Single nucleotide polymorphisms in C-type lectin genes, clustered in the IBD2 and IBD6 susceptibility loci, may play a role in the pathogenesis of inflammatory bowel diseases.
We aimed to define genotype-phenotype relationships and interactions with the IBD susceptibility gene CARD15for various IBD susceptibility loci (IBD1, IBD2, IBD5, IBD6, IBD7, and chromosome 4) by characterizing previously described peak LOD score short tandem repeat (STR) markers.
Our results provide confirmatory evidence for linkage between the IBD2 locus and the inflammatory bowel disease phenotype (lod = 2.12 at GATA91H06) and ulcerative colitis phenotype (lod = 1.44 at GATA91H06), but not the Crohn's disease phenotype.
Linkage studies have identified the inflammatory bowel disease (IBD)1 locus on chromosome 16 and the IBD2 locus on chromosome 12 to be involved in Crohn's disease.
The STAT6 gene is located on chromosome 12q13.3-14.1 (IBD2 region) and is therefore a positional and functional candidate gene for study in inflammatory bowel disease.
One of the potential susceptibility loci for inflammatory bowel disease (IBD2) was localized at 12q13-14 in the vicinity of the deoxyribonucleic acid marker D12S83 by linkage analysis.
In inflammatory bowel disease (IBD), linkage to two regions has elsewhere been reported at genomewide significance levels: the pericentromeric region on chromosome 16 (IBD1) and chromosome 12q (IBD2).
In the present study, we genotyped 581 relative pairs with inflammatory bowel disease (252 from CD-only families, 138 from UC-only families, and 191 from mixed families containing cases of both CD and UC), using 12 markers spanning the IBD2 locus.
Recent genome scans and replication studies have identified replicated linkage between CD and a locus on chromosome 16 (the IBD1 locus), replicated linkage between IBD (especially UC) and a locus on chromosome 12q (the IBD2 locus), and replicated linkage between IBD (especially CD) and a locus on chromosome 6p (the IBD3 locus).
Two European genome-wide screens for inflammatory bowel disease have identified two significant regions of linkage on chromosomes 16 (IBD1) and 12 (IBD2) and two regions with suggestive levels of significance (chromosomes 3p and 7q).