HLA-DRB1 and Sjogren syndrome: LD analysis indicates that the known GD risk locus, HLA DRB1*03, and rs3099844 studied in systemic lupus erythematous and Sjögren syndrome, are in partial LD with rs3094228 (HLA DRB1*03: r2 =0.45, D’ =0.86 in the Polish population (22), rs3099844: r2 =0.69, D’ =0.93 in the British population (28)).