Genome-wide association analysis identifies three psoriasis susceptibility loci

To identify novel psoriasis susceptibility loci, we carried out a meta-analysis of two recent genome-wide association studies 1,2, yielding a discovery sample of 1,831 cases and 2,546 controls. 102 of the most promising loci in the discovery analysis were followed up in a three-stage replication study using 4,064 cases and 4,685 controls from Michigan, Toronto, Newfoundland, and Germany. Association at a genome-wide level of significance for the combined discovery and replication samples was found for three genomic regions. One contains NOS2 (rs4795067, p = 4 × 10(−11)), another contains FBXL19 (rs10782001, p = 9 × 10(−10)), and a third contains PSMA6 and NFKBIA (rs12586317, p = 2 × 10(−8)). All three loci were also strongly associated with the subphenotypes of psoriatic arthritis and purely cutaneous psoriasis. Finally, we confirmed a recently identified3 association signal near RNF114.