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1.
The SLC11A1 (or NRAMP1) locus on human chromosome 2q35 encodes for the protein solute carrier family 11, member 1. It is expressed in macrophages and involved in the early stages of macrophage priming and activation. Different association studies have shown that the SLC11A1 gene affects susceptibility to infectious diseases and autoimmune inflammatory diseases. Although functional SLC11A1 polymorphisms may account for its role in affecting the susceptibility to these diseases, the positive association can also be because of flanking polymorphisms showing linkage disequilibrium (LD) with this locus. This is the first systematic study to investigate the LD pattern within and around the gene. LD was investigated by genotyping 17 genetic markers in a Chinese population (n=360). The results indicate that LD is maintained at least 110 kb both upstream and downstream of the locus. The complex LD pattern demands that association studies with SLC11A1 should be carried out with both 5' and 3' markers. The strong LD between IL8RB and the 5' SLC11A1 markers also dictates that IL8RB be tested for association with these diseases. Thus, positive association with SLC11A1 should be interpreted cautiously, and IL8RB should also be considered as a potential candidate susceptibility gene unless proven otherwise.  相似文献   

2.
Tuberculosis remains one of the most important infectious diseases worldwide. Several studies have suggested that genetic factors may affect susceptibility to tuberculosis, but the specific genes involved have not yet been fully characterized. NRAMP1/SLC11 A1 and P2X(7) genes have been linked to increased risk for tuberculosis in some African and Asiatic populations. To explore the potential role of these genes in the susceptibility to pulmonary tuberculosis in a Mexican mestizo population, we evaluated the association of D543N and 3'-UTR polymorphisms in NRAMP1/SLC11 A1 and - 762 and A1513C polymorphisms in P2X(7) genes with the risk for tuberculosis. Polymerase chain reaction (PCR) amplification of genomic DNA followed by restriction fragment length polymorphism analysis, and allelic-specific PCR was employed. We found no significant differences in allelic frequency in NRAMP1/SLC11 A1 gene polymorphisms in 94 patients with tuberculosis compared to 100 healthy contacts. Similarly, no significant association of the P2X(7)-762 gene polymorphism with tuberculosis was detected. In contrast, the P2X(7) A1513C polymorphism was associated significantly with tuberculosis (P = 0.02, odds ratio = 5.28, 95% CI, 0.99-37.69), an association that had not been reported previously. However, when the function of P2X(7) was assessed by an L-selectin loss assay, we did not find significant differences in patients compared to healthy contacts or between PPD(+) and PPD(-) control individuals. This study further supports the complex role of P2X(7) gene in host regulation of Mycobacterium tuberculosis infection, and demonstrates that different associations of gene polymorphisms and tuberculosis are found in distinct racial populations.  相似文献   

3.
Apoptosis is important in the pathogenesis of systemic lupus erythematosus (SLE). Several genome-wide scan studies have suggested chromosome 1q as a genetic susceptibility locus for SLE. This study investigated the association of apoptosis-related genes on chromosome 1q, Fas ligand (FasL), interleukin (IL)-10 and poly(ADP-ribose) polymerase (PARP), promoter microsatellite multi-allelic polymorphisms with SLE susceptibility and clinical characteristics in Taiwan. This study recruited 237 SLE patients and 304 healthy controls. FasL, IL-10 and PARP promoter microsatellite polymorphisms were genotyped employing gene scan. IL-10, located on 1q31-32, emerged as a significant susceptibility gene locus in Taiwanese SLE (T4 statistic = 0.01). IL-10 CA21 allele was the most common allele of 15 identified in Taiwanese, displaying skewed distribution of susceptibility in Taiwanese SLE patients. Conversely, the IL-10 CA20 allele showed a protective effect of SLE susceptibility. Additionally, the IL-10 CA26 allele displayed a negative significant association with ascites and IL-10 CA25 allele increased the occurrence of the anti-cardiolipin IgM antibody. This study identified five alleles of FasL and nine alleles of PARP of microsatellite polymorphisms in Taiwanese patients. FasL and PARP alleles displayed no skewing distribution between Taiwanese SLE patients and controls. However, FasL GT15 and PARP CA17 allele demonstrated a high discoid rash presentation (T4 statistic 0.01 and 0.03, respectively) and PARP CA12 allele displayed a significant association with anti-cardiolipin IgM antibody production (T4 statistic 0.02). IL-10, FasL and PARP microsatellite polymorphisms exhibited significant associations with SLE susceptibility and/or clinical characteristics in Taiwanese patients. Thus, SLE is a complex and multiple genetics determined autoimmune disease. Chromosome 1q23-42 is an important genetic locus for further SLE subphenotype susceptibility study.  相似文献   

4.
We identified a novel trinucleotide (ATA)n repeat polymorphism in intron 8 of SLC11AI, a candidate gene for susceptibility to tuberculosis (TB) infection. We characterized the frequency of this polymorphism in 485 individuals originating from eight globally diverse human populations and compared the distribution of (ATA)n alleles in 146 adults and in 80 cord blood samples from newborns in the Gambian population. Lastly, we tested for association of this microsatellite with pulmonary TB in 318 TB cases and 146 controls in the Gambian population. We found no significant difference in frequency or distribution of alleles in adult and cord blood samples, and we found no significant association between this marker and pulmonary TB.  相似文献   

5.
Tuberculosis (TB) is a leading cause worldwide of human mortality attributable to a single infectious agent. Recent studies targeting candidate genes and "case-control" association have revealed numerous polymorphisms implicated in host susceptibility to TB. Here, we review current progress in the understanding of causative polymorphisms in host innate immune genes associated with TB pathogenesis. We discuss genes encoding several types of proteins: macrophage receptors, such as the mannose receptor (MR, CD206), dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN, CD209), Dectin-1, Toll-like receptors (TLRs), complement receptor 3 (CR3, CD11b/CD18), nucleotide oligomerization domain 1 (NOD1) and NOD2, CD14, P2X7, and the vitamin D nuclear receptor (VDR); soluble C-type lectins, such as surfactant protein-A (SP-A), SP-D, and mannose-binding lectin (MBL); phagocyte cytokines, such as tumor necrosis factor (TNF), interleukin-1β (IL-1β), IL-6, IL-10, IL-12, and IL-18; chemokines, such as IL-8, monocyte chemoattractant protein 1 (MCP-1), RANTES, and CXCL10; and other important innate immune molecules, such as inducible nitric oxide synthase (iNOS) and solute carrier protein 11A1 (SLC11A1). Polymorphisms in these genes have been variably associated with susceptibility to TB among different populations. This apparent variability is probably accounted for by evolutionary selection pressure as a result of long-term host-pathogen interactions in certain regions or populations and, in part, by lack of proper study design and limited knowledge of molecular and functional effects of the implicated genetic variants. Finally, we discuss genomic technologies that hold promise for resolving questions regarding the evolutionary paths of the human genome, functional effects of polymorphisms, and corollary impacts of adaptation on human health, ultimately leading to novel approaches to controlling TB.  相似文献   

6.
A pilot study was conducted to determine if host genetic factors influence susceptibility and outcomes in human filariasis. Using the candidate gene approach, a well-characterized population in South India was studied using common polymorphisms in six genes (CHIT1, MPO, NRAMP, CYBA, NCF2, and MBL2). A total of 216 individuals from South India were genotyped; 67 normal (N), 63 asymptomatic microfilaria positive (MF+), 50 with chronic lymphatic dysfunction/elephantiasis (CP), and 36 tropical pulmonary eosinophilia (TPE). An association was observed between the HH variant CHIT1 genotype, which correlates with decreased activity and levels of chitotriosidase and susceptibility to filarial infection (MF+ and CP; P = 0.013). The heterozygosity of CHIT1 gene was over-represented in the normal individuals (P = 0.034). The XX genotype of the promoter region in MBL2 was associated with susceptibility to filariasis (P = 0.0093). Since analysis for MBL-sufficient vs insufficient haplotypes was not informative, it is possible the MBL2 promoter association results from linkage disequilibrium with neighboring loci. We have identified two polymorphisms, CHIT1 and MBL2 that are associated with susceptibility to human filarial infection, findings that merit further follow-up in a larger study.  相似文献   

7.
Host genetics plays an important role in individual susceptibility and resistance to infectious diseases, but no genes have yet been identified using genome-wide screens. Twin studies have indicated that tuberculosis susceptibility has a significant host genetic component, and several genes appear to be involved. Recently, a genome-wide linkage analysis of 136 African families identified chromosome 15q11-13 as a region with suggestive evidence of linkage, with a LOD score of 2.0. We tested 10 microsatellite markers and 5 positional candidate genes in this chromosomal region for deviation from random transmission from parents to affected offspring. The polymorphisms, lying in a region of 14 cM, were initially typed in the same 79 Gambian families used in the genome screen. A borderline significant association with a 7 bp deletion in UBE3A (P = 0.01) was found. This polymorphism was then evaluated further in a larger series of families with tuberculosis, including 44 Guinean families and 57 families from South Africa. Testing for association between the deletion and tuberculosis across all the families using the exact symmetry test further supported the association (overall P = 0.002). These fine-mapping data suggest that UBE3A or a closely flanking gene may be a tuberculosis-susceptibility locus.  相似文献   

8.
Similar to other mycobacterial diseases, susceptibility to Buruli ulcer (Mycobacterium ulcerans infection) may be determined by host genetic factors. We investigated the role of SLC11A1 (NRAMP1) in Buruli ulcer because of its associations with both tuberculosis and leprosy. We enrolled 182 Buruli ulcer patients (102 with positive laboratory confirmation) and 191 healthy neighbourhood-matched controls in Ghana, and studied three polymorphisms in the SLC11A1 gene: 3' UTR TGTG ins/del, D543N G/A, and INT4 G/C. Finger prick blood samples from study subjects were dried on filter papers (FTA) and processed. D543N was significantly associated with Buruli ulcer: the odds ratio (adjusted for gender, age, and region of the participant) of the GA genotype versus the GG genotype was 2.89 (95% confidence intervals (CI): 1.41-5.91). We conclude that a genetic polymorphism in the SLC11A1 gene plays a role in susceptibility to develop Buruli ulcer, with an estimated 13% population attributable risk.  相似文献   

9.
Chromosome 8p21-12 has been reported to be a susceptibility locus for schizophrenia based on genome-wide linkage scans. After neuregulin 1 (NRG1) was identified as a positional candidate gene for schizophrenia in this locus, several independent association studies have reported controversial results. To determine whether genetic variations in this locus are associated with schizophrenia in the Korean population, we investigated multiplex families and unrelated patients using linkage and association analyses. Seven microsatellite markers in 8p21-12 were genotyped for 40 families with schizophrenia, and a non-parametric linkage analysis was applied. The association study was performed with 242 unrelated schizophrenia patients and the same number of normal controls for three single nucleotide polymorphisms (SNPs), two microsatellite markers and their haplotypes. A significant linkage signal was observed on D8S1769, which is located 352 kb upstream of the 5' end of the first exon of NRG1 for two ("narrow" and "narrow with auditory hallucination (AH)") of the three adopted phenotype classes. In the association study, the G allele of SNP8NRG241930 was significantly in excess in the subgroup of patients with AHs. We also found haplotypes which were associated with schizophrenia with a protective effect. This study provides additional suggestive evidence for both the linkage and association of genetic variations on 8p12, a locus of NRG1, with schizophrenia. NRG1 might either play a role in the predisposition to schizophrenia or be in linkage disequilibrium (LD) with a causal locus of this illness.  相似文献   

10.
Vitamin D receptor (VDR) gene variants are associated with differential susceptibility or resistance to tuberculosis in different ethnic groups. We investigated the polymorphisms in the 5' regulatory region of VDR gene in 206 normal healthy subjects and 166 patients with pulmonary tuberculosis from south India. Cdx-2 polymorphism was studied by polymerase chain reaction (PCR) with allele-specific primers, while genotyping of A1012G was done by PCR-based restriction fragment length polymorphism. A significantly decreased frequency of Cdx-2 G allele (P = 0.016) and G/G genotype (P = 0.010) and an increased frequency of A-A haplotype (A allele of Cdx-2 and A allele of A1012G) (P = 0.015) were observed in patients compared to controls. The study suggests that Cdx-2 G/G genotype may be associated with protection and A-A haplotype with susceptibility to tuberculosis.  相似文献   

11.
Tumour necrosis factor (TNF) is a key proinflammatory mediator in rheumatoid arthritis (RA). The TNF locus, situated in the class III region of the MHC, is flanked by five microsatellite markers. It has previously been shown that this region influences susceptibility to RA; two TNF microsatellite haplotypes were found to be associated with RA. Evidence from murine studies has indicated that variation in the TNF 3' untranslated region (UTR) could be associated with altered regulation of TNF biosynthesis. In order to identify possible RA associated polymorphisms, more than 800 bp of the TNF 3' UTR was genetically analysed in RA affected and unaffected subjects possessing specific RA and non-RA associated TNF microsatellite haplotypes. The TNF 3' UTR region was analysed using two mutation detection methods, PCR-SSCP and NIRCA analysis and DNA sequencing. No genetic differences were observed in the human TNF 3' UTR between subjects, that is, irrespective of RA status or TNF haplotype, and also compared with previously published TNF sequences from human sources. Therefore it can be concluded that the TNF 3' UTR in this population was highly conserved and did not influence susceptibility to RA.  相似文献   

12.
Forty four families from Guinea–Conakry were analysed to test for association between NRAMP1 (Natural Resistance Associated Macrophage Protein 1) polymorphisms and tuberculosis. Each family included at least one affected sib and one parent. Healthy sibs were also analysed and on average the families included four members. A total of 160 individuals were included in the final dataset. The analysis of association was performed using an extended TDT test, TRANSMIT, to allow for missing information in the parental genotypes. Three polymorphisms in the NRAMP1 gene were typed: a microsatellite (CA) repeat, a 4 bp deletion in the 3' untranslated region and a single nucleotide change in intron 4. The single base change in intron 4 was significantly associated ( p = 0.036) with tuberculosis. Our results therefore confirm, using a family-based approach on a newly studied population, the previously reported association between this polymorphism and tuberculosis in a population-based study of West Africans.  相似文献   

13.
The histologic and clinical similarities between tuberculosis and sarcoidosis suggest a shared underlying pathophysiology. Human natural resistance-associated macrophage protein (NRAMP1), which is closely related to the mouse gene, has been associated with susceptibility to tuberculosis in some human populations. Given the importance of the Nramp1 gene in animal models of granulomatous disorders, the association with human tuberculosis, and the possible role of NRAMP1 in macrophage activation and function, we hypothesized that human NRAMP1 plays a role in susceptibility to sarcoidosis. We analyzed several NRAMP1 gene polymorphisms in a case-control study of 157 African American patients with sarcoidosis and 111 African American control subjects. Our results, in contrast to those in tuberculosis patients, showed that the less common genotypes were found more often in control subjects than in case patients (odds ratio, 0.48; 95% confidence interval, 0.28-0.81). In particular, one polymorphism, a (CA)(n) repeat in the immediate 5' region of the gene, was found to have a protective effect (P = 0. 014). Whereas NRAMP1 polymorphisms have been associated with increased susceptibility to tuberculosis, our results suggest that at least one NRAMP1 polymorphism may decrease susceptibility in sarcoidosis.  相似文献   

14.
NRAMP1 gene polymorphisms in patients with rheumatoid arthritis in Koreans   总被引:2,自引:0,他引:2  
Natural resistance-associated macrophage protein 1 (Nramp1) is a genetic locus associated with innate resistance or susceptibility of murine hosts to infection with intracellular pathogens such as Salmonella, Leishmania and Mycobacterium. The human homologue of the Nramp1 gene, designated NRAMP1, has been investigated as a candidate gene for genetic susceptibility to autoimmune diseases as well as infections. This study tries to determine whether NRAMP1 polymorphisms are associated with susceptibility to rheumatoid arthritis in Koreans. The nine NRAMP1 polymorphisms (1 microsatellite, 1 variation in 3' UTR, 5 silent substitution, 2 amino acid substitution) were typed by PCR-RFLP in 74 patients with rheumatoid arthritis (RA) and 53 healthy controls in Koreans. The distribution of allele and genotype frequencies were compared between patients and controls. Three NRAMP1 polymorphisms (823C/T, D543N and 1729+55del4) were significantly associated with RA. In addition, there were significant differences in the genotype frequencies for 823C/T, D543N and 1729+ 55del4 polymorphisms between RA patients and controls. Genotypes of A/A homozygote for D543N and TGTG deletion homozygote for 1729+55del4 were only detected in the patient group. These data indicate that genetic polymorphisms of NRAMP1 might be associated with the susceptibility to rheumatoid arthritis in Koreans.  相似文献   

15.
A microsatellite repeat polymorphism was identified in the 3' flanking region of the human ETS1 gene. Sequencing revealed two CA repeat segments in close proximity. Seven different alleles comprising various combinations of CA repeat units were identified in a healthy control population. Because ETS1 plays a role in lymphocyte development and function, apoptosis, and inflammation, we examined whether any of these polymorphisms were associated with a systemic inflammatory condition, systemic lupus erythematosus (SLE). Inheritance of this disease is polygenic and a recent genome-wide screen for SLE susceptibility loci revealed linkage with chromosome 11q14-23, the region in which the ETS1 gene lies. This region has also been identified as a general autoimmune susceptibility region. None of the seven distinct ETS1 alleles appeared statistically more frequently in SLE patients than controls, however, two alleles were associated with particular clinical manifestations. Allele 1 is associated with discoid lesions and allele 7 is associated with vasculitis. While this polymorphism does not directly affect the coding region of ETS1, it may be a marker for overexpression of a particular isoform or inheritance of another polymorphism which does affect function. These data suggest that ETS1 may be involved in the phenotypic expression of systemic lupus erythematosus.  相似文献   

16.
The vitamin D receptor (VDR) gene is a candidate gene for susceptibility to autoimmune disorders. Association studies of VDR polymorphisms and risk of type 1 diabetes often produced conflicting results in different ethnic backgrounds. The aim of this study was to test for association between common VDR polymorphisms and the genetic susceptibility to type 1 diabetes in the Portuguese population. We genotyped 207 patients with type 1 diabetes and 249 controls for the FokI T>C (rs10735810), BsmI A>G (rs1544410), ApaI G>T (rs7975232), and TaqI C>T (rs731236) single nucleotide polymorphisms by polymerase chain reaction and restriction fragment length polymorphism analysis. The distribution of VDR genotype, allele, and haplotype frequencies did not differ significantly between patients and controls. These data suggest that the single nucleotide polymorphisms of the VDR gene are unlikely to contribute significantly to type 1 diabetes susceptibility in the Portuguese population.  相似文献   

17.
The influence of the SLC11A1 (formerly NRAMP1) gene on the association between BCG vaccination and atopy in children was studied in 179 children, BCG vaccinated in infancy, and 307 children without BCG vaccination, all 3 to 8 years of age and with atopic heredity. DNAs were genotyped for a functional repeat polymorphism (designated GTn) in the promoter of SLC11A1 and a linked microsatellite D2S1471. Associations between genotype, atopic symptoms and allergen-specific IgE-antibodies in relation to the BCG status of the children were assessed. Atopy in relation to SLC11A1 GTn-alleles was similarly distributed between the two groups. In BCG vaccinated children, genotype associations were observed for D2S1471 and atopy, with carriage of allele 5 conferring increased risk of atopy (odds ratio (OR) 2.6; 95% confidence interval (CI) 1.3-5.5; P = 0.01), and particularly IgE responses to airborne allergens (OR = 4.3; 95% CI 1.7-10.7; P = 0.002). No linkage disequilibrium was found between the SLC11A1 GTn repeat and the microsatellite D2S1471, and therefore no haplotype associations were observed for atopy in BCG- or non-BCG vaccinated children. Stratification by BCG vaccination unmasked a potential genetic risk factor for atopy in the region of the SLC11A1 locus, and point to the importance of genotype by environment interactions in determining disease susceptibility.  相似文献   

18.
OBJECTIVE: A genome-wide screen has shown linkage to the GRD-2 locus in Graves' disease (GD). Furthermore, a positional candidate gene maps to this locus; the CD40 gene has been reported to be associated and may predispose to the disease. The aim of this study was to replicate/reject the GRD-2 and to determine if the single nucleotide polymorphism (SNP) of the CD40 (CD40 C/T-1) confers susceptibility to GD. METHODS: The present study examined a dataset of 11 families with GD using 10 microsatellite markers and a case-control study consisting of 76 sporadic GD patients and 66 healthy subjects to determine the implication of the GRD-2. Both non-parametric linkage and association tests were performed. Genotyping of the CD40 C/T-1 was carried out using a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: The intrafamilial association and the case-control study showed no association between CD40 C/T-1 and GD. In addition, a high percentage of the C allele (96.9%) of CD40 SNP among control data was observed. The linkage analyses showed that the highest non-parametric LOD score was 1.67 at the D20S119 marker and the maximum attainable LOD score was 1.66. This result provides interesting evidence for linkage between GRD-2 and GD. CONCLUSION: The CD40 gene seems to be not associated with GD in the Tunisian population, whereas the GRD-2 locus could harbour other candidate gene(s) to the genetic susceptibility of GD.  相似文献   

19.
Recent studies have indicated that the interleukin-12/interferon-gamma (IFN-gamma) axis is important in mycobacterial infection susceptibility. Using an intronic (CA)n polymorphic microsatellite marker within the IFN-gamma receptor-1 (IFNGR1) gene, we have compared the allelic frequencies of this marker in hospitalized tuberculosis patients (n = 120) with that of controls (n = 87) from Rijeka, Croatia. We identified 13 (CA)n alleles in the tuberculosis patients, whereas only 10 were found in the controls. A significant difference between one allelic marker and the control group was observed (P = 0.02, 95% confidence interval 0.14-0.94), suggesting a possible protective association. In contrast, several other allelic markers showed a trend towards association with the disease. We also found a trend towards an increased frequency in homozygosity of one allelic marker in patients (11.7%) as compared with controls (4.6%). We conclude that there is no evidence for disease association of the IFNGR1 gene marker in Mendelian-type (single-allele) inheritance. However, our results also suggest that unidentified allelic variations in the IFNGR1 gene might elevate or decrease the risk in this ethnic population, as a part of the multigenic predisposition to tuberculosis.  相似文献   

20.
《Human immunology》2023,84(2):80-88
Human Mannose-binding lectin (MBL) is a protein encoded by MBL2 gene involved in the activation of the lectin-complement pathway. Several studies emphasized the role of MBL2 gene in several infectious diseases’ susceptibility, including HIV-1 infection. We aim to investigate the impact of 10 MBL2 gene polymorphisms located in the promoter, 5′UTR and exon 1 regions on HIV-1 physiopathology. The polymorphisms genotyping of 400 individuals, which 200 were HIV-1 positive patients and 200 were controls, was performed by PCR-sequencing. Our results showed that rs503037 and rs1800451 polymorphisms are associated with a high risk of HIV-1 infection susceptibility while rs7096206 and rs11003123 showed a protective effect. A significant association between haplotype CGA and HIV-1 infection susceptibility was also found in the exon 1 region. Moreover, rs11003124, rs7084554, rs36014597 and rs11003123 polymorphisms revealed an association with treatment response outcome as measured by RNA viral load. This study highlights the importance of MBL2 polymorphisms in the modulation of HIV-1 infection susceptibility and the contribution to treatment response outcomes among Moroccan subjects.  相似文献   

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