Abstract:
objectives To investigate the association between selected single nucleotide polymorphisms (SNPs) in
TNF, LTA and SLC11A1 genes and risk of endemic cutaneous leishmaniasis (CL) in Sri Lanka through a
case–control disease association study.
methods An anonymized DNA resource representative of the Sri Lankan population was genotyped
initially to establish baseline parameters. This was followed up by genotyping 200 patients and 200
matched controls. Published or modified PCR ⁄ RFLP methods were employed for genotyping.
results Comparison of the different ethnic groups showed the distribution of alleles of LTA +252
A>G to differ significantly in Tamils and Moors when compared with Sinhalese. The differences seen at
allele level were also reflected in the haplotypes defined by these SNPs at the TNF locus. The case–
control analysis did not show an association between the SNPs or the haplotypes investigated and CL.
The distribution of these variant alleles in other populations, where they are positively associated with
leishmaniasis, differed significantly from the Sri Lankan study cohort.
conclusions The selected polymorphisms do not predispose to CL in the Sri Lankan population. The
study of extended haplotypes at these loci using a sufficiently powered sample collection would elaborate
the findings of this study. In the face of an evolving disease pattern in the country with other forms of
leishmaniasis now being reported, prevalence of polymorphisms predisposing to these forms calls for
heightened surveillance and preparedness.
