Genome-wide interaction study reveals age-dependent determinants of responsiveness to inhaled corticosteroids in individuals with asthma
PLOS ONE
Authors: Dahlin, Amber; Sordillo, Joanne E.; McGeachie, Michael; Kelly, Rachel S.; Tantisira, Kelan G.; Lutz, Sharon M.; Lasky-Su, Jessica; Wu, Ann Chen
Abstract
While genome-wide association studies have identified genes involved in differential treatment responses to inhaled corticosteroids (ICS) in asthma, few studies have evaluated the potential effects of age in this context. A significant proportion of asthmatics experience exacerbations (hospitalizations and emergency department visits) during ICS treatment. We evaluated the interaction of genetic variation and age on ICS response (measured by the occurrence of exacerbations) through a genome-wide interaction study (GWIS) of 1,321 adult and child asthmatic patients of European ancestry. We identified 107 genome-wide suggestive (P<10(-05)) age-by-genotype interactions, two of which also met genome-wide significance (P<5x10(-08)) (rs34631960 [OR 2.3 +/- 1.6-3.3] in thrombospondin type 1 domain-containing protein 4 (THSD4) and rs2328386 [OR 0.5 +/- 0.3-0.7] in human immunodeficiency virus type I enhancer binding protein 2 (HIVEP2)) by joint analysis of GWIS results from discovery and replication populations. In addition to THSD4 and HIVEP2, age-by-genotype interactions also prioritized genes previously identified as asthma candidate genes, including DPP10, HDAC9, TBXAS1, FBXL7, and GSDMB/ORMDL3, as pharmacogenomic loci as well. This study is the first to link these genes to a pharmacogenetic trait for asthma.
A comprehensive association study for genes in inflammation pathway provides support for their roles in prostate cancer risk in the CAPS study
PROSTATE
Authors: Zheng, S. Lilly; Liu, Wennuan; Wiklund, Fredrik; Dimitrov, Latchezar; Balter, Katarina; Sun, Jielin; Adami, Hans-Olov; Johansson, Jan-Erik; Sun, Jishan; Chang, Baoli; Loza, Matthew; Turner, Aubrey R.; Bleecker, Eugene R.; Meyers, Deborah A.; Carpten, John D.; Duggan, David; Isaacs, William B.; Xu, Jianfeng; Gronberg, Henrik
Abstract
BACKGROUND. Recently identified associations of prostate cancer risk with several genes involved in innate immunity support a role of inflammation in the etiology of prostate cancer. Considering inflammation is regulated by a complex system of gene products, we hypothesize sequence variants in many other genes of this pathway are associated with prostate cancer. METHODS. We evaluated 9,275 SNPs; in 1,086 genes of the inflammation pathway using a MegAlleleTM genotyping system among 200 familial cases and 200 unaffected controls selected from a large Swedish case-control population (CAPS). RESULTS. We found that significantly more than the expected numbers of SNPs were significant at a nominal P-value of 0.01, 0.05, and 0.1, providing overall support for our hypothesis. The excess was largest when using a more liberal nominal P-value (0.1); we observed 992 significant SNPs compared with the 854 significant SNPs expected by chance, and this difference was significant based on a permutation test (P = 0.0025). We also began the effort of differentiating true associated SNPs by selecting a small subset of significant SNPs (N = 26) and genotyped these in an independent sample of similar to 1,900 CAPS1 subjects. We were able to confirm 3 of these 26 SNPs. It is expected that many more true associated SNPs will be confirmed among the 992 significant SNPs identified in our pathway screen. CONCLUSIONS. Our study provides the first objective support for an association between prostate cancer and multiple modest-effect genes in inflammatory pathways.