Rheumatology Advance Access originally published online on June 22, 2004
Rheumatology 2004 43(9):1138-1141; doi:10.1093/rheumatology/keh261
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Rheumatology Vol. 43 No. 9 © British Society for Rheumatology 2004; all rights reserved
Concise Report |
Linkage and association studies of discoidin domain receptor 1 (DDR1) single nucleotide polymorphisms (SNPs) in juvenile oligoarthritis
CIGMR, 1 ARC Epidemiology Unit and 2 School of Biological Sciences, University of Manchester, Manchester, UK and 3 Department of Cell Biology, Harvard Medical School and Department of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Boston, MA, USA. 4 Contributors to the British Paediatric Rheumatology Study Group: M. Abinun, M. Becker, A. Bell, A. Craft, E. Crawley, J. David, H. Foster, J. Gardener-Medwin, J. Griffin, A. Hall, M. Hall, A. Herrick, P. Hollingworth, L. Holt, S. Jones, G. Pountain, C. Ryder, T. Southwood, I. Stewart, L. Wedderburn, P. Woo, S. Wyatt and H. Venning.
Correspondence to: E. Zeggini, WTCHG, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK. E-mail: elez{at}well.ox.ac.uk
Objectives. Multiple independent juvenile oligoarthritis susceptibility loci have been identified within the major histocompatibility complex (MHC), including HLA-A, HLA-DRB1 and an as yet unlocalized effect in the centromeric class I region. The discoidin domain receptor 1 (DDR1) gene resides within this region and codes for a receptor tyrosine kinase that plays an important role in regulating cell attachment to collagen, chemotaxis, proliferation and matrix metalloproteinase (MMP) production. DDR1 expression in chondrocytes has not been investigated. The objectives of this study were to investigate expression of DDR1 in healthy chondrocytes and to identify linkage and association of this candidate gene with juvenile oligoarthritis.
Methods. A set of 135 simplex juvenile idiopathic arthritis families consisting of one affected child and healthy parent(s) and 199 healthy unrelated individuals were genotyped for six single nucleotide polymorphisms (SNPs) within the DDR1 gene using the primer extension SNaPshotTM method. Single-point and multipoint transmission disequilibrium tests were carried out with the ETDT and TDTPHASE packages. Allele frequency comparisons between cases and controls were carried out with the
2 test. DDR1 expression was investigated in normal articular cartilage by RT-PCR and immunofluorescence methods.
Results. No linkage and association with any of the six SNPs or their haplotypic combinations were observed in the families studied. No significant differences were observed in allele frequencies between patients and controls. DDR1 expression was found in normal articular cartilage by RT-PCR and by immunofluorescence.
Conclusions. The DDR1 SNPs examined are not involved in susceptibility to juvenile oligoarthritis.
KEY WORDS: Juvenile oligoarthritis, DDR1, MHC, Linkage, Association, SNP, Haplotype