Abstract: Objective To explore the correlation of polymorphisms of AF4/FMR2 family genes and IL-10 gene with genetic susceptibility to ankylosing spondylitis (AS) and identify the high-risk factors of AS. Methods This case-control study was conducted among 207 AS patients and 321 healthy individuals. The tag single nucleotide polymorphisms (SNPs) rs340630, rs241084, rs10865035, rs1698105, and rs1800896 of the AF4/FMR2 family gene and IL-10 gene of the AS patients were genotyped, and the distribution frequencies of the genotypes and alleles were analyzed to explore the relationship between different genetic models and AS and the gene-gene and gene-environment interactions. Results Gender ratio, smoking history, drinking history, hypertension, erythrocyte sedimentation rate and C-reactive protein differed significantly between the case group and the control group (P<0.05). The dominant model and recessive model of AFF1 rs340630, the recessive model of AFF3 rs10865035, and the recessive model of IL-10 rs1800896 were significantly different between the two groups (P=0.031, 0.010, 0.031, and 0.019, respectively). Gene-environment interaction analysis suggested that the interaction model incorporating AFF1 rs340630, AFF2 rs241084, AFF3 rs10865035, AFF4 rs1698105, IL- 10 rs1800896, smoking history and drinking history was the best model. The genes related with AF4/FMR2 and IL-10 were enriched in the biological processes of AF4 super extension complex, interleukin family signal transduction, cytokine stimulation and apoptosis. The expression levels of AF4/FMR2 and IL- 10 were positively correlated with immune infiltration (r>0). Conclusion The SNPs of AF4/FMR2 and IL-10 genes are associated with the susceptibility to AS, and the interactions of AF4/FMR2 and IL-10 genes with the environmental factors contributes causes AS through immune infiltration.

Key words: AF4/FMR2; IL-10; gene polymorphism; ankylosing spondylitis