The Genetics of Cholesteatoma Study. Loss-of-function variants in an affected family.

The aetiology of cholesteatoma remains elusive. In a recent systematic review, we discussed reports of multiple cases of cholesteatoma within families, which suggests a genetic predisposition in some cases (1). We have established a U.K. database and DNA sample bank that can be used to identify genetic variants that co-segregate with cholesteatoma in multiply-affected families. Recruitment to this Genetics of Cholesteatoma (GOC) Study is via the U.K. National Institute of Health Research Clinical Research Network. This preliminary communication describes the results of whole exome sequencing (WES) of DNA extracted from participants in the first fully sequenced family recruited to the study. Rare variants were filtered for co-segregation with the cholesteatoma phenotype, and for their putative functional impact. We have identified loss of function variants in the genes EGFL8 and BTNL9 as candidate variants of interest. These are preliminary observations and the variants are of unknown significance to the disease pathology without replication or further investigation. This article is protected by copyright. All rights reserved.