Variations in the NRAMP1 gene and susceptibility of tuberculosis in Taiwanese

National Taiwan University Hospital, Taipei, Taiwan.

To study the variations in the NRAMP1 gene using five genotypes (274C/T, 577-18G/A, A318V, D543N and 3' untranslated region [UTR]), and the susceptibility of tuberculosis and HIV infection in Taiwanese.

The study sample included 49 patients with tuberculosis, 48 healthy control subjects and 60 HIV-infected patients. The polymerase chain reaction (PCR) products amplified from their genomic DNA were subjected to restriction enzyme digestion and were analysed using agarose gel electrophoresis.

A318V was not polymorphic in the studied population. Only D543N and 3'UTR were more heterozygous. In 274 C/T and 577-18G/A, the allele frequencies showed the predominant type to be the homozygous patterns C/C (94%) and G/G (94%), respectively. There were no statistically significant differences between the tuberculosis patients and the healthy control subjects. Despite the high susceptibility to Mycobacterium tuberculosis in HIV-infected patients, genotypic frequencies in the HIV-positive patients were not significantly different between tuberculous (n = 29) and non-tuberculous patients (n = 31). In comparison with previous studies, there were significant differences between different ethnic groups in allele frequencies for 274C/T, D543N and 3'UTR.

The allele and genotype of NRAMPI polymorphism among Taiwanese differed from those of Caucasians, Africans and Hispanics. No allelic associations were identified between the NRAMP1 alleles and tuberculosis susceptibility.