ABSTRACT
Asthma is a complex and multifactorial disease that affects nearly 155 million individuals worldwide.
A genetic component to asthma has long been suggested: the disease clusters in families and monozygotic twins show higher concordance rates compared with dizygotic twins,
but identifying asthma genes has been a daunting task. In contrast to monogenic disorders (e.g., cystic fibrosis) in which mutations in a single gene lead to the development of the disease in nearly all cases, the etiologies of common diseases such as asthma, coronary artery disease, and diabetes are complex (Figure 8.1), making genetic studies challenging.
