Assessment of the complexities of genetic contributions to Ankylosing Spondylitis

Abstract

Objectives This research assesses whether structural variations can predict disease expression and whether gene-environment interactions can predict radiographic severity and progression. Methods In a cohort of 896 AS patients the associations of UGT2B17 CNV with HLA B27 and extra-­‐articular features were compared using the Chi-­‐ Squared test. A second cohort of 76 AS patients were assessed using multiple linear regression analysis of serial radiographic assessments and SNPs from three genes related to smoking metabolism. Results No association was found between having UGT2B17 CNV 2 and IBD (p-value = 0.155), psoriasis (p-value = 0.481), uveitis (p-value = 0.466) or HLA-B27 positivity (pvalue = 0.118). Two SNPs from CHRNA7 were associated with radiographic severity: rs11071593 and rs7178176 (p-value = 0.0005). Two SNPs from CHRNA7 were associated with radiographic progression: rs2337506 and rs12910885 (p-value < 0.0001). Conclusion No association was found between UGT2B17 CNVs and disease expression; however, we have demonstrated an association between CHRNA7 SNPs and AS radiographic severity and progression.