title: Tumor necrosis factor promoter polymorphism TNF*-857 is a risk allele for psoriatic arthritis independent of the PSORS1 locus.
abstract: OBJECTIVE
  The strongest susceptibility locus of psoriatic arthritis (PsA) is within the major histocompatibility complex (MHC) region (psoriasis susceptibility region 1, or PSORS1), and HLA-Cw*06:02 has been reported as the PSORS1 susceptibility allele. Non-HLA genes within the MHC region have also been implicated in PsA, but because of the strong linkage disequilibrium at chromosome 6p21, it is difficult to make a distinction between susceptibility alleles and linked markers. Recent studies have demonstrated that the association between PsA and the tumor necrosis factor (TNF) promoter polymorphism TNF*-857 is independent of PSORS1. The aim of this study was to replicate the independent association of TNF*-857 in patients with PsA.
  
  
  METHODS
  A total of 909 patients with PsA and 1,315 healthy controls originating from the UK, Germany, and Italy were typed for TNF*-857 and for the estimated risk alleles of HLA-Cw*06:02.
  
  
  RESULTS
  Overall, the results of genotyping in these 3 case-control cohorts replicated the finding that the frequency of carriers of TNF*-857 TT/CT who were negative for the PSORS1 risk allele was significantly higher among patients with PsA compared with control subjects (30% versus 21%; P = 9.17 × 10(-5)).
  
  
  CONCLUSIONS
  The results of this collaborative study indicate that TNF*-857T is a susceptibility allele for PsA independent of the PSORS1 allele.
authors: University of Rome Tor Vergata and Fondazione Policlinico Tor Vergata, Rome, Italy.
authors: Emiliano
authors: E
authors: Giardina
authors: Ulrike
authors: U
authors: Hüffmeier
authors: Jaya
authors: J
authors: Ravindran
authors: Frank
authors: F
authors: Behrens
authors: Tiziana
authors: T
authors: Lepre
authors: Neil J
authors: NJ
authors: McHugh
authors: Eleanor
authors: E
authors: Korendowych
authors: Harald
authors: H
authors: Burkhardt
authors: Giuseppe
authors: G
authors: Novelli
authors: André
authors: A
authors: Reis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D015535:Arthritis, Psoriatic / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D005858:Germany; D015236:HLA-C Antigens / Q000235:genetics; D006801:Humans; D007558:Italy; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D006113:United Kingdom
chemical_list: D015236:HLA-C Antigens; C491620:HLA-C*06:02 antigen; C484393:PSORS1C1 protein, human; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha