An insertion-deletion polymorphism in the Interferon Regulatory Factor 5 (IRF5) gene confers risk of inflammatory bowel diseases

[Guest guest]

Hmmm, as a sufferer of UC, SLE and "sero-negative spondyloarthritis" as well as severe asthma, chronic heart failure, uveitis, dermatology problems, probable PSC (still no Dx after 7 years), multiple allergies etc etc, it seems they might be getting closer to finding better clues to diagnosis for us sufferers. Changed days from when I developed UC, 50 years ago (!!) and was promptly sent to a psychiatrist because it was a "psychiatric disorder"!!

DutchPat

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Human Molecular Genetics Advance Access originally published online on September 19, 2007 Human Molecular Genetics 2007 16(24):3008-3016; doi:10.1093/hmg/ddm259

© The Author 2007. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@...

An insertion–deletion polymorphism in the Interferon Regulatory Factor 5 (IRF5) gene confers risk of inflammatory bowel diseases

Vinciane Dideberg1,6, Gudlaug Kristjansdottir6, Lili Milani6, Cécile Libioulle3, Snaevar Sigurdsson6, Edouard Louis2, Ann-Christin Wiman6, Séverine Vermeire4, Rutgeerts4, Jacques Belaiche2, Denis Franchimont5, André Van Gossum5, Bours1 and Ann- Syvänen6,*

1 Department of Human Genetics, CHU de Liège, 2 Department of Hepatology and Gastroenterology, CHU de Liège and 3 Factorial and Molecular Genetics, GIGA-R, University of Liège, Liège, Belgium, 4 Department of Gastroenterology, UZ Gasthuisberg, Leuven, Belgium, 5 Department of Gastroenterology, Erasme University Hospital, Brussels, Belgium and 6 Molecular Medicine, Department of Medical Sciences, Uppsala University, Uppsala, Sweden

* To whom correspondence should be addressed at: Department of Medical Sciences, Uppsala University, Academic Hospital, Entrance 70, Third Floor, Research Department 2, 75185 Uppsala, Sweden. Tel: +46 186112959; Fax: +46 18553601; Email: ann-christine.syvanen@...

Received August 9, 2007; Accepted September 4, 2007 The interferon regulatory factor 5 (IRF5) gene encodes a transcription factor that plays an important role in the innate as well as in the cell-mediated immune responses. The IRF5 gene has been shown to be associated with systemic lupus erythematosus and rheumatoid arthritis. We studied whether the IRF5 gene is also associated with inflammatory bowel diseases (IBD), Crohn disease (CD) and ulcerative colitis (UC). Twelve polymorphisms in the IRF5 gene were genotyped in a cohort of 1007 IBD patients (748 CD and 254 UC) and 241 controls from Wallonia, Belgium. The same polymorphisms were genotyped in a confirmatory cohort of 311 controls and 687 IBD patients (488 CD and 192 UC) from Leuven, Belgium. A strong signal of association [P=1.9x10–5, odds ratio (OR) 1.81 (1.37–2.39)] with IBD was observed for a 5 bp indel (CGGGG) polymorphism in the promoter region of the IRF5 gene. The association was detectable also in CD patients (P=6.8x10–4) and was particularly strong among the UC patients [P=5.3x10–8, OR=2.42 (1.76–3.34)]. The association of the CGGGG indel was confirmed in the second cohort [P=3.2x10–5, OR=1.59 (1.28–1.98)]. The insertion of one CGGGG unit is predicted to create an additional binding site for the transcription factor SP1. Using an electrophoretic mobility shift assay, we show allele-specific differences in protein binding to this repetitive DNA-stretch, which suggest a potential function role for the CGGGG indel.