Genome-wide association study for Crohn's disease in the Quebec Founder Population identifies multiple validated disease loci.

Authors:
John V Raelson, Randall D Little, Andreas Ruether, Hélène Fournier, Bruno Paquin, Paul Van Eerdewegh, W E C Bradley, Pascal Croteau, Quynh Nguyen-Huu, Jonathan Segal, Sophie Debrus, René Allard, Philip Rosenstiel, Andre Franke, Gunnar Jacobs, Susanna Nikolaus, Jean-Michel Vidal, Peter Szego, Nathalie Laplante, Hilary F Clark, René J Paulussen, John W Hooper, Tim P Keith, Abdelmajid Belouchi, Stefan Schreiber
Year of publication:
2007
Volume:
104
Issue:
37
Issn:
0027-8424
Journal title abbreviated:
P NATL ACAD SCI USA
Journal title long:
Proceedings of the National Academy of Sciences of the United States of America
Impact factor:
9.423
Abstract: 
Genome-wide association (GWA) studies offer a powerful unbiased method for the identification of multiple susceptibility genes for complex diseases. Here we report the results of a GWA study for Crohn''s disease (CD) using family trios from the Quebec Founder Population (QFP). Haplotype-based association analyses identified multiple regions associated with the disease that met the criteria for genome-wide significance, with many containing a gene whose function appears relevant to CD. A proportion of these were replicated in two independent German Caucasian samples, including the established CD loci NOD2 and IBD5. The recently described IL23R locus was also identified and replicated. For this region, multiple individuals with all major haplotypes in the QFP were sequenced and extensive fine mapping performed to identify risk and protective alleles. Several additional loci, including a region on 3p21 containing several plausible candidate genes, a region near JAKMIP1 on 4p16.1, and two larger regions on chromosome 17 were replicated. Together with previously published loci, the spectrum of CD genes identified to date involves biochemical networks that affect epithelial defense mechanisms, innate and adaptive immune response, and the repair or remodeling of tissue.