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IBD5 Locus (ibd5 + locus)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

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

INFLAMMATORY BOWEL DISEASES, Issue 6 2002
C. Noel Williams
Abstract 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 IBD5 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. [source]

Runt-related transcription factor 3 is associated with ulcerative colitis and shows epistasis with solute carrier family 22, members 4 and 5

INFLAMMATORY BOWEL DISEASES, Issue 12 2008
Rinse K. Weersma MD
Abstract Background: Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), are intestinal inflammatory disorders with a complex genetic background. Mice deficient for the runt-domain-transcription-factor3 (Runx3) develop spontaneous colitis. Human RUNX3 resides in an IBD-susceptibility locus. We studied the association of RUNX3 in a cohort of IBD patients and analyzed the interaction with SLC22A4/5. RUNX3 and OCTN1 mRNA expression was assessed in inflamed and noninflamed mucosa from patients and controls. Methods: 543 IBD patients (309 CD / 234 UC) and 296 controls were included. Four single nucleotide polymorphisms (SNPs) and 4 microsatellite markers were studied for RUNX3. Five SNPs (including SNP-207G,C and SNP1672C,T) were analyzed for SLC22A4/5. RUNX3, and OCTN1 expression in mucosal tissue from 30 patients (14 UC / 16 CD) and 6 controls were determined by quantitative polymerase chain reaction. Results: A significant association between RUNX3 -SNP rs2236851 and UC (OR 1.61; 95% confidence interval [CI] 1.11,2.32, P = 0.020) was found. Carriership is associated with pancolitis (odds ratio [OR] 1.86; 95% CI 1.08,3.21). SLC22A4/5 -SNPs rs272893 and rs273900 are associated with CD (OR 2.16; 95% CI 1.21,3.59 and OR 2.40; 95% CI 1.43,4.05). We found epistasis for carriership of a risk-associated allele in RUNX3 and SLC22A4/5 for UC patients versus CD patients (OR 3.83; 95% CI 1.26,11.67). RUNX3 mRNA expression is increased (P = 0.01) in inflamed colonic mucosa of UC patients compared to noninflamed mucosa and controls. Conclusions: We provide evidence for the genetic association of RUNX3 with UC and for CD with the IBD5 locus including SLC22A4/5. An epistatic effect of RUNX3 and SLC22A4 was associated with an increased risk for UC. Our data suggest a role for RUNX3 in UC susceptibility. (Inflamm Bowel Dis 2008) [source]

Contribution of the novel inflammatory bowel disease gene IL23R to disease susceptibility and phenotype

INFLAMMATORY BOWEL DISEASES, Issue 9 2007
J.R. Fraser Cummings MRCP(UK)
Abstract Background: A North American genome-wide single nucleotide polymorphism (SNP) association study identified IL23R as a novel inflammatory bowel disease (IBD) susceptibility gene. Association was reported with multiple risk variants in the centromeric portion of IL23R in 3 large independent cohorts. The aims of this study were to replicate the association of IL23R with Crohn's disease (CD), examine subphenotype relationships, and look for evidence of epistasis with the known CD susceptibility gene CARD15 and susceptibility haplotype IBD5 in a large collection of CD patients. We further investigated the relationship between IL23R and ulcerative colitis (UC). Methods: In all, 604 CD and 647 UC patients who had been rigorously phenotyped and who had been recruited from a single UK center were used in this study. Controls were either spouses of patients (141) or were recruited from well-person clinics (993). Eight SNPs were genotyped using MassArray (Sequenom). All 8 SNPs genotyped were significantly associated with CD. Results: The association with the nonsynonymous SNP rs11209026 was confirmed (P = 6.65 × 10,6, odds ratio [OR], 0.43, 95% confidence interval [CI]: 0.29-0.64). The most significant SNP in our study was rs7517847 (P = 4.9 × 10,9, OR 0.65, 0.56,0.75), which is statistically independent of rs11209026. Preliminary evidence suggests an epistatic interaction with the IBD5 risk haplotype. The effects of mutations in this IL23R appear weaker in UC (P = 0.008, OR 0.63, 0.45,0.89 and 0.005 OR, 0.81, 0.71,0.94, respectively). No subphenotype associations were identified. Conclusions: We confirmed the findings that IL23R is a susceptibility gene for IBD with suggestive epistasis with the IBD5 locus in the CD population. (Inflamm Bowel Dis 2007) [source]

Review article: inflammatory bowel disease and genetics

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2007
R. K. WEERSMA
Summary Introduction, Inflammatory bowel disease (IBD) comprising ulcerative colitis (UC) and Crohn's disease (CD) is multigenic disorder. Tremendous progress has been achieved in unravelling the genetic background of IBD. It has led to the discovery of mutations in NOD2 associated with ileal CD and numerous other genes have been found to be associated with IBD susceptibility. Methods, A review of the literature on the genetic background of IBD was performed. Results, It is only partially understood how mutations in NOD2 lead to CD. Mouse models, in vitro data and studies in humans offer conflicting data as regards whether there is a loss or gain of function of NOD2 in CD. Several additional genes have been identified of which only a few are currently being recognized as potential disease causing or disease modifying genes. Promising candidate genes include TLR4, MDR1, NOD1 (CARD4), DLG5 as well as the IBD5 locus including SLC22A4/5. Conclusions, Although genetic research has not yet led to a better prediction of the disease course or patient selection for medical therapy, remarkable progress has been made in the understanding of the pathogenesis of IBD. For future genetic research, accurate phenotyping of patients is very important and large population-based cohorts are needed. Eventually, genetic research may be able to classify different disease phenotypes on a more detailed molecular basis and may provide important contributions in the development of new therapeutic approaches. [source]