MTHFR C677T Polymorphism Research Articles

More severe toxicity of genetic polymorphisms on MTHFR activity in osteosarcoma patients treated with high-dose methotrexate.

5,10-Methylenetrahydrofolate reductase (MTHFR), a key enzyme for folate metabolism, catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, which is located at the end of the short arm (1p36.3). Two common non-synonymous variants, the C677T (Ala222Val) and A1298C (Glu429Ala), were mainly described with decreased enzymatic activity and an alteration of intracellular folate distribution. Osteosarcomas are currently treated with high dose of methotrexate (MTX). The decreased enzyme activity of MTHFR theoretically could increase the drug action of MTX and at the same time increase toxic and side effect. Germline variants of C677T and A1298C were studied in 59 osteosarcoma patients, with whom the A1298C is detected with particularly low rate of mutant genotype (N = 1, 0.8%) and could not proceed with statistical calculations. 15 patients were wild type of C677T (CC, 25.4%), 20 were heterozygous mutant genotype (CT, 33.9%) and 24 were homozygous mutant genotype (TT, 40.7%). Patients harboring the TT/CT genotype had the same progression-free survival and tumor necrosis rate in comparison with patients having the CC genotype (P = 0.349 and P = 0.465 respectively). And the C677T polymorphisms had no significant correlation with MTX initial plasma concentration (P = 0.867; r = 0.024) and delayed elimination (P = 0.305; r = −0.136). However patients with mutant genotype of C677T were associated with higher degree of liver toxicity (P = 0.043) and fever reaction of MTX (P = 0.050) while G3/G4 hematologic toxicity were more likely to be noticed with TT than CT/CC (P = 0.095). The study suggests that genetic polymorphism of MTHFR C677T in the MTX metabolic pathway seems to be associated with the trend for more side effects statistically, but has no obvious effect on histologic response and survival.

A possible synergistic effect of MTHFR C677T polymorphism on homocysteine level variations increased risk for ischemic stroke

Background:Homocysteine (Hcy) plays an important role in vascular function and Hcy level contributes to pathogenesis of ischemic stroke (IS). MTHFR gene polymorphism may have effects on IS risks by influencing the Hcy metabolic pathway. In the present study, a case–control study was designed to evaluate the relationship among MTHFR C677Tpolymorphism, plasma Hcy level, and susceptibility of IS in Chinese population.Methods:A total of 300 patients with IS and 261 matched control subjects were recruited. Plasma Hcy concentration was determined using enzymatic cycling assay. MTHFR C677T polymorphisms were genotyped by PCR-RFLP.Results:Compared with controls, the plasma Hcy level was significantly higher in the IS patients (P < .05). After adjusting for conventional risk factors, the T allele frequency of MTHFR C677T in IS group (54%) was significantly higher than that in the controls (38.3%) (P < .05; OR = 1.890, 95% CI: 1.489–2.399). Additionally, the plasma Hcy level of the TT genotype is significantly higher than that of the CC and CT genotypes (P < .05).Conclusion:Our study provided evidence that hyperhomocysteinemia (HHcy) and MTHFR C677T polymorphism were associated with IS. More importantly, suggesting that a possible synergistic effect of MTHFR C677T polymorphism on Hcy level variations increased risk for IS in Chinese population.

INVESTIGATION THE ASSOCIATION BETWEEN MTHFR GENE POLYMORPHISM AND HOMOCYSTEINE IN IRANIAN PREGNANT WOMEN

Objective: This study was aimed to investigate the association between polymorphisms in MTHFR gene and Vitamin B12-dependent homocysteine metabolism.Methods: Hyperhomocysteinemia has been implicated as a risk factor for complications in pregnancy including abortion, preeclampsia, and placental abruption. Several epidemiological studies have investigated the associations of MTHFR C677T polymorphism with hypertension or hypertension in pregnancy. However, the results were controversial. Numbers of 100 samples from healthy pregnant women as control criteria and 100 samples from fertile women have been collected. Due to research on MTHFR polymorphism, special primers have been designed. The research on MTHFR polymorphism has been done by restriction fragment length polymorphism assay.Results: The results demonstrated 9.26% have been registered for heterozygous individuals and the homocysteine level of homozygous individuals was 41.18% (higher than the normal level). The results showed a significant difference in the homocysteine levels of homozygous individuals and the homocysteine levels of healthy individuals (p=0.004). Furthermore, there was no significant difference in the homocysteine levels of heterozygous individuals and the homocysteine levels of healthy individuals (p=0.34). Similarly, a significant difference in the B12 levels in blood of homozygous individuals and the homocysteine levels of healthy individuals have been showed (p=0.00).Conclusion: The mutation of gene MTHFR C677T causes an increase of the homocysteine level, decrease of the level of folic acid and B12 vitamin in heterozygous individuals but a relationship among homocysteine level, the level of folic acid and B12 vitamin not found.

DPYD*2A and MTHFR C677T predict toxicity and efficacy, respectively, in patients on chemotherapy with 5-fluorouracil for colorectal cancer.

Significant inter-individual variation in the sensitivity to 5-fluorouracil (5-FU) represents a major therapeutic hindrance either by impairing drug response or inducing adverse drug reactions (ADRs). This study aimed at exploring the cause behind this inter-individual alterations in consequences of 5-fluorouracil-based chemotherapy by investigating the effects of DPYD*2A and MTHFR C677T polymorphisms on toxicity and response of 5-FU in Bangladeshi colorectal cancer patients. Colorectal cancer patients (n = 161) receiving 5-FU-based chemotherapy were prospectively enrolled. DPYD and MTHFR polymorphisms were assessed in peripheral leukocytes. Multivariate analyses were applied to evaluate which variables could predict chemotherapy-induced toxicity and efficacy. Multivariate analyses showed that DPYD*2A polymorphism was a predictive factor (P = 0.023) for grade 3 and grade 4 5-fluorouracil-related toxicities. Although MTHFR C677T polymorphism might act as forecasters for grade 3 or grade 4 neutropenia, diarrhea, and mucositis, this polymorphism was found to increase significantly (P = 0.006) the response of 5-FU. DPYD*2A and MTHFR C677T polymorphisms could explain 5-FU toxicity or clinical outcome in Bangladeshi colorectal patients.

MTRR A66G, RFC1 G80A, and MTHFR C677T and A1298C Polymorphisms and Disease Activity in Mexicans with Rheumatoid Arthritis Treated with Methotrexate.

Aim: To investigate the relationships of polymorphisms in genes whose protein products are related in the metabolic pathway of folic acid, particularly MTRR A66G, RFC1 G80A, and MTHFR C677T and A1298C, and disease activity in Mexican patients with rheumatoid arthritis (RA) treated with methotrexate (MTX).Materials and Methods: Sixty-eight patients with RA were included in the study who were being treated with MTX, either with or without other drugs. In addition to general data, disease activity was measured by the disease activity score 28 (DAS28). Single nucleotide polymorphisms (SNPs) genotyping was performed by allelic discrimination using real-time polymerase chain reaction.Results: Differences in genotype (homozygotic or heterozygotic for each allele), allele distributions, and phenotype were not statistically different between the RA group and control populations. We did not find any association between the studied polymorphisms and disease activity nor with the intragroup variables (e.g., clinical activity, body mass index, and single- or combined-drug treatment) or between genetic markers; we also did not find any association within the RA group or between the RA group and control populations.Conclusion: Additional studies of more polymorphisms related to this or other metabolic pathways are required to determine the influence of genetics on disease activity in RA.

MTHFR C677T and A1298C polymorphisms may contribute to the risk of Parkinson's disease: A meta-analysis of 19 studies.

The 5,10-methylenetetrahydrofolate reductase (MTHFR) gene has been reported to be a candidate gene for susceptibility to Parkinson's disease (PD), but results of different studies are conflicting. Here, we conducted a meta-analysis of published case-control studies to evaluate the association between MTHFR C677T and A1298C gene polymorphisms with the risk of PD. Electronic search through PubMed, EmBase, ScienceDirect and Cochrane Library was conducted to identify all relevant studies. A total of 19 studies with 2746 cases and 8967 controls were included. No significant association between MTHFR C677T polymorphism and PD risk was found in the overall population in all five genetic models. In the subgroup analysis stratified by ethnicity, a significant association between MTHFR C677T and PD risk was observed in the dominant model in Caucasians (OR=1.175, 95%CI: 1.008-1.369, P=0.040), but not in Asians. Significant association was found between MTHFR A1298C polymorphism and PD risk in the overall population in the dominant (OR=1.168, 95%CI: 1.008-1.353, P=0.039) and heterozygous model (OR=1.172, 95%CI: 1.004-1.367, P=0.044). But in the subgroup analysis, no association was found between MTHFR A1298C and PD neither in Caucasians nor in Asians. Our meta-analysis suggests that MTHFR C677T polymorphism may be associated with increased PD risk in Caucasians and MTHFR A1298C polymorphism may also increase susceptibility to PD.

Anterior Encephalocele and Its Association with MTHFR Polymorphisms: A Case-Control Study

Background Neural tube defects (NTDs) are thought to be associated with genetic defects and environmental factors. This study aims to determine the association of MTHFR gene polymorphisms and maternal body mass index (BMI) with anterior encephalocele (AE). Methods Blood samples of 20 patients (out of 41 children) were available for genetic analysis. Genomic DNA was extracted from whole blood samples using Wizard genomic DNA purification kit. The MTHFR C677T and A1298C polymorphisms genotyping protocols were adapted from Cicek et al. Eighty-two age- (1–14 years) and sex-matched apparently healthy children were taken as controls. We assessed the nutritional status of all the volunteers by measuring their BMI and then classified according to WHO BMI cutoff points. Results Nasofrontal AE was seen mostly among the female cases while among males, nasoethmoidal AE was predominant. We observed a weak association between MTHFR 677CT genotype and AE. In the case of MTHFR A1298C, both the 1298AC and 1298CC genotypes increased the risk of acquiring AE by several folds. Multivariate analysis revealed that both 1298AC and 1298CC genotypes increased the risk of acquiring AE. However, only 1298AC was significantly associated with the risk of AE. The study also showed significantly low BMI among the children and their mothers. Conclusion There is a strong association between MTHFR A1298C polymorphism and the risk of anterior encephalocele in this community. The C677T polymorphism, however, did not constitute a genetic risk factor in this study. Children with AE also had significantly low BMI.

Association of MTHFR C677T polymorphism with weight gain induced by risperidone in schizophrenia

Objective To explore the association of methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with weight gain induced by risperidone. Methods 356 patients with schizophrenia according to the DSM-IV criteria in this study. The height and body weight of the patients were measured before starting risperidone treatment and 8-week later. The MTHFRC677T polymorphism was genotyped using direct DNA sequencing method. Results A significant association was found between MTHFR gene C677T and body weight mass index (BMI) change after 8-week risperidone treatment. CC-carriers experienced higher BMI gain than CT/TT-carriers (CC(4.47±1.09), CT(4.54±1.27), TT(2.31±0.75), F=5.634, P 7%) was higher than that in non-bodyweight gain groups (48.4% vs 32.4%, χ2=11.342, P<0.01). Conclusion MTHFRC677T polymorphism is associated with risperidone induced weight gain in Chinese Han population. Key words: Schizophrenia; MTHFR gene; Antipsychotics; Body weight gain

Prevalence of common hereditary risk factors for thrombophilia in Somalia and identification of a novel Gln544Arg mutation in coagulation factor V

Thrombophilia, commonly manifested as venous thromboembolism (VTE), is a worldwide concern but little is known on its genetic epidemiology in many parts of the globe particularly in the developing countries. Here we employed TaqMan genotyping and pyrosequencing to evaluate the prevalence of known common nucleotide polymorphisms associated with thrombophilia in a Somali population in the Puntland region of Somalia. We also employed next generation sequencing (NGS) to investigate other genetic variants in a Somali patient with deep venous thrombosis (DVT). As expected, we found no existence of factor V Leiden (rs6025) and prothrombin G20210A (rs1799963) in the Somali population. The G allele of ABO [261G/delG] polymorphism (rs8176719) was found at a frequency of 29%, similar to that observed in other African populations. We found the lowest so far reported frequency of MTHFR C677T (rs1801133) polymorphism in the Somali population (T allele frequency 1.5%). A novel and deleterious single nucleotide variation in exon 11 of coagulation factor V (c.1631A>G) causing Gln544Arg exchange in factor V was identified in a 29 years old Somali female with DVT. The same patient was heterozygous to VKORC1 Asp36Tyr polymorphism (rs61742245) that predisposes to warfarin resistance. In conclusion, this study shows that common hereditary factors for thromboembolism found in Caucasians are either less frequent or absent in the Somali population—similar to the situation in other Africans. NGS is possibly a better choice to detect genetic risk variants for thrombosis in this ethnic group.

Use of a haptic biofeedback in the rehabilitation of patients with total knee arthroplasty (TKA): A pilot study

To investigate the association between increased carotid intima-media thickness (CIMT), homocysteine level, and MTHFR C677T (rs1801133) gene polymorphism in Egyptian people with rheumatoid arthritis (RA).280 Egyptian women (160 RA patients and 120 controls) were included in the study. CIMT was measured using high resolution B-mode ultrasonography and homocysteine levels were measured using enzyme-linked immunosorbent assay. While, MTHFR C677T polymorphism was analyzed by polymerase chain reaction–restriction fragment length polymorphism.We found that subjects who carried the TT genotype and T allele were significantly more likely to develop RA with 2.9 and 1.5 fold, respectively. RA patients carrying the T allele presented a statistically significant increased risk of developing atherosclerosis compared with those carrying the C allele. Moreover, MTHFR TT genotype was independent risk factor of thick CIMT.C677T MTHFR gene polymorphism is associated with RA in Egyptians. MTHFR 677TT carriers had higher concentrations of serum Hcy than did subjects harboring the CC and CT genotypes. The presence of 677T allele increases the risk of atherosclerosis in patients with RA. This increased risk of atherosclerosis could be due to hyperhomocysteinemia.

Analysis of MTHFR C677T polymorphism significance in patient preparation for the in vitro fertilization procedure

Analysis of MTHFR C677T polymorphism significance in patient preparation for the in vitro fertilization procedure

Homocysteine: A Potential Common Route for Cardiovascular Risk and DNA Methylation in Psoriasis.

Objective:Homocysteine is a sulfur-containing amino acid with potential clinical significance. Abnormal homocysteine levels have been found in patients with psoriasis. This review summarizes the possible correlations among homocysteine, cardiovascular risk, and DNA methylation in psoriasis.Data Sources:We retrieved the articles published in English from the PubMed database up to January 2017, using the keywords including “psoriasis,” “homocysteine,” “cardiovascular risk,” “DNA methylation,” “methylenetetrahydrofolate reductase,” “MTHFR,” and “MTHFR C677T.”Study Selection:Articles about the roles of homocysteine in the cardiovascular risk and DNA methylation in psoriasis were obtained and reviewed.Results:Observational studies consistently reported that elevated homocysteine is an independent risk factor for cardiovascular diseases. Several studies also consistently reported an association between psoriasis and increased cardiovascular risk. A substantial body of evidence also suggested that an elevated homocysteine level is related to the demethylation of DNA. Data from clinical trials also demonstrated that MTHFR C677T polymorphisms as well as DNA methylation aberrations are associated with psoriasis.Conclusions:This review highlighted the relationships among homocysteine, cardiovascular risk, and DNA methylation, suggesting that homocysteine may be a biological link between cardiovascular risk and DNA methylation in psoriasis.

Association of C677T polymorphism (rs1801133) in MTHFR gene with depression.

Depression is one of the mental disorders with a state of low mood and aversion to activities that exerts a negative effect on a person's thoughts and behavior. Genetic association studies on MTHFR C677T polymorphism and depression have been repeatedly performed over the last two decades, but results are inconsistent. The aim of the present study was to assess the relationship between MTHFR C677T polymorphism and depression by literature review and meta-analysis. Four electronic databases, PubMed, Google Scholar, Science direct and Springer Link were searched for case control articles focusing on MTHFR C677T polymorphism and the risk of depression. A total of 30 studies including 4,802 cases and 17,362 controls were involved in present meta-analysis. When all the eligible studies were pooled into this meta-analysis, significant association between depression risk and MTHFR C677T polymorphism was found in three genetic models (Additive model: OR T vs C= 1.20, 95 % CI= 1.00-1.34, p=0.0004; homozygote model: OR TT vs.CC=1.37, 95% CI= 1.13-1.65, p=0.0004; dominant model: OR TT+CT vs CC=1.13, 95 % CI= 0.99-1.28, p=0.04), while meta-analysis with other two genetic models did not show association with other two genetic models ( recessive model: OR TT vs CT+CC= 1.36, 95 % CI = 0.91-2.04, p=0.13; co-dominant model: OR CT vs CC=1.00, 95 % CI=0.93-1.08,p=0.84). Present meta-analysis supports that there is a meager significant association between MTHFR C677T polymorphism and depression risk.

Association between Thrombophilic Genes Polymorphisms and Recurrent Pregnancy Loss Susceptibility in the Iranian Population: a Systematic Review and Meta-Analysis

Studies have indicated that thrombophilic genes polymorphisms are associated with recurrent pregnancy loss (RPL) in the Iranian population. We aimed to evaluate the precise association between thrombophilic genes polymorphisms (MTHFR C677T, MTHFR A1298C, Prothrombin G20210A, FVL G1691A, and PAI-1 4G/5G) and RPL risk in the Iranian population. PubMed, Web of Science, Google Scholar, and ISC were searched for eligible articles published up to April 1, 2017. In total, 37 case-control studies in 18 relevant publications were selected: 1,199, 1,194, 630, 830, and 955 RPL cases and 1,079, 1079, 594, 794, and 499 controls for MTHFR C677T, MTHFR A1298C,Prothrombin G20210A, FVL G1691A, and PAI-1 4G/5G, respectively. The results indicated a significant increased risk of RPL in all genetic models in the population. Also, Prothrombin G20210A and FVL G1691A as well as PAI-1 4G/5G polymorphisms were associated with RPL risk in the Iranian population. Hence, thrombophilic genes polymorphisms are associated with an increased RPL risk in the Iranian population.

Genetic polymorphisms and folate status.

Moderate hyperhomocysteinemia‐induced low folate status is an independent risk factor for cardiovascular disease, dementia, and depression. Folate is an essential cofactor in the one‐carbon metabolism pathway and is necessary in amino acid metabolism, purine and thymidylate synthesis, and DNA methylation. In the folate cycle and homocysteine metabolism, folate, vitamin B12, vitamin B6, and vitamin B2 are important cofactors. Many enzymes are involved in folate transport and uptake, the folate pathway, and homocysteine (Hcy) metabolism, and various polymorphisms have been documented in these enzymes. Serum folate and total Hcy (tHcy) levels are influenced by folate intake and genetic polymorphisms in 5,10‐methylenetertahydrofolate reductase (MTHFR) such as C677T. The prevalence of the MTHFR 677TT genotype varies across ethnic groups and regions, with a frequency of approximately 15% in Japanese populations. Individuals with the TT genotype have significantly higher tHcy levels and lower folate levels in serum than those with the CT and TT genotypes. However, administration of folic acid has been shown to eliminate these differences. Moreover, data have suggested that interventions based on genotype may be effective for motivating individuals to change their lifestyle and improve their nutrition status. Accordingly, in this review, we discuss the effects of MTHFR C677T polymorphisms on serum tHcy and folate levels with folic acid intervention and evaluate approaches for overcoming folic acid deficiency and related symptoms.

Inherited Thrombophilias Could Influence the Reproductive Outcome in Women with Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease associated with different reproductive complications in the affected women. Inherited thrombophilias are genetic factors increasing the risk for thromboembolism and recurrent pregnancy loss, but their influence on other reproductive disturbances in SLE patients has not been completely clarified. Two hundred and twenty-three Caucasian women (112 with SLE and 111 controls) were included in the study. Complete reproductive history of all SLE patients was carefully obtained. Genotyping for the FVLeiden, FIIG20210A, and MTHFRC677T polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. No significant differences in the prevalence of the FVLeiden, FIIG20210A, and MTHFRC677T polymorphisms between patients and controls were established. Patients with FVLeiden had fewer pregnancies (0.57 ± 0.98 vs. 2.18 ± 1.58; p = 0.007) than the others, while no significant differences in the reproductive history of FIIG20210A carriers and non-carriers were observed (p >0.05). In the SLE group, 41.67% of women with the MTHFRC677T TT genotype had at least one miscarriage in comparison to only 14.00% of the other female patients (p = 0.030). While the prevalence of the investigated thrombophilias was similar in patients with SLE and healthy women, a substantial influence of the inherited prothrombotic factors on the reproductive history of patients was revealed. The investigations of the FVLeiden and MTHFRC677T polymorphisms in SLE patients could help to identify women at highest risk for reproductive failure and thus, further studies in other ethnic groups would be of strong clinical importance.

TS Gene Polymorphisms Correlate with Susceptibility to Acute Lymphocytic Leukemia in Children.

BackgroundAcute lymphocytic leukemia (ALL) in children is a clonal disease of bone marrow hematopoietic stem cells. This study aimed to explore the associations between MTHFR or TS genetic polymorphisms and susceptibility to acute lymphocytic leukemia (ALL) in children.Material/MethodsThis case-control study included 79 ALL patients (case group) and 102 non-ALL patients (control group). Post-PCR genomic DNA sequencing revealed MTHFR C677T and MTHFR A1298C genotypes and TS polymorphisms. The χ2 test was used to compare differences in MTHFR and TS polymorphisms (including genotypic and allelic distributions) between groups. Logistic regression analysis was used to determine genetic polymorphisms and ALL risk associations.ResultsThe results indicated that TS 3R allele frequency was significantly higher in the case group than in the control group (χ2=7.45, P<0.05). The MTHFR C677T and MTHFR A1298C polymorphisms were not associated with ALL risk. Compared to the TS 2R/2R genotype, subjects carrying TS 2R/3R were twice as likely to develop ALL, and the TS 3R/3R+3R/4R genotype carried a 4-fold higher risk of developing ALL (OR=1.96, CI: 1.14–3.36).ConclusionsThe TS genetic polymorphisms increase the ALL risk. The TS 3R allele was a risk factor for ALL. There were no associations between MTHFR C677T or MTHFR A1298C polymorphisms and ALL susceptibility.

Effect of GSTP1 and MTHFR Gene Polymorphism on Side Effects of HD-MTX in ALL Children

To Study the effect of C677T and MTHFR gene polymorphism on side effects of HD-MTX in ALL children. The gene polymorphism of C677T A303G and MTHFR C677T were detected by PCR in 98 ALL children from January 2014 to January 2016. The side effects during HD-MTX therapy were observed, and the relationship among GSTP1, MTHFR gene polymorphism and incidence of side effect of HD-MTX were analyzed. Among 98 ALL children, the gene variation was observed in 61 ALL children (62.24%). Polymorphism study on C677T A303G showed that the gene frequency of A was 84.69%, while that of G was 15.31%; for polymorphism of MTHFR C677T, gene frequency of C was 66.33%, and that of T was 33.67%. Seven patients(7.14%) experienced with bone marrow supression, 23 patients(23.47%) with liver function damage, 15 patients(15.31%) with renal function damage, 48 patients(48.98%) with gastrointestinal reactions and 46 patients(46.94%) with mucosal lesions. After adjustment of sex, age, risk stratification and dosage of MTX, the gene polymorphism had no significant relationship with bone marrow suppression, gastrointestinal reactions and mucosal lesions(P>0.05). However, the number of the mutant genes had statistically significant relationship with liver and renal function damage(P<0.05). The risk of side effects during HD-MTX therapy increases in ALL children with combined mutation of MTHFR and C677T.

Effect of alcohol and its metabolites in lung cancer: CAPUA study

Background and objectiveAlcohol and its metabolites play an important role in carcinogenesis. This effect could be modulated by polymorphisms in genes encoding enzymes involved in the metabolism of alcohol and folate. Therefore, we analyzed the effect of alcohol consumption and ADH1B Arg48His, ADH1B Arg370Cys, ADH1C Ile349Val, ALDH2 Glu540Lys, CYP2E1 RsaI, CYP2E1 DraI, CYP2E1 TaqI and MTHFR C677T polymorphisms on the risk of developing lung cancer. Patients and methodsWe included 876 lung cancer cases and 840 controls of the CAPUA hospital-based case–control study. Genotyping was performed using the Sequenom MassArray (iPLEX GOLD) technology. ResultsAn alcohol consumption of 0.1–9.9g/day decreased lung cancer risk (ORadjusted=0.71; 95% CI 0.48–1.05), although statistical significance was not achieved. A consumption ≥30g/day of alcohol and ≥36PY of tobacco increases lung cancer risk (ORadjusted=26.68; 95% CI 12.69–56.10). On the other hand, a high consumption of vegetables (≥116.65g/day) and fruits (≥233.13g/day) decreases lung cancer risk with an alcohol consumption of 0.1–9.9g/day (ORadjusted=0.52; 95% CI 0.30–0.89; ORadjusted=0.58; 95% CI 0.33–1.03, respectively). An alcohol consumption of 10–29.9g/day in ADH1B 48His allele-carriers increases lung cancer risk (ORadjusted=3.32; 95% CI 1.03–10.70). ConclusionsAlcohol and polymorphisms in genes involved in the metabolism of alcohol and folate are related to the onset of lung cancer.

The role of the MTHFR C677T polymorphism in methotrexate-induced toxicity in pediatric osteosarcoma patients.

Osteosarcoma patients receive high doses of methotrexate (MTX). However, pharmacogenetic information remains limited and has mainly been investigated in leukemia so far. We investigated the link between the MTHFR C677T genotype, toxicity levels (mucositis, MTX plasma level, hematological toxicity and hepatotoxicity) and survival of 48 pediatric osteosarcoma patients. The TT genotype did not show more toxicity compared with the CC/CT genotype. However, plasma MTX levels were related with mucositis, but not with hematological toxicity, nor hepatotoxicity. Survival rates did not differ between homozygous and non-homozygous patients. Yet, homozygous patients had higher relapse risk. The MTHFR C667T polymorphism is not predictive for toxicity or overall survival, but could be used for relapse risk stratification.