Differential NRAMP1gene's D543N genotype frequency: Increased risk of contracting tuberculosis among Venezuelan populations.

NRAMP1 and VDR gene polymorphisms have been variably associated with susceptibility to tuberculosis (TB) amongst populations having different genetic background. NRAMP1 and VDR gene variants' association with susceptibility to active infection by Mycobacterium tuberculosis (Mtb) was analyzed in the Warao Amerindian population, an ethnic population from Venezuela's Orinoco delta region. Genomic DNA was extracted from individuals with and without TB to evaluate genetic polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Four NRAMP1 gene polymorphisms were analyzed: D543N (rs17235409), 3' UTR (rs17235416), INT4 (rs3731865), and 274C/T (rs2276631), and one VDR gene polymorphism: FokI (rs2228570). The results showed that the genotypes D543N-A/A, 3'UTR-TGTG+/+, INT4-C/C, and 274C/T-T/T of known polymorphism in the NRAMP1 gene, as well as the genotypes FokI-F/f and FokI-f/f in the VDR gene were most often found in indigenous Warao with active TB. Binomial logistic regression was used for evaluating associations between polymorphisms and risk of contracting TB, an association between NRAMP1-D543N-A/A genotype distribution and TB susceptibility was found in Warao Amerindians. Regarding Venezuelan populations having different genetic backgrounds; statistically significant TB associations concerning NRAMP1-D543N-A/A, INT4-C/C and 3'UTR-TGTG+/+ variant genotype distributions in Warao Amerindians (indigenous) compared to Creole (admixed non-indigenous population) individuals were found. In conclusion, the results thus indicated that the association between NRAMP1-D543N-A/A genotype and TB in Warao Amerindians could support such allele's role in host susceptibility to Mtb infection.

Association of the solute carrier family 11 member 1 gene polymorphisms with susceptibility to leprosy in a Brazilian sample

Natural resistance-associated macrophage protein 1/solute carrier family 11 member 1 gene (Nramp1/Slc11a1) is a gene that controls the susceptibility of inbred mice to intracellular pathogens. Polymorphisms in the human Slc11a1/Nramp1 gene have been associated with host susceptibility to leprosy. This study has evaluated nine polymorphisms of the Slc11a1/Nramp1 gene [(GT)n, 274C/T, 469+14G/C, 577-18G/A, 823C/T, 1029 C/T, 1465-85G/A, 1703G/A, and 1729+55del4] in 86 leprosy patients (67 and 19 patients had the multibacillary and the paucibacillary clinical forms of the disease, respectively), and 239 healthy controls matched by age, gender, and ethnicity. The frequency of allele 2 of the (GT)n polymorphism was higher in leprosy patients [p = 0.04, odds ratio (OR) = 1.49], whereas the frequency of allele 3 was higher in the control group (p = 0.03; OR = 0.66). Patients carrying the 274T allele (p = 0.04; OR = 1.49) and TT homozygosis (p = 0.02; OR = 2.46), such as the 469+14C allele (p = 0.03; OR = 1.53) of the 274C/T and 469+14G/C polymorphisms, respectively, were more frequent in the leprosy group. The leprosy and control groups had similar frequency of the 577-18G/A, 823C/T, 1029C/T, 1465-85G/A, 1703G/A, and 1729+55del4 polymorphisms. The 274C/T polymorphism in exon 3 and the 469+14G/C polymorphism in intron 4 were associated with susceptibility to leprosy, while the allele 2 and 3 of the (GT)n polymorphism in the promoter region were associated with susceptibility and protection to leprosy, respectively.

Polymorphisms of the coding region of Slc11a1 (Nramp1) gene associated to natural resistance against bovine brucellosis / Polimorfismos na região codificadora do gene Slc11a1 (Nramp1) associados à resistência natural contra brucelose bovina

Brucelose bovina causada por Brucella abortus é uma importante doença zoonótica, caracterizada pela ocorrência de aborto durante o último trimestre da gestação, o que resulta em diminuição da fertilidade da produção de leite em vacas. A identificação de genes associados à resistência natural contra brucelose tem sido investigada com o objetivo de selecionar animais resistentes à doença. Em bovinos, é controversa a resistência natural contra B. abortus associada ao polimorfismo da região 3' UTR do gene Slc11A1 (Nramp1). Polimorfismos localizados na sequência codificadora de Slc11A1 têm sido identificados em bovinos, contudo a influência sobre a resistência natural contra brucelose não é conhecida. No presente estudo, três novos polimorfismos do gene Slc11A1 foram genotipados por análise conformacional de fita simples em vacas experimentalmente ou naturalmente infectadas por B. Abortus, e foram avaliadas a frequência de cada genótipo e sua associação com o fenótipo de resistência ou susceptibilidade à brucelose bovina. Os resultados deste estudo demonstram que alguns genótipos foram mais frequentes em animais considerados fenotipicamente susceptiveis à brucelose.

Polymorphisms of the coding region of Slc11a1 (Nramp1) gene associated to natural resistance against bovine brucellosis

Brucelose bovina causada por Brucella abortus é uma importante doença zoonótica, caracterizada pela ocorrência de aborto durante o último trimestre da gestação, o que resulta em diminuição da fertilidade da produção de leite em vacas. A identificação de genes associados à resistência natural contra brucelose tem sido investigada com o objetivo de selecionar animais resistentes à doença. Em bovinos, é controversa a resistência natural contra B. abortus associada ao polimorfismo da região 3' UTR do gene Slc11A1 (Nramp1). Polimorfismos localizados na sequência codificadora de Slc11A1 têm sido identificados em bovinos, contudo a influência sobre a resistência natural contra brucelose não é conhecida. No presente estudo, três novos polimorfismos do gene Slc11A1 foram genotipados por análise conformacional de fita simples em vacas experimentalmente ou naturalmente infectadas por B. Abortus, e foram avaliadas a frequência de cada genótipo e sua associação com o fenótipo de resistência ou susceptibilidade à brucelose bovina. Os resultados deste estudo demonstram que alguns genótipos foram mais frequentes em animais considerados fenotipicamente susceptiveis à brucelose.

The NRAMPI, VDR and TNF-¦Á gene polymorphisms in Iranian tuberculosis patients: the study on host susceptibility

The natural resistance-associated macrophage protein (NRAMP1), Vitamin-D receptor (VDR) and Tumor necrosis factor (TNF-¦Á) have been associated in susceptibility to tuberculosis, but the results have been inconsistent. This study aimed to determine the association of NRAMP1, VDR, and TNF-¨¢ variant with development of pulmonary tuberculosis (PTB) among Iranian patients. The single nucleotide polymorphisms (SNPs) at INT4, D543, 3'UTR of NRAMP1 gene, SNPs in restriction sites of BsmI, and FokI of the VDR gene and SNPs of TNF-¦Á at -238,-308, -244,857,-863 positions were analyzed by PCR-RFLP among two groups of individual; patients with PTB (n=117) and healthy controls (n=60). Thereafter, the frequencies of extended haplotypes and diplotypes were estimated. No statistically significant differences were observed in allele frequencies of INT4, D543, 3'UTR of NRAMPI, FokI of VDR and TNF-¦Á at -238, -244,-863 and -857 position. Although, the frequency of b allele of BsmI [ORs: 0.24 CI95 percent (0.07-0.67 (p=0.001)] and -308 A variant in TNF-¦Á promoter region [ORs:0.26 CI95 percent( 0.07-0.77) (p=0.006)] were significantly more in PTB patients than healthy controls. The frequency of extended diplotypes of NRAMP [GG TGTG++GA; 0.02(0.001-0.0035)], VDR [FFBB; 0.2(0.6-0.6] and TNF-¦Á [CCCCGGGGGG; 0.49(0.25-0.97)] were statistically different in patients and control subjects (p<0.05). This study confirmed the association of SNPs in BsmI (B/b + b/b) of VDR and SNPs in -308A (G/A +G/G) of TNF-¦Á genes with susceptibility to tuberculosis in Iranian PTB patients. Furthermore, the extended haplotypes and diplotypes analysis can be considered as an alternative way to determine the host susceptibility to TB.