Genome-wide association study identifies inversion in the <i>CTRB1-CTRB2</i> locus to modify risk for alcoholic and non-alcoholic chronic pancreatitis
Authors: Jonas Rosendahl, Holger Kirsten, Eszter Hegyi, Peter Kovacs, Frank Ulrich Weiss, Helmut Laumen, Peter Lichtner, Claudia Ruffert, Jian-Min Chen, Emmanuelle Masson, Sebastian Beer, Constantin Zimmer, Katharina Seltsam, Hana Algül, Florence Bühler, Marco J Bruno, Peter Bugert, Ralph Burkhardt, Giulia Martina Cavestro, Halina Cichoz-Lach, Antoni Farré, Josef Frank, Giovanni Gambaro, Sebastian Gimpfl, Harald Grallert, Heidi Griesmann, Robert Grützmann, Claus Hellerbrand, Péter Hegyi, Marcus Hollenbach, Sevastitia Iordache, Grazyna Jurkowska, Volker Keim, Falk Kiefer, Sebastian Krug, Olfert Landt, Milena Di Leo, Markus M Lerch, Philippe Lévy, Markus Löffler, Matthias Löhr, Maren Ludwig, Milan Macek, Nuria Malats, Ewa Malecka-Panas, Giovanni Malerba, Karl Mann, Julia Mayerle, Sonja Mohr, Rene H M te Morsche, Marie Motyka, Sebastian Mueller, Thomas Müller, Markus M Nöthen, Sergio Pedrazzoli, Stephen P Pereira, Annette Peters, Roland Pfützer, Francisco X Real, Vinciane Rebours, Monika Ridinger, Marcella Rietschel, Eva Rösmann, Adrian Saftoiu, Alexander Schneider, Hans-Ulrich Schulz, Nicole Soranzo, Michael Soyka, Peter Simon, James Skipworth, Felix Stickel, Konstantin Strauch, Michael Stumvoll, Pier Alberto Testoni, Anke Tönjes, Lena Werner, Jens Werner, Norbert Wodarz, Martin Ziegler, Atsushi Masamune, Joachim Mössner, Claude Férec, Patrick Michl, Joost P H Drenth, Heiko Witt, Markus Scholz, Miklós Sahin-Tóth
Journal: Gut (2017)

Objective Alcohol-related pancreatitis is associated with a disproportionately large number of hospitalisations among GI disorders. Despite its clinical importance, genetic susceptibility to alcoholic chronic pancreatitis (CP) is poorly characterised. To identify risk genes for alcoholic CP and to evaluate their relevance in non-alcoholic CP, we performed a genome-wide association study and functional characterisation of a new pancreatitis locus. Design 1959 European alcoholic CP patients and population-based controls from the KORA, LIFE and INCIPE studies (n=4708) as well as chronic alcoholics from the GESGA consortium (n=1332) were screened with Illumina technology. For replication, three European cohorts comprising 1650 patients with non-alcoholic CP and 6695 controls originating from the same countries were used. Results We replicated previously reported risk loci CLDN2-MORC4 , CTRC , PRSS1-PRSS2 and SPINK1 in alcoholic CP patients. We identified CTRB1-CTRB2 (chymotrypsin B1 and B2) as a new risk locus with lead single-nucleotide polymorphism (SNP) rs8055167 (OR 1.35, 95% CI 1.23 to 1.6). We found that a 16.6 kb inversion in the CTRB1-CTRB2 locus was in linkage disequilibrium with the CP-associated SNPs and was best tagged by rs8048956 . The association was replicated in three independent European non-alcoholic CP cohorts of 1650 patients and 6695 controls (OR 1.62, 95% CI 1.42 to 1.86). The inversion changes the expression ratio of the CTRB1 and CTRB2 isoforms and thereby affects protective trypsinogen degradation and ultimately pancreatitis risk. Conclusion An inversion in the CTRB1-CTRB2 locus modifies risk for alcoholic and non-alcoholic CP indicating that common pathomechanisms are involved in these inflammatory disorders.