The minor haplotype -3575A/-2849G/-2763C in IL-10 promoter has been defined as a marker of disease resistance to leprosy and its severity in Brazilian population. Our investigation of six single-nucleotide polymorphisms (SNPs) in IL-10 promoter in 282 Indian leprosy patients and 266 healthy controls by direct PCR sequencing, however, showed that the extended haplotype: -3575T/-2849G/-2763C/-1082A/-819C/-592C was associated with resistance to leprosy per se and to the development of severe form of leprosy, using either a binomial (controls vs cases, P=0.01, OR=0.58, CI=0.37-0.89) or ordinal (controls vs paucibacillary vs multibacillary, P=0.004) model. Whereas, IL-10 haplotype -3575T/-2849G/-2763C/-1082A/-819T/-592A was associated with the risk of development of severe form of leprosy (P=0.0002) in contrast to the minor risk haplotype -3575T/-2849A/-2763C in the Brazilian population. The role of IL-10 promoter SNPs in Brazilian and Indian population strongly suggests the involvement of IL-10 locus in the outcome of leprosy.

Single nucleotide polymorphisms (SNPs) in the regulatory region shared by PARK2 and PACRG have been identified as major risk factors for leprosy susceptibility in two ethnically distinct populations. We investigated the association of six SNPs present in this regulatory region with leprosy susceptibility in an Indian population. Genotyping was performed by direct PCR sequencing in 286 leprosy patients and 350 healthy controls. Our results showed that T allele of SNPs PARK2_e01 (À2599) and 28 kb target_2_1 was significantly associated with susceptibility to leprosy per se (P ¼ 0.03 and 0.03, respectively). The T allele of SNPs PARK2_e01 (À2599) showed a significant recessive effect (P ¼ 0.04) in susceptibility to leprosy in Indian population as against the dominant effect of haplotype T-C of the major risk SNPs PARK2_e01 (À2599) and rs1040079 in Brazilian and Vietnamese population. However, after bonferroni corrections, these significant differences disappeared. Haplotype analysis also showed a lack of significant association of any haplotype with cases or controls. The noninvolvement of major risk SNPs in the regulatory region of PARK2 and PACRG locus with leprosy susceptibility in Indian population highlights the differential effect of these SNPs in regulating genetic susceptibility to leprosy in different populations.

Since the publication of the above paper, the authors have identified a typographical error regarding the primer sequences for the forward and reverse primers of rs1040079 (SNP), where the reverse primer sequence is duplicated for the forward primer. The correct forward and reverse primer sequences are as follows: Forward: 5-CTCGTGCCAGGAGGAAAAT-3 Reverse: 5-GGACTAAAGGGCATGGTGAG-3.