Genetic Risk Factors for Severe Asthma

Asthma is one of the most common chronic diseases in the United States. It is well known that asthma susceptibility is inherited; however, it is unknown if asthma severity is heritable. Studies suggest that levels of interleukin-16 (IL-16) may influence asthma severity. This study will examine the role of differences in the control region of the IL-16 gene in a racially diverse group of asthmatics and nonasthmatics and will determine if the IL-16 gene control region is related to asthma severity. Participants in this study will undergo lung function and blood tests; they will also complete a questionnaire about their respiratory health. Asthmatic participants will complete a severity-of-asthma questionnaire.