer than two years presented lower tNRT thresholds. Participants with a mean time hearing aid supply prior CI surgery also provided a trend towards lower tNRTs. The impact of tNRTs on residual hearing in dependence of different shaped electrode arrays as well as the effect on speech perception should be focused in upcoming studies.

Reduction of Cellular Expression Levels Is a Common Feature of Functionally Affected Pendrin (SLC26A4) Protein Variants.

Sequence alterations in the pendrin gene (SLC26A4) leading to functionally affected protein variants are frequently involved in the pathogenesis of syndromic and nonsyndromic deafness. Considering the high number of SLC26A4 sequence alterations reported to date, discriminating between functionally affected and unaffected pendrin protein variants is essential in contributing to determine the genetic cause of deafness in a given patient. In addition, identifying molecular features common to the functionally affected protein variants can be extremely useful to design future molecule-directed therapeutic approaches. Here we show the functional and molecular characterization of six previously uncharacterized pendrin protein variants found in a cohort of 58 Brazilian deaf patients. Two variants (p.T193I and p.L445W) were undetectable in the plasma membrane, completely retained in the endoplasmic reticulum and showed no transport function; four (p.P142L, p.G149R, p.C282Y and p.Q413R) showed reduced function and significant, although heterogeneous, expression levels in the plasma membrane. Importantly, total expression levels of all of the functionally affected protein variants were significantly reduced with respect to the wild-type and a fully functional variant (p.R776C), regardless of their subcellular localization. Interestingly, reduction of expression may also reduce the transport activity of variants with an intrinsic gain of function (p.Q413R). As reduction of overall cellular abundance was identified as a common molecular feature of pendrin variants with affected function, the identification of strategies to prevent reduction in expression levels may represent a crucial step of potential future therapeutic interventions aimed at restoring the transport activity of dysfunctional pendrin variants.

Prevalence of 35de1G/GJB2 and del (GJB6-D13S1830) mutations in patients with non-syndromic deafness from a population of Espírito Santo - Brazil

Mutations in GJB2 gene are the leading cause of deafness in autosomal recessive inheritance, and the 35delG mutation is the most common in many ethnic groups. Besides the 35delG mutation in homozygosis, the mutation is also found in compound heterozygosis, coupled with other mutations in genes GJB2 and GJB6. AimTo determine the prevalence of 35delG/GJB2 and del (GJB6-D13S1830) mutations in patients with sensorineural hearing impairment in residents from the Espirito Santo state, Brazil. Materials and methods77 unrelated individuals with moderate to profound sensorineural hearing loss were evaluated. The 35delG mutation was studied by PCR / RFLP; and the del (GJB6-D13S1830) mutation was screened by the technique of multiplex PCR. Results88.3% had normal genotype for the studied mutations, 1.3% were compound heterozygotes, 3.9% homozygotic for the 35delG mutation, 6.5% heterozygotic for 35delG/GJB2. The frequency of 35delG/GJB2 and del (D13S1830/GJB6) alleles in the sample was 7.8% and 0.65%, respectively. ConclusionThe data confirmed the existence of the mutations studied in cases of sensorineural hearing loss in a population from Espírito Santo / Brazil. These findings reinforce the importance of genetic diagnosis, which can provide early treatment for children and genetic counseling for the affected families.

A Mayan founder mutation is a common cause of deafness in Guatemala.

Over 5% of the world's population has varying degrees of hearing loss. Mutations in GJB2 are the most common cause of autosomal recessive non-syndromic hearing loss (ARNHL) in many populations. The frequency and type of mutations are influenced by ethnicity. Guatemala is a multi-ethnic country with four major populations: Maya, Ladino, Xinca, and Garifuna. To determine the mutation profile of GJB2 in a ARNHL population from Guatemala, we sequenced both exons of GJB2 in 133 unrelated families. A total of six pathogenic variants were detected. The most frequent pathogenic variant is c.131G>A (p.Trp44*) detected in 21 of 266 alleles. We show that c.131G>A is associated with a conserved haplotype in Guatemala suggesting a single founder. The majority of Mayan population lives in the west region of the country from where all c.131G>A carriers originated. Further analysis of genome-wide variation of individuals carrying the c.131G>A mutation compared with those of Native American, European, and African populations shows a close match with the Mayan population.

Pepsinogen Assay as a Marker of Reflux in Children with Otitis Media with Effusion

Background: Otitis media with effusion remains the most common cause of deafness in childhood. Reflux of gastric contents into the nasopharynx and then into the middle ear cleft has been reported as a contributing factor in the development of OME. Objective: To investigate the relationship between gastro esophageal reflux diseases (GERD) and Otitis media with effusion (OME) by evaluation of the presence of gastric pepsinogen in middle ear fluid of children with OME. Materials and Methods: In this prospective study, middle ear effusions as well as blood samples were collected from 25 patients suffering from OME and undergoing bilateral myringotomy with ventilation tube insertion. Total pepsinogen concentrations of effusions and serum samples were measured with an enzyme-linked immuno sorbent assay (ELISA) using Human Pepsinogen I ELISA Kit. Results: 64% (16 cases) of the study sample (25 children) were found with pepsinogen in the middle ear effusions while 36% (9 cases) were not found to have pepsinogen in the middle ear. The concentrations of pepsinogen measured in the effusions were found to be higher than the levels found in the serum of the same patients as detected in each case separately. Conclusion: GERD should be considered one of the contributing factors in the etiopathogenesis of OME.