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Otitis media (OM) is common in young children and can cause hearing loss and speech, language, and developmental delays. OM has high heritability; however, little is known about OM-related molecular and genetic processes. CDHR3 was previously identified as a locus for OM susceptibility, but to date, studies have focused on how the CDHR3 p.Cys529Tyr variant increases epithelial binding of rhinovirus-C and risk for lung or sinus pathology. In order to further delineate a role for CDHR3 in OM, we performed the following: exome sequencing using DNA samples from OM-affected individuals from 257 multi-ethnic families; Sanger sequencing, logistic regression and transmission disequilibrium tests for 407 US trios or probands with OM; 16S rRNA sequencing and analysis for middle ear and nasopharyngeal samples; and single-cell RNA sequencing and differential expression analyses for mouse middle ear. From exome sequence data, we identified a novel pathogenic CDHR3 splice variant that co-segregates with OM in US and Finnish families. Additionally, a frameshift and six missense rare or low-frequency variants were identified in Finnish probands. In US probands, the CDHR3 p.Cys529Tyr variant was associated with the absence of middle ear fluid at surgery and also with increased relative abundance of Lysobacter in the nasopharynx and Streptomyces in the middle ear. Consistent with published data on airway epithelial cells and our RNA-sequence data from human middle ear tissues, Cdhr3 expression is restricted to ciliated epithelial cells of the middle ear and is downregulated after acute OM. Overall, these findings suggest a critical role for CDHR3 in OM susceptibility. KEY MESSAGES: • Novel rare or low-frequency CDHR3 variants putatively confer risk for otitis media. • Pathogenic variant CDHR3 c.1653 + 3G > A was found in nine families with otitis media. • CDHR3 p.Cys529Tyr was associated with lack of effusion and bacterial otopathogens. • Cdhr3 expression was limited to ciliated epithelial cells in mouse middle ear. • Cdhr3 was downregulated 3 h after infection of mouse middle ear., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Otitis media (OM) susceptibility has significant heritability; however, the role of rare variants in OM is mostly unknown. Our goal is to identify novel rare variants that confer OM susceptibility., Methods: We performed exome and Sanger sequencing of >1000 DNA samples from 551 multiethnic families with OM and unrelated individuals, RNA-sequencing and microbiome sequencing and analyses of swabs from the outer ear, middle ear, nasopharynx and oral cavity. We also examined protein localisation and gene expression in infected and healthy middle ear tissues., Results: A large, intermarried pedigree that includes 81 OM-affected and 53 unaffected individuals cosegregates two known rare A2ML1 variants, a common FUT2 variant and a rare, novel pathogenic variant c.1682A>G (p.Glu561Gly) within SPINK5 (LOD=4.09). Carriage of the SPINK5 missense variant resulted in increased relative abundance of Microbacteriaceae in the middle ear, along with occurrence of Microbacteriaceae in the outer ear and oral cavity but not the nasopharynx. Eight additional novel SPINK5 variants were identified in 12 families and individuals with OM. A role for SPINK5 in OM susceptibility is further supported by lower RNA counts in variant carriers, strong SPINK5 localisation in outer ear skin, faint localisation to middle ear mucosa and eardrum and increased SPINK5 expression in human cholesteatoma., Conclusion: SPINK5 variants confer susceptibility to non-syndromic OM. These variants potentially contribute to middle ear pathology through breakdown of mucosal and epithelial barriers, immunodeficiency such as poor vaccination response, alteration of head and neck microbiota and facilitation of entry of opportunistic pathogens into the middle ear., Competing Interests: Competing interests: AR is a cofounder of, shareholder in and uncompensated consultant to Otonomy, Inc, a relationship that was approved by the University of California San Diego., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Otitis media (OM), a very common disease in young children, can result in hearing loss. In order to potentially replicate previously reported associations between OM and PLG, exome and Sanger sequencing, RNA-sequencing of saliva and middle ear samples, 16S rRNA sequencing, molecular modeling, and statistical analyses including transmission disequilibrium tests (TDT) were performed in a multi-ethnic cohort of 718 families and simplex cases with OM. We identified four rare PLG variants c.112A > G (p.Lys38Glu), c.782G > A (p.Arg261His), c.1481C > T (p.Ala494Val) and c.2045 T > A (p.Ile682Asn), and one common variant c.1414G > A (p.Asp472Asn). However TDT analyses for these PLG variants did not demonstrate association with OM in 314 families. Additionally PLG expression is very low or absent in normal or diseased middle ear in mouse and human, and salivary expression and microbial α-diversity were non-significant in c.1414G > A (p.Asp472Asn) carriers. Based on molecular modeling, the novel rare variants particularly c.782G > A (p.Arg261His) and c.2045 T > A (p.Ile682Asn) were predicted to affect protein structure. Exploration of other potential disease mechanisms will help elucidate how PLG contributes to OM susceptibility in humans. Our results underline the importance of following up findings from genome-wide association through replication studies, preferably using multi-omic datasets.

A genetic basis for otitis media is established, however, the role of rare variants in disease etiology is largely unknown. Previously a duplication variant within A2ML1 was identified as a significant risk factor for otitis media in an indigenous Filipino population and in US children. In this report exome and Sanger sequencing was performed using DNA samples from the indigenous Filipino population, Filipino cochlear implantees, US probands, Finnish, and Pakistani families with otitis media. Sixteen novel, damaging A2ML1 variants identified in otitis media patients were rare or low-frequency in population-matched controls. In the indigenous population, both gingivitis and A2ML1 variants including the known duplication variant and the novel splice variant c.4061 + 1 G>C were independently associated with otitis media. Sequencing of salivary RNA samples from indigenous Filipinos demonstrated lower A2ML1 expression according to the carriage of A2ML1 variants. Sequencing of additional salivary RNA samples from US patients with otitis media revealed differentially expressed genes that are highly correlated with A2ML1 expression levels. In particular, RND3 is upregulated in both A2ML1 variant carriers and high-A2ML1 expressors. These findings support a role for A2ML1 in keratinocyte differentiation within the middle ear as part of otitis media pathology and the potential application of ROCK inhibition in otitis media., (© 2019 Wiley Periodicals, Inc.)

Background: Predisposition to childhood otitis media (OM) has a strong genetic component, with polymorphisms in innate immunity genes suspected to contribute to risk. Studies on several genes have been conducted, but most associations have failed to replicate in independent cohorts., Methods: We investigated 53 gene polymorphisms in a Finnish cohort of 624 cases and 778 controls. A positive association signal was followed up in a tagging approach and tested in an independent Finnish cohort of 205 cases, in a British cohort of 1269 trios, as well as in two cohorts from the United States (US); one with 403 families and the other with 100 cases and 104 controls., Results: In the initial Finnish cohort, the SNP rs5030717 in the TLR4 gene region showed significant association (OR 1.33, P = .003) to OM. Tagging SNP analysis of the gene found rs1329060 (OR 1.33, P = .002) and rs1329057 (OR 1.29, P = .003) also to be associated. In the more severe phenotype the association was stronger. This finding was supported by an independent Finnish case cohort, but the associations failed to replicate in the British and US cohorts. In studies on TLR4 signaling in 20 study subjects, the three-marker risk haplotype correlated with a decreased TNFα secretion in myeloid dendritic cells., Conclusions: The TLR4 gene locus, regulating the innate immune response, influences the genetic predisposition to childhood OM in a subpopulation of patients. Environmental factors likely modulate the genetic components contributing to the risk of OM.

Otitis media is one of the most common childhood infections leading to doctor's visits and a leading cause of antibiotic prescriptions in children. Twin and family studies have confirmed that the predisposition of developing a bacterial middle ear infection is genetically determined. Several case-control studies have been performed to analyze genes involved in inflammatory processes in search of potential associations. Modern genome-wide association approaches that require no prior assumptions of the involvement of a given gene locus in the risk of otitis media are currently being used to identify otitis media genes, and will hopefully give more detailed information on the pathogenesis of childhood otitis media. That information could be used in finding the high-risk patient, in the prevention of the disease, and in the design of new treatments.

Objective: Otitis media is a multifactorial disease where genetic background may have an important role. For genome-wide association studies, it is important to understand the degree of heritability. The objective of this study was to estimate the heritability of recurrent acute otitis media and chronic otitis media with effusion., Methods: Children operated because of recurrent or chronic otitis media at the Helsinki University Central Hospital, Finland, as well as their families were recruited during 2008-2009. A cohort of 2436 subjects was enrolled consisting of 1279 children and their parents. The study subjects answered a questionnaire concerning their otitis media history and treatment, as well as tobacco exposure, allergy and asthma history. Heritability estimates were calculated for recurrent acute, chronic and any episodes of otitis media using software especially designed for estimating heritability in family cohorts., Results: Altogether 901 subjects suffered from recurrent otitis media and 559 from chronic otitis media with effusion. The heritability estimates in our cohort were 38.5% for recurrent (P=7.3 × 10(-9)), 22.1% for chronic (P=4.6 × 10(-3)) and 47.8% for any otitis media (P=1.5 × 10(-11))., Conclusions: Our results demonstrate a moderately strong and statistically significant genetic component for both recurrent acute otitis media and chronic otitis media with effusion. These results highlight the importance of unraveling the genetic factors for otitis media that are still poorly known., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective: Exposure to environmental tobacco smoke has been reported to be a risk factor for childhood otitis media. The effect of parental smoking on the risk of otitis media after the insertion of tympanostomy tubes is unknown. We evaluated the effect of parental smoking on the risk of recurrent otitis media in children who had received tympanostomy tubes., Methods: We enrolled 217 children aged 1-4 years who underwent insertion of tympanostomy tubes because of middle ear disease. The children were followed-up for 12 months. Otitis media episodes were recorded in patient diaries by primary care physicians. Parental smoking habits were assessed by a questionnaire at the start of the trial and after the 12 month follow-up had ended. The main outcome measure was risk of recurrent otitis media as defined by four or more otitis media episodes after tympanostomy. Altogether 198 children completed the follow-up., Results: Maternal smoking was associated with a highly increased risk of recurrent acute otitis media (OR 4.15, 95% CI 1.45-11.9) after the insertion of tympanostomy tubes., Conclusion: Exposure to passive smoking is associated with four-fold risk of recurrent otitis media after tympanostomy. This finding should be used to encourage parents to stop smoking even after the insertion of tympanostomy tubes to their children.

Objective: To evaluate the efficacy of adenoidectomy in reducing the incidence of otitis media among children who are younger than 4 years and receive tympanostomy tubes., Methods: A randomized trial was conducted at a tertiary center clinic. A total of 217 children who were aged 12 to 48 months and had recurrent acute otitis media (>3 episodes during the past 6 months) or chronic otitis media with effusion, no obstructive symptoms as a result of adenoid enlargement, and no previous surgical intervention were enrolled in the study. Adenoidectomy in conjunction with the insertion of tympanostomy tubes or insertion of tympanostomy tubes without adenoidectomy was studied. The number of otitis media episodes during the follow-up period of 12 months was measured., Results: During the follow-up, the mean number of otitis media episodes was 1.7 among children who underwent adenoidectomy with concurrent insertion of tympanostomy tubes and 1.4 among children who received tympanostomy tubes only. The risk for recurrent otitis media (>or=3 episodes) could not be reduced by adenoidectomy (odds ratio: 1.66; 95% confidence interval: 0.80-3.46)., Conclusion: Adenoidectomy does not significantly reduce the incidence of acute otitis media in otitis prone children who are younger than 4 years and receive tympanostomy tubes.

Objectives: To test the effect of adenoidectomy in connection with tympanostomy compared with tympanostomy only in preventing otitis media in children younger than 2 years., Design: Prospective trial with randomized and nonrandomized arms., Setting: Primary care study clinics., Participants and Interventions: The study participants were selected from 2497 children who had been enrolled in the Finnish Otitis Media Vaccine Trial at the age of 2 months. A total of 306 children, aged 1 to 2 years, who had experienced recurrent episodes of otitis media were randomized into 2 treatment groups: tympanostomy with or without adenoidectomy. Of the 306 children, 137 were operated on according to random basis (randomized trial). The 169 children whose parents declined participation in the randomized trial were operated on according to the parents' preferences (nonrandomized trial). All children were followed up until 2 years of age. The mean follow-up time was 7 months., Main Outcome Measure: The rate of acute otitis media episodes., Results: The average reduction in the rate of all acute otitis media episodes in the adenoidectomy group was 19% (95% confidence interval [CI], -14% to 43%) among children enrolled in the randomized trial and 25% (95% CI, -13% to 50%) in the nonrandomized trial. The reduction in the randomized trial was mainly due to reduction in the rate of pneumococcal otitis media (58%, 95% CI, 16%-79%)., Conclusion: In children younger than 2 years, concurrent adenoidectomy during the insertion of tympanostomy tubes does not seem to have a major advantage over the insertion of tympanostomy tubes alone in preventing otitis media.

Objectives: To test the effect of adenoidectomy in connection with tympanostomy compared with tympanostomy only in preventing otitis media in children younger than 2 years. Design: Prospective trial with randomized and nonrandomized arms. Setting: Primary care study clinics. Participants and Interventions: The study participants were selected from 2497 children who had been enrolled in the Finnish Otitis Media Vaccine Trial at the age of 2 months. A total of 306 children, aged 1 to 2 years, who had experienced recurrent episodes of otitis media were randomized into 2 treatment groups: tympanostomy with or without adenoidectomy. Of the 306 children, 137 were operated on according to random basis (randomized trial). The 169 children whose parents declined participation in the randomized trial were operated on according to the parents' preferences (nonrandomized trial). All children were followed up until 2 years of age. The mean follow-up time was 7 months. Main Outcome Measure: The rate of acute otitis media episodes. Results: The average reduction in the rate of all acute otitis media episodes in the adenoidectomy group was 19% (95% confidence interval [CI], -14% to 43%) among children enrolled in the randomized trial and 25% (95% CI, -13% to 50%) in the nonrandomized trial. The reduction in the randomized tidal was mainly due to reduction in the rate of pneumococcal otitis media (58%, 95% CI, 16%-79%). Conclusion: In children younger than 2 years, concurrent adenoidectomy during the insertion of tympanostomy tubes does not seem to have a major advantage over the insertion of tympanostomy tubes alone in preventing otitis media. [ABSTRACT FROM AUTHOR]

Aim: To determine if there is an association between ABO variants or blood types and otitis media. Methods: DNA samples from 214 probands from Finnish families with recurrent acute (RAOM) and/or chronic otitis media with effusion (COME) were submitted for exome sequencing. Fisher exact tests were performed when (a) comparing frequencies of ABO genotypes in the Finnish probands with otitis media vs. counts in gnomAD Finnish, and (b) within the Finnish family cohort, comparing occurrence of RAOM vs. COME according to ABO genotype/haplotype and predicted blood type. Results: Female sex is protective against having both RAOM and COME. The wildtype genotype for the ABO c.260insG (p.Val87_Thr88fs*) variant resulting in blood type O was protective against RAOM. On the other hand, type A was associated with increased risk for COME. These findings remained significant after adjustment for age and sex. Conclusions: Within the Finnish family cohort, the wildtype genotype for the ABO c.260insG (p.Val87_Thr88fs*) variant and type O are protective against RAOM while type A increases risk for COME. This suggests that the association between the ABO locus and otitis media is specific to blood type, otitis media type and cohort. [ABSTRACT FROM AUTHOR]