Asthma and other allergic diseases are complex genetic disorders that result from interactions between multiple genes and environmental factors. In this review, we summarize findings from candidate gene analyses, discuss the recent success of genome-wide association (GWA) studies, and outline challenges facing the field.
In the past year, five GWA studies have been reported for asthma, one for atopic dermatitis, and four for intermediate phenotypes using quantitative trait loci. These results have in general been more robust to replication than prior candidate gene studies, and have allowed the identification of novel loci for both asthma (i.e. 1q31, 9q21.31) and atopic dermatitis (11q13).
The integration of results from recent GWA studies with careful analyses of candidate gene associations studies has confirmed the importance of immune detection and TH2-cell mediated immune responses in the pathogenesis of allergic disease, and has raised new interest in the role of epithelial barrier function and tissue-level responses. GWA studies appear to provide a robust way to identify novel gene loci contributing to disease susceptibility. Dissecting gene–gene and gene–environment interactions, and exploring the contribution of epigenetic phenomena to allergic disease susceptibility remain important challenges to understanding the complex nature of asthma and other allergic diseases.
aDepartment of Pediatrics, Baylor College of Medicine & Texas Children's Hospital, Texas
bDivision of Human Genetics, The Abramson Research Center of the Joseph Stokes Jr. Research Institute, The Children's Hospital of Philadelphia
cThe Center for Applied Genomics, The Abramson Research Center of the Joseph Stokes Jr. Research Institute, The Children's Hospital of Philadelphia
dDepartment of Pediatrics, The University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
Correspondence to Hakon Hakonarson, Center for Applied Genomics, 1216E Abramson Research Center, 3615 Civic Center Blvd., Philadelphia, PA 19104-4318, USA Tel: +1 267 426 0088; fax: +1 267 426 0363; e-mail: firstname.lastname@example.org