TREX1 polymorphisms associated with autoantibodies in patients with systemic lupus erythematosus

Three-prime repair exonucleases 1 and 2 (TREX1 and TREX2) play a role in the metabolism and clearance of DNA. The objective of this study was to confirm whether polymorphisms of TREX1 and TREX2 are associated with genetic susceptibility to systemic lupus erythematosus (SLE), and examine associations with autoantibodies (auto-Abs) in SLE. We investigated the genetic variants in 24 Korean individuals by direct sequencing. The genotype distributions of single-nucleotide polymorphisms (SNPs) and haplotypes were analyzed with multiple logistic regression models while controlling for covariates. We identified 12 and 5 SNPs of TREX1 and TREX2, of which −20260G>C, −389T>C, −381C>T, and +531C>T SNPs of TREX1; −23386G>C, −14703G>A, −7279C>T, and +1747C>T SNPs of TREX2; and each of three haplotypes were selected for larger scale genotyping (n = 1,053). No statistically significant association with the risk of SLE was observed in TREX1 and TREX2. TREX1 polymorphism −20260G>C showed protective effect on the production of anti-Ro Ab, and +531C>T in exon 16 and ht2 [G–T–C–T] showed also protective effect on the production of anti-dsDNA Ab, although the effect of +531C>T disappeared after multiple correction.