Previously, two small studies reported a leprosy per se risk effect of HLA-DRB1*15:01 and a serotype linked to HLA-DQA1*01, and a well powered study of Brazilian leprosy patients detected a risk effect for both HLA-DRB1*10 and HLA-DRB1*15 [36–38]. This evidence concerns the gene HLA-DRB1 and leprosy.