Rare and low-frequency variants in families with otitis media

Otitis media is a highly frequent diagnosis in children that causes significant morbidity but remains understudied as a genetic trait despite significant heritability in families. To identify rare or low-frequency variants within genes that confer susceptibility to otitis media, exome sequence data of 287 individuals from 243 families were analyzed. Identified variants were tested for co-segregation with otitis media in family members. Genome sequence data from a case-control cohort was imputed and analyzed for association of specific genes with otitis media. Single-cell RNA-sequence data of identified genes were noted in acutely infected mouse middle ears. Thirty-three variants within 24 genes co-segregated with otitis media in 28 families, of which 18 variants were considered pathogenic or likely pathogenic. An additional 81 variants in 21 of the same genes were identified in 83 unrelated probands with otitis media. Of the 24 genes, 12 were associated with otitis media in mouse models, while 15 genes were replicated from previous human studies. A common variant EYA4 c.829G > A was associated with OM in the case-control cohort. Using network analysis, 22 of the 24 genes were connected in a subnetwork enriched in various signaling pathways, Th1/Th2/Th17 cell differentiation, and viral infections. Majority (87.5%) of the identified genes were expressed in mouse middle ear cells, with differential expression after acute infection. The identification of novel genes and variants for susceptibility to otitis media will be useful in future risk screening and clinical management in children that require a more personalized approach due to poor response to standard treatments. KEY MESSAGES: Thirty-three variants in 24 genes were identified in 28 families with otitis media. Eighteen of these variants within 10 genes were considered (likely) pathogenic. A common variant EYA4 c.829G > A was associated with OM in a case-control cohort. The novel genes were differentially expressed in mouse middle ear post-infection. Genetic screening could identify children for targeted treatment for otitis media.