Identification of Genetic Predisposition to Sjögren’s Syndrome by Whole Exome Sequencing

A comprehensive understanding of the genetic predisposition associated with the initiation and development of Sjögren’s syndrome (SjS) is imperative. This would not only enrich our knowledge of the pathogenesis underlying this autoimmune disease but also address the long-standing clinical challenges of more timely diagnosis and effective treatment to retain organ function and improve prognosis. In this study, we used whole exome sequencing analysis of 50 patients with SjS to investigate the predisposing variants, genes, and their associated biological functions. Hundreds of predisposing genes were identified, and numerous biological processes and pathways were highlighted; suggesting a heterogeneity of genetic predisposition to SjS. Female patients carrying a greater number of enriched variants tended to have higher levels of serum IgG and corresponding systemic involvement, demonstrating the pivotal role of genetic predisposition in the pathogenesis of SjS. Biological function analysis indicated that a subset of SjS and neuropathies may share a similar genetic predisposition. Our results showed that extracellular matrix-receptor interactions, macrophage-associated biological functions, and motor proteins may play important roles in the pathogenesis of SjS, and macrophage-associated biological functions may be associated with early onset SjS in female patients. Furthermore, the identification of highly enriched variants in the patient cohort provides the possibility of advancing the diagnosis of SjS. In conclusion, our study provides an extensive framework for analysis of the genetic predisposition to SjS which can facilitate further focused and in-depth investigation of the pathogenetic mechanisms of specific genes, biological processes, and pathways; thereby contributing to the pathophysiology, diagnosis, and therapeutics of SjS.