A Meniere's disease gene linked to chromosome 12p12.3

An Update on the Epidemiology and Clinicodemographic Features of Meniere's Disease

OBJECTIVE

To characterize the estimated prevalence and clinicodemographic features of Ménière's disease (MD) using current diagnostic criteria.

METHODS

A cross-sectional study was undertaken at our tertiary academic referral center. All patients seen in Otolaryngology clinic with ICD-10 diagnoses of MD, from January 1, 2013 to July 31, 2022 were identified. Chart review was undertaken to determine the estimated prevalence of MD meeting AAO-HNS diagnostic criteria. Clinicodemographic features were evaluated against a comparator group without MD seen in our health system.

RESULTS

Of 806 ICD-10 diagnoses of MD, we identified 480 MD cases meeting diagnostic criteria (168 definite). Mean age at presentation for MD cases was 49 years. Forty-seven percent of cases were male. A significantly higher proportion of MD cases than comparators were white (76% vs. 66%, p < 0.001). Mean time since MD symptom onset was 6.7 years, with a mean attack duration of 4.6 h; 7.5% of MD cases reported a positive family history, and 7% had bilateral disease. The odds of reporting migraine were significantly greater among MD patients than comparators (OR 1.74 [1.26-2.42]); the odds of having autoimmune conditions were lower (OR 0.45 [0.28-0.74]); and the odds of reporting allergies were no different (OR 0.96 [0.74-1.25]) versus comparator patients after controlling for demographic characteristics.

CONCLUSIONS

Among MD diagnoses, there is a low estimated prevalence of MD meeting diagnostic criteria, and an even lower prevalence of definite MD. Compared to a comparator group of patients seen for any disorder, patients with MD are more likely to be white, male, and have a history of migraine.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3310-3315, 2024.

The genomic landscape of Ménière's disease: a path to endolymphatic hydrops

BACKGROUND

Ménière's disease (MD) is a disorder of the inner ear that causes episodic bouts of severe dizziness, roaring tinnitus, and fluctuating hearing loss. To date, no targeted therapy exists. As such, we have undertaken a large whole genome sequencing study on carefully phenotyped unilateral MD patients with the goal of gene/pathway discovery and a move towards targeted intervention. This study was a retrospective review of patients with a history of Ménière's disease. Genomic DNA, acquired from saliva samples, was purified and subjected to whole genome sequencing.

RESULTS

Stringent variant calling, performed on 511 samples passing quality checks, followed by gene-based filtering by recurrence and proximity in molecular interaction networks, led to 481 high priority MD genes. These high priority genes, including MPHOSPH8, MYO18A, TRIOBP, OTOGL, TNC, and MYO6, were previously implicated in hearing loss, balance, and cochlear function, and were significantly enriched in common variant studies of hearing loss. Validation in an independent MD cohort confirmed 82 recurrent genes. Pathway analysis pointed to cell-cell adhesion, extracellular matrix, and cellular energy maintenance as key mediators of MD. Furthermore, the MD-prioritized genes were highly expressed in human inner ear hair cells and dark/vestibular cells, and were differentially expressed in a mouse model of hearing loss.

CONCLUSION

By enabling the development of model systems that may lead to targeted therapies and MD screening panels, the genes and variants identified in this study will inform diagnosis and treatment of MD.

Genetic advances in Meniere Disease

Meniere Disease (MD) is an idiopathic inner ear disease with complex etiology and pathogenesis, which is still unclear. With the development in gene analysis technology, the genetic research of MD has attracted extensive attention, resulting in a large number of studies on the research of the relationship between human genes and MD. This paper aims to review the studies on this topic in recent years. The studies mainly focused on the genetics of familial MD and the correlation between MD and potentially related functional genes. The results of these studies have demonstrated the complexity and diversity of the pathogenesis of MD with both genetic and epigenetic alterations, suggesting that MD might be related to inflammation, immunity, aqua and ion balance in the lymphatic fluid, virus infection, metabolism, and abnormal function of nerve conduction. The finding of rare mutations in TECTA, MYO7A and OTOG genes and other genes such as CDH23, PCDH15 and ADGRV1 in the same families suggest that the integrity of the stereocilia and their interaction with the tectorial and otolithic membranes could be involved in the pathophysiology of familial MD.

New Genetic Variants in CYP2B6 and SLC6A Support the Role of Oxidative Stress in Familial Ménière’s Disease

The objective was to study the genetic etiology of Ménière’s disease (MD) using next-generation sequencing in three families with three cases of MD. Whole exome sequencing was used to identify rare genetic variants co-segregating with MD in Finnish families. In silico estimations and population databases were used to estimate the frequency and pathogenicity of the variants. Variants were validated and genotyped from additional family members using capillary sequencing. A geneMANIA analysis was conducted to investigate the functional pathways and protein interactions of candidate genes. Seven rare variants were identified to co-segregate with MD in the three families: one variant in the CYP2B6 gene in family I, one variant in GUSB and EPB42 in family II, and one variant in each of the SLC6A, ASPM, KNTC1, and OVCH1 genes in family III. Four of these genes were linked to the same co-expression network with previous familial MD candidate genes. Dysfunction of CYP2B6 and SLC6A could predispose to MD via the oxidative stress pathway. Identification of ASPM and KNTC1 as candidate genes for MD suggests dysregulation of mitotic spindle formation in familial MD. The genetic etiology of familial MD is heterogenic. Our findings suggest a role for genes acting on oxidative stress and mitotic spindle formation in MD but also highlight the genetic complexity of MD.

Cytokines and Inflammation in Meniere Disease

Meniere disease (MD) is a rare set of conditions associated with the accumulation of endolymph in the cochlear duct and the vestibular labyrinth with a decrease of endocochlear potential. It is considered a chronic inflammatory disorder of the inner ear with a multifactorial origin. The clinical syndrome includes several groups of patients with a core phenotype: sensorineural hearing loss, episodes of vertigo, and tinnitus with a non-predictable course. Genetic factors and the innate immune response seem to play a central role in the pathophysiology of the condition. Autoimmune MD should be diagnosed if a patient fulfills the diagnostic criteria for MD and one of the following autoimmune disorders: autoimmune thyroid disease, psoriasis, autoimmune arthritis, ankylosing spondylitis, or systemic lupus erythematosus. We summarize the evidence to support autoimmune MD as an endophenotype in bilateral MD associated with the allelic variant rs4947296 and nuclear factor-kappa B (NF-κB)-mediated inflammation, the role of cytokines (particularly interleukin-1β and tumor necrosis factor-α) in defining a subset of patients with autoinflammation, and the potential role of cytokines as biomarkers to distinguish between patients with MD and vestibular migraine. Finally, we also introduce a list of potential drugs that could regulate the immune response in MD with potential for repurposing in clinical trials.

Burden of Rare Variants in the OTOG Gene in Familial Meniere's Disease

OBJECTIVES

Meniere's disease (MD) is a rare inner ear disorder characterized by sensorineural hearing loss, episodic vertigo, and tinnitus. Familial MD has been reported in 6 to 9% of sporadic cases, and few genes including FAM136A, DTNA, PRKCB, SEMA3D, and DPT have been involved in single families, suggesting genetic heterogeneity. In this study, the authors recruited 46 families with MD to search for relevant candidate genes for hearing loss in familial MD.

DESIGN

Exome sequencing data from MD patients were analyzed to search for rare variants in hearing loss genes in a case-control study. A total of 109 patients with MD (73 familial cases and 36 early-onset sporadic patients) diagnosed according to the diagnostic criteria defined by the Barany Society were recruited in 11 hospitals. The allelic frequencies of rare variants in hearing loss genes were calculated in individuals with familial MD. A single rare variant analysis and a gene burden analysis (GBA) were conducted in the dataset selecting 1 patient from each family. Allelic frequencies from European and Spanish reference datasets were used as controls.

RESULTS

A total of 5136 single-nucleotide variants in hearing loss genes were considered for single rare variant analysis in familial MD cases, but only 1 heterozygous likely pathogenic variant in the OTOG gene (rs552304627) was found in 2 unrelated families. The gene burden analysis found an enrichment of rare missense variants in the OTOG gene in familial MD. So, 15 of 46 families (33%) showed at least 1 rare missense variant in the OTOG gene, suggesting a key role in familial MD.

CONCLUSIONS

The authors found an enrichment of multiplex rare missense variants in the OTOG gene in familial MD. This finding supports OTOG as a relevant gene in familial MD and set the groundwork for genetic testing in MD.

Systematic Review of Sequencing Studies and Gene Expression Profiling in Familial Meniere Disease

Familial Meniere Disease (FMD) is a rare inner ear disorder characterized by episodic vertigo associated with sensorineural hearing loss, tinnitus and/or aural fullness. We conducted a systematic review to find sequencing studies segregating rare variants in FMD to obtain evidence to support candidate genes for MD. After evaluating the quality of the retrieved records, eight studies were selected to carry out a quantitative synthesis. These articles described 20 single nucleotide variants (SNVs) in 11 genes (FAM136A, DTNA, PRKCB, COCH, DPT, SEMA3D, STRC, HMX2, TMEM55B, OTOG and LSAMP), most of them in singular families-the exception being the OTOG gene. Furthermore, we analyzed the pathogenicity of each SNV and compared its allelic frequency with reference datasets to evaluate its role in the pathogenesis of FMD. By retrieving gene expression data in these genes from different databases, we could classify them according to their gene expression in neural or inner ear tissues. Finally, we evaluated the pattern of inheritance to conclude which genes show an autosomal dominant (AD) or autosomal recessive (AR) inheritance in FMD.

Rare Variants of Putative Candidate Genes Associated With Sporadic Meniere's Disease in East Asian Population

Objectives: The cause of Meniere's disease (MD) is unclear but likely involves genetic and environmental factors. The aim of this study was to investigate the genetic basis underlying MD by screening putative candidate genes for MD.

Methods: Sixty-eight patients who met the diagnostic criteria for MD of the Barany Society were included. We performed targeted gene sequencing using next generation sequencing (NGS) panel composed of 45 MD-associated genes. We identified the rare variants causing non-synonymous amino acid changes, stop codons, and insertions/deletions in the coding regions, and excluded the common variants with minor allele frequency >0.01 in public databases. The pathogenicity of the identified variants was analyzed by various predictive tools and protein structural modeling.

Results: The average read depth for the targeted regions was 1446.3-fold, and 99.4% of the targeted regions were covered by 20 or more reads, achieving the high quality of the sequencing. After variant filtering, annotation, and interpretation, we identified a total of 15 rare heterozygous variants in 12 (17.6%) sporadic patients. Among them, four variants were detected in familial MD genes (DTNA, FAM136A, DPT), and the remaining 11 in MD-associated genes (PTPN22, NFKB1, CXCL10, TLR2, MTHFR, SLC44A2, NOS3, NOTCH2). Three patients had the variants in two or more genes. All variants were not detected in our healthy controls (n = 100). No significant differences were observed between patients with and without a genetic variant in terms of sex, mean age of onset, bilaterality, the type of MD, and hearing threshold at diagnosis.

Conclusions: Our study identified rare variants of putative candidate genes in some of MD patients. The genes were related to the formation of inner ear structures, the immune-associated process, or systemic hemostasis derangement, suggesting the multiple genetic predispositions in the development of MD.

The Polymorphic Analysis of the Human Potassium Channel KCNE Gene Family in Meniere's Disease-A Preliminary Study

OBJECTIVES

To investigate the correlation between KCNE gene family and Meniere's disease (MD) in the Chinese population.

MATERIALS AND METHODS

This study analyzed the single-nucleotide polymorphism (SNP) of KCNE1 and KCNE3 genes between the MD group and the control group and between the familial Meniere's disease (FMD) group and the sporadic Meniere's disease (SMD) group.

RESULTS

A total of 653 C/T SNPs of KCNE1 had a statistical difference between the FMD and SMD groups (p=0.0082<0.05); 492 A/C SNPs of KCNE3 were statistically different between the FMD group and the control group (genotype p=0.037<0.05 and allele p=0.006<0.05).

CONCLUSION

SNPs of KCNE1 and KCNE3 gene mutations were, respectively, different between the SMD and FMD groups. KCNE3 gene polymorphism was key to FMD disease, whereas KCNE1 was more important to the onset of SMD.

Whole-exome sequencing suggests multiallelic inheritance for childhood-onset Ménière's disease

The genetic background of Ménière's disease (MD) was studied in one patient with childhood-onset MD and his grandfather affected with middle age-onset MD. Whole-exome sequencing was performed and the data were compared to 76 exomes from unrelated subjects without MD. Thirteen rare inner ear expressed variants with pathogenic estimations were observed in the case of childhood-onset MD. These variants were in genes involved in the formation of cell membranes or the cytoskeleton and in genes participating in cell death or gene-regulation pathways. His grandfather shared two of the variants: p.Y273N in HMX2 and p.L229F in TMEM55B. HMX2 p.Y273N was considered the more likely candidate for MD, as the gene is known to affect both hearing and vestibular function. The variant in the HMX2 gene may affect inner ear development and structural integrity and thus might predispose to the onset of MD. As there was a significant difference in onset between the patients, an accumulation of defects in several pathways is probably responsible for the exceptionally early onset of the disease, and the genetic etiology of childhood-onset MD is most likely multifactorial. This is the first molecular genetic study of childhood-onset MD.

Update on Vertigo in Autoimmune Disorders, from Diagnosis to Treatment

The prevalence of autoimmune diseases has been increasing over the last 20 years. The clinical presentation of this large and heterogeneous group of disorders depends on whether the involvement is organ-specific or non-organ-specific. Dizziness, vertigo, and disequilibrium are common symptoms reported by patients with vestibulocochlear involvement. The association of vertigo and autoimmune diseases has been largely documented, suggesting that autoimmune disorders could be overrepresented in patients with vertigo in comparison to the general population. The aim of this review is to present the recent literature findings in the field of autoimmune-mediated diseases with cochleovestibular involvement, focusing on the clinical presentation, diagnosis, and treatment of immune-mediated inner ear diseases including autoimmune inner ear disease (AIED), Meniere's disease, and bilateral vestibulopathy, as well as of systemic autoimmune diseases with audiovestibular disorders, namely, Behçet's disease, Cogan's syndrome, sarcoidosis, autoimmune thyroid disease, Vogt-Koyanagi-Harada syndrome, relapsing polychondritis, systemic lupus erythematosus, antiphospholipid syndrome, IgG4-related disease, and ANCA-associated vasculitides.

The aetiopathologies of Ménière's disease: a contemporary review

Ménière's disease, a condition first described in the 1800's, has been an advancing area of clinical interest and scientific research in recent decades. Guidelines published by the American Academy of Otolaryngology - Head and Neck Surgery remained nearly static for almost 20 years, although we have certainly expanded our knowledge of the aetiology of the disease since that time. This review of the literature highlights the breadth and detail of the current theories in understanding the pathophysiology of this enigmatic disease. Histopathological specimens providing evidence of many of the aetiologies are presented as well. We aim to provide a centralised and updated resource regarding current and emerging theories for Ménière's disease.

Meniere's Disease and Vestibular Migraine: Updates and Review of the Literature

The diagnosis of Meniere's disease (MD) and vestibular migraine (VM) is primarily based on clinical criteria and their differentiation is often difficult. Currently, there are no known definitive diagnostic tests that can reliably distinguish the two conditions. Patients with MD and patients with VM are treated differently, therefore improving the diagnosis of these two pathologies should avoid errors in management. A systematic review was conducted according to PRISMA guidelines. Medline-Ovid and Embase databases were used to conduct a thorough search of English-language publications dating from 1948 to March 2016. The primary search objective was to identify all papers explicitly comparing MD and VM in order to clarify and validate the diagnosis of these two diseases. A total of 13 articles out of 831 were reviewed. Among other differences, MD showed later age of onset, more hearing loss, tinnitus, aural fullness, abnormal nystagmus, abnormal caloric testing results, abnormal vestibular evoked myogenic potential and endolymphatic hydrops. VM showed more headaches, photophobia, vomiting and aura. Even though differences were noted between the two diseases, only one study focused on assessing the differences between VM, MD and patients fulfilling both diagnostic criteria (MDVM). This study showed no difference between the three groups. Since the introduction of the new International Headache Society and Barany Society criteria for VM, no studies have focused on comparing these three groups. We strongly encourage authors to focus on comparing MD and VM from MDVM in future studies to help adequately distinguish the diagnosis of both diseases.

A pipeline combining multiple strategies for prioritizing heterozygous variants for the identification of candidate genes in exome datasets

BACKGROUND

The identification of disease-causing variants in autosomal dominant diseases using exome-sequencing data remains a difficult task in small pedigrees. We combined several strategies to improve filtering and prioritizing of heterozygous variants using exome-sequencing datasets in familial Meniere disease: an in-house Pathogenic Variant (PAVAR) score, the Variant Annotation Analysis and Search Tool (VAAST-Phevor), Exomiser-v2, CADD, and FATHMM. We also validated the method by a benchmarking procedure including causal mutations in synthetic exome datasets.

RESULTS

PAVAR and VAAST were able to select the same sets of candidate variants independently of the studied disease. In contrast, Exomiser V2 and VAAST-Phevor had a variable correlation depending on the phenotypic information available for the disease on each family. Nevertheless, all the selected diseases ranked a limited number of concordant variants in the top 10 ranking, using the three systems or other combined algorithm such as CADD or FATHMM. Benchmarking analyses confirmed that the combination of systems with different approaches improves the prediction of candidate variants compared with the use of a single method. The overall efficiency of combined tools ranges between 68 and 71% in the top 10 ranked variants.

CONCLUSIONS

Our pipeline prioritizes a short list of heterozygous variants in exome datasets based on the top 10 concordant variants combining multiple systems.

Variants in the KCNE1 or KCNE3 gene and risk of Ménière's disease: A meta-analysis

BACKGROUND

Ménière's disease (MD) is defined as an idiopathic disorder of the inner ear characterized by the triad of tinnitus, vertigo, and sensorineural hearing loss. Although many studies have evaluated the association between variants in the KCNE1 or KCNE3 gene and MD risk, debates still exist.

OBJECTIVE

Our aim is to evaluate the association between KCNE gene variants, including KCNE1 rs1805127 and KCNE3 rs2270676, and the risk of MD by a systematic review.

METHODS

We searched the literature in PubMed, SCOPUS and EMBASE through May 2015. We calculated pooled odds ratios (OR) and 95% confidence intervals (CIs) using a fixed-effects model or a random-effects model for the risk to MD associated with different KCNE gene variants. The heterogeneity assumption decided the effect model.

RESULTS

A total of three relevant studies, with 302 MD cases and 515 controls, were included in this meta-analysis. The results indicated that neither the KCNE1 rs1805127 variant (for G vs. A: OR = 0.724, 95%CI 0.320, 1.638, P= 0.438), nor the KCNE3 rs2270676 variant (for T vs. C: OR = 0.714, 95%CI 0.327, 1.559, P = 0.398) was associated with MD risk.

CONCLUSIONS

Based on current evidence from published studies, neither of the two variants from KCNE was significantly associated with the risk of MD. Larger studies with mixed ethnicity subjects and stratified by clinical and sub-clinical characteristics are needed to validate our findings.

Genetics of vestibular disorders: pathophysiological insights

The two most common vestibular disorders are motion sickness and vestibular migraine, affecting 30 and 1–2 % of the population respectively. Both are related to migraine and show a familial trend. Bilateral vestibular hypofunction is a rare condition, and some of patients also present cerebellar ataxia and neuropathy. We present recent advances in the genetics of vestibular disorders with familial aggregation. The clinical heterogeneity observed in different relatives of the same families suggests a variable penetrance and the interaction of several genes in each family. Some Mendelian sensorineural hearing loss also exhibits vestibular dysfunction, including DFNA9, DFNA11, DFNA15 and DFNA28. However, the most relevant finding during the past years is the familial clustering observed in Meniere’s disease. By using whole exome sequencing and combining bioinformatics tools, novel variants in DTNA and FAM136A genes have been identified in familial Meniere’s disease, and this genomic strategy will facilitate the discovery of the genetic basis of familial vestibular disorders.

Menière's disease

Menière's disease (MD) is a chronic multifactorial disorder of the inner ear characterized by episodic vestibular symptoms associated with sensorineural hearing loss, tinnitus, and aural pressure. Epidemiologic and genomic evidence supports a genetic susceptibility with multiple biochemical pathways involved, including the endocrine system, innate immune response, and autonomic nervous system. Allergens, infectious agents, vascular events, or genetic factors could modify inner-ear homeostasis and trigger MD. The diagnosis of MD is based on clinical criteria and requires the observation of an episodic vertigo syndrome associated with low- to medium-frequency sensorineural hearing loss and fluctuating aural symptoms (hearing loss, tinnitus, and/or fullness) in the affected ear. Headache is also found during the attacks and bilateral involvement is found in 25-40% of cases. Audiologic and vestibular assessment is recommended to monitor the clinical course. The treatment of MD is symptomatic to obtain relief of vestibular episodes and preventive to limit hearing loss progression. Treatment options include sodium restriction, betahistine, intratympanic gentamicin, or steroids and eventually surgery, such as cochlear implantation.

Genetic aspects and clinical characteristics of familial Meniere's disease in a South Korean population

OBJECTIVES/HYPOTHESIS

This study was undertaken to investigate the prevalence, inheritance patterns, and clinical characteristics of familial Meniere's disease (MD) in a South Korean population.

STUDY DESIGN

Direct interviews, telephone interviews, and reviews of the medical records of definite Meniere's disease patients and their families.

METHODS

Direct and telephone interviews were performed for 286 definite MD patients and their family members who were suspected of having MD. The diagnosis of MD in family members was made by obtaining a detailed history, performing basic neurotological examinations and reviewing hearing test results. The clinical characteristics as well as the prevalence and inheritance patterns of familial MD were analyzed.

RESULTS

The prevalence of familial Meniere-like syndrome (at least one family member with definite MD and other members with probable MD) and definite familial MD (two or more family members with definite Meniere's disease) were 9.8% and 6.3%, respectively, and the most common inheritance pattern was autosomal dominant with incomplete penetrance. The significant clinical characteristics of familial cases were an early disease onset and a higher prevalence of migraines.

CONCLUSIONS

This is the first report describing the genetic aspects of MD in a single large Asian population. The prevalence of definite familial MD was 6.3% with an incomplete autosomal dominant inheritance pattern in most cases. Early-onset age and a high prevalence of migraines were significant clinical features of familial MD in this South Korean population. These data could provide a basis for the analysis of the genetic mechanism of familial MD in Asian populations.

LEVEL OF EVIDENCE

4.

The genetics of Ménière's disease

Our understanding of the genetic basis of Ménière’s disease (MD) is still limited. Although the familial clustering and the geographical and racial differences in incidence strongly suggest a certain role for genetic factors in the development of MD, no convincing evidence for an association with any gene exists, at present. In this review, starting from rational bases for a genetic approach to MD, we explored the numerous reports published in literature and summarize the recent advances in understanding of the genetic fundaments of the disease.

Identification of two novel mutations in FAM136A and DTNA genes in autosomal-dominant familial Meniere's disease

Meniere's disease (MD) is a chronic disorder of the inner ear defined by sensorineural hearing loss, tinnitus and episodic vertigo, and familial MD is observed in 5-15% of sporadic cases. Although its pathophysiology is largely unknown, studies in human temporal bones have found an accumulation of endolymph in the scala media of the cochlea. By whole-exome sequencing, we have identified two novel heterozygous single-nucleotide variants in FAM136A and DTNA genes, both in a Spanish family with three affected cases in consecutive generations, highly suggestive of autosomal-dominant inheritance. The nonsense mutation in the FAM136A gene leads to a stop codon that disrupts the FAM136A protein product. Sequencing revealed two mRNA transcripts of FAM136A in lymphoblasts from patients, which were confirmed by immunoblotting. Carriers of the FAM136A mutation showed a significant decrease in the expression level of both transcripts in lymphoblastoid cell lines. The missense mutation in the DTNA gene produces a novel splice site which skips exon 21 and leads to a shorter alternative transcript. We also demonstrated that FAM136A and DTNA proteins are expressed in the neurosensorial epithelium of the crista ampullaris of the rat by immunohistochemistry. While FAM136A encodes a mitochondrial protein with unknown function, DTNA encodes a cytoskeleton-interacting membrane protein involved in the formation and stability of synapses with a crucial role in the permeability of the blood-brain barrier. Neither of these genes has been described in patients with hearing loss, FAM136A and DTNA being candidate gene for familiar MD.

Sex-specific association of RANTES gene -403 variant in Meniere's disease

Several studies have shown the correlation between RANTES gene and inflammatory disorders; the aim of the present study was to investigate the association between RANTES promoter gene polymorphism and Meniere's disease (MD) in an Iranian population. In this study patients with MD comprising definite MD (N = 56) and probable MD (N = 15) were selected according to diagnostic criteria of AAO-HNS. The control group (N = 101) were healthy normal subjects who did not have a history of ear disease and vertigo. PCR-RFLP for RANTES -403G>A has been performed. We found a protective role for RANTES -403A allele in male group in our population. None of the male patients with MD were carrier of allele A which was significantly different from the presence of allele A in the male control group (AA+GA vs. GG: p = 0.0004, OR 0.05, 95 % CI 0.001-0.39). This difference was not significant in female group. There was no significant association between RANTES gene polymorphism and the level of hearing loss. our results showed a sex-specific association between RANTES gene polymorphism and MD but more studies are necessary to further assess this association.

High incidence of Meniere-like symptoms in relatives of Meniere patients in the areas of Oulu University Hospital and Kainuu Central Hospital in Finland

Objective of this study was to systematically investigate the family histories of a large set of patients affected with Meniere's disease to determine the prevalence of familial MD and Meniere-like symptoms in their families. All 640 patients treated at the Oulu University Hospital and Kainuu Central Hospitals during 2005-2010 for Meniere's disease were selected as the initial study population. A postal family history survey was sent to all subjects. Hospital records of all patients were studied to confirm diagnosis and sufficient differential diagnosis. All patients that revealed a positive family history of Meniere's disease or Meniere-like symptoms were phone interviewed and the probability of Meniere's disease in a relative was estimated on a three level scale: probable, possible or unlikely. Affected family members of the patients were recruited to the study if possible. Familial Meniere's disease could be confirmed in 9.3% of patients, but 32.7% patients reported Meniere-like symptoms in their family. It was not possible to confirm all cases, but a family history of Meniere's disease was convincing (confirmed or probable) in 23.4% of the patients. Genetic factors are significant in the development of Meniere's disease.

Genetic disorders of the vestibular system

PURPOSE OF REVIEW

This review highlights the current body of literature related to the genetics of inherited vestibular disorders and provides a framework for the characterization of these disorders. We emphasize peripheral causes of vestibular dysfunction and highlight recent advances in the field, point out gaps in understanding, and focus on key areas for future investigation.

RECENT FINDINGS

The discovery of a modifier gene that leads to a more severe Usher syndrome phenotype calls into question the assumption that Usher syndrome is universally a monogenic disorder. Despite the use of several investigational approaches, the genetic basis of Menière's disease remains poorly understood. Evidence for a vestibular phenotype associated with DFNB1 suggests that mutations in other genes causally related to nonsyndromic hearing loss also may have an unrecognized vestibular phenotype.

SUMMARY

Our understanding of the genetic basis for vestibular disorders is superficial. Significant challenges include defining the genetics of inherited isolated vestibular dysfunction and understanding the pathological basis of Menière's disease. However, improved characterization of inherited vestibular dysfunction, coupled with advanced genetic techniques such as targeted genome capture and massively parallel sequencing, provides an opportunity to investigate these diseases at the genetic level.

A replication study on proposed candidate genes in Ménière's disease, and a review of the current status of genetic studies

OBJECTIVE

Multiple candidate genes have been presented for Ménière's disease (MD), but to date no positive replications have been reported. We review here all the previously proposed candidate genes for MD and report our results on the analysis of six such genes, AQP2, KCNE1, KCNE3, HCFC1, COCH, and ADD1.

STUDY SAMPLE

A well-defined sample set of 38 sporadic and 21 familial Finnish MD patients.

DESIGN

Mutation analysis, case-control study, and review of literature.

RESULTS

A polymorphism rs1805127 in the potassium channel gene, KCNE1, was associated with MD in sporadic (p = 0.011), but not familial patients (p = 0.62). In addition, we identified four novel unique variations in the KCNE1 gene. PolyPhen and Mutation Taster analyses indicated that at least one of the variations c.259T > C; p.Trp87Arg is probably damaging to the coded protein.

CONCLUSIONS

Our review of the reported candidate genes shows that the current understanding of the genetic factors contributing to the development of MD is limited, and that the study of its etiology would benefit greatly from more comprehensive genetic knowledge.

Does Ménière's Disease in the Elderly Present Some Peculiar Features?

Object. Aim of our study was to establish some peculiar features of Ménière's Disease (MD) in a group of elderly MD patients, in which the first vertigo spell happened when over 65 years old. Material and Methods. We analyzed a group of 73 younger than 65-years-old and a group of 30 elderly MD patients. All patients underwent a neurotological evaluation, an anamnestic evaluation including a lifetime history of migraine, and blood withdrawal for autoantibody screening. Results. Some differences were found between elderly and younger MD patients. Elderly MD patients presented a higher prevalence of Tumarkin attacks and a lower prevalence of lifetime history of migraine; moreover, they presented a faster develop of hearing loss and vertigo spells than a subgroup of 32 younger patients matched for the duration of illness. Conclusions. Some clinical features of MD in elderly have been pointed out. Particularly, the lower rate of migrainous history and positivity for autoantibodies often associated with MD, in our opinion, support the hypothesis of a vascular disorder acting as a predisposing factor for MD in elderly.

The -1364A/C Aquaporin 5 Gene Promoter Polymorphism Is Not Associated with Menière's Disease

Objective. Aquaporin 5 plays an important role in maintaining inner ear water and fluid homeostasis. Since the aquaporin (AQP) 5 promoter-1364A/C polymorphism is associated with altered AQP5 expression and this could impact upon key mechanisms of Menière's disease, we tested the hypothesis that genotypes of the AQP5 promoter-1364A/C polymorphism are associated with the incidences of Menière's disease (MD), familial Menière's disease (FMD), or endolymphatic hydrops (EH). Methods. With approval of the local ethics committee, DNA of 102 patients (39 with MD, 54 with FMD, and 9 with EH) and of 292-matched Caucasian controls was isolated from blood samples and genotyped for the AQP 5 promoter-1364A/C polymorphism. The χ²-test was applied to compare genotype distributions and allele frequencies between patients and controls. Results. Overall, genotype frequencies were not different between controls (AA 69%, AC 30%, CC 1%) and patients with MD AA: 65.7% (23 MD, 37 FMD, and 8 EH); AC: 23.5% (12 MD, 11 FMD, and 1 EH); CC: 3.9% (1 MD, 3 FMD, and 0 EH). However, subgroup analysis revealed the CC genotype to be more frequent in patients with FMD (5.9%) than in healthy controls (1%) (P = 0.042). Conclusions. Overall, genotypes of the -1364A/C AQP5 gene polymorphism are not associated with a significant increased risk for Menière's disease.

Genetic aspects of familial Ménière's disease

OBJECTIVE

Ménière's disease (MD) is a chronic illness characterized by sensorineural hearing loss, recurring vertigo attacks, and tinnitus. It is possibly of multifactorial origin, although several families with autosomal dominant inheritance and reduced penetrance have been described. To elucidate the genetic basis of MD, patients and their families were investigated, and linkage analysis was performed.

STUDY DESIGN

Retrospective and prospective family survey.

PATIENTS AND METHODS

Of 193 patients diagnosed with MD, 37 patients could be ascertained as having a positive family history, which means a frequency of 19.2%. Nineteen families with 81 members (52 positive for MD and 29 negative for MD) were investigated according to the guidelines of the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology. Blood samples were obtained, and a genome-wide linkage analysis was performed with microsatellite markers.

RESULTS

Age of onset diminished in subsequent generations. We found suggestive evidence of linkage assuming heterogeneity of MD on chromosome 5 with a maximum multipoint logarithm of the odds of linkage (LOD) score of 1.9 for 13 of 17 families and a potential region on chromosome 12 for 8 families. Of the 81 subjects, 27 (33.3%) reported MD only, 25 (30.9%) reported migraine and MD, and 7 (8.6%) reported migraine only.

CONCLUSION

Family trees suggest an autosomal dominant inheritance with reduced penetrance and anticipation. A probable candidate region for MD was located on chromosome 5.

Genetics of recurrent vertigo and vestibular disorders

We present recent advances in the genetics of recurrent vertigo, including familial episodic ataxias, migraneous vertigo, bilateral vestibular hypofunction and Meniere's disease.Although several vestibular disorders are more common within families, the genetics of vestibulopathies is largely not known. Genetic loci and clinical features of familial episodic ataxias have been defined in linkage disequilibrium studies with mutations in neuronal genes KCNA1 and CACNA1A. Migrainous vertigo is a clinical disorder with a high comorbidity within families much more common in females with overlapping features with episodic ataxia and migraine. Bilateral vestibular hypofunction is a heterogeneous clinical group defined by episodes of vertigo leading to progressive loss of vestibular function which also can include migraine. Meniere's disease is a clinical syndrome characterized by spontaneous episodes of recurrent vertigo, sensorineural hearing loss, tinnitus and aural fullness and familial Meniere's disease in around 10-20% of cases. An international collaborative effort to define the clinical phenotype and recruiting patients with migrainous vertigo and Meniere's disease is ongoing for genome-wide association studies.

Finnish familial Meniere disease is not linked to chromosome 12p12.3, and anticipation and cosegregation with migraine are not common findings

PURPOSE

To study the inheritance and characteristics of familial Meniere disease in Finland and genetic linkage to the previously proposed locus on chromosome 12p12.3.

METHODS

Sixteen Meniere families recruited from Kainuu Central Hospital and Helsinki and Oulu University Hospitals in the period 2001-2004 were reevaluated in 2009 using hospital records and mailed questionnaire forms. Ten highly polymorphic microsatellite markers were selected from the area of chromosome 12p12.3 and studied for linkage using the GENEHUNTER protocol.

RESULTS

The families showed autosomal dominant inheritance without cosegregation with migraine. Anticipation was seen only in one family, and in the rest of the families, the age of onset varied randomly among generations and individuals. The severity of the disease was not related to descending generations. None of the maximum logarithm of odds (LOD)/heterogeneity LOD scores in the analysis of chromosome 12p12.3 in Finnish Meniere families reached a significant value of 3.0 (maximum cumulative LOD score: -7.29, heterogeneity LOD: -0.95, α = 0.4).

CONCLUSIONS

Families affected by Meniere disease are highly heterogeneous. Migraine, age at onset, anticipation, or penetrance was not a shared feature. The findings support the multifactorial nature of the disease and indicate that genetic heterogeneity exists within familial Meniere disease.

Genetic investigations of Meniere's disease

Meniere's disease remains a disorder of unknown origin despite the collective efforts to determine the pathogenesis, although experts have long recognized that disease development likely has some heritable component. Although genetic studies of Meniere's disease have been inconclusive, increasing knowledge of human genetic structure and mutation and investigative techniques have potential to further understanding of this disorder.

Familiar Meniere's disease restricted to 1.48 Mb on chromosome 12p12.3 by allelic and haplotype association

Meniere's disease (MD) is a disorder of the inner ear characterized by episodes of vertigo, tinnitus and fluctuating sensorineural hearing loss. Most MD cases are sporadic, but 5-15% of patients are familial following an autosomal dominant mode of inheritance with incomplete penetrance. We have previously identified a candidate gene region for MD on chromosome 12p12.3 using linkage analysis. We genotyped 15 Swedish families segregating familial MD (FMD) to further clarify the role of chromosome 12p in a larger cohort of families. Highly polymorphic marker loci were analyzed over the 16-Mb candidate region in affected and healthy family members as well as in control subjects. The results revealed allelic association between FMD and several individual polymorphic marker alleles and single-nucleotide polymorphisms. Moreover, a common three-marker haplotype spanning 1.48 Mb co-segregates with FMD in 60% of the families investigated, forming the core of a possible ancestral haplotype associated with FMD in Sweden.

Sequence variants in host cell factor C1 are associated with Ménière's disease

HYPOTHESIS

There is a genetic basis for the development of Ménière's (MD) disease.

BACKGROUND

The cause of MD is unknown, although many potential theories have been proposed. A genetic basis for the disease is suggested by greater prevalence in Caucasians and familial cases that display an autosomal dominant pattern of inheritance.

METHODS/DESIGN

Case-control association study of selected candidate genes among patients with MD and selected control individuals.

RESULTS

Several single-nucleotide polymorphisms (SNPs) within the host cell factor C1 (HCFCI) gene displayed a significant increase in prevalence of the major allele in subjects with MD disease. The most individually significant SNP is rs2266886. The minor allele at this site displays an odds ratio of 0.26 (95% confidence intervals, 0.010-0.65; p = 0.003) for disease development.

CONCLUSION

The minor allele at each SNP site was significantly more common in controls, suggesting that individuals bearing these alleles are at reduced risk of developing MD. The functional consequences of the SNPs in host cell factor C1 are unknown. A viable hypothesis for disease development is presented based on the known interaction between HCFC1 and the herpes simplex viral protein VP16.

Familial clustering of migraine, episodic vertigo, and Ménière's disease

OBJECTIVE

To evaluate the association between migraine, episodic vertigo, and Ménière's disease in families.

STUDY DESIGN

Clinical report.

SETTING

University Neurotology Clinic.

PATIENTS

Index patients identified with Ménière's disease and migraine and their family members.

INTERVENTION

Structured interview to assess a diagnosis of migraine, episodic vertigo, and Ménière's disease in 6 families. Genotyping was performed on 3 sets of twins to analyze monozygosity or dizygosity.

MAIN OUTCOME MEASURES

Clinical history of migraine, episodic vertigo, and Ménière's disease.

RESULTS

Six index patients and 57 family members were interviewed either by a senior neurologist in person or over the phone by a trained study coordinator. An additional 6 family members completed questionnaires by mail. All 6 index patients had Ménière's disease and migraine. Twenty-six (41%) of the 63 relatives met International Classification of Headache Disorders II criteria for migraine headaches. Thirteen (50%) of these 26 experienced migraine with aura. Three others experienced typical aura without headache. Seventeen (27%) of 63 family members experienced recurrent spells of spontaneous episodic vertigo. There was one twin pair in each of 3 families; 2 pairs were monozygotic and one was dizygotic. In each twin pair, one twin had migraine and Ménière's disease, whereas the other experienced migraine and episodic vertigo without auditory symptoms.

CONCLUSION

The frequent association of episodic vertigo, migraine, and Ménière's disease in closely related individuals, including identical twins supports the heritability of a migraine-Ménière's syndrome, with variable expression of the individual features of hearing loss, episodic vertigo, and migraine headaches.

Meniere’s disease: rare or underdiagnosed among Africans

Meniere's disease can easily be misdiagnosed because several otological disorders mimic the disease. Conflicting reports on the incidence of this disease among the Africans had been documented. The goal of our study was to verify the prevalence and clinical features of Meniere's disease in WA sub-region. A 10 year (1996-2005) retrospective study carried out in our hospital. The diagnostic criteria for the disease were outlined and Oyedeji's social classification instrument was adapted for socio-economic stratification of patients. The method of treatment and prognostic out-come were discussed. Out of 11,463 patients seen within the period, 25 (16 females and 9 males) met the diagnostic criteria for Meniere's disease. The age ranged from 27 to 75 years (mean=47.2 SD13.2) and the most predominant age group was 41-50 years. Sixty-eight percent were of low socio-economic class and the rest high. About 84% had unilateral and 16% bilateral Meniere's disease. All the patients presented with tinnitus, vertigo and audiologically confirmed sensorineural hearing loss. CT-scan and MRI were used to rule out some differentials, while caloric and recruitment tests were used to strengthen the diagnosis. Treatment regimen (conservative) outcome: 72% had good improvement, 8% fair, while 20% absconded from follow-up. The prevalence of Meniere's disease in West African sub-region is 0.22%. This prevalence among Africans may not differ from the Caucasians. Under- or over-diagnosis of the disease previously must have been responsible for the contrasting results. Appropriate diagnostic tools are necessary for accurate diagnosis of the disease.

Psychological Characteristics of Patients with Ménière's Disease Compared with Patients with Vertigo, Tinnitus, or Hearing Loss

An association between Ménierè's disease and psychological distress is frequently reported. Patients who do not have Ménière's disease but who have similar symptoms also experience various kinds of psychological disturbances. We conducted a study to investigate the relationship between Ménière's disease and personality traits, illness behavior, depression, and anxiety. We compared these factors in 77 patients who had Ménière's disease and 133 controls who did not have the disease but had one of its symptoms—either vertigo, tinnitus, or hearing loss. The mental status of study participants was assessed with standard tests. Patients in both groups had higher than normal levels of anxiety and neuroticism. The only significant difference between the two groups was a higher rate of extroversion in the Ménière's disease group. Minor differences emerged when Ménière's patients with tinnitus or vertigo were compared with similar controls. Relationships between psychological observations and otologic symptomatology or an otologic diagnosis were not specific, which illustrates the need to consider the role of illness behavior and personality as targets for psychological support or therapy associated with ENT treatment.