PT  - JOURNAL ARTICLE
AU  - John Bowes
AU  - Sabine Loehr
AU  - Ashley Budu-Aggrey
AU  - Steffen Uebe
AU  - Ian N Bruce
AU  - Marie Feletar
AU  - Helena Marzo-Ortega
AU  - Philip Helliwell
AU  - Anthony W Ryan
AU  - David Kane
AU  - Eleanor Korendowych
AU  - Gerd-Marie Alenius
AU  - Emiliano Giardina
AU  - Jonathan Packham
AU  - Ross McManus
AU  - Oliver FitzGerald
AU  - Matthew A Brown
AU  - Frank Behrens
AU  - Harald Burkhardt
AU  - Neil McHugh
AU  - Ulrike Huffmeier
AU  - Pauline Ho
AU  - Andre Reis
AU  - Anne Barton
TI  - PTPN22 is associated with susceptibility to psoriatic arthritis but not psoriasis: evidence for a further PsA-specific risk locus
AID  - 10.1136/annrheumdis-2014-207187
DP  - 2015 Oct 01
TA  - Annals of the Rheumatic Diseases
PG  - 1882--1885
VI  - 74
IP  - 10
4099  - http://ard.bmj.com/content/74/10/1882.short
4100  - http://ard.bmj.com/content/74/10/1882.full
SO  - Ann Rheum Dis2015 Oct 01; 74
AB  - Objectives Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis; it has a higher estimated genetic component than psoriasis alone, however most genetic susceptibility loci identified for PsA to date are also shared with psoriasis. Here we attempt to validate novel single nucleotide polymorphisms selected from our recent PsA Immunochip study and determine specificity to PsA.Methods A total of 15 single nucleotide polymorphisms were selected (PImmunochip <1×10−4) for validation genotyping in 1177 cases and 2155 controls using TaqMan. Meta-analysis of Immunochip and validation data sets consisted of 3139 PsA cases and 11 078 controls. Novel PsA susceptibility loci were compared with data from two large psoriasis studies (WTCCC2 and Immunochip) to determine PsA specificity.Results We found genome-wide significant association to rs2476601, mapping to PTPN22 (p=1.49×10−9, OR=1.32), but no evidence for association in the psoriasis cohort (p=0.34) and the effect estimates were significantly different between PsA and psoriasis (p=3.2×10−4). Additionally, we found genome-wide significant association to the previously reported psoriasis risk loci; NOS2 (rs4795067, p=5.27×10−9).Conclusions For the first time, we report genome-wide significant association of PTPN22 (rs2476601) to PsA susceptibility, but no evidence for association to psoriasis.