Exome-wide association study reveals novel psoriasis susceptibility locus at TNFSF15 and rare protective alleles in genes contributing to type I IFN signalling
Dand N, Mucha S, Tsoi LC, Mahil SK, Stuart PE, Arnold A, Baurecht H, Burden AD, Callis Duffin K, Chandran V, Curtis CJ, Das S, Ellinghaus D, Ellinghaus E, Enerback C, Esko T, Gladman DD, Griffiths CE, Gudjonsson JE, Hoffman P, Homuth G, Hüffmeier U, Krueger GG, Laudes M, Lee S, Lieb W, Lim HW, Löhr S, Mrowietz U, Müller-Nurayid M, Nöthen M, Peters A, Rahman P, Reis A, Reynolds N, Rodriguez E, Schmidt C, Spain S, Strauch K, Tejasvi T, Voorhees J, Warren R, Weichenthal M, Weidinger S, Zawistowski M, Nair R, Capon F, Smith C, Trembath R, Abecasis G, Elder J, Franke A, Simpson M, Barker J. Exome-wide association study reveals novel psoriasis susceptibility locus at TNFSF15 and rare protective alleles in genes contributing to type I IFN signalling. Human molecular genetics 2017; 26(21):4301-4313.
Human molecular genetics
Psoriasis is a common inflammatory skin disorder for which multiple genetic susceptibility loci have been identified, but few resolved to specific functional variants. In this study, we sought to identify common and rare psoriasis-associated gene-centric variation. Using exome arrays we genotyped four independent cohorts, totalling 11 861 psoriasis cases and 28 610 controls, aggregating the dataset through statistical meta-analysis. Single variant analysis detected a previously unreported risk locus at TNFSF15 (rs6478108; P = 1.50 × 10-8, OR = 1.10), and association of common protein-altering variants at 11 loci previously implicated in psoriasis susceptibility. We validate previous reports of protective low-frequency protein-altering variants within IFIH1 (encoding an innate antiviral receptor) and TYK2 (encoding a Janus kinase), in each case establishing a further series of protective rare variants (minor allele frequency < 0.01) via gene-wide aggregation testing (IFIH1: pburden = 2.53 × 10-7, OR = 0.707; TYK2: pburden = 6.17 × 10-4, OR = 0.744). Both genes play significant roles in type I interferon (IFN) production and signalling. Several of the protective rare and low-frequency variants in IFIH1 and TYK2 disrupt conserved protein domains, highlighting potential mechanisms through which their effect may be exerted.
Medical Subject Headings
Alleles; Case-Control Studies; Cohort Studies; Exome; Female; Gene Frequency; Genetic Predisposition to Disease; Genetic Variation; Genome-Wide Association Study; Genotype; Humans; Interferon-Induced Helicase, IFIH1; Male; Polymorphism, Single Nucleotide; Psoriasis; Risk Factors; TYK2 Kinase; Tumor Necrosis Factor Ligand Superfamily Member 15; Whole Exome Sequencing