Interleukin-17F Gene Polymorphisms Research Articles

Interleukin-17A and Interleukin-17F Gene Polymorphisms in Egyptian Patients with Chronic Hepatitis C and Hepatocellular Carcinoma.

Interleukin IL-17A and IL-17F are critical cytokines involved in inflammatory processes. Genetic variations in IL-17A and IL-17F might be linked to chronic hepatitis C (CHC) and an increased risk of hepatocellular carcinoma (HCC), a cancer associated with long-term inflammation. This study aims to examine the relationship between specific polymorphisms in IL-17A (rs2275913) and IL-17F (rs763780) and their association with HCV-related HCC in an Egyptian population. Authors conducted a case-control study involving 52 patients with chronic hepatitis C, 49 patients with HCV-related HCC, and 51 healthy controls. The study assessed the connection between the IL-17A rs2275913 and IL-17F rs763780 polymorphisms and chronic hepatitis C patients. Genotyping was performed using real-time PCR with TaqMan MGB-probe allelic discrimination. No significant differences in genotype and allele frequencies for IL-17A rs2275913 and IL-17F rs763780 were observed between CHC or HCC patients and control subjects. However, significant associations were found indicating an increased risk of HCC linked to CHC: the GG genotype of IL-17A rs2275913 in a recessive model (P = 0.0129); and CT and CT + CC genotypes as well as the C allele of IL-17F rs763780 (P = 0.0038, P = 0.0055 and P = 0.0277, respectively). The study identifies a significant association between IL-17F rs763780 polymorphisms and a higher risk of HCC in Egyptian patients with chronic hepatitis C. No significant correlation was found between the IL-17A rs2275913 polymorphism and either chronic hepatitis C or HCC.

Role of Interleukin-17F Gene Polymorphism in Susceptibility to Acute Myeloid Leukemia: Relation to Serum Level of IL-17

Abstract Background The pathogenesis of acute myeloid leukemia (AML) is complex and not fully understood. A variety of interleukins have been shown to regulate the survival, growth, and apoptosis of leukemia cells. The IL-17 family includes interleukin-17F [rs763780; A7488G]. The IL-17F rs763780 polymorphism inhibits the wild-type IL-17F's activity and raises tumor susceptibility contributing to the emergence of certain tumor types including AML. Objectives This work aimed to study the relation between IL-17F gene polymorphism and susceptibility to AML and evaluated IL-17 plasma levels in AML with different IL-17F genotypes. Results There was no statistically significant difference in the distribution of different IL-17F genotypes between cases and controls. While the statistical comparison between both groups showed a significant difference with p-value <0.001 regarding IL-17 plasma level being higher in the case group with cutoff value >35 ng/L. Conclusion We concluded that IL-17 gene polymorphism doesn’t increase susceptibility to AML in Egyptian adults. IL-17 plasma level is an excellent diagnostic biomarker in AML patients.

Interleukin 17F Gene Polymorphism as a Potential Protective Factor in the Immunopathology of Ocular Toxoplasmosis.

Ocular toxoplasmosis (OT) is characterised by intraocular inflammation due to Toxoplasma gondii infection. Studies have found that interleukin 17 (IL-17) plays a central role in the pathology of OT. However, nucleotide variability in IL17 and interleukin 17 receptor (IL17R) genes has not been characterised in OT. As cytokine gene polymorphisms may influence the expression of these molecules, the aim of this study was to verify whether IL17A (rs2275913), IL17F (rs763780), IL17RA (rs4819554) and IL17RC (rs708567) polymorphisms are associated with OT in a Brazilian population. This study enrolled 214 patients seropositive for T. gondii (110 with OT and 104 without) and 107 controls. Polymorphisms were identified by PCR-restriction fragment length polymorphism analysis, validated by DNA sequencing with chi-square and multivariate analyses being used to assess possible associations between polymorphisms and OT. Logistic regression under the dominant model revealed a protection factor against OT of the C mutant allele of the IL17F (rs763780) polymorphism. The T/C-C/C genotypes were significantly more common in patients without OT compared to those with OT (p value = 0.0066) and controls (p value = 0.014). Findings from this study suggest that the IL17F polymorphism may have an influence in the immunopathology of OT in Brazilian individuals.

Association of Interleukin-17A and Interleukin-17F Gene Polymorphisms with Atopic Dermatitis in Chinese Children.

Background: Atopic dermatitis (AD) is a chronic, recurrent inflammatory disease associated with an unbalanced immune response in the upper layers of the skin tissue, mostly starting in childhood. As important factors in gene expression regulation, polymorphisms in interleukin (IL)-17A and IL-17F may be associated with the susceptibility and severity of AD. Methods: Blood samples and clinical information were obtained from 132 patients with AD and 100 healthy children. Using multiplex polymerase chain reaction and next-generation sequencing, five potential single-nucleotide polymorphisms (SNPs) of IL-17A and IL-17F were genotyped in all participants. The relationship between SNPs and susceptibility to or severity of AD was examined by analyzing haplotypes and genetic models. Results: The IL-17A rs3819025 polymorphism was substantially associated with higher AD risk in both the allele model (p = 0.03; odds ratio [OR] = 1.76; confidence interval [CI]: 1.05-2.95) and the dominant model (p = 0.04, OR = 1.85; CI: 1.03-3.33). There was no correlation between AD susceptibility and the IL-17A (rs2275913 and rs4711998) or IL-17F (rs763780 and rs12203736) SNPs (all p > 0.05). Additionally, the five IL-17A and IL-17F SNPs did not significantly differ across the mild-to-moderate and severe subgroups (all p > 0.05). Conclusions: The IL-17A/rs3819025 polymorphism was linked to the development of AD, whereas the IL-17F polymorphism was unrelated to the susceptibility to and severity of AD. The IL-17A polymorphism may provide valuable information to speculate on the susceptibility to AD in Chinese Han children.

Association of IL-17F Gene Polymorphism and Its Serum Level with SARS-CoV-2 Infection.

Although multiple studies have addressed the clinical outcomes of coronavirus disease, little data exist regarding the defi- nition of immune and inflammatory profiles associated with this infection. Its clinical manifestations often worsen in association with hypercytokinemia (elevated interleukin 8 and interleukin 17). We conducted this research to elucidate the effect of interleukin 17 levels and interleukin 17F gene polymorphism on the severity and outcomes of coronavirus disease. Ninety patients with confirmed coronavirus disease and 30 healthy controls were enrolled. Coronavirus disease cases were classified into nonsevere, severe, and critical according to the World Health Organization definition. Approximately 10 mL peripheral blood sample was collected from all patients and controls by venipuncture in-plane and ethylenediaminetetraacetic acid tube. Enzyme-linked immunosorbent assay kits were used for calculating serum interleukin 17 levels, whereas real-time polymerase chain reaction was used for genotyping using the 5'-nuclease allelic discrimination assay for single nucleotide polymorphisms genotyping. As regards interleukin 17 levels, there was a significant elevation of interleukin 17 in coronavirus disease cases compared to control healthy persons (P < .001). Moreover, serum interleukin 17 levels tended to be significantly higher with increased disease sever- ity (P = .004). Patients with critical diseases expressed a significant rise of interleukin 17 compared to severe (P = .03) and nonsevere cases (P = .02). We noted no significant difference between the critical, severe, and nonsevere cases regarding different interleukin 17F genotypes. Coronavirus disease is associated with elevated levels of interleukin 17, which tended to be considerably higher with disease severity. However, different interleukin 17F genotypes do not affect either the predisposition or the severity of coronavirus disease.

Screening of interleukin 17F gene polymorphisms and eight subgingival pathogens in chronic periodontitis in Libyan patients

ABSTRACT Background: Chronic periodontitis (CP) is triggered by periodontal pathogens influenced by genetic and environmental factors. Recent studies have suggested that anti-inflammatory cytokines such as interleukin 17 (IL−17) play a prominent role in the pathogenesis of CP. Aim:This study aimed to investigate the association between eight sub-gingival pathogens and interleukin 17F (IL−17F) gene single nucleotide polymorphisms with CP among Libyans. Materials and Methods: A case–control study was conducted on 100 individuals between the ages of 25–65 years. Species-specific 16S rRNA primers for each pathogen were used in a multiplex PCR reaction to detect sub-gingival pathogens from a paper point sample. DNA was also extracted from buccal swab samples and IL−17F polymorphisms were detected by Sanger sequencing. Results: A highly significant association between the seven sub-gingival pathogens and CP, (p-value 0.0001) and a high prevalence of P. intermedia (100%), T. forsythia (96%), T. denticola and E. corrodens (92%), P. gingivalis (82%), C. rectus (74%), P. nigrescens (72%), A. actinomvcetcmcomitans (40%) were found in the case group compared with control group. A novel variant in the c. *34 G>A in IL−17F gene caused a change in glutamic amino acid to lysine amino acid, position on chromosome number (6) in the third exon, mRNA/genomic position 597, found in 14.6% of CP patients (p-value = 0.010) while the IL−17F (rs763780) SNP showed no association with CP (p-value = 0.334). Conclusion: P. intermedia appear as keystone pathogen for CP in the Libyan population. A novel variant in the IL−7F gene may be related to the severity of CP.

Genetic polymorphism of IL-17F rs763780 contributes to the susceptibility to bipolar disorder but not to schizophrenia in the Turkish population

This study aims to investigate the genetic polymorphism in the interleukin-17F (IL-17F) (rs763780, 7488 A/G) gene in bipolar disorder (BD) and schizophrenia (SCZ) patients by comparing it with healthy controls considering clinical parameters. A sample of 107 patients with BD, 129 patients with SCZ, and 100 healthy volunteers were included. SCID-I was used to confirm the diagnosis according to DSM-IV-TR criteria. The Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HAM-D) were administered to BD patients. The Positive and Negative Symptoms Scale (PANSS) was applied to the patients with SCZ. PCR-RFLP was used to determine IL-17F gene polymorphism. Our results demonstrated that the distributions of the IL-17F genotype and the allele frequencies of BD patients were statistically significantly different from the control group. The AA genotype (OR: 0.283; 95% Cl: 0.140–0.573; p<.001) and A allele (OR: 0.333; 95% Cl: 0.171–0.646; p=.001) frequencies were significantly higher in the control group than in the BD group. The IL-17F genotype and the allele frequency distributions of SCZ patients were not statistically significantly different from the control group. When comparing scale scores due to the IL-17F genotype distributions in patients with BD or SCZ, there was no statistically significant difference between the groups of IL-17F genotypes. In summary, whereas the IL-17F polymorphism may be associated with BD, this polymorphism was not related to SCZ.

Association of Interleukin 17F with Arthritis in Punjabi Families of Pakistan

Arthritis is a chronic inflammatory disease that causes severe joint pain. Interleukin 17F (IL17F) is considered as a candidate gene functionally; it mediates pro-inflammatory responses, depending on the type and site of inflammation. The present study examined the polymorphism of IL17F (rs763780 and rs2397084) among the families affected by arthritis. Demographic data and blood samples were collected from the families with at least one affected offspring with arthritis. Analysis of the IL17F gene polymorphism was performed by the digestion of DNA with NlaIII and AvaII. The results showed that IL17F rs763780 (AA, AG and GG genotypes) and rs2397084 (AA, AG and GG genotypes) were associated with arthritis (OA &amp; RA). It was evaluated that about 65 and 21 percent of the individuals mutated with homozygous mutation for wild type allele A, heterozygous mutation A/G against selected SNPs respectively. But homozygous polymorphic allele for allele G was only found against rs2397084. Mutation in rs2397084 resulted to change Lysine into Arginine, whereas mutation in rs763780 changed Histidine into Arginine. Maternal history was found as a stronger factor in transferring arthritis. The results of this study revealed an association of arthritis with IL17F among Pakistani population.

Role of Interleukin17F (IL17F) Gene Polymorphism in Susceptibility to Acute Myeloid Leukemia

Th17 cells (subset of CD4+ cells) are characterized by interleukin (IL)-17A and IL-17F production, which share strong homology, and surface expression of the IL-23 receptor (IL-23R). They have been implicated in the pathogenesis of inflammatory, autoimmune diseases and in many different types of human tumors, including lymphoma and myeloma. Objectives: The aim of this study was to determine the association between the polymorphic features located within the IL-17A, IL-17F and IL-23R genes and susceptibility to or association with AML and the relationship between these polymorphic variants and the plasma IL-17 levels in all studied groups. Subjects and Methods: 82 individual of Egyptian population including 27 AML patients, 40 individual who are relatives of those patients and 15 apparently healthy controls. All were subjected to detection of Interleukin 17F gene polymorphism by 2 steps: first Conventional Polymerase Chain Reaction then Restriction Fragment length Polymorphism by Restriction enzymeHIN1II (NLAIII) (PCR-RFLP) assay, Detection of Interleukin 17A and Interleukin23 receptor genetic polymorphisms by real time Polymerase Chain Reaction and Quantification of Interleukin 17 gene protein product by Enzyme Linked Immunosorbent Assay (ELISA). Results: our results revealed that the (G) variant of IL17F and its homozygosity were significantly higher among patients compared to relatives and healthy individual. While IL17-A and IL23-R polymorphisms elicit non statistical significant difference among the three groups. Also a significant correlation was observed between IL17 protein plasma level and the three polymorphisms (IL17F, IL17A and IL23R genetic polymorphisms). Conclusions: IL-17F gene G single mutant and GG homozygous mutant were associated with acute myeloid leukemia susceptibility in Egyptian population while IL17-A and IL23-R polymorphisms were not associated with susceptibility to the disease. Also there were statistical significant association (P˂0.05) and high statistical significant (P˂0.001) association between ELISA (IL17 plasma level) results and the three genetic polymorphisms in studied groups. There was high statistical significant difference (P˂0.001) between patients and other two groups in IL17 plasma level by ELISA.

Association of Interleukin-17F gene polymorphisms with susceptibility to severe enterovirus 71 infection in Chinese children.

Enterovirus 71 (EV71) is a single-strand RNA virus that causes hand, foot and mouth disease (HFMD) in infants and young children, leading to neurological complications with significant morbidity and mortality. Unfortunately, the pathogenesis of EV71 infection is not well understood. In this study, we investigated the IL-17F rs1889570 and rs4715290 gene polymorphisms in a Chinese Han population. Severe cases and cases with EV71 encephalitis had a significantly higher frequency of the rs1889570 T/T genotype and T allele. The serum IL-17F levels in rs1889570 T/T and C/T genotypes were also significantly elevated when compared to C/C genotypes. However, there was no significant difference observed in rs4715290 genotype distribution and allele frequency. These findings suggest that IL-17F rs1889570 gene polymorphisms are significantly associated with the susceptibility to severe EV71 infection in Chinese Han children.

Impact of Interleukin-17F Gene Polymorphisms in Outcome of Kidney Transplantation in Tunisian Recipients

BackgroundGenetic polymorphisms of interleukin (IL)-17F, associated with functional and/or quantitative change in this glycoprotein, have been described as predisposing to various autoimmune diseases. The proinflammatory IL-17 has some roles in renal transplantation. In this context, the relationship between the most common IL-17F polymorphisms with acute renal allograft rejection susceptibility in Tunisian renal recipients has been investigated. MethodsWe examined 93 renal transplant recipients who were enrolled and classified as follows: GI, 48 transplant recipients who developed at least one episode of acute rejection; and GII, 45 controls, kidney recipients who also were followed for at least 1 year and had stable renal function. Single nucleotide polymorphisms (SNPs) of IL-17F gene, including -1507 C/T (rs18889570), 7384 A/G (rs2397084), 7469 C/T (rs11465553), and 7489 A/G (rs763780), were evaluated using direct sequencing. ResultsNo statistically significant association of the IL-17F SNPs studied with the onset of acute rejection was observed. However, AA genotype on 7489A/G SNP showed anti-HLA antibodies less than other genotypes and a higher graft survival time (P = .017). ConclusionThe AA genotype on 7489A/G SNP of IL-17F and the A allele might be associated with a lower risk of acute rejection with better graft survival.

Interleukin-17A and interleukin-17F gene polymorphisms and hepatitis B virus-related hepatocellular carcinoma risk in a Chinese population.

Interleukin (IL)-17A and IL-17F are inflammatory cytokines, which play a critical function in inflammation. Genetic variations in the IL-17A and IL-17F genes may be associated with a risk of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), which is a typical inflammation-related cancer. However, their relationship with HBV-related HCC has not been thoroughly investigated. We conducted a case-control study including 155 patients with HBV-related HCC and 171 healthy controls to assess the association between IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms and risk of HCC. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing. There were no significant differences in the genotype and allele frequencies of IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms between the HBV-related HCC patients and healthy controls. However, our results revealed a statistically significant association between the ACA haplotype and increased HCC risk [odds ratio (OR) 1.820, 95% confidence interval (CI) 1.181-2.624, P=0.013]. In contrast, the GCG haplotype was associated with a significantly decreased risk of HBV-related HCC (OR 0.454, 95% CI 0.112-0.898, P=0.035). Our results suggest that IL-17A rs4711998, IL-17A rs2275913, and IL-17F rs763780 polymorphisms do not contribute to HBV-related HCC susceptibility independently. However, the ACA and GCG haplotypes in the IL-17 gene might be a risk factor and a protective marker, respectively, for HBV-related HCC in a Chinese population.

Effect of interleukin-17A and interleukin-17F gene polymorphisms on the risk of gastric cancer in a Chinese population

We selected six tagged single-nucleotide polymorphisms (SNPs) in the IL-17A and IL-17F genes, and evaluated the relationship between the six common SNPs and H. pylori infection, tobacco smoking and subsites of gastric cancer in gastric cancer patients. Genotyping of IL-17A (rs2275913, rs3748067 and rs3819025) and IL-17A (rs763780, rs9382084, and rs12203582) was performed in a 384-well plate format on the MassARRAY® platform. An unconditional multiple logistical regression model was performed to determine the association between IL-17A and IL-17F genetic variations and gastric cancer risk. Unconditional logistic regression analysis showed that subjects carrying the rs2275913AA and rs3748067 TT genotypes were 1.70 and 3.45 times more likely to develop gastric cancer. Furthermore, rs2275913 and rs3748067 genetic variants significantly interacted with H. pylori infection on the risk of gastric cancer. The interaction between rs3748067 and rs9382084 genetic variants and tobacco smoking trend was significant. In addition, rs2275913, rs3748067 and rs9382084 genetic variants were only associated with non-cardia gastric cancer. The findings suggest that the rs2275913, rs3748067 and rs9382084 polymorphisms increase the risk of gastric cancer, and they interact with H. pylori infection, tobacco smoking and subsites of gastric cancer. These findings could be helpful in identifying individuals at increased risk for developing gastric cancer.

Association of Interleukin-17F Gene Polymorphism with Enterovirus 71 Encephalitis in Patients with Hand, Foot, and Mouth Disease

Enterovirus 71 (EV71) is one of the common pathogenic agents of hand, foot, and mouth disease (HFMD) and is associated with severe complications including encephalitis. Interleukin (IL)-17F plays an important role in tissue inflammation by inducing release of proinflammatory cytokines and chemokines. We investigated the association between EV71 encephalitis and of IL-17F 7488T/C (rs763780) gene polymorphism, which is known to cause a His-to-Arg substitution at amino acid 161. The study was performed in 58 Chinese patients with EV71 encephalitis and 127 Chinese patients with EV71-related HFMD without complications. Genotyping was determined by the polymerase chain reaction-restriction fragment length polymorphism technique. The patients with EV71 encephalitis had a significantly lower frequency of the IL-17F 7488TC+CC genotypes (10.3%) as compared to the patients with EV71-related HFMD without complications (27.6%, p = 0.008). The frequency of IL-17F 7488C alleles was also significantly lower among the patients with EV71 encephalitis (5.2%) as compared to that of the patients with EV71-related HFMD without complications (15%, OR = 0.310, 95% CI = 0.127-0.756, p = 0.006). Furthermore, homozygotes with the T allele had significantly higher levels of C-reactive protein, white blood cell count, and neutrophil count as compared to the patients with CC+CT genotypes (p = 0.004, 0.001, and 0.000, respectively). These findings suggested that the IL-17F 7488C allele could be significantly associated with protection against encephalitis in Chinese patients with EV71-related HFMD.

Influence of Interleukin-17f Gene Polymorphisms on Renal Transplantation Outcome

Interleukin-17 (IL-17) plays an important role in the regulation of cellular and humoral immune responses. Although recent studies suggest a role of IL-17 in transplantation, there has been no report about influence of IL-17 gene polymorphism on renal transplantation outcomes. We investigated whether IL-17F gene polymorphisms have influence on graft outcomes in renal transplantation. We analyzed 227 patients who received living donor renal transplantation at Seoul National University Hospital between Jan 1996 and Jul 2004 and 210 healthy controls. IL-17F single nucleotide polymorphisms (SNPs) at 5 sites were analyzed using direct sequencing for 7384A/G, 7470G/A, and 7489A/G and sequence-specific priming for -1507C/T and 6329C/T polymorphisms. There was no difference in IL-17F ▪ gene polymorphism between patient and control groups. Patients with AA genotype at 7489A/G showed a tendency for higher frequency of underlying inflammatory kidney diseases than those with AG or GG genotypes (70.6% vs. 51.9%, P = 0.061). In addition, patients with G allele at 7384A/G showed a significant decrease of 3-year recurrence-free survival of original renal diseases than those without G allele (80.0% vs. 95.5%, P = 0.002). Patients with CC or CT genotypes at 6329C/T showed a tendency for higher frequency of acute rejection than those with TT genotype (30.2% vs 12.5%, P = 0.09). No other IL-17F gene polymorphism showed association with acute or chronic rejections. In summary, we found that 1) the distribution of IL-17F SNP allele frequencies at 5 sites studied is not different between kidney recipients and healthy controls; 2) 7489A/G and 7384A/G polymorphisms are associated with the occurrence of inflammatory renal disease and the recurrence of underlying disease after renal transplantation, respectively; 3) 6329C/T polymorphism might be associated with acute rejection. Further studies in larger number of patients are needed to confirm the roles of IL17F gene polymorphisms on renal transplantation outcomes or underlying renal diseases.

Interleukin-17F gene polymorphism in patients with chronic immune thrombocytopenia

IL-17F is a novel inflammatory cytokine and plays an important role in some autoimmune diseases. We investigated the association between chronic ITP and the frequency of the single-nucleotide polymorphism rs763780 (7488T/C), which causes a His-to-Arg substitution at amino acid 161. We examined 102 patients (men/women, 40/62; median age, 42) diagnosed with chronic ITP and 188 healthy controls (men/women, 78/110; median age, 38). Genotyping was determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Compared with the control group, patients with chronic ITP had a significantly lower frequency of the IL-17F 7488CC genotype (0% vs. 4.8%, P<0.05). The number of IL-17F 7488C alleles among the patients with chronic ITP was also significantly lower than in the control group (8.7% vs. 15.2% OR=0.48, 95%CI=0.27-0.84, P=0.016). Furthermore, patients with the IL-17F 7488TT genotype showed a severe thrombocytopenic state (platelet count<10×10(9) /L) at diagnosis than those with the IL-17F 7488TC genotype (20.9% vs. 0%, P=0.04). These findings suggest that the IL-17F 7488 T allele is significantly associated with the development of chronic ITP, suggesting a role for IL-17F in the pathogenesis of chronic ITP.

Association between IL‐17F Gene Polymorphisms and Susceptibility to and Severity of Rheumatoid Arthritis (RA)

Interleukin-17F (IL-17F) is a novel proinflammatory cytokine. IL-17F gene is an excellent candidate for chronic inflammatory disease. We investigated the association between rheumatoid arthritis (RA) and His161Arg (7488A/G; rs763780) and Glu126Gly (7383A/G; rs2397084) polymorphism of IL-17F gene. The gene polymorphisms in 220 Polish patients with RA and 106 healthy subjects were amplified by polymerase chain reaction with restriction endonuclease mapping. Overall, the polymorphisms of the IL-17F gene were not correlated with susceptibility to RA in Polish population. However, the IL-17F His161Arg variant was associated with parameters of disease activity, such as number of tender joints, HAQ score or DAS-28-CRP. Moreover, our findings have shown that Glu126Gly IL-17F gene polymorphism may be correlated with longer disease duration in patients with RA. Our results for the first time showed the relationship between IL-17F gene polymorphisms and severity of RA.

Interleukin-17F gene polymorphisms in Korean patients with Behçet’s disease

IL-17 is a novel cytokine that is characterized by an ability to induce several types of cells to secrete proinflammatory cytokines in various inflammatory diseases. This study analyzed the influence of IL-17F gene polymorphisms on disease susceptibility and clinical features. Ninety-nine Behçet's disease (BD) patients and 114 controls were genotyped to analyze three single nucleotide polymorphisms (SNPs) including A126G, G155A, and A161G of the IL-17F gene using automated sequencing. We compared the frequencies of IL-17F alleles, genotypes, and haplotypes in patients with BD and controls using the chi-square or Fisher's exact test. Significant differences in the frequencies of allele and genotype in A126G SNP of IL-17 gene were found between BD patients and controls (P<0.001 and P<0.001, respectively). None of three IL-17F SNPs were associated with diverse clinical features in BD. The frequency of haplotype AA did not differ between patients with BD and controls (P=0.985). The haplotypes, AG, and GG, have positive and inverse association with BD susceptibility (P<0.001 and P<0.001, respectively). These findings suggest that IL-17 gene SNPs may influence the susceptibility of BD.