| description |
Otitis media is the most common disease diagnosed in children and if undertreated can lead to chronic otitis media with complications such as permanent hearing loss, meningitis and even death. The World Health Organisation recognises the health burden of otitis media as being equivalent to that of polio. It suggests that research emphasis should be placed on identifying the risk factors for otitis media. Mouse models of otitis media, such as the ENU-induced Jeff mutant have been used to identify genes like Fbxo11 that have subsequently been shown to predispose to otitis media in humans. The dearisch mouse mutant is also an ENU-induced mutant. It was identified as losing the Preyer reflex (ear flick in response to sound) by 5 months of age. Auditory Brainstem Responses however, reveal that mice display hearing loss from as early as three weeks of age. Pedigree analysis shows the threshold shift to be dominantly inherited with low penetrance. Middle ear dissections show mice with high ABR thresholds have white exudate and frequent incudomalleal fusion. Gross inner ear anatomy, round and oval window areas and the sensory hair cells all appear normal. Due to the low penetrance of the phenotype normal backcross mapping of the mutation has not been possible. Whole mouse exome sequencing is therefore being performed to identify the mutation. |