Using a subset of 11 ADRβ2 polymorphisms similar to those used by Drysdale et al[25], we identified nine Caucasian haplotypes whose frequency was similar to published data.[4], [25] Importantly two new haplotypes (2′ and 4′) were identified exclusively in asthmatics and possibly represent a rarer subset of Drysdale's haplotypes 2 and 4 contributing to asthma severity. This evidence concerns the gene ADRB2 and asthma.