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) (pcombined= 1.4 × 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.

Additional Metadata
Persistent URL dx.doi.org/10.1136/ard.2008.089060, hdl.handle.net/1765/28881
Albers, H.M, Kurreeman, F.A.S, Houwing-Duistermaat, J.J, Brinkman, D.M.C, Kamphuis, S.S.M, Girschick, H.J, … ten Cate, R. (2008). The TRAF1/C5 region is a risk factor for polyarthritis in juvenile idiopathic arthritis. Annals of the Rheumatic Diseases: an international peer-reviewed journal for health professionals and researchers in the rheumatic diseases, 67(11), 1578–1580. doi:10.1136/ard.2008.089060