Recent advances in the genetics of allergy and asthma.

Asthma is a common condition that results from the interaction of an unknown number of genes with environmental factors. About 10% of children have asthma, usually as part of a syndrome of atopy, which is characterized by the presence of allergy, asthma, seasonal rhinitis and eczema, and tends to occur in familial clusters. The incidence of asthma is lower in adults (5%) and a significant proportion is seen without an atopic background. The prevalence of asthma has increased substantially over the past decades, particularly in the western world. Allergy and asthma are not inherited as single-gene disorders and do not show a simple pattern of inheritance. Environmental and genetic factors interact in a complex fashion to produce disease susceptibility and expression. Here, we describe the recent advances in the understanding of the inherited susceptibility to asthma and atopy and discuss their potential implications.