This is a study to help determine the role of surfactant proteins in asthma. Asthma is a lung disease with great variability. Why this variability exists is not known. One of the possible explanations may be that surfactant levels (a protein in the lung) may affect how severe asthma is. Surfactant is made up of fat and proteins and these proteins are important to the functions of the lungs. The study will look at genes for the proteins in the surfactant or the genes next to the surfactant protein. This information will be used as part of studies looking for a tendency for severe asthma.