Asthma genetics: pitfalls and triumphs.

Asthma is a complex genetic disorder. Significant progress has been made in identifying genes that convey risk of development and expression of the asthma phenotype. This review critically examines the approaches that have been used, the successes achieved and the difficulties that have been encountered. The multi-factorial nature of the disease and the complex interplay of the various risk factors with one another have highlighted the importance of adequate power and study design in pinpointing genes of real interest.