Variations in the NRAMP1 gene and susceptibility of tuberculosis in Taiwanese

SETTING: National Taiwan University Hospital, Taipei, Taiwan. OBJECTIVE: 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. DESIGN: 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. RESULTS: 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 nontuberculous 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. CONCLUSION: The allele and genotype of NRAMP1 polymorphism among Taiwanese differed from those of Caucasians, Africans and Hispanics. No allelic associations were identified between the NRAMP1 alleles and tuberculosis susceptibility.