Objective: To determine whether 3'UTR polymorphisms of the NRAMP1 gene are associated with tuberculosis in Hans.
Methods: 3'UTR polymorphisms of NRAMP1 gene were typed by PCR-RFLP among 147 patients with active tuberculosis and 145 healthy individuals. The relationship between 3'UTR polymorphisms and susceptibility to tuberculosis was studied, and cases were grouped according to genotypes.
Results: In the tuberculosis patients, genotype TGTG/TGTG, TGTG/TGTG deleted, and TGTG deleted/TGTG deleted were observed in 95, 50 and 2 cases respectively, while the genotypes of the healthy controls were TGTG/TGTG in 115, TGTG/TGTG deleted in 29 and TGTG deleted/TGTG deleted in 1 case. The frequency of the genotype TGTG/TGTG was found more often among controls than that in patients (chi(2) = 7.79, P < 0.01). The frequency of allele TGTG and the frequency of variant allele were 0.85 and 0.15 respectively.
Conclusions: 3'UTR polymorphisms of NRAMP1 gene are associated with susceptibility to tuberculosis in Hans. The variant allele observed in Hans is more common than that in Caucasians. These observations might explain in part why Hans have greater susceptibility to tuberculosis than Caucasians.