title: The TRAF1/C5 region is a risk factor for polyarthritis in juvenile idiopathic arthritis.
abstract: OBJECTIVE
  Juvenile idiopathic arthritis (JIA) is a chronic disorder in which both genetic and environmental factors are involved. Recently, we identified the TRAF1/C5 region (located on chromosome 9q33-34) as a risk factor for rheumatoid arthritis (RA) (p(combined) = 1.4 x 10(-8)). In the present study the association of the TRAF1/C5 region with the susceptibility to JIA was investigated.
  
  
  METHODS
  A case-control association study was performed in 338 Caucasian patients with JIA and 511 healthy individuals. We genotyped the single nucleotide polymorphism rs10818488 as a marker for the TRAF1/C5 region.
  
  
  RESULTS
  The A allele was associated with the susceptibility to rheumatoid factor-negative polyarthritis with an 11% increase in allele frequency (OR 1.54, 95% CI 1.09 to 2.18; p = 0.012). This association was stronger when combining subtypes with a polyarticular phenotype (OR 1.46, 95% CI 1.12 to 1.90; p = 0.004). In addition, we observed a trend towards an increase in A allele frequency in patients with extended oligoarthritis versus persistent oligoarthritis (49%, 38% respectively); p = 0.055.
  
  
  CONCLUSIONS
  Apart from being a well replicated risk factor for RA, TRAF1/C5 also appears to be a risk factor for the rheumatoid factor-negative polyarthritis subtype of JIA and, more generally, seems to be associated with subtypes of JIA characterised by a polyarticular course.
authors.affiliation: Department of Paediatrics, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: H M
authors.initials: HM
authors.lastname: Albers
authors.forename: F A S
authors.initials: FA
authors.lastname: Kurreeman
authors.forename: J J
authors.initials: JJ
authors.lastname: Houwing-Duistermaat
authors.forename: D M C
authors.initials: DM
authors.lastname: Brinkman
authors.forename: S S M
authors.initials: SS
authors.lastname: Kamphuis
authors.forename: H J
authors.initials: HJ
authors.lastname: Girschick
authors.forename: C
authors.initials: C
authors.lastname: Wouters
authors.forename: M A J
authors.initials: MA
authors.lastname: Van Rossum
authors.forename: W
authors.initials: W
authors.lastname: Verduijn
authors.forename: R E M
authors.initials: RE
authors.lastname: Toes
authors.forename: T W J
authors.initials: TW
authors.lastname: Huizinga
authors.forename: M W
authors.initials: MW
authors.lastname: Schilham
authors.forename: R
authors.initials: R
authors.lastname: ten Cate
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D047990:TNF Receptor-Associated Factor 1 / Q000235:genetics*
chemical_list: D047990:TNF Receptor-Associated Factor 1