A genome-wide association study in Han Chinese identifies a susceptibility locus for primary Sjogren's syndrome at 7q11.23

Primary Sjogren's syndrome is one of the most common autoimmune diseases. So far, genetic studies of Sjogren's syndrome have relied mostly on candidate gene approaches. To identify new genetic susceptibility loci for primary Sjogren's syndrome, we performed a three-stage genome-wide association study in Han Chinese. In the discovery stage, we analyzed 556,134 autosomal SNPs in 542 cases and 1,050 controls. We then validated promising associations in 2 replication stages comprising 1,303 cases and 2,727 controls. The combined analysis identified GTF2I at 7q11.23 (rs117026326: P-combined = 1.31 x 10(-53), combined odds ratio (ORcombined) = 2.20) as a new susceptibility locus for primary Sjogren's syndrome. Our analysis also confirmed previously reported associations in Europeans in the regions of STAT4, TNFAIP3 and the major histocompatibility complex (MHC). Fine mapping of the region around GTF2I showed that rs117026326 in GTF2I had the most significant association, with associated SNPs extending from GTF2I to GTF2IRD1-GTF2I.