Association of PDCD1 genetic variation with risk and clinical manifestations of systemic lupus erythematosus in a multiethnic cohort

We evaluated the roles of five single-nucleotide polymorphisms (SNPs) within PDCD1, and haplotypes defined by these SNPs, for the development of systemic lupus erythematosus (SLE) and specific sub-phenotypes (nephritis, antiphospholipid antibody positive, arthritis and double-stranded DNA positive) within a multiethnic US cohort of 1036 patients. Family based analyses were performed using 844 simplex families from four ethnic groups (Caucasian, Asian, Hispanic and African American). Subjects were genotyped for five 'tag' SNPs (selected from 15) to provide complete genetic information in all main ethnic groups. We employed transmission disequilibrium testing to assess risk for SLE by allele or haplotype, and multiple logistic regression analysis of SLE cases to examine associations with specific sub-phenotypes. In family based analyses, a haplotype containing the PD1.3A allele was significantly associated with SLE susceptibility among Caucasian families (P=0.01). Among Hispanic families, two novel SNPs were associated with SLE risk (P=0.005 and 0.01). In multivariate logistic regression analyses, five haplotypes were associated with specific sub-phenotypes among the different ethnic groups. These results suggest that PDCD1 genetic variation influences the risk and expression of SLE and that these associations vary according to ethnic background.     

Effects of the programmed cell death 1 (PDCD1) polymorphisms in susceptibility to systemic lupus erythematosus

The failure of immunological tolerance to self‐antigens plays a fundamental role in the pathogenesis of systemic lupus erythematosus (SLE). PD‐1 is an inhibitory receptor for regulating the immune system and preventing development of autoimmune disorders. This study aimed to determine the role of four single‐nucleotide polymorphisms (SNPs) within programmed cell death 1 (PDCD1 or PD‐1) gene and haplotypes defined by these SNPs in susceptibility to SLE in the Iranian population. Blood samples were obtained from 253 SLE and 564 healthy subjects. Red blood cells were lysed and genomic DNAs were extracted using salting‐out method. Genotype determinations of PD1.1, PD1.3, PD1.5 and PD1.9 SNPs were performed by polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP), and 12 haplotypes were constructed by PDCD1 SNPs. Our results showed significant differences in PD1.5 genotype frequencies between patient and control groups (p < .001). The frequencies of PD1.5 C/C, C/T and T/T genotypes versus other genotypes in SLE patients significantly differed from healthy subjects (p < .001, p = .001 and p = .002, respectively). Allelic analysis indicated a significant association between the frequency of PD1.5C allele and development of SLE in our population (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.51–2.42, p < .001). At the haplotype level, GGCC, GACT and GGCT haplotypes were significantly different between SLE and control groups (OR = 2.14, 95% CI = 1.73–2.66, p < .001; OR = 9.76, 95% CI = 4.47–21.3, p < .001; and OR = 0.32, 95% CI = 0.24–0.42, p < .001, respectively). Based on these findings, PD1.5 SNP and some haplotypes of PDCD1 contribute to SLE risk in the Iranian population.     

No evidence of association between genetic variants of the PDCD1 ligands and SLE

PDCD1, an immunoreceptor involved in peripheral tolerance has previously been shown to be genetically associated with systemic lupus erythematosus (SLE). PDCD1 has two ligands whose genes are located in close proximity on chromosome 9p24. Our attention was drawn to these ligands after finding suggestive linkage to a marker (gata62f03, Z=2.27) located close to their genes in a genome scan of Icelandic families multiplex for SLE. Here, we analyse Swedish trios (N=149) for 23 single nucleotide polymorphisms (SNPs) within the genes of the PDCD1 ligands. Initially, indication of association to eight SNPs was observed, and these SNPs were therefore also analysed in Mexican trios (N=90), as well as independent sets of patients and controls from Sweden (152 patients, 448 controls) and Argentina (288 patients, 288 controls). We do not find support for genetic association to SLE. This is the first genetic study of SLE and the PDCD1 ligands and the lack of association in several cohorts implies that these genes are not major risk factors for SLE.     

Association of programmed death‐1 gene polymorphisms with the risk of basal cell carcinoma

Environmental and genetic factors play a fundamental role in the pathogenesis of basal cell carcinoma (BCC) defined as the most common cancer of skin. Programmed death‐1 (PD‐1), encoded by programmed cell death‐1 (PDCD1) gene, serves as an inhibitory molecule in the suppression of immune responses and a risk factor in the development of different cancers. In this study, we investigated the role of two single nucleotide polymorphisms (SNPs) within PDCD1 gene, and haplotypes defined by these SNPs, in the development of BCC in an Iranian population. Whole blood samples were obtained from 210 BCC and 320 healthy subjects. Genomic DNA was extracted from whole blood samples, polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) was used to genotype determinations of PD1.3 (rs11568821) and PD1.5 (rs2227981) SNPs, and 4 haplotypes were constructed by PDCD1 SNPs. The frequency of G allele of PD1.3 was significantly higher in BCC patients than healthy subjects (p < 0.02), while these significant differences were not observed in the frequencies of PD1.5 alleles between BCC and healthy subjects. Moreover, we found that there were no statistically significant differences in PD1.3 and PD1.5 genotypes between BCC and control groups. Of all estimated haplotypes for PDCD1, only AC haplotype was associated with BCC (OR = 0.22, 95% CI = 0.06–0.79, p < 0.01). These findings suggest that PD1.3G allele and AC haplotype of PDCD1 contribute to BCC in the Iranian population. However, further studies in different populations with larger sample size are required to confirm this study.     

PDCD1 single nucleotide genes polymorphisms confer susceptibility to juvenile-onset systemic lupus erythematosus

Abstract

Juvenile-onset systemic lupus erythematosus (JSLE) is a multisystem autoimmune disease in which both the genetic and environmental factors seem to be involved in the etiopathogenesis of the disease. The aim of this study was to evaluate the association of programmed cell death 1 (PDCD1, also called PD-1) gene polymorphisms with JSLE susceptibility in Iranian population. In this case-control association study, three PDCD1 SNPs, including PD-1.1 G/A, PD-1.3 G/A and PD-1.9 C/T were genotyped in 50 Iranian patients with JSLE and 202 healthy unrelated controls, using PCR-RFLP method. The PD-1.1 A allele was found to be more frequent in the case group compared with controls (6% vs. 1.5%, p?=?0.024). Moreover, the GG genotype was less frequent in cases than in controls (88% vs. 97%, p?=?0.021). The other PDCD1 SNPs did not show association. At the haplotypic level, no significant differences was recognized between the two groups of case and control neither for the GAC (PD-1.1 G, PD-1.3 A, PD-1.9 C) nor for the GGC haplotype (PD-1.1 G, PD-1.3 G, PD-1.9 C). Our findings support the influence of the PD1.1 A SNP on the development of JSLE in Iranian population.     

Association of interleukin-10 promoter polymorphisms with systemic lupus erythematosus

Several lines of evidence suggest interleukin-10 gene (IL-10) is a candidate gene in susceptibility to systemic lupus erythematosus (SLE). We investigated the association of IL-10 promoter single-nucleotide polymorphisms (SNPs) (-3575T/A, -2849G/A, -2763C/A, -1082A/G, -819T/C and -592A/C) and microsatellites (IL10.R, IL10.G) with SLE in 554 Hong Kong Chinese patients and 708 ethnically matched controls. Six haplotypes (hts) were identified from the SNPs. The genotype distribution of the ht1 (T-C-A-T-A), which is associated with low IL-10 production, was different in patients and controls (P=0.009). The homozygous genotype of non-ht1 was significantly increased in patients (P=0.009, odds ratio (OR)=1.80, 95% CI: 1.15-2.82). The frequency of IL10.G4 of IL10.G was also significantly increased in patients (P=0.017, OR=2.53, 95% CI: 1.18-5.40). We found that the homozygous non-ht1 combined with short allele (CA repeat number < or =21) of IL10.G has a dose-dependent effect on SLE susceptibility: non-ht1/non-ht1 with homozygous short allele showed a higher OR (OR=4.11, 95% CI: 1.27-13.2, P=0.018) of association with SLE than the genotype of non-ht1/non-ht1 with heterozygous short/long allele (OR=2.98, 95% CI: 1.26-7.07, P=0.013) and homozygous long allele (OR=1.05, 95% CI: 0.62-1.78, P=0.848). The frequency of non-ht1 was significantly increased in patients with serositis (P<0.0001, OR=2.42, 95% CI: 1.55-3.80). In conclusion, the high expression promoter genotype is associated with SLE in Chinese.     

Decreased risk for myocardial infarction and lower tumor necrosis factor-alpha levels in carriers of variants of the PDCD1 gene

Increasing interest has been directed toward the inflammatory mechanisms involved in the pathogenesis of myocardial infarction (MI). In the search for genetic mechanisms underlying these inflammatory components, we studied variants of programmed cell death-1 (PDCD1), an immunoinhibitory receptor that inhibits lymphocyte activation and cytokine production, previously shown to be associated with several autoimmune disorders. The PD1.1, PD1.3, and PD1.6 polymorphisms of the PDCD1 gene were typed in the Stockholm Heart Epidemiology Program, a population-based clinical material consisting of 1179 first-time MI case patients and 1528 unaffected control subjects. Individual alleles and haplotypes were studied for association with levels of the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-6, and C-reactive protein and risk for MI. We observed a weak protective effect of PD1.3A allele for MI (odds ratio: 0.78, 95% confidence interval: 0.61-0.98). We also observed decreased levels of TNF-alpha in carriers of the PD1.1A/PD1.3G/PD1.6A haplotype, which is consistent with our previous observation that this haplotype may be protective from autoimmune conditions. Carriers of variants of the PDCD1 gene exhibit a decreased risk for nonfatal myocardial infarction, and PDCD1 mediates variation in TNF-alpha levels.     

Evaluation of IDDM8 susceptibility locus in a Russian simplex family data set

Type 1 diabetes (T1D) susceptibility locus, IDDM8, has been accurately mapped to 200 kilobases at the terminal end of chromosome 6q27. This is within the region which harbours a cluster of three genes encoding proteasome subunit beta 1 (PMSB1), TATA-box binding protein (TBP) and a homologue of mouse programming cell death activator 2 (PDCD2). In this study, we evaluated whether these genes contribute to T1D susceptibility using the transmission disequilibrium test of the data set from 114 affected Russian simplex families. The A allele of the G/A1180 single nucleotide polymorphism (SNP) at the PDCD2 gene, which was significant in its preferential transfer from parents to diabetic children (75 transmissions vs. 47 non-transmissions, chi2=12.85, P corrected=0.0038), was found to be associated with T1D. G/A1180 dimorphism and two other SNPs, C/T771 TBP and G/T(-271) PDCD2, were shown to share three common haplotypes, two of which (A-T-G and A-T-T) have been associated with higher development risk of T1D. The third haplotype (G-T-G) was related to having a lower risk of disease. These findings suggest that the PDCD2 gene is a likely susceptibility gene for T1D within IDDM8. However, it was not possible to exclude the TBP gene from being another putative susceptibility gene in this region.     

Association of RIP2 gene polymorphisms and systemic lupus erythematosus in a Chinese population

The aim of this study was to investigate the association of receptor interacting protein 2 (RIP2) single-nucleotide polymorphisms (SNPs) with susceptibility to systemic lupus erythematosus (SLE) in a Chinese population. A case-control study was performed on the SNPs rs16900617 and rs16900627 in 590 Chinese SLE patients and 660 healthy controls. These SNPs were typed by TaqMan allele discrimination assays. We found a significant association of rs16900617 G allele [odds ratio (OR) = 0.54, 95% confidence interval (CI) 0.41-0.72] and rs16900627 G allele (OR = 1.28, 95% CI 1.04-1.58) with SLE. Significant differences in genotype frequency distribution were also found in SLE and control individuals (rs16900617: AG versus AA, OR = 0.59, 95% CI 0.44-0.81; GG versus AA, OR = 0.08, 95% CI 0.01-0.65; AG + GG versus AA, OR = 0.55, 95% CI 0.41-0.75; rs16900627: AG versus AA, OR = 1.51, 95% CI 1.17-1.93; AG + GG versus AA, OR = 1.43, 95% CI 1.13-1.82). Analysis of the haplotypes revealed that two haplotypes of AG and GA were also significantly associated with SLE (OR = 1.37, 95% CI 1.11-1.70; OR = 0.60, 95% CI 0.45-0.79). Our findings suggest that the RIP2 gene polymorphisms may be associated with susceptibility to SLE in the Chinese population.     

A Single Nucleotide Polymorphism of IL-21 Gene is Associated with Systemic Lupus Erythematosus in a Chinese Population

The aim of this study was to examine the association of single-nucleotide polymorphisms (SNPs) in IL-21 gene with susceptibility to systemic lupus erythematosus (SLE) in a Chinese population. A total of 605 independent SLE patients and 666 unrelated healthy controls were recruited for the case?Ccontrol association study. Two SNPs (rs2221903 and rs907715) within the IL-21 gene intronic region were genotyped by TaqMan SNP allelic discrimination methods. The allele T frequency of SNP rs2221903 in patients and healthy controls was 89.4?% and 86.8?%, respectively [T versus C, odds ratio (OR)?=?1.287, 95?% confidence interval (CI)?=?1.010?C1.640]. No significant differences in genotype frequencies were shown between SLE patients and healthy controls (P value?=?0.705, 0.406, respectively). However, the effect of recessive model (TT versus CC?+?CT, OR?=?1.368, 95?% CI?=?1.050?C1.781) was observed. Distributions of allele and genotype frequencies of the SNP rs907715 showed no significant differences between SLE patients and controls. Analysis of the haplotypes revealed that CC haplotype was significantly associated with SLE (OR?=?0.734, 95?% CI?=?0.573?C0.941). In conclusion, our findings suggest that a SNP (rs2221903) and CC haplotype (rs2221903 and rs907715) of the IL-21 gene is associated with SLE in the Chinese population. However, further studies are needed to determine the functional consequences of this polymorphism with SLE susceptibility.     

Associations Between G/A1229, A/G3944, T/C30875, C/T48200 and C/T65013 Genotypes and Haplotypes in the Vitamin D Receptor Gene, Ultraviolet Radiation and Susceptibility to Prostate Cancer

Ultraviolet radiation (UVR) may protect against prostate cancer via a mechanism involving vitamin D. Thus, the vitamin D receptor (VDR) gene is a susceptibility candidate, though published data are discrepant. We studied the association of prostate cancer risk with five VDR single nucleotide polymorphisms (SNPs): G/A¹²²⁹ (SNP 1), A/G³⁹⁴⁴ (SNP 2), T/C³⁰⁸⁷⁵ (SNP 3), C/T⁴⁸²⁰⁰ (SNP 4) and C/T⁶⁵⁰¹³ (SNP 5), in 430 cancer and 310 benign prostatic hypertrophy (BPH) patients. The SNP 2 GG genotype frequency was lower in cancer than BPH patients (odds ratio = 0.63, 95% CI = 0.41–0.98, p = 0.039). SNPs 1 and 2, and SNPs 4 and 5, were in linkage disequilibrium. Two copies of haplotypes comprising SNPs 1‐2, G‐G (odds ratio = 0.63, p = 0.039), SNPs 2‐3 G‐C (odds ratio = 0.45, p = 0.008) and SNPs 1‐2‐3 G‐G‐C (odds ratio = 0.44, p = 0.006), but not SNPs 1‐3, G‐C (odds ratio = 0.81, p = 0.34), were associated with reduced risk (reference, no copies of the haplotypes) . These associations were observed after stratification of subjects by extent of UVR exposure. These data show that SNP 2 GG genotype mediates prostate cancer risk, complementing studies reporting this allele is protective in malignant melanoma pathogenesis. They further suggest that published associations of risk with SNP 1 may result from linkage disequilibrium with SNP 2.     

Prolactin promoter polymorphism (-1149 G/T) is associated with anti-DNA antibodies in Mexican patients with systemic lupus erythematosus

Prolactin (PRL) is a 23-kDa protein hormone that is synthesized mainly by the anterior pituitary gland. However, PRL can also be synthesized and secreted by extrapituitary tissues, particularly immune cells. A biallelic polymorphism (-1149 G/T) in the prolactin promoter has been shown to be functionally important, as modulation of prolactin expression has been associated with SLE in some populations. We have performed an association study using Mexican patients with SLE. We used qPCR to determine the SNP allele and genotype frequencies. We did not find statistically significant differences in allele and genotype frequencies between patients and healthy controls. However, we found a statistically significant association between the G allele and the presence of anti-dsDNA antibodies in serum (Allele frequency (G): P?=?0.005; Genotyping frequency (GG): P?=?0.001, OR?=?7.8, 95% CI 3.59-27.1). Our data demonstrate that the prolactin promoter polymorphism -1149 G/T does not significantly contribute to SLE disease susceptibility but does predispose carriers to other immunological changes.     

Failure to confirm association between PDCD1 polymorphisms and rheumatoid arthritis in a Japanese population

Programmed cell death 1 (PDCD1) is a necessary negative regulator to maintain peripheral tolerance and is a key molecule in the development of autoimmune diseases. Although PDCD1 gene polymorphisms and haplotypes were reported to be associated with rheumatoid arthritis (RA), replication studies later on showed conflicting results. Here, we analyzed the association of PDCD1 with RA using a large series of Japanese RA patients and population-based controls. DNA samples were obtained from 1,504 RA patients and 449 sex-matched controls. All samples were genotyped for three SNPs on PDCD1 (PD-1.1, PD-1.3 and PD-1.5) using the TaqMan fluorogenic 5′ nuclease assay. Chi-square testing was performed for a case-control study, and the PENHAPLO program was used for haplotype estimation. We could not observe any significant association of PD-1.1 or PD-1.5 polymorphisms between RA. PD-1.3, which was reported to be involved in susceptibility to RA in patients of European descent, was non-polymorphic in the Japanese population. We conclude that polymorphisms in the PDCD1 gene analyzed here are not associated with RA in a Japanese population.     

A polymorphic variant in the MHC2TA gene is not associated with systemic lupus erythematosus

Single-nucleotide polymorphisms (SNPs) in the major histocompatibility complex class II transactivator (MHC2TA) gene encoding the class II transactivator have been associated with multiple sclerosis, rheumatoid arthritis, and myocardial infarction in the Swedish population. We used a case-control approach to investigate the prevalence of a relevant variant in Swedish systemic lupus erythematosus (SLE) cohorts to determine whether SLE shares the same MHC2TA susceptibility allele as the other diseases. No differences were observed between cases and control subjects at either the allele or genotype levels. Furthermore, no significant correlations were found when comparing different clinical and serological SLE phenotypes. This particular polymorphism rs3087456 of the MHC2TA gene does not appear to influence genetic susceptibility to SLE in the Swedish population. We conclude that our data support neither allelic nor genotype association between the MHC2TA SNP and SLE.     

MCP-1 promoter polymorphism in Spanish patients with systemic lupus erythematosus

The possible role of the functional polymorphism located in the regulatory region of the monocyte chemoattractant protein-1 (MCP-1) gene in the susceptibility to systemic lupus erythematosus (SLE) was investigated. Two hundred and seventy-six SLE patients (among them, 99 with lupus nephritis and 55 with cutaneous vasculitis) and 194 ethnically matched healthy controls were included in the study. Genotyping for -2518 (A/G) MCP-1 gene polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. No association between -2518 (A/G) MCP-1 polymorphism and susceptibility to SLE nor to lupus nephritis was found. However, a significant increase in the frequency of genotype AG and a decrease in the frequency of genotype AA were found among patients with cutaneous vasculitis (51% of AG vs. 32% in individuals without cutaneous vasculitis; P=0.008, OR=2.2, 95% CI: 1.18-4.25; and 47% of AA vs. 64%; P=0.03, OR=0.5, 95% CI: 0.27-0.96, respectively). These results indicate an association between the presence of G at position -2518 in the MCP-1 promoter region and the presence of cutaneous vasculitis among patients with SLE. This polymorphism does not seem to influence the susceptibility to SLE nor the appearance of lupus nephritis. Further studies are necessary in order to elucidate the role of this polymorphism in the pathogenesis of other inflammatory autoimmune diseases.     

Analysis of MDR1 haplotypes in Parkinson's disease in a white population

The MDR1 multidrug transporter is important in regulating environmental xenobiotics and hence may play a causative role in Parkinson's disease (PD). MDR1 haplotype comprising 2677 G > T/A and 3435 C > T may be protective against PD. Using a case control methodology, we investigated the association of MDR1 haplotypes (single nucleotide polymorphisms (SNPs) 2677 G > T/A and 3435 C > T) in a Polish PD population. Seven SNPs, extending from the promoter to exon 28 of the MDR1 gene in 158 PD patients and 139 healthy controls were evaluated. Specifically we examined the association of haplotypes containing SNPs 2677 G > T/A and 3435 C > T and risk of PD. The multivariate logistic regression model was used to evaluate the effects of the covariates on the phenotypes. Haplotypes' frequencies were estimated using the Expectation-Maximization algorithm. The frequency of each individual SNPs; -41 A > G (intron -1), -145 C > G (exon 1), -129 T > C (exon 1), 1236 T > C (exon 12), 2677 G > T/A (exon 21), 3435 C > T (exon 26), and 4036 A > G (exon 28) did not differ between PD and controls. However, there was a trend towards significance in PD patients having the haplotype 2677G-3435C (p < 0.09, chi-square 2.85, odds ratio 0.25, 95% CI 0.06-1.08). Haplotype constructs of the other loci did not differ significantly between the two groups. There was a weak protective effect of the haplotype 2677G-3435C in our white population. However, the MDR1 haplotypes did not generally modulate the risk of PD.     

Study of programmed cell death 1 (PDCD1) gene polymorphims in Iranian patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease, characterized by axial arthritis in which the genetic-environmental factors seem to be involved in the pathogenesis of the disease. This study was performed to investigate the role of polymorphisms of the programmed cell death 1 (PDCD1) gene on susceptibility to AS. In this study, 161 Iranian patients with AS and 208 normal controls were enrolled; two single-nucleotide polymorphisms (SNPs) of the PDCD1 gene PD-1.3 (G, A) in nucleotide position +7146 of intron 4 and PD-1.9 (C, T) in nucleotide +7625 of exon 5 were studied. Analysis of PD-1.3 revealed that 82% of patients and 79% of controls had GG genotype, while GA and AA genotypes were detected in 17% and 0.6% of patients, respectively, and 20% and 1.4% of controls, respectively. Moreover, the genotype CC (PD-1.9) was present in 92% of patients and 97% of controls. Although these differences were not statistically significant between patients and controls, comparisons of genotypes frequencies in the AS patients, based on human leukocyte antigen (HLA)-B27, revealed that all patients who had CT genotype (PD-1.9) were HLA-B27 positive, whereas 30% of patients with CC genotype were HLA-B27 negative. There was no evidence of association for PDCD1 SNPs with AS in our study, but CT genotype (PD-1.9) seems to be associated with HLA-B27 positivity in the patients with AS.     

Both risk alleles for FcgammaRIIA and FcgammaRIIIA are susceptibility factors for SLE: a unifying hypothesis

The aim of this study was to analyze in families with SLE for the presence of linkage and the structure and transmission of haplotypes containing alleles for the low-affinity Fcgamma receptors. The Fcgamma receptor polymorphisms FcgammaRIIA-131R/H, FcgammaRIIIA-176F/V and FcgammaRIIIB-NA1/2 and a polymorphism in the FcgammaRIIB gene were genotyped with RFLP, allele-specific PCR or pyrosequencing. Individual SNPs and haplotypes were tested for linkage in multicase families and for association using contingency tables, transmission disequilibrium test and affected family-based control groups in Swedish and Mexican single-case families. No linkage or association could be detected using the FcgammaR polymorphisms in the multicase families. However, an association was found for both FcgammaRIIA-131R and IIIA-176F alleles in the single-case families, but not for IIIB or IIB. Allelic association to SLE was found for a haplotype that included both risk alleles, but not in haplotypes where only one or the other was present. We propose that FcgammaRIIA-131R and FcgammaRIIIA-176F are both risk alleles for SLE transmitted primarily, but not exclusively on a single major haplotype that behaves functionally in a situation similar to that of compound heterozygozity.     

Genetic susceptibility to SLE is associated with TNF-alpha gene polymorphism -863, but not -308 and -238, in Thai population

The production of cytokine varies among individuals and correlates with the polymorphism of cytokine genes. Three functional single nucleotide polymorphisms (SNPs) at position -863, -308, and -238 in the tumour necrosis factor alpha (TNF-alpha) gene promoter were analysed for association with systemic lupus erythematosus (SLE) (n = 154), and clinical manifestations in a Thai population were compared with 154 ethnically matched controls. The genotyping was determined by polymerase chain reaction-restriction fragment length polymorphism method. The association between these SNPs and SLE was analysed using chi-squared test. The -863A allele and -863A, -308G, -238G haplotype were found to be significantly increased in SLE patients (25%) compared with healthy controls (15.3%) (Pc = 0.009, OR = 1.85, 95% CI = 1.21-2.83). In addition -863A allele was found to be significantly increased in the SLE group with Raynaud's phenomenon compared to SLE without Raynaud's phenomenon (35% vs. 19.4%) (Pc = 0.048, OR = 2.23, 95% CI = 1.21-4.10). The -863A allele of TNF-alpha gene and the extended haplotype of -863A, -308G, -238G can be used as a genetic marker for SLE susceptibility in Thai populations. In addition, the -863A genotype could produce high TNF levels and potentially induce the occurrence of Raynaud's phenomenon.