We tested the hypothesis that the ADAM33 gene is associated with atopic or non atopic asthma, lung function and BHR in a large nested case control study of German children (N = 1,872; comparing 624 asthmatics and/or BHR positives and 1,248 non-asthmatic, BHR negative, non-atopic controls) and a German multicentre family based birth cohort study (MAS) (888 children with DNA available, 96 asthmatics and 792 non-asthmatics). The gene discussed is ADAM33; the disease is asthma.