The IRF5-TNPO3 region showed the strongest association and largest OR for SLE (rs10488631: genomic control-adjusted P [Pgcadj ] = 2.61 × 10(-29), OR 2.12 [95% CI 1.88-2.39]), followed by HLA class II on the DQA2-DQB1 loci (rs9275572: Pgcadj = 1.11 × 10(-16), OR 1.62 [95% CI 1.46-1.80] and rs9271366: Pgcadj = 6.46 × 10(-12), OR 2.06 [95% CI 1.71-2.50]).
To replicate a single nucleotide polymorphism (SNP) of known genes for lupus (IRF5 rs10488631, PTPN22 rs2476601, BLK rs2736340 and TNFAIP3 rs5029939) and other autoimmune diseases (CD28 rs1980422, IL2RA rs2104286 and KIF5A rs1678542) on a newly studied Egyptian cohort to investigate the genetic disparity with different studied ethnic groups in relation to lupus susceptibility.
The variants of IRF5 with the highest posterior probabilities (1.00 and 0.71, respectively) of being causal in SLE are a SNP (rs10488631) located 3' of IRF5, and a novel CGGGG insertion-deletion (indel) polymorphism located 64 bp upstream of the first untranslated exon (exon 1A) of IRF5.