Background: Tuberculosis is an urgent public health problem caused by Mycobacterium tuberculosis infection. Many factors, including host genetic factors, are involved in tuberculosis pathogenesis. The SLC11A1 gene (formerly NRAMP1) is a primary candidate for association with tuberculosis susceptibility.
Methods: We examined the association between SLC11A1 polymorphisms and susceptibility to tuberculosis in Han Chinese children. The study included 136 pediatric patients with tuberculosis and 435 pediatric control subjects. Polymerase chain reaction restriction fragment-length polymorphism analysis was performed with blood samples to distinguish allele genotypes of INT4 (a G-->C single nucleotide change in intron 4, 469 + 14G/C) and the 3'UTR (TGTG deletion in the 3' untranslated region, 1729 + 55del) in the SLC11A1 gene. Differences in genotype frequency were analyzed for patients with tuberculosis and control subjects.
Results: We did not identify any statistically significant differences between the tuberculosis and control groups with regard to the frequency of genotype variants G/C and C/C at the INT4 locus. The frequency of genotype variants (TGTG +/delete and TGTG delete/delete) was significantly higher in the tuberculosis group than in the control group at the 3'UTR locus. Differences in genotype distribution at the 3'UTR locus were only identified in female subjects, with a greater number of variant genotypes in the tuberculosis group.
Conclusions: Variant genotypes at the 3'UTR locus in the SLC11A1 gene were associated with pediatric tuberculosis in Chinese patients. Patient sex may affect the outcome of M. tuberculosis infection in children.