Genetic susceptibility to otitis media in childhood: a Western Australian study

[Truncated abstract] Otitis media (OM) is a common disease of early childhood that affects up to 80% of children by the age of 3. This disease is characterised by inflammation of the middle ear cavity in the presence of middle ear effusion. For some children, OM becomes severe; experiencing infections three or more times per year (recurrent) or middle ear effusion persisting for over 3 months (chronic). Recurrent/chronic OM can result in conductive hearing loss, which can lead to delays in speech development and learning difficulties in school. Treatment includes surgery to insert typanostomy tubes. Otitis media is a complex multi-factorial condition with heritability estimates showing 45 - 74% of the phenotypic variation is attributable to genetics. This thesis aims to identify genes underlying childhood susceptibility to recurrent and chronic OM using both candidate gene/region and genome-wide approaches. To carry out these genetic analyses the samples and data available in two Western Australian cohorts have been used. This includes the Western Australian Family Study of Otitis Media (WAFSOM), an otitis media cohort that has recruited affected children and their parents, and the Western Australian Pregnancy Cohort (Raine) Study, a longitudinal birth cohort with extensiveclinical,genetic and epidemiological data available...