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Vermeire S, Satsangi J, Peeters M, Parkes M, Jewell DP, Vlietinck R, Rutgeerts P. Evidence for inflammatory bowel disease of a susceptibility locus on the X chromosome. Gastroenterology 2001; 120:834-40. [PMID: 11231937 DOI: 10.1053/gast.2001.22453] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS The technique of genomewide scanning has been applied successfully in inflammatory bowel disease (IBD). A number of putative susceptibility loci have been identified through genomewide searches including replicated regions of linkage on chromosomes 12, 16, 6 (the HLA region), and 14. We have investigated the contribution of the X chromosome in 145 Belgian affected relative pairs. METHODS In the first stage of the study, 79 (68 CD, 11 mixed) sibling pairs were genotyped at 12 microsatellite markers covering the X chromosome. In the second stage, 10 additional markers in the X-pericentromeric region were studied in the families involved in stage 1 together with 62 additional families (52 sibling pairs, 14 second-degree relative pairs). RESULTS In the first stage, evidence for linkage was found over a 30-cM pericentromeric region spanning dXs991, dXs990, and dXs8096 (multipoint maximum LOD score in the CD subgroup, 2.5; P = 0.0003). The remainder of the X chromosome was excluded (exclusion under LOD-2) for a locus with lambda(s) = 2. Fine mapping in the second stage confirmed linkage, and narrowed and shifted the linked region to Xq21.3 around dXs1203 (nonparametric linkage [NPL], 2.90; P = 0.0017). The NPL-1 interval around the linkage peak comprises 19.7 cM. CONCLUSIONS These data provide suggestive evidence for the presence and chromosomal location of an X-linked susceptibility gene in IBD.
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Affiliation(s)
- S Vermeire
- Gastroenterology Unit, University Hospital Gasthuisberg, Leuven, Belgium
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52
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Abstract
The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.
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Affiliation(s)
- R J Farrell
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
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53
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Brant SR, Panhuysen CI, Bailey-Wilson JE, Rohal PM, Lee S, Mann J, Ravenhill G, Kirschner BS, Hanauer SB, Cho JH, Bayless TM. Linkage heterogeneity for the IBD1 locus in Crohn's disease pedigrees by disease onset and severity. Gastroenterology 2000; 119:1483-90. [PMID: 11113069 DOI: 10.1053/gast.2000.20245] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS There is evidence for the IBD1 Crohn's disease (CD) susceptibility locus on chromosome 16 in several but not all populations studied. Genetic and phenotypic heterogeneity may underlie ability to replicate IBD1. We determined if age and severity stratification could identify a clinical subgroup at risk for IBD1. METHODS Linkage analysis at microsatellites spanning chromosome 16 was performed in 2 groups of CD pedigrees: group 1, 57 pedigrees with at least one affected relative classified as having "severe" disease, by history of surgical resection or immunomodulator therapy, and with disease diagnosed before age 22; and group 2, 33 pedigrees with no history of early-onset, severe CD. RESULTS Group 1 pedigrees demonstrated genomewide significant linkage evidence for the IBD1 locus (nonparametric multipoint logarithm of the odds [Mlod], 3.84; P = 1.3 x 10(-5)) with linkage evidence greater than all 90 pedigrees (Mlod, 2.12; P = 9.0 x 10(-4)). Group 2 pedigrees had near zero nonparametric 2-point and Mlod scores for the IBD1 region. Heterogeneity between groups 1 and 2 was significant (P = 0.002). CONCLUSIONS Presence of early-onset, more severe CD identifies pedigrees at high risk for IBD1. These pedigrees will have more power to refine the IBD1 locus and identify the causative gene.
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Affiliation(s)
- S R Brant
- Harvey M. and Lyn P. Meyerhoff Inflammatory Bowel Disease Center, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Parkes M, Barmada MM, Satsangi J, Weeks DE, Jewell DP, Duerr RH. The IBD2 locus shows linkage heterogeneity between ulcerative colitis and Crohn disease. Am J Hum Genet 2000; 67:1605-10. [PMID: 11078482 PMCID: PMC1287939 DOI: 10.1086/316905] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2000] [Accepted: 10/10/2000] [Indexed: 01/03/2023] Open
Abstract
The IBD2 locus on chromosome 12 has been linked to both Crohn disease (CD) and ulcerative colitis (UC) but has not been detected in some CD-dominated data sets. 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. A GENEHUNTER-PLUS multipoint LOD score of 3.91 was detected for pairs from UC-only families, compared with 1.66 for CD-only and 1.29 for mixed families. The difference between the LOD scores for UC and CD was significant in two different tests for heterogeneity (P=.0057 for one test and P=.0375 for the other). IBD2 thus appears to make a major contribution to UC susceptibility but to have only a relatively minor effect with regard to CD, for which there may be substantially more locus heterogeneity.
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Affiliation(s)
- Miles Parkes
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
| | - M. Michael Barmada
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
| | - Jack Satsangi
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
| | - Daniel E. Weeks
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
| | - Derek P. Jewell
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
| | - Richard H. Duerr
- Gastroenterology Unit, Nuffield Department of Medicine, Radcliffe Infirmary, and The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford; Department of Human Genetics, Graduate School of Public Health, and Department of Medicine and Center for Genomic Sciences, School of Medicine, University of Pittsburgh, Pittsburgh
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55
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Vermeire S, Peeters M, Vlietinck R, Parkes M, Satsangi J, Jewell D, Rutgeerts P. Exclusion of linkage of Crohn's disease to previously reported regions on chromosomes 12, 7, and 3 in the Belgian population indicates genetic heterogeneity. Inflamm Bowel Dis 2000; 6:165-70. [PMID: 10961588 DOI: 10.1097/00054725-200008000-00002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Susceptibility to inflammatory bowel disease (IBD) is significantly determined by genetic factors. Linkage data from genome-wide searches have identified regions on chromosomes 16, 12, 7, and 3. Our goal was to replicate these four regions in a Belgian population of IBD families. Fifty-four IBD families were studied (47 with Crohn's disease [CD] and 7 with mixed CD and ulcerative colitis, containing 79 affected sibpairs (68 CD only, 11 mixed) for the regions previously implicated to chromosomes 16, 12, 7, and 3. In this study, no evidence for linkage was found on any of the four chromosomal regions studied for either the whole IBD dataset or the CD subgroup. The multipoint maximum logarithm of odds scores were less than 0.7 for all four regions. Exclusion mapping could significantly exclude chromosomes 3, 7, and 12. Despite earlier findings, we could significantly exclude linkage of CD with previously reported regions on chromosomes 12, 7, and 3, and could not find evidence for linkage to chromosome 16. It is important to report these findings in light of the genetic heterogeneity of IBD. A genome-wide search on a larger group of affected siblings is being analyzed to detect other possible susceptibility loci in the Belgian population.
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Affiliation(s)
- S Vermeire
- Gastroenterology Unit, University Hospital Gasthuisberg, Leuven, Belgium
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56
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Abstract
Genomic technologies offer new approaches to the investigation of etiology and pathophysiology of inflammatory bowel disease (IBD). Several areas of application for these new technologies are possible. One such application is the search for gene variations predisposing to the development of the disorder in multiply-affected families. Genome-wide linkage studies have defined replicated susceptibility regions for IBD on chromosomes 6, 12, and 16. These susceptibility regions are still very large and each contain several hundred positional candidate genes. Efforts are under way at several centers to define the underlying molecular variants using systematic linkage disequilibrium and candidate gene methods. The pharmacogenetic investigation of gene variations may predict response to certain medications to target these therapeutic interventions more precisely. The use of global gene expression technologies may allow the identification of new pathways or molecules in the inflammatory process. This seems to be especially relevant because currently only approximately 8,000 of the estimated 100,000 human genes are characterized. In summary, genomic methodologies will profoundly influence the progress of IBD research and may lead to novel insights into both etiology and pathophysiology of chronic intestinal inflammation.
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Affiliation(s)
- S Schreiber
- Ist Department of Medicine, Christian-Albrechts-University, Kiel, Germany.
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57
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Duerr RH, Barmada MM, Zhang L, Pfützer R, Weeks DE. High-density genome scan in Crohn disease shows confirmed linkage to chromosome 14q11-12. Am J Hum Genet 2000; 66:1857-62. [PMID: 10747815 PMCID: PMC1378032 DOI: 10.1086/302947] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Accepted: 03/15/2000] [Indexed: 11/03/2022] Open
Abstract
Epidemiological studies have shown that genetic factors contribute to the pathogenesis of the idiopathic inflammatory bowel diseases (IBD), Crohn disease (CD) and ulcerative colitis (UC). 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). Since the estimated locus-specific lambdas values for the regions of replicated linkage do not account for the overall lambdas in CD, and since the published genome scans in IBD show at least nominal evidence for linkage to regions on all but two chromosomes, we performed an independent genome scan using 751 microsatellite loci in 127 CD-affected relative pairs from 62 families. Single-point nonparametric linkage analysis using the GENEHUNTER-PLUS program shows evidence for linkage to the adjacent D14S261 and D14S283 loci on chromosome 14q11-12 (LOD = 3.00 and 1.70, respectively), and the maximal multipoint LOD score is observed at D14S261 (LOD = 3.60). In the multipoint analysis, nominal evidence for linkage (P<.05) is observed near D2S117 (LOD = 1.25), near D3S3045 (LOD = 1.31), between D7S40 and D7S648 (LOD = 0.91), and near D18S61 (LOD = 1.15). Our finding of significant linkage to D14S261 and the finding of suggestive linkage to the same locus in an independent study (multipoint LOD = 2.8) satisfies criteria for confirmed linkage, so we propose that the region of interest on chromosome 14q11-12 should be designated the IBD4 locus.
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Affiliation(s)
- R H Duerr
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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58
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Rioux JD, Silverberg MS, Daly MJ, Steinhart AH, McLeod RS, Griffiths AM, Green T, Brettin TS, Stone V, Bull SB, Bitton A, Williams CN, Greenberg GR, Cohen Z, Lander ES, Hudson TJ, Siminovitch KA. Genomewide search in Canadian families with inflammatory bowel disease reveals two novel susceptibility loci. Am J Hum Genet 2000; 66:1863-70. [PMID: 10777714 PMCID: PMC1378042 DOI: 10.1086/302913] [Citation(s) in RCA: 378] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2000] [Accepted: 03/30/2000] [Indexed: 11/03/2022] Open
Abstract
The chronic inflammatory bowel diseases (IBDs)-Crohn disease (CD) and ulcerative colitis (UC)-are idiopathic, inflammatory disorders of the gastrointestinal tract. These conditions have a peak incidence in early adulthood and a combined prevalence of approximately 100-200/100,000. Although the etiology of IBD is multifactorial, a significant genetic contribution to disease susceptibility is implied by epidemiological data revealing a sibling risk of approximately 35-fold for CD and approximately 15-fold for UC. To elucidate the genetic basis for these disorders, we undertook a genomewide scan in 158 Canadian sib-pair families and identified three regions of suggestive linkage (3p, 5q31-33, and 6p) and one region of significant linkage to 19p13 (LOD score 4.6). Higher-density mapping in the 5q31-q33 region revealed a locus of genomewide significance (LOD score 3.9) that contributes to CD susceptibility in families with early-onset disease. Both of these genomic regions contain numerous genes that are important to the immune and inflammatory systems and that provide good targets for future candidate-gene studies.
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Affiliation(s)
- J D Rioux
- Whitehead Institute/Massachusetts Institute of Technology, Center for Genome Research, Cambridge, MA 02139, USA.
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Cho J. Genetic aspects of inflammatory bowel disease: how far have we come, and where are we heading? Curr Gastroenterol Rep 1999; 1:491-5. [PMID: 10980992 DOI: 10.1007/s11894-999-0009-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Crohn"s disease and ulcerative colitis are related complex genetic disorders, with gene-gene and gene-environment interactions that are critical to their pathogenesis. Multiple genetic loci have been implicated through genome-wide searches. Of these, a locus on Crohn"s disease has been definitively established in the pericentromeric region of chromosome 16. Multiple candidate gene studies have been forwarded, and functionally significant variants in immune-associated genes will provide additional insight. Characterization of the genetic variation responsible for causing inflammatory bowel disease will result in development of novel therapeutic approaches as well as in tailoring of specific therapies to individual patients based on their specific molecular pathogenesis.
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Affiliation(s)
- J Cho
- Emma Getz Inflammatory Bowel Disease Research Center, Department of Medicine, Gastroenterology Section, The University of Chicago, 5841 South Maryland Avenue, G705, MC 6084, Chicago, IL 60637-1521, USA
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60
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Ma Y, Ohmen JD, Li Z, Bentley LG, McElree C, Pressman S, Targan SR, Fischel-Ghodsian N, Rotter JI, Yang H. A genome-wide search identifies potential new susceptibility loci for Crohn's disease. Inflamm Bowel Dis 1999; 5:271-8. [PMID: 10579120 DOI: 10.1097/00054725-199911000-00005] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chronic inflammatory bowel disease (IBD) presents as two major clinical forms, Crohn's disease (CD) and ulcerative colitis (UC). Genetic epidemiological studies and animal models suggest that inherited factors play significant roles in the susceptibility to both forms of IBD. From four genome-wide scans, putative susceptibility loci on chromosome 16 (IBD1 for CD), and on chromosomes 1, 3, 4, 6, 7, 10, and 12 for IBD, have been identified. Several other groups, including ours, have confirmed linkage to the loci on chromosomes 12 and 16. The aim of this study is to identify other potential susceptibility loci for CD with a genome-wide search approach. In our sample of 222 individuals from 46 families (20 Jewish and 26 non-Jewish), with a total of 65 sibpairs diagnosed with CD, we observed a novel locus with suggestive linkage [multipoint logarithm of the odds score (Mlod) > 2] at chromosome 14q11.2 (Mlod = 2.8, p = 0.0002). In addition, suggestive linkage was observed in our Jewish families at chromosome 17q21-q23 (Mlod = 2.1, p = 0.01) and chromosome 5q33-q35 (Mlod = 2.2, p = 0.0003). The syntenic regions of the latter locus are mapped within two putative loci on mouse chromosomes 11 and 18, which were identified in a mouse IBD model induced by dextran sulfate sodium (29). Our preliminary results provide potential evidence for several susceptibility loci contributing to the risk of CD. The observation of man-mouse synteny may accelerate the identification of CD susceptibility gene(s) on human chromosome 5.
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Affiliation(s)
- Y Ma
- Parke-Davis Laboratory for Molecular Genetics (PDLMG), Alameda, California, USA
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Yang H, Ohmen JD, Ma Y, Bentley LG, Targan SR, Fischel-Ghodsian N, Rotter JI. Additional evidence of linkage between Crohn's disease and a putative locus on chromosome 12. Genet Med 1999; 1:194-8. [PMID: 11256672 DOI: 10.1097/00125817-199907000-00005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are chronic intestinal disorder of unknown etiology. Genetic factors play an important role in the pathogenesis of these diseases, but with a complex pattern of inheritance. A number of genome-wide scans have identified several putative susceptibility loci for both CD and UC, including a locus on chromosome 12 reported in a set of British families. We aim to evaluate the linkage between CD or UC and this chromosome 12 locus in an independent set of U.S. Caucasian families (36% being of Ashkenazi Jewish origin). METHODS Microsatellite markers along chromosome 12 spaced at approximately 10 cm intervals were used to test the putative loci in CD only families (65 sib pairs from 46 families). Regions with positive linkage for CD were then tested in a panel of UC and mixed families (44 sib pairs from 29 families). Two point linkage analysis was performed with SIBPAL. Multipoint linkage analysis was carried out with MAPMAKER/SIBS. RESULTS We observed evidence of linkage between the region on chromosome 12 and Crohn's disease, because there was a significant excess of allele sharing in CD sib pairs (pi = 0.62, p = 0.0004 from two-point linkage; and logarithm of the odds score (LOD) = 2.0 from multipoint linkage). However, we did not observe the same linkage in UC and mixed families (p = 0.48; not significant [ns]). CONCLUSION Our data provided further evidence that the region on chromosome 12 is likely to contain a gene predisposing to CD.
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Affiliation(s)
- H Yang
- Department of Medicine, Cedars-Sinai Research Institute, Cedars-Sinai Medical Center, Los Angeles 90048, USA
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62
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Abstract
Genetic factors have a definite role in the etiology of inflammatory bowel disease (IBD). The mode of inheritance suggests a polygenic disease with the penetrance of the genetic factors being strongly influenced by the lifestyle of an industrialized society. Molecular techniques, which have become available through the progress of the human genome project, allowed a first series of linkage studies in pairs of affected siblings with IBD, which suggested multiple genomic susceptibility regions. These regions are still large, but considerable progress is being made toward the identification of actual disease genes. It is hoped that an understanding of the genetic etiology of IBD will lead to enhanced diagnostic procedures, more effective therapeutic interventions, and preventive strategies in the future.
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Affiliation(s)
- S Schreiber
- 1st Department of Medicine, Christian-Albrechts-University, Kiel, Germany.
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