To investigate SLC26A2, the gene that causes diastrophic dysplasia, in juvenile idiopathic arthritis (JIA).
Nine polymorphisms across the SLC26A2 gene locus were investigated using MassArray genotyping in 826 UK Caucasian JIA cases and 617 ethnically matched healthy controls.
Significant associations between multiple single-nucleotide polymorphisms (SNPs) across SLC26A2 and systemic-onset JIA were found. In each case, homozygosity for the minor allele conferred the increased risk of disease susceptibility: rs1541915 (odds ratio [OR] 2.3, 95% confidence interval [95% CI] 1.4-3.7, P=0.0003), rs245056 (OR 2.8, 95% CI 1.7-4.6, P=0.00002), rs245055 (OR 2.5, 95% CI 1.2-5.0, P=0.004), rs245051 (OR 2.3, 95% CI 1.4-3.7, P=0.0005), rs245076 (OR 2.7, 95% CI 1.3-5.4, P=0.0015), and rs8073 (OR 2.3, 95% CI 0.9-5.6, P=0.04).
These findings show the value of using monogenic disease loci as candidates for investigation in JIA. We identified a subgroup-specific association between SNPs within the SLC26A2 gene and systemic-onset JIA. Our findings also highlight systemic-onset JIA as being a distinctly different disease from that in the other JIA subgroups.