Associations of protein tyrosine phosphatase nonreceptor 22 (PTPN22) gene polymorphisms with susceptibility to Graves' disease in a Japanese population

BACKGROUND: The polymorphism of the protein tyrosine phosphatase nonreceptor 22 (PTPN22) gene, which encodes an important negative regulator of T cell activation, has been reported to be associated with susceptibility to Graves' disease (GD) in Caucasians. The objective of this study was to investigate whether PTPN22 gene polymorphisms confer susceptibility to GD and Graves' ophthalmopathy (GO) in a Japanese population. METHODS: We performed a case-control study of PTPN22 gene polymorphisms in Japanese GD patients (n = 414) and healthy control subjects with no antithyroid autoantibodies or family history of autoimmune disorders (n = 231). The G-1123C polymorphism (rs2488457) in the promoter region, Arg620Trp (C1858T) polymorphism (rs2476601) in exon 14, IMS-JST146695 polymorphism (rs3789607) in intron 19, and SNP37 (rs3789604) downstream of the PTPN22 gene were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism using restriction enzymes and direct PCR sequencing methods. RESULTS: None of the GD patients or control subjects had the 1858T allele of the PTPN22 gene polymorphism. The AA-genotype and A-allele frequencies of SNP37 were significantly higher in GD patients than in control subjects (A-allele frequency: p = 0.0085, odds ratio = 1.45). The genotype frequencies and allele frequencies of the G-1123C and IMS-JST146695 polymorphisms did not differ between GD patients and control subjects. The -1123G/1858C/JST146695T/SNP37C haplotype frequency was significantly lower in GD patients than in control subjects. There were no associations between PTPN22 gene polymorphisms and GO. CONCLUSIONS: The results suggest that SNP37 of the PTPN22 gene is associated with susceptibility to GD in a Japanese population. Further studies including functional analyses are required.     

Interleukin-12B gene polymorphism does not confer susceptibility to Graves' ophthalmopathy in Japanese population

Graves' disease (GD) is an autoimmune disorder with genetic predisposition and frequently associated with Graves' ophthalmopathy (GO). Interleukin 12 (IL-12) is an important mediator of inflammatory immune responses and is expressed in the thyroid and orbit. IL-12B gene, which encodes the p40 subunit of IL-12, is located at chromosome 5q31-33. The aim of the present study was to investigate whether IL-12B gene polymorphism is associated with the development of GD or GO. IL-12B gene polymorphism was studied in Japanese GD patients (n = 329) and healthy control subjects without anti-thyroid autoantibodies or a family history of autoimmune disorders (n = 226). The A/C polymorphism at position 1188 of the 3' untranslated region (3'UTR) of the IL-12B gene was analyzed using the polymerase chain reaction--restriction fragment length polymorphism method. There was no difference in allele or genotype frequency of the IL-12B gene polymorphism (1188A/C) between GD patients and control subjects. There was no association of the IL-12B gene polymorphism with ophthalmopathy, severity of hyperthyroidism or serum IgE levels. There was no association of the IL-12B gene polymorphism with serum IL-12 levels, which were significantly elevated in hyperthyroid phase of GD. In conclusion, IL-12B gene 1188A/C polymorphism is not associated with GD or GO susceptibility in Japanese.     

Association of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene polymorphism and non-genetic factors with Graves' ophthalmopathy in European and Japanese populations

OBJECTIVE: The development and severity of Graves' ophthalmopathy (GO) may result from a complex interplay of genetic and environmental factors. The aim of this study was to investigate the association of cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene polymorphism and non-genetic factors (age, sex, cigarette smoking) with GO in two different populations, Polish-Caucasians and Japanese. DESIGN: We investigated the distribution of CTLA-4 A49G polymorphism in 264 Caucasian patients with Graves' disease (GD), of which 95 had clinically evident GO (NOSPECS class >or=3) and 319 Japanese patients with GD, of which 99 had ophthalmopathy. The control groups consisted of healthy Polish adults (n=194), Polish centenarians (n=51) and Japanese adults (n=112). RESULTS: Allele G and G/G genotype were significantly increased in Caucasian patients with GD (48% and 25% respectively) and in Japanese patients with GD (69% and 47% respectively) compared with control groups. There were no significant differences in the G allele and G/G genotype frequencies in GO patients compared with GD patients without ophthalmopathy. Multiple logistic regression analysis demonstrated that cigarette smoking (P=0.03, odds ratio (OR)=1.7) and age of onset of GD over 42 Years (P=0.08; OR=1.6) were contributing factors associated with susceptibility to GO in Polish patients. In Japanese patients, a younger age of onset of GD had an effect on the development of GO (P=0.02, OR=1.8). CONCLUSIONS: (i) Allele G and G/G genotype confer genetic susceptibility to GD; (ii) CTLA-4 A49G polymorphism is not associated with the development of GO; (iii) different non-genetic factors may contribute to GO in different populations.     

Interleukin-13 gene polymorphisms confer the susceptibility of Japanese populations to Graves' disease

Graves' disease (GD) is an autoimmune disorder with genetic predisposition. IL-13 is an important mediator of antiinflammatory immune responses and is expressed in the thyroid and orbit. The aim of the present study was to investigate whether IL-13 gene polymorphisms are associated with the development of GD. IL-13 gene polymorphisms were studied in Japanese GD patients (n = 310) and healthy control subjects without antithyroid autoantibodies or a family history of autoimmune disorders (n = 244). A C/T polymorphism at position -1112 of the promoter region was measured using the direct sequencing method, and an Arg(130)Gln (G2044A) polymorphism in exon 4 was examined using the PCR-restriction fragment length polymorphism method. There was a significant decrease in -1112T allele frequency in GD patients compared with controls (16% vs. 23%; P = 0.0019). The frequency of the 2044A allele on exon 4 also appeared lower in GD patients compared with controls. Haplotype analysis showed a significant decrease in the -1112T/2044A haplotype in GD patients. There was no association between IL-13 gene polymorphisms and ophthalmopathy, severity, or serum IgE levels. In conclusion, IL-13 gene polymorphisms are associated with GD susceptibility in Japan.     

Interleukin-13 gene polymorphisms in patients with Graves' disease

OBJECTIVE: In patients with Graves' disease (GD), an elevation of serum immunoglobulin E (IgE) has been recently reported to be associated with the severity of hyperthyroidism and ophthalmopathy. Interleukin 13 (IL-13) is a major cytokine involved in IgE synthesis and therefore may be a potential candidate gene contributing to the development of GD or influencing the clinical course of the disease. DESIGN: In a case-control study, we examined IL-13 gene single-nucleotide polymorphisms in the 5' promoter region at position -1112 (C to T change, termed as C-1112T) and in exon 4 at position 2044 (G to A change, G2044A, which results in an amino acid exchange Arg130Gln) in 261 patients with GD. The control groups consisted of healthy young subjects (n=168) and subjects over 100 years old with no history of autoimmune or allergic diseases recruited from the Polish Centenarians Project (n=50). MEASUREMENTS: C-1112T and G2044A polymorphisms were defined by fluorescent single-strand conformational polymorphism and by restriction fragment length polymorphism analysis, respectively. RESULTS: In patients with GD, the distribution of IL-13 alleles (-1112T 31%; 2044A 25%) and genotypes (-1112T/T 10%; 2044A/A 7%) did not differ significantly compared to control groups. Subdividing GD patients according to clinically evident ophthalmopathy (NOSPECS class III or higher, n=93) revealed no significant differences in the frequencies of -1112T allele (33%vs. 29%; P=0.4), -1112T/T genotype (13%vs. 8%; P=0.3), 2044A allele (27%vs. 24%; P=0.5) and 2044A/A genotype (9%vs. 7%; P=0.7) between GD patients with and without eye involvement. In order to analyse the association with the severity of hyperthyroidism, we examined patients with a first onset of GD treated with antithyroid drugs (n=32). IL-13 genotypes were not associated with the laboratory findings at diagnosis (thyroid volume, serum levels of FT4, TRAb, TPOAb, TGAb) and with the outcome of antithyroid drug treatment. CONCLUSIONS: Our results suggest that IL-13 gene polymorphisms at positions -1112 (C-->T) and 2044 (G-->A): (1) do not confer genetic susceptibility to Graves' disease; (2) do not contribute to the development of clinically evident ophthalmopathy; (3) are not associated with severity of hyperthyroidism.     

Interleukin (IL)-23 receptor is a major susceptibility gene for Graves' ophthalmopathy: the IL-23/T-helper 17 axis extends to thyroid autoimmunity

CONTEXT: IL-23 and its receptor (IL-23R) guide T cells toward the T-helper 17 phenotype. IL-23R single nucleotide polymorphisms (SNPs) have been associated with several autoimmune diseases, including Crohn's disease and rheumatoid arthritis. OBJECTIVE: Our objective was to determine whether variants in the IL-23R gene are associated with Graves' disease (GD) and Graves' ophthalmopathy (GO). DESIGN AND PARTICIPANTS: A total of 216 North American Caucasian GD patients and 368 healthy controls were genotyped for four SNPs spanning the IL-23R gene. SNPs rs11209026 and rs7530511 were genotyped using the TaqMan allelic discrimination assays (Applied Biosystems, Foster City, CA), and SNPs rs2201841 and rs10889677 were genotyped using a fluorescent-based restriction fragment length polymorphism method. RESULTS: The A allele of rs2201841 was present in 78.8% of GD patients with GO and 64.7% of controls [P=1.1x10(-4); odds ratio (OR)=2.04]; the AA genotype was also significantly increased in GO patients compared with controls (62.5 and 41%, respectively; P=1.0x10(-4); OR=2.4). The C allele of rs10889677 was present in 78.6% of GO patients and 64.5% of controls (P=1.3x10(-4); OR=2.03), and the CC genotype was also significantly increased in GO patients vs. controls (62.1 and 41.0%, respectively; P=1.4x10(-4); OR=2.36). The TT genotype of rs7530511 was significantly associated with GD, but not specifically with GO; it was present in 2.5% of GD patients and 0.3% of controls (P=0.02; OR=9.4). The rs11209026 SNP, which is the most strongly associated with Crohn's disease, was not associated with GD or GO in our data set. CONCLUSIONS: Variants in the IL-23R gene are strongly associated with GO. These variants may predispose to GO by changing the expression and/or function of IL-23R, thereby promoting a proinflammatory signaling cascade.     

L-selectin gene polymorphisms in Graves' disease

OBJECTIVE: Graves' disease (GD) is an autoimmune disorder with genetic predisposition. There is strong evidence that members of the selectin family participate in the interaction between leucocytes and the endothelium, as well as in inflammatory cell recruitment. Moreover, a high serum level of a soluble form of L-selectin (SL-selectin) has been reported in untreated GD patients. However, the impact of L-selectin polymorphisms on GD has not yet been investigated. The aim of the present study was to elucidate whether L-selectin gene polymorphisms were associated with the development of GD. SUBJECTS AND DESIGN: L-selectin gene polymorphisms were investigated in 230 Chinese GD patients and 208 healthy control subjects without antithyroid autoantibodies or a family history of autoimmune disorders. Two L-selectin SNPs were genotyped by the PCR-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: A C/T polymorphism at position -642 of the promoter region and a Pro213Ser (c.725 C-T) polymorphism in exon 6 were examined using PCR-RFLP. There was a significant increase in -642T allele frequency in GD patients compared with healthy controls (70 vs. 62%; P = 0.0126; P(c) = 0.0252). The frequency of the c.725C allele in exon 6 also appeared higher in GD patients than in controls. Haplotype analysis showed a significant decrease in the -642C/c.725T haplotype in GD patients (26 vs. 34%; P = 0.0095; Pc = 0.0190). However there was no association between polymorphisms and certain GD clinical phenotypes, including age of onset and ophthalmopathy. CONCLUSIONS: L-selectin gene polymorphisms are associated with GD susceptibility in Chinese patients.     

IL-18 gene polymorphism confers susceptibility to the development of anti-GAD65 antibody in Graves' disease.

AIMS: This study aimed to investigate whether interleukin-18 (IL-18) gene polymorphisms are associated with the development of antibody against the 65-kDa isoform of recombinant human glutamic acid decarboxylase (GAD65Ab) in patients with Graves' disease. METHODS: A total of 398 unrelated Japanese patients with Graves' disease, with and without GAD65Ab, were recruited. Three single nucleotide polymorphisms in the IL-18 gene were examined and the polymorphic allele and the genotype and haplotype frequencies calculated. RESULTS: The frequency of the GG genotype at position -4675 of the IL-18 gene was significantly lower in Graves' disease patients with GAD65Ab than those without (4% vs. 24%, P = 0.0126). The -4675C allele frequency was significantly greater in patients with GAD65Ab than those without (69% vs. 53%, P = 0.0168). The homozygous -4675G/-607A/-137G haplotype was less common in Graves' disease patients with GAD65Ab than those without (4% vs. 23%, P = 0.0144). CONCLUSIONS: These findings in a Japanese population indicate that Graves' disease patients carrying the GG genotype at position -4657 of the promoter of the IL-18 gene or a gene in linkage disequilibrium with the -4675G/-607A/-137G haplotype have a low risk for the development of GAD65Ab in Graves' disease.     

Association between a C/T polymorphism in exon 33 of the thyroglobulin gene is associated with relapse of Graves' hyperthyroidism after antithyroid withdrawal in Taiwanese

CONTEXT: Graves' disease (GD) is an autoimmune disorder with genetic predisposition. The thyroglobulin (Tg) is a major autoantigen for GD. The human Tg gene polymorphism has specific features that make it important in GD. OBJECTIVE: This study investigated whether Tg single nucleotide polymorphisms (SNPs) relate to GD development in a Taiwanese population. DESIGN AND SETTING: This was a case-control association study. PATIENTS AND MAIN OUTCOME MEASURES: We enrolled 215 Taiwanese patients with GD and 141 controls from the Endocrine Clinic of Kaohsiung Medical University Chung-Ho Memorial Hospital. This study investigated the association between gene polymorphism and relapse of hyperthyroidism after medication was discontinued in three GD patient groups and a control group. We also compared clinical and laboratory data obtained from patients with the three different genotypes with the three different Tg SNPs (E10SNP158, E12SNP, and E33SNP). RESULTS: We found a significant increase in the T/T genotype of E33SNP compared with the control group (P < 0.001). We also found the E33SNP C/C genotype of the Tg gene was strongly associated with a subgroup of GD patients who were also characterized as having a higher relapse rate, significantly higher levels of persisting TSH-receptor antibody at the end of treatment, a higher frequency in smoking, and a higher incidence of ophthalmopathy (P < 0.05). CONCLUSIONS: This study showed that Taiwanese patients with the C/C genotype of E33SNP, smoking, ophthalmopathy, and positive TSH-receptor antibodies at the end of the treatment were more likely to have a relapse of Graves' hyperthyroidism after antithyroid medication is withdrawn.     

A C/T polymorphism in the 5' untranslated region of the CD40 gene is associated with later onset of Graves' disease in Japanese

Graves' disease (GD) is an autoimmune disorder with genetic predisposition. CD40, which stimulates lymphocyte proliferation and differentiation, is an important immunomodulator and is expressed in the thyroid follicular cells as well as antigen-presenting cells. A single nucleotide polymorphism (SNP) at position -1 of the Kozak sequence of the CD40 gene has been reported to be associated with the development of GD. The aim of the present study was to investigate whether CD40 gene polymorphism confers susceptibility to GD in Japanese. CD40 gene polymorphisms were studied in Japanese GD patients (n = 324) and healthy control subjects without anti-thyroid autoantibodies or a family history of autoimmune disorders (n = 229). A C/T polymorphism at position -1 of the CD40 gene was measured using the polymerase chain reaction restriction fragment length polymorphism. There was no significant difference in allele or genotype frequency of the CD40 SNP between GD and control subjects. There was a significant decrease in the TT genotype frequency in the GD patients, who developed GD after 40 years old, than those under 40 year of age. These data suggest that the SNP of CD40 gene is associated with susceptibility to later onset of GD in Japanese.     

Intercellular adhesion molecule 1 gene polymorphisms do not contribute to Graves' disease in Chinese patients

Objective In order to study the association of G241R polymorphism of ICAM-1 gene with an earlier onset of Graves’ disease (GD) and the susceptibility of K469E polymorphism to Graves’ ophthalmopathy (GO) in Chinese population. Study Design A case-control and replication study was performed in 212 GD patients and 204 healthy subjects to analyze the genotypes. Furthermore the distribution of ICAM-1 genotypes was investigated in subgroups of patients with GD according to the onset age and the ophthalmopathy. Results No G241R polymorphism of ICAM-1 gene was detected in Chinese. No significant differences of allele and genotype frequencies regarding K469E polymorphism were found between GD patients and healthy controls (χ2 = 0.092, P = 0.762; χ2 = 1.089, P = 0.580). In addition, the genotype–phenotype correlation was not identified either. Conclusions We found no association of G241R and K469E polymorphisms of the ICAM-1gene with the development of GD in a Chinese population. However, we could not rule out possible contributions of other polymorphisms of the ICAM-1gene to the pathogenesis of GD. Therefore, further studies are needed to elucidate the role of ICAM-1gene in Graves’ disease in different population. Shu Wang and Hua Sun contributed equally to this work.     

Intercellular adhesion molecule 1 gene polymorphisms in Graves' disease

It was recently suggested that genetic factors could play a major role in the development of Graves' disease (GD). The aim of the present study was to evaluate the frequency of the c.721G-->A polymorphism and the c.1405A-->G polymorphism of the intercellular adhesion molecule 1 (ICAM-1) gene in subjects with GD compared with that in healthy controls, because ICAM-1 was found to play a key role in lymphocyte infiltration into the thyroid gland and the concentration of the soluble form of ICAM-1 correlates significantly with the clinical activity and treatment status in GD. We have analyzed the association of ICAM-1 polymorphisms with the age at onset of GD and the presence of ophthalmopathy. In a group of 235 patients with GD and 211 healthy controls we have shown that polymorphism at position c.721G-->A is associated with an earlier age of GD onset and that the c.1405A-->G polymorphism of the ICAM-1 gene could predispose to Graves' ophthalmopathy. This suggests that G241R and K469E amino acid substitutions in the ICAM-1 molecule could influence the intensity/duration of the autoimmunity process and the infiltration of orbital tissues. It could be speculated that therapy that modulates ICAM-1 function may delay the onset and/or prolong the remission and/or have an influence on clinical manifestations of GD.     

No Association Between IL12B Gene Polymorphisms and Graves' Disease in the Chinese Population

Background. Graves' disease (GD) is one of the most common autoimmune thyroid disorders and has a striking characteristic of female preponderance. Objective. The main objective of this study was to investigate whether IL12B gene polymorphisms were associated with either GD itself or with gender bias in GD. Methods. GD patients (151 males, 97 females) and 211 healthy control subjects without antithyroid autoantibodies or a family history of autoimmune disorders were recruited for this study. The G/C polymorphism (rs6887695) of the IL12B gene was analyzed using the polymerase chain reaction-restriction fragment length polymorphism, and the deletion and insertion polymorphism (rs41292470) in the IL12B promoter was detected after polyacrylamide gel electrophoresis-silver staining method. Results. There was no significant difference between GD patients and normal subjects, and no differences in frequencies of genotypes or alleles of either polymorphism between male and female GD subjects. Conclusion. We conclude that these IL12B gene polymorphisms were not associated with sex bias in GD and do not confer susceptibility to Graves' disease (GD) in the Chinese population.     

More on smoking habits and Graves' ophthalmopathy

Since a relationship between cigarette smoking and the occurrence of Graves' ophthalmopathy has been recently postulated, we reviewed the smoking habits of 1730 women, including subjects without thyroid disease, with nontoxic goiter (NTG), toxic nodular goiter or toxic adenoma (TNG), Hashimoto's thyroiditis (HT), Graves' disease without ophthalmopathy (GD) or with ophthalmopathy (GO). The prevalence of smokers in NTG, TNG and HT was about 30%, not different from that of controls. Smokers were 47.9% in GD and 64.2% in GO groups. The latter figures were highly different from those of the other groups and also from each other. The percentage of heavy smokers was higher in patients with more severe ophthalmopathy. No clear explanation for this phenomenon can be offered. The absence of a high prevalence of smokers among patients with non-toxic goiter, nonautoimmune hyperthyroidism and Hashimoto's thyroiditis, limits the impact that smoking might have had in the pathogenesis of goiter, hyperthyroidism and autoimmune phenomena of GD and GO.     

Limited genetic susceptibility to severe Graves' ophthalmopathy: no role for CTLA-4 but evidence for an environmental etiology.

Graves' disease (GD) is an autoimmune thyroid disease (AITD) characterized by hyperthyroidism and by the occurrence of a distinctive ophthalmopathy (orbitopathy), which presents with varying degrees of severity. Graves' disease clusters in families but the importance of heredity in the pathogenesis of the associated ophthalmopathy is unclear. We have studied the family history of 114 consecutive, ethnically mixed patients with severe Graves' ophthalmopathy (GO). Patients were selected by unambiguous single ascertainment. Seventy-seven percent of patients were female and 59% smoked. The mean age at onset of their GD was 43 years (range 17-78 years). Forty-one patients (36%) had a family history of AITD, defined as a first- and/or a second-degree relative affected with either Graves' disease (GD) or Hashimoto's thyroiditis (HT). The segregation ratio for AITD in nuclear families in our ascertained Graves' ophthalmopathy families was 0.07 (0.12 in Caucasians only). Hence, the higher prevalence of AITD among relatives of Graves' ophthalmopathy patients agreed with the known genetic predisposition to AITD and this predisposition was stronger in women than in men. However, only 3 of the 114 patients had a family history of severe Graves' ophthalmopathy (all second-degree relatives) and the segregation ratio for GO was 0. These data did not support a major role for familial factors in the development of severe Graves' ophthalmopathy distinct from Graves' disease itself. In addition, we tested 4 candidate genes, human leukocyte antigen (HLA), tumor necrosis factor-beta (TNF-beta), CTLA-4 and the thyrotropin receptor (TSHR), for association with Graves' ophthalmopathy. These were negative except for the HLA and CTLA-4 genes, which were found to be weakly associated with GO giving similar relative risk (RR) as in GD patients without ophthalmopathy. These data suggested that environmental factors, rather than major genes, were likely to predispose certain individuals with AITD to severe Graves' ophthalmopathy. Smoking remains one example of such potential external insults.     

Lack of association of the vitamin D receptor gene with Graves' disease in UK Caucasians

OBJECTIVE: Vitamin D modulates the immune system by suppressing the proliferation of activated T cells, with its actions being directed through the vitamin D receptor (VDR). A number of single nucleotide polymorphisms (SNPs) have been identified in the VDR gene, of which several have been associated with autoimmune diseases, including type 1 diabetes and Graves' disease (GD) in Japanese females. The aim of this study was to test for association of polymorphisms of the VDR gene in the genetic susceptibility to GD in UK Caucasians. DESIGN: Target DNA for five previously published SNPs, four novel SNPs and one microsatellite marker was amplified by the polymerase chain reaction (PCR). Subsequent genotyping was performed using restriction fragment length polymorphism (RFLP) or microsatellite genotyping analysis, according to the type of VDR polymorphism. PATIENTS: We obtained DNA from a case-control dataset consisting of 768 patients with GD and 864 control subjects. All patients and control subjects were Caucasians born in the UK, and all gave informed, written consent. MEASUREMENTS: Frequencies of the alleles and genotypes of the ten VDR gene polymorphisms were compared between patients and control subjects using the chi2 test. Odds ratios were calculated using Woolf's method with Haldane's modification for small numbers and D prime (D') was calculated to assess the level of linkage disequilibrium (LD) between the ten polymorphisms. RESULTS: No differences in allele or genotype frequencies were observed between GD cases and control subjects for any of the nine SNPs studied. The S allele of the PolyA microsatellite marker was slightly more frequent in GD cases when compared with control subjects (chi2= 4.364, P = 0.04). Strongest LD between markers was observed towards the 3' end of the VDR gene but there was no evidence of association with disease. CONCLUSION: This is the largest and most comprehensive study of the VDR gene in GD to date and these data suggest that these polymorphisms of the VDR gene do not contribute to GD susceptibility in the UK.     

Vitamin D receptor gene polymorphism is associated with Graves' disease in the Japanese population

Susceptibility to Graves' disease (GD), which is determined by environmental and genetic factors, is conferred by genes in the human leukocyte antigen (HLA) and genes unlinked to HLA, including the CTLA-4 gene. We recently described the association of GD with the vitamin D receptor (VDR) exon 2 initiation codon (VDR-FOK:I) polymorphism. An association of some VDR genotypes with osteoporosis, primary hyperparathyroidism, and some autoimmune diseases, such as insulin-dependent diabetes mellitus and multiple sclerosis, has been reported. We investigated the distribution of VDR gene polymorphism in 180 Japanese patients with GD (48 males and 132 females) and 195 controls (67 males and 128 females). A VDR allelic polymorphism was assessed by BSM:I endonuclease restriction after specific PCR amplification. Genotypic polymorphism was clearly defined as BB (no restriction site on both alleles), bb (restriction site on both alleles), or Bb (heterozygous). The distribution of genotype frequencies differed between patients with GD and controls (chi(2) = 7.53; 2 degrees of freedom; P: = 0.023). The relative risk conferred by at least 1 B allele (BB or Bb) was 1.5. We also found an association between VDR-APA:I polymorphism and GD. No relation was detected between this polymorphism and the VDR-FOK:I polymorphism in the patients. The present results support the association of the VDR gene with GD in Japanese by showing that the VDR gene could be a non-HLA-linked gene predisposing an individual to GD. The role of the VDR gene polymorphism should be further studied in other populations, and the distribution of other polymorphisms, such as the polyadenylase polymorphism further down the VDR 3'-untranslated region, should be studied in terms of GD susceptibility.     

Association of CD40 gene polymorphism (C-1T) with susceptibility and phenotype of Graves' disease.

OBJECTIVE: Recently, a functional polymorphism in the CD40 gene at position -1, C to T change (C-1T) has been identified and the C/C genotype has been reported to be associated with Graves' disease (GD). DESIGN: We performed a case-control, replication study on 556 patients with GD and 611 healthy subjects in a Polish population. Furthermore, we analyzed the distribution of CD40 genotypes in subgroups of patients with GD divided according to age of onset, gender, family history, tobacco smoking, ophthalmopathy, and genetic parameters (CTLA4 49G, PTPN22/LYP 1858T or HLA-DRB1*03 alleles). RESULTS: Although the frequency of C/C genotype was increased in GD compared to controls, the difference was not significant (60.5% versus 55.8%, p = 0.062, odds ratio [OR] = 1.21, 95% confidence interval [CI]: 0.96-1.53). Because our study was underpowered to detect such a modest association, we performed a meta-analysis with the data from previous studies. The combined OR for the C/C genotype as a risk factor for GD was 1.22 (95% CI: 1.08-1.38, p = 0.001). We failed to find an interaction between CD40 genotypes and other GD susceptibility alleles. No significant genotype-phenotype associations were found. CONCLUSIONS: Our results support the notion that CD40 C-1T polymorphism has a modest effect on genetic susceptibility to sporadic GD.     

Association between IL-18 gene promoter polymorphisms and inflammatory bowel disease in a Japanese population

BACKGROUND: Interleukin-18 (IL-18) is a pleiotropic cytokine that induces the production of interferon (IFN)-gamma and also to regulate Th2 cytokines. Recently, association studies between IL-18 gene promoter polymorphisms and several Th1- or Th2-mediated inflammatory diseases were reported. In inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), recent evidence suggests that IL-18 is involved in the pathogenesis. METHODS: Using DNA direct sequencing, we investigated IL-18 gene promoter polymorphisms at -607C/A and -137G/C. Allele, genotype, and haplotype frequencies were determined in 210 Japanese patients with UC, 205 patients with CD, and 212 controls. RESULTS: In UC, the -137C allele frequency was significantly higher in the proctitis-type patients than in controls (Pc = 0.0068). The -137 genotype frequency was also significantly different in the proctitis-type patients than in controls (Pc = 0.032). No other allele and genotype frequencies were significantly associated with UC after Bonferroni correction. Furthermore, the frequency of haplotype 2 (-607A, -137C), which had a lower promoter activity and IFN-gamma mRNA level than the other haplotypes as previously reported, was significantly higher in the proctitis-type patients than in controls (Pc = 0.01). In CD, we could not find any significant differences. CONCLUSIONS: IL-18 gene promoter polymorphisms may not be associated with disease susceptibility but related to the extent of disease in UC.     

Association of Graves' disease with intragenic polymorphism of the thyrotropin receptor gene in a cohort of Singapore patients of multi-ethnic origins.

Thyrotropin (TSH) receptor (TSHr) mutations have been investigated in relation to Graves' disease (GD) genetic susceptibility under the hypothesis that a modified antigen may have novel immunogenic properties. The prevalence of three germline polymorphisms--D36H, P52T, and D727E--were studied in a cohort of multiracial GD patients together with their associations with disease state, Graves' ophthalmopathy, and thyroid autoantibodies titers. Polymerase chain reaction products of exon 1 and 10e of the TSHr were generated from 164 GD patients (109 Chinese, 34 Malays, and 21 Indians) and 240 individuals with no thyroid illnesses (74 Chinese, 84 Malays, and 82 Indians). Mutations were detected by single-strand conformational polymorphism and confirmed with direct sequencing. The D36H mutation was absent, while significant ethnic differences in the distribution of the P52T and D727E mutations were found. The levels of thyroid autoantibodies also differed significantly amongst the three ethnic groups, with the Indian cohort having the lowest titer. Both the P52T and D727E mutations were not associated with GD. An intron mutation, C/G+63IVS1, was detected and showed significant association with GD. Overall, it conferred a twofold increase risk of GD, while subgroup analysis showed increased odds ratios of 2.4 for Chinese (p = 0.008) and 2.8 for Indian (p = 0.049) but not for the Malay ethnic group. Together with recent identification of disease susceptibility markers in the region of the TSHr gene, these results are supportive of genetic factors existing in this region that may be in linkage disequilibrium with the inheritance of various TSHr polymorphisms.