Murphy, Amy JSoto-Quiros, Manuel EAvila, LydianaCeledón, Juan CO'Connor, George THimes, BlancaLasky-Su, JessicaWu, AnnWilk, JemmaHunninghake, GaryKlanderman, BarbaraLazarus, RossLange, ChristophRaby, BenjaminSilverman, EdwinWeiss, Scott2011-05-152010Himes, Blanca E., Jessica Lasky-Su, Ann C. Wu, Jemma B. Wilk, Gary M. Hunninghake, Barbara Klanderman, Amy J. Murphy, et al. 2010. Asthma-susceptibility variants identified using probands in case-control and family-based analyses. BMC Medical Genetics 11: 122.1471-2350http://nrs.harvard.edu/urn-3:HUL.InstRepos:4889501Background: Asthma is a chronic respiratory disease whose genetic basis has been explored for over two decades, most recently via genome-wide association studies. We sought to find asthma-susceptibility variants by using probands from a single population in both family-based and case-control association designs. Methods: We used probands from the Childhood Asthma Management Program (CAMP) in two primary genome-wide association study designs: (1) probands were combined with publicly available population controls in a case-control design, and (2) probands and their parents were used in a family-based design. We followed a two-stage replication process utilizing three independent populations to validate our primary findings. Results: We found that single nucleotide polymorphisms with similar case-control and family-based association results were more likely to replicate in the independent populations, than those with the smallest p-values in either the case-control or family-based design alone. The single nucleotide polymorphism that showed the strongest evidence for association to asthma was rs17572584, which replicated in 2/3 independent populations with an overall p-value among replication populations of 3.5E-05. This variant is near a gene that encodes an enzyme that has been implicated to act coordinately with modulators of Th2 cell differentiation and is expressed in human lung. Conclusions: Our results suggest that using probands from family-based studies in case-control designs, and combining results of both family-based and case-control approaches, may be a way to augment our ability to find SNPs associated with asthma and other complex diseases.en-USJournal Article2011-05-1510.1186/1471-2350-11-122