Stratification of the SLE patients and controls in Central Europeans and Southern Europeans showed that two of the 11 SNPs (rs3131379 in MSH5, P = 0.003; and rs2187668 in HLA-DQA1, P = 0.046) were significantly more associated in the Southern subgroup than in the Central European subgroup in the Mantel-Haenszel meta-analysis (Figure 1B); but none was significantly different in the random-effects meta-analysis (see Figure S2 in Additional file 1). Here, HLA-DQA1 is linked to systemic lupus erythematosus.