Using the twin study approach, the investigators demonstrated that time with middle ear effusion (MEE), number of episodes of MEE and numbers of episodes of acute otitis media (AOM) have a strong genetic component. The point estimate of heritability of time with MEE was 0.73. While there is significant evidence that susceptibility to recurrent/persistent OM is largely genetically determined, the specific genes which confer susceptibility are unknown. The overall research strategy to identify genes underlying OM is to apply a three-stage study design that will allow the investigators to balance cost efficiency with statistical power. Five hundred evaluable pairs of siblings with a history of tympanostomy tube insertion (affected), their parent(s) and available non-affected full siblings will be recruited. A blood sample will be obtained from each subject for genotyping.
