Using a genome-wide scan and meta-analysis to identify a novel IBD locus and confirm previously identified IBD loci

Seven loci that potentially confer susceptibility to inflammatory bowel disease (IBD) or one of its subtypes have been identified to date; however, most are unconfirmed, and the complete set of loci contributing to disease susceptibility has not yet been determined. The authors aim to identify loci contributing to disease susceptibility in an IBD population from Canada and to compare their results in a systematic manner with those of previously published IBD data sets. The authors performed genome-wide linkage analysis on 63 IBD families from Nova Scotia, Canada. They then undertook a meta-analysis to combine the results of their study with those of the four previously published IBD genome-wide scans with complete data reported. Their genome-wide scan identified three regions of suggestive linkage to IBD: 11p, IBD3, and IBD1. The locus on chromosome 11p has not been previously reported. Meta-analysis of multiple scans revealed linked regions corresponding to the IBD1, IBD3, and 1BD5 loci. Meta-analysis of linkage data is a powerful approach for identifying and confirming common susceptibility loci and specifically shows that IBD1, IBD3, and IBD5 are the major, common IBD susceptibility loci in the populations studied thus far.