To explore the potential role of these genes in the susceptibility to pulmonary tuberculosis in a Mexican mestizo population, we evaluated the association of D543N and 3'-UTR polymorphisms in NRAMP1/SLC11 A1 and - 762 and A1513C polymorphisms in P2X(7) genes with the risk for tuberculosis.
Polymorphisms at the four loci had no statistically significant association between the SLC11A1 variants and susceptibility to TB in subjects of European descent, while they showed a statistically significant association in Asian subjects (except the INT4 variant), African subjects (except the 3'UTR variant) and the population as a whole (except the INT4 variant).
These data therefore confirm the importance of SLC11A1 in tuberculosis susceptibility in humans and suggest that SLC11A1 influences tuberculosis susceptibility by regulation of interleukin-10.
To determine the model of inheritance for genetic susceptibility to tuberculosis, and to test the hypothesis that TNFA and NRAMP1 are candidate susceptibility genes.
We then examine the putative role of iron-related host genes by focussing on two candidate genes, haptoglobin and NRAMP1, for which there are common polymorphic variants in humans with strong evidence of functionally distinct biochemical phenotypes that would be predicted to influence the course of HIV and TB infections.
The findings of the present study support the hypothesis that genetic variants of NRAMP1 may have an effect on bacilli growth and on outcomes of pulmonary tuberculosis, but not on susceptibility to M. tuberculosis infection.
The 5' (GT)n allele driving the highest rate of transcription of SLC11A1 appears to be associated with protection against TB in the majority of the populations studied.
The association between SLC11A1 polymorphisms and tuberculosis susceptibility observed in our analyses supports the hypothesis that NRAMP1 might play an important role in the host defense to the development of tuberculosis.
These results indicate that variant alleles in the Nramp1 gene are associated with increased mycobacterial replication rather than susceptibility for tuberculosis and may thus confer increased risk of severe disease.
Several studies now provide evidence for a role for NRAMP1 in determining human susceptibility to autoimmune (rheumatoid arthritis. juvenile rheumatoid arthritis, diabetes, Crohn's disease) and infectious (tuberculosis, leprosy) diseases.Amongst these. data are accumulating to support the hypothesis that a functional Z-DNA forming repeat polymorphism in the promoter region of human NRAMP1 contributes directly to disease susceptibility.
Human susceptibility to infectious and inflammatory diseases, including rheumatoid arthritis, inflammatory bowel disease, and tuberculosis, shows allelic association with a highly polymorphic regulatory, Z-DNA-forming microsatellite of (GT/AC)n dinucleotides within the proximal SLC11A1 promoter.