IFNG and leprosy: In particular, the IFNG rs1861494 SNP was a good candidate to study the genetic association because it has been widely validated (sequenced in 1000 Genome project, Genotyped by HapMap project, and multiple, independent submissions to the ref SNP cluster) [33] and associated with different diseases immunoglobulin A (IgA) nephropathy, vitiligo, inflammatory bowel disease, leprosy, tuberculosis, between others) [28,34,35,36,37].