The genetics of asthma.

Asthma is a complex respiratory disease that, based on familial aggregation studies, has long been recognized to have a significant genetic component. Understanding the genetics of asthma is complicated by the fact that there are multiple different pathophysiological mechanisms leading to a complicated heterogeneous phenotype that is difficult to define. It is generally recognized as a complex genetic disease that cannot be explained by single gene models, and in most cases it appears to result from the interaction of multiple genetic and environmental factors. Although linkage and association studies have demonstrated several important relationships between asthma and a variety of genetic loci, no single gene or group of genes has been definitively demonstrated to be responsible for asthma. However, population studies, candidate gene approaches, genome-wide screens, and pharmacogenetic studies have all resulted in an increased understanding of the complexities of asthma genetics and may lead to better preventive strategies, diagnostic tools, and therapies for this disease.