RT Journal Article SR Electronic T1 Pharmacogenetic basis for severe asthma exacerbations JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 429 OP 429 VO 63 IS 5 A1 Shoaib Faruqi YR 2008 UL http://thorax.bmj.com/content/63/5/429.abstract AB