However, we observed that CARD9 allele C (p = 0.012) and genotype CC (p = 0.012) were significant protective factors against AS only in HLA-B27-negative patients, and IL1R2 rs2310173 genotype GT was mildly protective against AS only in HLA-B27-negative status.
Our study confirmed that an SNP rs11145835 in 9q34.3 that harbors CARD9 and SNAPC4 is associated with AS in a Chinese Han population, and rs11145835 in SNAPC4 is a potential causal variant.
Here we report the identification of three variants in the RUNX3, LTBR-TNFRSF1A and IL12B regions convincingly associated with ankylosing spondylitis (P < 5 × 10(-8) in the combined discovery and replication datasets) and a further four loci at PTGER4, TBKBP1, ANTXR2 and CARD9 that show strong association across all our datasets (P < 5 × 10(-6) overall, with support in each of the three datasets studied).