P665. A genome-wide association study identifies DSE-FAM26F as a risk locus for ulcerative colitis
E. Domènech1, A. Juliá2, M. Chaparro3, V. García-Sánchez4, F. Gomollón5, J. Panés6, M. Mañosa7, M. Barreiro-de Acosta8, A. Gutiérrez9, E. García-Planella10, P. Nos11, F. Muñoz12, M. Esteve13, J.L. Mendoza14, M. Vera15, L. Marquez16, R. Tortosa2, M. López-Lasanta2, A. Alonso2, J.L. Gelpí17,18, A. García-Montero19, J. Bertanpetit20, D. Absher21, R. Myers21, S. Marsal2, J.P. Gisbert3, 1Hospital Universitari Germans Trias i Pujol and CIBERehd, Gastroenterology Unit, Badalona, Spain, 2Vall d'Hebron Hospital Research Institute, Rheumatology Research Group, Barcelona, Spain, 3Hospital Universitario de La Princesa, IP and CIBERehd, Gastroenterology Unit, Madrid, Spain, 4Hospital Universitario Reina Sofía, Gastroenterology Unit, Córdoba, Spain, 5Hospital Clínico Universitario and CIBERehd, Gastroenterology Unit, Zaragoza, Spain, 6Hospital Clinic de Barcelona, IDIBAPS and CIBERehd, Gastroenterology Unit, Barcelona, Spain, 7Hospital Universitari Germans Trias i Pujol and CIBERehd, Gastroenterology Unit, Barcelona, Spain, 8Hospital Clínico Universitario, Gastroenterology Unit, Santiago de Compostela, Spain, 9Hospital General de Alicante and CIBERehd, Gastroenterology Unit, Alicante, Spain, 10Hospital de la Santa Creu i Sant Pau, Gastroenterology Unit, Barcelona, Spain, 11Hospital La Fe and CIBERehd, Gastroenterology Unit, Valencia, Spain, 12Complejo Hospitalario de León, Gastroenterology Unit, León, Spain, 13Hospital Universitari Mutua de Terrasa, Gastroenterology Unit, Barcelona, Spain, 14Hospital Clínico San Carlos, Gastroenterology Unit, Madrid, Spain, 15Hospital Universitario Puerta de Hierro, Gastroenterology Unit, Madrid, Spain, 16IMIM. Hospital del Mar Medical Research Institute. Pompeu Fabra University, Gastroenterology Unit, Barcelona, Spain, 17National Institute of Bioinformatics, Life Sciences, Barcelona Supercomputing Centre, Barcelona, Spain, 18University of Barcelona, Biochemistry and Molecular Biology, Barcelona, Spain, 19University of Salamanca, Banco Nacional de ADN Carlos III, Salamanca, Spain, 20Universitat Pompeu Fabra, Nacional Genotyping Centre (CeGen), Barcelona, Spain, 21Hudson Alpha Institute for Biotechnology, Alabama, United States
The genetic background that influences the risk to develop ulcerative colitis (UC) is complex and much of its heritability remains to be identified. We have conducted the first Genome-Wide Association Study in a Southern European population to identify new UC risk loci.
We genotyped 620,901 genome markers on 825 UC patients and 1,525 healthy controls from the Spanish population. We conducted a meta-analysis with the results from six previously published GWAS comprising 6,687 cases and 19,718 controls from Northern European ancestry. Additionally, we selected the most significantly associated loci in our GWAS (n = 61, P < 5×10−4) and conducted a validation study using an independent cohort of 1,290 UC patients and 1,279 controls from the same ancestry.
In the GWAS meta-analysis we identified a genome-wide significant association of DSE-FAM26F locus SNP rs2858829 and UC risk [P = 8.97×10−9, OR (95% CI) = 1.12 (1.08–1.16)]. This SNP shows a strong cis-eQTL association with FAM26F gene, which is selectively upregulated in colonic mucosa with active inflammation. Eight out of the 61 loci analyzed in the replication cohort were nominally replicated (P < 0.05, same direction of effect) and there is a high likelihood that these loci are true UC risk factors.
In the first GWAS performed in a Southern European population we have found a new risk locus for UC and identified eight loci with highly suggestive evidence of association with UC. This study confirms that using different ancestry populations is a powerful approach to identify new genetic risk factors for UC.