No evidence of association of the KLF12 gene with rheumatoid arthritis in Spanish and Dutch cohorts and a meta-analysis of published data

The aim of the present study was to replicate the previously reported association of KLF12 gene polymorphisms with rheumatoid arthritis (RA). Two independent cohorts from Spain (1,360 RA patients and 1,520 controls) and the Netherlands (1,018 RA patients and 1,150 controls) were genotyped for KLF12 rs1887346 and rs9565072 single-nucleotide polymorphisms using a TaqMan 5'-allele discrimination assay. No evidence of association of RA with the minor T allele of rs9565072 (31.82% vs 33.73%; p = 0.14, odds ratios [OR] 0.92 [95% confidence interval (CI) 0.82-1.03]) or the minor A allele of rs1887346 polymorphism (21.60% vs 21.77%; p = 0.88, OR 0.99 [95% CI 0.87-1.13]) was observed in Spanish patients compared with healthy controls. This lack of association was also confirmed in the Dutch cohort: the minor T allele frequency of rs9565072 in Dutch RA patients was 35.34% versus 35.57% in controls; p = 0.87, OR 0.99 (95% CI 0.87-1.12); and the minor A allele frequency of rs1887346 in Dutch RA patients was 27.64% versus 28.17% in controls; p = 0.70, OR 0.97 (95% CI 0.85-1.12). A meta-analysis of published KLF12 gene association with RA revealed a pooled OR of 0.99 (95% CI 0.93-1.04) for rs1887346 and a pooled OR of 0.99 (95% CI 0.95-1.04) for rs9565072. In conclusion, our findings indicate that the KLF12 rs1887346 and rs9565072 polymorphisms do not play a relevant role in RA.