Markers and genes in chromosomal region 5q31-33 have been shown to be linked or associated to asthma or components of the asthma phenotype, suggesting that this chromosomal region is important in the genetic susceptibility to asthma, yet it has been difficult to show that a specific gene in this region plays a major role in asthma development or progression. Some of this difficulty arises from the fact that many genes are likely to be involved in the pathogenesis of asthma, with no single gene having an effect that will emerge as a major contributor, as well as the fact that the strong influence of environmental factors will complicate the analyses. Having recognized these issues, the investigators will use components of the asthma-associated phenotype, including eosinophilia and a compound "atopy" phenotype, to identify relevant asthma-related genes in this region. The identification of the genes and their genetic variants that may be associated with asthma and its related phenotypes may provide important new information on the pathogenesis of asthma.