MTHFR A1298C and C677T gene polymorphisms and susceptibility to chronic myeloid leukemia in Egypt

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme regulating the intracellular folate metabolism which plays an important role in carcinogenesis through DNA methylation. We aimed to evaluate the association between MTHFR A1298C and C677T polymorphisms and the risks of chronic myeloid leukemia (CML). Eighty-five patients with CML and a control group containing 100 healthy, age and sex matched individuals were examined for MTHFR C677T and A1298C polymorphisms using polymerase chain reaction-restriction fragment-length (PCR-RFLP) method. The frequency of 677TT genotype in patients with CML was significantly higher compared to controls (OR = 2.513, 95% CI: 0.722-4.086, P = 0.025). No such association was shown for heterozygous 677CT (OR = 1.010, 95% CI: 0.460-2.218, P = 0.981). Moreover, for A1298C genotype, a statistically significant higher frequency of 1298CC was also detected in CML patients compared to control group (OR = 1.1816, 95% CI: 0.952-3.573, P = 0.036), 0.036). No such statistical significance was demonstrable for heterozygote 1298AC (OR = 1.046, 95% CI: 0.740-1.759, P = 0.092). In addition, patients with joint 677CT/1298AC or 677TT/1298CC genotypes showed an association with increased risk of CML (OR = 1.849, 95% CI: 0.935-2.540, P = 0.024; OR = 1.915, 95% CI: 1.202-3.845, P = 0.020 respectively). .A statistically significant increased risk of resistant to therapy was observed with 677CT and 1298AC genotypes (P = 0.001, P = 0.002 respectively). We conclude that both MTHFR 677TT and 1298CC polymorphisms have been associated with risk of CML and both 677CT and 1298AC genotypes are associated with higher risk of resistant to therapy.     

Different roles of MTHFR C677T and A1298C polymorphisms in colorectal adenoma and colorectal cancer: a meta-analysis

Association studies on the MTHFR polymorphisms (C677T and A1298C) in colorectal cancer (CRC) and colorectal adenoma have shown conflicting results. We performed a meta-analysis to better assess the purported associations. Overall, the 677T allele (10,131 patients and 15,362 controls) showed a small but significant protective effect against CRC compared to the 677C allele [P=0.0003, odds ratio (OR)=0.93; 95% confidence interval (CI) 0.89–0.98, P=0.22 (for heterogeneity)] for a worldwide population. Meta-analyses of other genetic contrasts suggested that the 677T allele is more likely to affect CRC in a recessive genetic model worldwide (P<0.0001, OR=0.86; 95% CI 0.76–0.96, P=0.06) and in Asians (P=0.0005, OR=0.75; 95% CI 0.64–0.88, P=0.71). Similarly, we found a significantly decreased risk of CRC for 1298C polymorphism (4,764 CRC patients and 6,592 controls) for a recessive genetic model worldwide (P=0.005, OR=0.81; 95% CI 0.70–0.94, P=0.40) and in Caucasians (P=0.04, OR=0.75 95% CI 0.57–0.99, P=0.35). No evidence of association of C677T (4,616 patients and 6,338 controls) and A1298C (1,272 patients and 1,684 controls) with colorectal adenoma were found. The evidence accumulated suggests that MTHFR may represent a low-penetrance susceptible gene for CRC, and that the two polymorphisms might protect against colorectal adenoma developing into cancer. A larger single study is required to further evaluate gene–gene and gene–environment interactions for MTHFR polymorphisms and the cancer risk in a specific population. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Association Between Polymorphisms in Genes Encoding Methylenetetrahydrofolate Reductase and the Risk of Ménière's Disease

Abstract

Folate metabolism is essential for cellular functioning. Despite extensive research on the roles of folate-metabolism-related gene polymorphisms in the pathophysiology of many diseases, such as cardiovascular disease, cancers, and sudden sensorineural hearing loss, little is known about their association with Ménière's disease (MD). The aim of this study was to investigate the effect of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) on the risk of MD in a Japanese population. We examined the C677T and A1298C (rs1801133 and rs1801131) polymorphisms in the MTHFR gene and compared them between 1946 adults (986 men and 960 women) participating in the National Institute for Longevity Sciences Longitudinal Study of Aging and 86 cases of MD. A multiple logistic regression was performed to obtain odds ratios (ORs) for the risk of MD regarding the MTHFR polymorphisms before (model 1) and after (model 2) adjustment for age and sex factors. The OR of MTHFR C677T for the risk of MD was 0.669 (95% confidence interval [CI], 0.479–0.934) in model 1 and 0.680 (95% CI, 0.484–0.954) in model 2. In contrast, the OR of MTHFR A1298C for the risk of MD was 1.503 (95% CI, 1.064–2.123) in model 1 and 1.505 (95% CI, 1.045–2.167) in model 2. Our results imply that the MTHFR C677T and A1298C polymorphisms are associated with the risk of MD.     

Functional Inference of Methylenetetrahydrofolate Reductase Gene Polymorphisms on Enzyme Stability as a Potential Risk Factor for Down Syndrome in Croatia

Understanding the biochemical structure and function of the methylenetetrahydrofolate reductase gene (MTHFR) provides new evidence in elucidating the risk of having a child with Down syndrome (DS) in association with two common MTHFR polymorphisms, C677T and A1298C. The aim of this study was to evaluate the risk for DS according to the presence of MTHFR C677T and A1298C polymorphisms as well as the stability of the enzyme configuration. This study included mothers from Croatia with a liveborn DS child (n = 102) or DS pregnancy (n = 9) and mothers with a healthy child (n = 141). MTHFR C677T and A1298C polymorphisms were assessed by PCR-RFLP. Allele/genotype frequencies differences were determined using χ² test. Odds ratio and the 95% confidence intervals were calculated to evaluate the effects of different alleles/genotypes. No statistically significant differences were found between the frequencies of allele/genotype or genotype combinations of the MTHFR C677T and A1298C polymorphisms in the case and the control groups. Additionally, the observed frequencies of the stable (677CC/1298AA, 677CC/1298AC, 677CC/1298CC) and unstable (677CT/1298AA, 677CT/1298AC, 677TT/1298AA) enzyme configurations were not significantly different. We found no evidence to support the possibility that MTHFR polymorphisms and the stability of the enzyme configurations were associated with risk of having a child with DS in Croatian population.     

Klotho gene polymorphisms are related to colorectal cancer susceptibility

Aim: The purpose of this study was to investigate the relationship of Klotho gene G-395A and C1818T polymorphisms with colorectal cancer (CRC) susceptibility. Methods: 125 CRC patients and 125 controls were enrolled in the study. G-395A and C1818T polymorphisms were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Haploview software was utilized to conduct linkage disequilibrium and haplotype analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were used to analyze the correlation of genotypes and haplotypes with CRC susceptibility. Results: AA and GA genotypes of G-395A polymorphisms were related with CRC risk (AA: OR = 4.161, 95% CI = 1.437-12.053; GA: OR = 1.958, 95% CI = 1.133-3.385). The frequency of A allele was much higher in case group, compared with controls (31.2% vs.17.6%) and the value of OR AND 95% CI suggested that A allele served as a risk factor for CRC (OR = 2.123, 95% CI = 1.393-3.236). Haplotypes analysis indicated that A-C and A-T haplotypes were significantly associated with risk of CRC (OR = 1.822, 95% CI = 1.124-2.954; OR = 2.877, 95% CI = 1.340-6.176). Conclusion: G-395A polymorphism of Klotho gene could increase the risk of CRC.     

Methylenetetrahydrofolate reductase gene polymorphisms and lung cancer: a meta-analysis

So far, case-control studies on the association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and lung cancer provide controversial or inconclusive results. To clarify the effect of MTHFR polymorphisms on the risk of lung cancer, a meta-analysis of all case-control observational studies was performed. The studies provided 5,111/6,415 cases/controls for C677T and 5,087/6,232 cases/controls for A1298C. The heterogeneity (P = 0.0001, I ² = 76.6%) for C677T among the eight studies was extreme. Cluster analyses based on the frequencies of the C677T genotype of the control group in each study revealed that the studies could not cluster together according to their ethnicity. The random effects (RE) model showed that the 677T allele was not associated with the risk of lung cancer compared with the C allele [OR = 1.12, 95% confidence interval (CI) (0.97–1.28), P = 0.12]. The contrast of homozygotes, recessive model, dominant model produced the same pattern of results as the allele contrast. In regard to the A1298C polymorphism, there was no heterogeneity among the seven studies comparing the C versus the A allele (P = 0.24, I ² = 24.4%), but no significant association was detected by the RE model or the fixed effects model [FE odds ratio (OR) = 0.99 (0.93–1.05) and RE OR = 1.00 (0.92–1.08)]. The effect of MTHFR polymorphisms (C677T, A1298C) on the risk of lung cancer was undetectable, even though analyzed on a relatively good number of subjects (totally 11,526 subjects) by meta-analysis (statistical power = 93.9%). Although MTHFR polymorphisms were associated with the risk of colorectal cancer, leukemia, and gastric cancer supported by other meta-analysis, our pooled data suggest no evidence for a major role of these two variants in carcinogenesis of lung cancer. The results implied that different tumors evolve by different pathological pathways and the roles of MTHFR in cancer is determined by its target genes.     

ABCB1 polymorphisms associated with osteonecrosis of the femeral head

Aims: This case-control study was conducted to investigate the relation of ATP-binding cassette subfamily B member 1 (ABCB1) C1236T and C3435T polymorphisms and non-traumatic osteonecrosis of the femeral head (ONFH). Methods: We gathered 113 ONFH patients and 116 controls in the study. The polymorphisms of ABCB1 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Odds ratio (OR) with 95% confidence interval (CI) were adopted to analyze the correlation between ABCB1 polymorphisms and ONFH. Results: In the study, we found that the frequency of C3435T TT genotype was much lower in case group, compared with that of controls (17.7% vs. 23.3%). Moreover, OR and 95% CI values indicated that C3435T TT genotype served as a protective factor for ONFH (OR=0.34, 95% CI=0.15-0.75). Meanwhile, the risk for the T allele carriers was much lower than C allele (OR=0.60, 95% CI=0.42-0.87). However, C1236T polymorphism showed no significant effects on the pathogenesis of ONFH. In the haplotype analysis, T-T haplotype appeared to be an inhibitor for ONFH (OR=0.45, 95% CI=0.23-0.87). Conclusions: Based on the results, ABCB1 polymorphisms were associated with the risk for ONFH.     

MTHFR polymorphisms and breast cancer risk

Introduction

Two functional single nucleotide polymorphisms (SNPs) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, lead to decreased enzyme activity and affect chemosensitivity of tumour cells.

Material and methods

We evaluated these two common polymorphisms and breast cancer risk association in an Iranian sporadic breast cancer population-based case-control study of 294 breast cancer cases and 306 controls using a PCR-RFLP-based assay.

Results

Analyses of affected and controls show that homozygote genotype MTHFR 677CC has the highest frequency in both groups (28.3% in patients and 25.3% in control group). Genotype MTHFR 677CT and genotype MTHFR 1298AC were found to be statistically significant risk factors in our population (odds ratio: 1.6, 95% CI: 1.019-2.513, p = 0.041; and odds ratio: 2.575, 95% CI: 1.590-4.158, p = 0.001 respectively).

Conclusions

We can conclude based on the results of our study that a significant association between breast cancer and C677T and A1298C polymorphism might exist.     

Association of Methylenetetrahydrofolate Reductase (MTHFR 677C>T and 1298A>C) Polymorphisms and Haplotypes with Silent Brain Infarction and Homocysteine Levels in a Korean Population

Purpose

Methylenetetrahydrofolate reductase (MTHFR) is the main regulatory enzyme for homocysteine metabolism. In the present study, we evaluated whether the MTHFR 677C>T and 1298A>C gene polymorphisms are associated with SBI and plasma homocysteine concentration in a Korean population.

Materials and Methods

We enrolled 264 patients with SBI and 234 healthy controls in South Korea. Fasting plasma total homocysteine (tHcy) concentrations were measured, and genotype analysis of the MTHFR gene was carried out.

Results

The plasma tHcy levels were significantly higher in patients with SBI than in healthy controls. Despite a significant association between the MTHFR 677TT genotype and hyperhomocysteinemia, the MTHFR 677C>T genotypes did not appear to influence susceptibility to SBI. However, odds ratios of the 1298AC and 1298AC + CC genotypes for the 1298AA genotype were significantly different between SBI patients and normal controls. The frequencies of 677C-1298A and 677C-1298C haplotypes were significantly higher in the SBI group than in the control group.

Conclusion

This study demonstrates that the MTHFR 1298A>C polymorphism is a risk factor for SBI in a Korean population. The genotypes of 677C>T and 1298A>C polymorphisms interact additively, and increase the risk of SBI in Korean subjects.     

Relationship between hWAPL polymorphisms and cervical cancer susceptibility

Purpose: To analyze the correlation of the polymorphisms of human wing-apart like (hWAPL) gene (rs7083506 and rs11202058) with the susceptibility to cervical cancer. Besides, the relationship of haplotypes between the polymorphisms with cervical cancer susceptibility was analyzed. Methods: Taqman probe genotyping method was adopted to detect the genotype distribution of hWAPL rs7083506 and rs11202058 polymorphisms in 117 cervical cancer patients and 128 healthy controls. Linkage disequilibrium and haplotypes were analyzed by Haploview software. χ² test was utilized to analyze the differences of genotype, allele and haplotype frequencies between the case and control groups. Results: Correlation analysis of hWAPL rs7083506 and rs11202058 polymorphisms with cervical cancer susceptibility was based on the five genetic models. TT genotype of rs7083506 increased the susceptibility of cervical cancer in TT vs. CC model and TT vs. CT+TT model (OR=2.249, 95% CI=1.018-4.970; OR=2.287, 95% CI=1.069-4.896). For rs11202058, the A allele increased the cervical cancer susceptibility (A vs. G, OR=1.502, 95% CI=1.005-2.245). No significant correlation was observed between rs11202058 genotypes and cervical cancer susceptibility. We performed the haplotype analysis between the two polymorphisms, and found that T-A haplotype significantly correlated with cervical cancer, the susceptibility of cervical cancer increased to 1.78 times. Conclusions: Rs7083506 and rs11202058 polymorphisms of hWAPL and their haplotype T-A were associated with cervical cancer.     

Association of PTEN gene polymorphisms with liver cancer risk

Objective: To find out if there are any relationship between three single nucleotide polymorphisms (SNPs) of phosphatase and tensin homolog (PTEN) gene (rs1234213, rs1234220, and rs2299939) and the susceptibility of liver cancer. Methods: Genotypes of the three SNPs in the PTEN gene were achieved utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Comparison of genotypes and alleles distribution differences between the case and the control subjects was accomplished with χ² test. The analysis of linkage disequilibrium (LD) and haplotypes of the three SNPs was performed using SHEsis software. We adopted odds ratios (ORs) with 95% confidence intervals (95% CIs) to show the relative risk of liver cancer. Results: TC genotype and C allele of rs1234220 polymorphism showed much more frequently in cases than in controls, reflecting that the TC genotype and the C allele may be linked to the increased risk of liver cancer (OR=2.225, 95% CI=1.178-4.204; OR=1.941, 95% CI=1.124-3.351). Rs2299939 polymorphism showed an opposite result that the GT genotype probably reduce the risk of liver cancer (OR=0.483, 95% CI=0.259-0.900). Statistical significance was not found in the distribution differences of the genotypes of rs1234213 between two groups. LD and haplotype analysis results of the three SNPs showed that the T-C-G haplotype frequency was much higher in cases than in healthy objects, which proved that the T-C-G haplotype might be a susceptibility haplotype for liver cancer (OR=3.750, 95% CI=1.396-10.077). Conclusions: PTEN gene polymorphisms might relate to liver cancer risk.     

Genotype and haplotype distributions of <Emphasis Type="Italic">MTHFR </Emphasis>677C>T and 1298A>C single nucleotide polymorphisms: a meta-analysis

 Common single nucleotide polymorphisms (SNPs; 677C>T and 1298A>C) in the methylenetetrahydrofolate reductase gene (MTHFR) decrease the activity of the enzyme, leading to hyperhomocysteinemia, particularly in folate-deficient states. We calculate herein the haplotype frequencies of the MTHFR 677 and 1298 polymorphisms in pooled general populations derived from published data. We selected 16 articles that provided reliable data on combined MTHFR genotypes in general populations (n = 5389). The combined data comprised the following totals for each genotype at nucleotide positions 677 and 1298: 838 CC/AA (i.e., 677CC/1298AA), 1225 CC/AC, 489 CC/CC, 1120 CT/AA, 1093 CT/AC, 8 CT/CC, 606 TT/AA, 10 TT/AC, and 0 TT/CC. The estimated haplotype frequencies, and the fractional contribution of each, were 677C/1298A, 0.37; 677C/1298C, 0.31; 677T/1298A, 0.32; and 677T/1298C, 0.0023 to 0.0034. Thus, a vast majority of 677T alleles and 1298C alleles are associated with 1298A alleles and 677C alleles, respectively. There may be an increased frequency of the very rare cis 677T/1298C haplotype in some parts of the United Kingdom and Canada, possibly due to a founder effect. Further studies on both SNPs are needed to determine their exact role in various clinical settings. Received: August 22, 2002 / Accepted: October 7, 2002 Correspondence to:S. Ogino     

Gene-gene interaction in folate-related genes and risk of neural tube defects in a UK population

Objective: To investigate the contribution of polymorphic variation in genes involved in the folate-dependent homocysteine pathway in the aetiology of neural tube defects (NTD).

Design: Case-control association study.

Subjects: A total of 530 individuals from families affected by NTD, 645 maternal controls, and 602 healthy newborn controls from the northern UK.

Main outcome measures: Seven polymorphisms in six genes coding for proteins in the folate-dependent homocysteine pathway (MTHFR 677C→T, MTHFR 1298A→C, MTRR 66A→G, SHMT 1420C→T, CßS 844ins68, GCPII 1561C→T, RFC-1 80G→A). The impact of each polymorphism and the effect of gene–gene interactions (epistasis) upon risk of NTD were assessed using logistic regression analysis.

Results: The MTHFR 677C→T polymorphism was shown to represent a risk factor in NTD cases (CC v CT+TT odds ratio (OR) 2.03 [95% confidence interval (CI) 1.09, 3.79] p = 0.025) and the MTRR 66A→G polymorphism was shown to exert a protective effect in NTD cases (AA v AG+GG OR 0.31 [95% CI 0.10, 0.94] p = 0.04). When statistical tests for interaction were conducted, three genotype combinations in cases (MTRR/GCPII; MTHFR 677/CßS; MTHFR 677/MTRR) and one combination in case mothers (CßS/RFC-1) were shown to elevate NTD risk. Maternal–fetal interaction was also detected when offspring carried the MTHFR 677C→T variant and mothers carried the MTRR 66A→G variant, resulting in a significantly elevated risk of NTD.

Conclusion: Both independent genetic effects and gene–gene interaction were observed in relation to NTD risk. Multi-locus rather than single locus analysis might be preferable to gain an accurate assessment of genetic susceptibility to NTD.

     

Polymorphisms of methylenetetrahydrofolate reductase and methionine synthase genes and bladder cancer risk: a case–control study with meta-analysis

Folate deficiency due to the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) variants leads to carcinogenesis by affecting DNA synthesis, repair, and methylation. We hypothesized that the MTHFR C677T, A1298C, and MS A2756G polymorphisms are associated with risk of bladder cancer. In a case-control study of 239 bladder cancer cases and 250 cancer-free controls, we found that the MTHFR 677TT genotype was statistically significantly associated with an increased risk of bladder cancer compared with the 677CC genotype (OR = 2.06, 95% CI = 1.16-3.64). Furthermore, the TA haplotype was associated with a significantly increased bladder cancer risk (OR = 1.38, 95% CI = 1.05-1.81) than was the most common haplotype, CA (e.g., CA denotes MTHFR 677C -1298A). We also found that the combined genotypes with 4-6 variant (risk) alleles (i.e., MTHFR 677T, 1298A, and MS 2756G alleles) were associated with an increased risk of bladder cancer (OR = 1.62, 95% CI = 1.03-2.53) compared with those with 0-3 variants, and this increased risk was more pronounced among subgroup of older people (OR = 1.71, 95% CI = 1.03-2.83). A meta-analysis of seven studies did not show a significant risk of bladder cancer in the MTHFR polymorphisms. The MTHFR polymorphisms and their haplotypes appear to jointly contribute to risk of bladder cancer.     

Association of complement factor H gene polymorphisms with age-related macular egeneration susceptibility

Objective: This study was aimed to confirm whether I62V and Y402H polymorphisms of complement factor H (CFH) were risk factors for age-related macular degeneration (AMD). Method: 109 AMD patients and 165 AMD-free controls were enrolled in the study. The I62V and Y402H polymorphisms were analyzed by polymerase chain reaction-restriction fragment length of polymorphism (PCR-RFLP). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by the X² test to assess the relationship of I62V and Y402H polymorphisms with AMD risk. Analysis of haplotype and stratification by age and smoking status was conducted as well. Results: AA genotype and A allele of I62V polymorphism was significantly associated with increased risk for AMD (OR = 3.75, 95% CI = 1.70-8.30; OR = 1.64, 95% CI = 1.14-2.36). For Y402H polymorphism, CT genotype showed strong effects on the occurrence of AMD (OR = 2.10, 95% CI = 1.04-4.27). Moreover, C allele was also a risk factor for AMD (OR = 1.95, 95% CI = 1.02-3.72). The haplotypes analysis suggested that the risk for AT haplotype carriers was high, compared with GT haplotype (OR = 3.91, 95% CI = 2.58-5.94). In addition, we found that smoking status could affect the genotype distribution of Y402H polymorphism (P < 0.05). Conclusions: Our results revealed that CFH polymorphisms I62V and Y402H might be associated with the susceptibility to AMD in Chinese population.     

MTHFR C677T and A1298C polymorphisms are risk factors for Down’s syndrome in Indian mothers

Downs syndrome (DS), a chromosomal disorder due to trisomy 21, results mostly from nondisjunction in maternal meiosis. The present case-control study examined the association of genetic polymorphisms with predisposition to nondisjunction. Two common polymorphisms (SNPs), C677T and A1298C, in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene involved in folate metabolism, are known to lower the activity of this enzyme. Three hundred and fourteen mothers (with DS children and controls), mostly from the eastern states of India, were genotyped for the two above-mentioned SNPs. Significant association with both of these SNPs were detected, more specifically, in the mothers of DS children homozygous for the polymorphic alleles 677 T and 1298 C. The relative risk of T (C677T) and C (A1298C) homozygosity in mothers for DS-affected pregnancy was 7 (OR 7.67, 95% CI 1.67–35.08, P=0.003) and 4 (OR 4.40, 95% CI 1.45–13.26, P=0.008), respectively. Moreover, all 677TT mothers studied were less than 31 years of age, whereas no correlation with maternal age was observed for A1298C genotypes. Interestingly, all of the young 677TT mothers had either a first- or secondborn child with DS. Thus, this study reports that young Indian mothers with TT genotypes are genetically predisposed to nondisjunction due to abnormal folate metabolism.     

Genetic association of cyclooxygenase-2 gene polymorphisms with Parkinson’s disease susceptibility in Chinese Han population

Objective: The aim of this study was to explore the genetic association of cyclooxygenase-2 (COX2) gene promoter region polymorphisms with Parkinson’s disease (PD) susceptibility in Chinese Han population. Methods: The genotyping of COX2 gene polymorphisms was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 122 patients with PD and 120 healthy persons. The association strength of gene polymorphism with disease was measured by odds ratio (OR) and 95% confidence interval (95% CI) calculated using χ² test which also evaluated the Hardy-Weinberg equilibrium (HWE) of gene polymorphism in controls. The linkage disequilibrium and haplotype were also analyzed as evidence in the analysis of association. Results: On condition that the genotypes distributions of COX2 -1290A>G, -1195G>A, -765G>C in the control group all conformed to HWE, however, only the homozygous genotype AA of -1195G>A polymorphism showed an association with PD (OR=0.432, 95% CI=0.196-0.950). In addition, in haplotype analysis, G-A-C haplotype frequency in cases was significantly lower than the controls, compared with the common haplotype A-G-G (P=0.031, OR=0.375, 95% CI=0.149-0.940). Conclusions: COX2 -1195G>A polymorphism might play a protective role in the onset of PD and G-A-C haplotype in this three promoter region polymorphisms also showed a negative association.     

Single nucleotide polymorphisms of HER2 related to osteosarcoma susceptibility

Aims: The purpose of this study was to investigate the correlation between single necleotide polymorphisms (SNPs) of human epidermal growth factor receptor-2 (HER2) gene with osteosarcoma susceptibility in Chinese Han population. Methods: 90 patients with osteosarcoma and 100 healthy controls who were frequency-matched with the former by age and gender were enrolled for a case-control study. 5 SNPs of HER2, namely rs2952155, rs1810132, rs2952156, rs1136201 and rs1058808, were tested by Sequenom time of flight mass spectrometry technique. The linkage disequilibrium and haplotype were analyzed using haploview software. The risk intensity of osteosarcoma was expressed by odds ratio (OR) with 95% confidence interval (CI) which was calculated by chi-squared text. Hardy-Weinberg equilibrium (HWE) was also evaluated by chi-squared text. Results: HER2 gene rs1136201 and rs1058808 polymorphisms were associated with the increased risk of osteosarcoma (P=0.04 and 0.02, respectively). Allele G in rs1136201 was 1.67 higher risk for osteosarcoma in cases than the control group (OR=1.67, 95% CI=1.11-2.51) and G allele of rs1058808 polymorphism also significantly increased osteosarcoma susceptibility (OR=2.06, 95% CI=1.27-3.22). The haplotype analysis showed that haplotype C-T-G-G might be a susceptible haplotype to osteosarcoma (OR=1.74, 95% CI=1.01-3.00). HWE test was eligible in controls (P>0.05). Conclusion: HER2 gene rs1136201 and rs1058808 polymorphisms and haplotype C-T-G-G may be related to osteosarcoma susceptibility in Chinese Han population, indicating that the interaction of gene polrmorphism plays an role in osteosarcoma risk.     

Renal cell carcinoma risk is associated with the interactions of APOE,VHL and MTHFR gene polymorphisms

Objective: The study was designed to explore the association of renal cell carcinoma (RCC) with VHL (rs779805), MTHFR (rs1801133) and APOE (rs8106822 and rs405509) polymorphisms, investigate the interactions among the single nucleotide polymorphisms (SNPs), and explore roles of the interactions in the pathogenesis of RCC in Chinese Han population. Methods: 81 RCC patients and 80 healthy controls were included in the study. Polymerase chain reaction (PCR) and direct sequencing methods were used in the analysis on the genotypes of APOE, VHL and MTHFR gene polymorphisms. Multifactor dimensionality reduction (MDR) method was adopted to conduct gene-gene interaction analysis. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were utilized to evaluate the correlation between gene-gene interactions and RCC risk. Results: Significant correlations were found between RCC risk and 3 SNPs (rs8106822, rs779805 and rs1801133). Genotype AA and allele A of APOE rs8106822 were significantly associated with RCC susceptibility (OR=2.65, 95% CI=1.05-6.69). Meanwhile, we found that the frequencies of genotype GG and allele G were much higher in case group, compared with controls (P<0.05 for both) and they appeared to be risk factors for RCC (OR=2.90, 95% CI=1.22-6.87; OR=1.78, 95% CI=1.14-2.27). While, allele T of MTHFR rs1801133 could decrease the risk of RCC (OR=0.62, 95% CI=0.40-0.97). MDR analysis showed that gene-gene interactions among APOE, VHL and MTHFR SNPs were closely related with RCC susceptibility. Conclusion: APOE, VHL and MTHFR gene polymorphisms were related to the risk of RCC. The interactions among APOE, VHL and MTHFR genes could increase the risk of RCC.     

Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and age of onset in schizophrenia: A combined analysis of independent samples

Methylenetetrahydrofolate reductase (MTHFR) is involved in the one‐carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme activity. The T‐allele of the C677T polymorphism has recently been associated with earlier age at onset of schizophrenia. In the present study we examined the association between the MTHFR C677T and A1298C polymorphisms and age at onset of schizophrenia in twelve samples consisting of 3,213 unrelated schizophrenia patients, including the original Scandinavian sample. There was no consistent relationship between MTHFR C677T, A1298C or combined 677T/1298C carriers and age of onset in schizophrenia when the results of each study were combined using meta‐analysis. The present results suggest that the investigated MTHFR polymorphisms do not influence age of onset in schizophrenia. © 2011 Wiley‐Liss, Inc.