Identification of susceptibility gene associated with female primary Sjögren’s syndrome in Han Chinese by genome-wide association study

Primary Sjögren’s syndrome (PSS) is an autoimmune disease targeting exocrine glands. It ten times more dominantly affects women than men with an onset peak at menopause. The genetic factor predisposing women to PSS remains unclear. Therefore, we aimed to identify susceptibility loci for PSS in women. We performed genome-wide association study (GWAS) using 242 female PSS patients and 1444 female control in Han Chinese population residing in Taiwan. Replication was conducted in an independent cohort of 178 female PSS and 14,432 control subjects. We identified rs117026326 on GTF2I with GWAS significance (P = 1.10 × 10⁻¹⁵) and rs13079920 on RBMS3 with suggestive significance (P = 2.90 × 10⁻⁵) associating with PSS in women. The association of RBMS3 was further evidenced by imputation in which rs13072846 (P = 4.89 × 10⁻⁵) was identified and confirmed as female PSS associating SNP within the same LD with rs13079920. PSS pathogenesis involves both immune (effector) and exocrine (target) system. We suggested that while GTF2I is a previously reported associating gene which may function in immune system, RBMS3 is a novel susceptibility gene that predisposes women to PSS potentially through modulating acinar apoptosis and TGF-β signaling in target exocrine system.