Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Early life stress is shown to have a life-span outcome on human and animal behavior, increasing the risk for psychopathology. The gene methylenetetrahydrofolate reductase (MTHFR), which encodes for a key enzyme in one carbon metabolism, shows a high prevalence of polymorphism in patients with developmental disorders. Here we examined the hypothesis that MTHFR deficiency results in an increased susceptibility of the developing brain to mild neonatal stress (NS). Mild NS failed to alter corticosterone levels in young and adult Wt mice. However, an elevated level of corticosterone was found in the MTHFR deficient-NS female, exemplifying enhanced sensitivity to NS. Behavioral phenotyping of Wt and MTHFR deficient mice provides evidence that the effect of mild NS may be amplified by the MTHFR deficient genotype. Distinct behavioral characteristics were altered in male and female mice. In general, three patterns of influence on mice behavior were observed: (1) an additive suppressive effect of NS and MTHFR deficiency on exploration and activity was evident in females; (2) stress related parameters were significantly sensitive to genotype in females, presenting an interaction between genotype and sex; (3) various aspects of behavior in a social setting were modified preferably in males by genotype, NS and the interaction between the two, while females exhibited a smaller effect that was restricted to NS with no genotype effect. Overall, our results support an interaction between mild NS, the MTHFR genotype and sex. We suggest using this animal model to study the molecular mechanism linking these two risk factors and their involvement in neurodevelopmental disorders such as schizophrenia and autism.
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PMID:Increased susceptibility to mild neonatal stress in MTHFR deficient mice. 2389 51

Genetic variants of the methylenetetrahydrofolate reductase (MTHFR) gene involved in homocysteine metabolism may be important predictors of antipsychotic drug-induced weight gain (AIWG). We tested whether two functional MTHFR polymorphisms are related to AIWG. Weight gain was studied in two cohorts of first-episode, initially drug-naive schizophrenia patients; Chinese Han (n = 182) and Spanish Caucasians (n = 72) receiving antipsychotics for 10 wk and 3 months respectively. Blood DNA was genotyped for 677C/T and 1298A/C MTHFR polymorphisms. Patients with the 677 CC genotype had a significantly greater increase in BMI compared to T-allele carriers in both Chinese (p = 0.012) and Spanish (p = 0.017) samples. The 677C/T MTHFR polymorphism showed an additive effect, but no significant interaction, with the -759C/T HTR2C polymorphism previously associated with AIWG. These results suggest that the 677C/T MTHFR polymorphism might, along with the -759C/T HTR2C polymorphism and other genetic factors, provide a useful marker for the important and limiting side effect of AIWG.
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PMID:Methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphism is associated with antipsychotic-induced weight gain in first-episode schizophrenia. 2422 35

To review the data with respect to prevalence of metabolic syndrome (MetS) and its correlates in schizophrenia. For this review, electronic search engines PUBMED, Sciencedirect, and Google Scholar were used. Available data suggests that most of the studies have been of cross-sectional design. Prevalence rates of MetS have varied from 11% to 69% in medicated patients, and 4-26% in drug naive patients in cross-sectional evaluations. Longitudinal studies have shown the prevalence rates to range from 0% to 14% at the baseline in drug naive patients, which increase to as high as 52.4% by 3 months of antipsychotic medication treatment. The prevalence rates of MetS in patients with schizophrenia are much higher than that seen in general population or healthy controls. Though there is no causal association with any demographic or clinical variables, the risk increases with increase in age. Among antipsychotics, there seems to be an association between MetS and atypical antipsychotics like clozapine and olanzapine. Therefore, the psychiatrists should be more vigilant regarding the presence of MetS in these high risk groups. Research on biological correlates of MetS in schizophrenia is still in its primitive stage, however, these is some evidence to suggest an association of MetS with adiponectin levels, hematological indices, methylenetetrahydrofolate reductase (MTHFR) and Alpha-1A adrenergic receptor (ADRA1A) gene. These areas hold promise, and targeting these with appropriate interventions may help us to prevent the occurrence of MetS in patients with schizophrenia in future.
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PMID:Metabolic syndrome in schizophrenia. 2424 23

Previous studies suggest that elevated blood homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism are risk factors for schizophrenia. However, the effects of gender and MTHFR C677T genotypes on blood homocysteine levels in schizophrenia have not been consistent. We first investigated whether plasma total homocysteine levels were higher in patients with schizophrenia than in controls with stratification by gender and by the MTHFR C677T genotypes in a large cohort (N = 1379). Second, we conducted a meta-analysis of association studies between blood homocysteine levels and schizophrenia separately by gender (N = 4714). Third, we performed a case-control association study between the MTHFR C677T polymorphism and schizophrenia (N = 4998) and conducted a meta-analysis of genetic association studies based on Japanese subjects (N = 10 378). Finally, we assessed the effect of plasma total homocysteine levels on schizophrenia by a mendelian randomization approach. The ANCOVA after adjustment for age demonstrated a significant effect of diagnosis on the plasma total homocysteine levels in all strata, and the subsequent meta-analysis for gender demonstrated elevated blood homocysteine levels in both male and female patients with schizophrenia although antipsychotic medication might influence the outcome. The meta-analysis of the Japanese genetic association studies demonstrated a significant association between the MTHFR C677T polymorphism and schizophrenia. The mendelian randomization analysis in the Japanese populations yielded an OR of 1.15 for schizophrenia per 1-SD increase in plasma total homocysteine. Our study suggests that increased plasma total homocysteine levels may be associated with an increased risk of schizophrenia.
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PMID:Meta-analyses of blood homocysteine levels for gender and genetic association studies of the MTHFR C677T polymorphism in schizophrenia. 2453 49

Previous studies examining the possible role of the methylenetetrahydrofolate reductase (MTHFR) polymorphisms in the development of schizophrenia (SZ) and bipolar disorder (BPD) have provided inconclusive findings, this meta-analysis was therefore designed to get a more reliable assessment. A total of 38 articles were identified through a search of electronic databases, up to 27 February 2014. Odds ratios (ORs) with 95% confidence interval (CIs) were calculated using random effects models. Meta-analysis showed that MTHFR C677T was significantly associated with SZ, the highest OR was found for the recessive model (for TT vs. CT + CC: OR = 1.34, 95% CI: 1.18-1.53); a marginal association of MTHFR C677T with increased risk of BPD has also been found for the recessive model (OR = 1.26, 95% CI: 1.00-1.59). Subgroup analysis by ethnicity indicated that the significant association with SZ and BPD existed among Asian and African populations, but not for the white. MTHFR A1298C was significant associated with SZ, the highest OR for the dominant model (OR = 1.13, 95% CI: 1.03-1.24). Subgroup analysis indicated a significant association with SZ existed in Asian populations, not among the white populations and no significant association was detected between the MTHFR A1298C and BPD in all groups. We conclude that MTHFR polymorphism is associated with SZ and BPD among Asian, African populations, but not the white.
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PMID:Methylenetetrahydrofolate reductase (MTHFR) polymorphism susceptibility to schizophrenia and bipolar disorder: an updated meta-analysis. 2493 71

Cardiovascular disease (CVD) is a well-described complication of schizophrenia, however, mechanisms connecting CVD with other facets of psychotic disorders, such as neurocognition, are not understood. The current study examined folate metabolism as a potential mechanism of CVD and neurocognitive deficits by: 1) using endothelial dysfunction as a biomarker of CVD, and 2) comparing enzymes associated with neurocognition, CVD, and critical to folate metabolism, methylenetetrahydrofolate reductase (MTHFR) and catechol-o-methyl transferase (COMT). Endothelial function was assessed in 147 participants with schizophrenia, schizoaffective disorder, and psychotic disorder not otherwise specified grouped by MTHFR and COMT allele status. Regression models were used to compare neurocognitive performance based on the Brief Assessment of Cognition in Schizophrenia (BACS). Overall, endothelial function predicted BACS composite z-scores after controlling for age, race, level of education, serum folate levels, and MTHFR/COMT risk allele status. Participants with at least one or more MTHFR and/or COMT risk alleles had lower BACS Composite and BACS Symbol Coding adjusted mean z-scores than those with both MTHFR CC and COMT Met/Met genotypes. Thus, endothelial dysfunction may contribute to the neurocognitive deficits seen in psychotic disorders. CVD interventions may not only reduce CVD-related morbidity, but also lessen progressive neurocognitive deficits reported in psychotic disorders.
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PMID:Endothelial function, folate pharmacogenomics, and neurocognition in psychotic disorders. 2572 32

One-carbon metabolism is a process whereby folate transters one-carbon groups in a range of biological processes, including DNA methylation and homocysteine metabolism. We have focused on and examined the potential roles of this one-carbon metabolism in the pathology of schizophrenia. Firstly, we revealed that aberrant DNA methylation in schizophrenia occurred across the whole genome in peripheral leukocytes by conducting genome-wide DNA methylation profiling. Secondly, we demonstrated that plasma total homocysteine was associated with DNA methylation in patients with schizophrenia at specific genes. Thirdly, we demonstrated that blood homocysteine levels were significantly higher in patients with schizophrenia than in non-psychiatric controls by conducting meta-analysis of previous observational studies. Fourthly, we demonstrated a causal relationship between blood homocysteine and schizophrenia by conducting Mendelian randomization analysis. Finally, we demonstrated that the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which causes reduced enzyme activity and higher homocysteine levels, was a risk factor for developing schizophrenia in a Japanese population by conducting meta-analysis of previous genetic association studies. These results will add new insights into the pathology and treatment of schizophrenia.
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PMID:[One-carbon Metabolism and Schizophrenia]. 2650 13

Metabolic syndrome (MetS) is a cluster of factors that increases the risk of cardiovascular disease (CVD), one of the leading causes of mortality in patients with schizophrenia. Incidence rates of MetS are significantly higher in patients with schizophrenia compared to the general population. Several factors contribute to this high comorbidity. This systematic review focuses on genetic factors and interrogates data from association studies of genes implicated in the development of MetS in patients with schizophrenia. We aimed to identify variants that potentially contribute to the high comorbidity between these disorders. PubMed, Web of Science and Scopus databases were accessed and a systematic review of published studies was conducted. Several genes showed strong evidence for an association with MetS in patients with schizophrenia, including the fat mass and obesity associated gene (FTO), leptin and leptin receptor genes (LEP, LEPR), methylenetetrahydrofolate reductase (MTHFR) gene and the serotonin receptor 2C gene (HTR2C). Genetic association studies in complex disorders are convoluted by the multifactorial nature of these disorders, further complicating investigations of comorbidity. Recommendations for future studies include assessment of larger samples, inclusion of healthy controls, longitudinal rather than cross-sectional study designs, detailed capturing of data on confounding variables for both disorders and verification of significant findings in other populations. In future, big genomic datasets may allow for the calculation of polygenic risk scores in risk prediction of MetS in patients with schizophrenia. This could ultimately facilitate early, precise, and patient-specific pharmacological and non-pharmacological interventions to minimise CVD associated morbidity and mortality.
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PMID:A systematic review of genetic variants associated with metabolic syndrome in patients with schizophrenia. 2662 Oct 2

The 5,10-methylenetetrahydrofolate reductase (MTHFR) gene plays a central role in folate metabolism. Many studies have demonstrated an association between MTHFR C677 T variant with depression, schizophrenia and bipolar disorder as one of them being comorbid to other. This has justified the use of folate supplement in psychiatric disorders mainly depression but still not in various other comorbid complex psychiatric disorders. Here we have tried to show how the l-methylfolate in conjunction with the conventional psychotropic drugs can be useful in a state of such complex psychiatric phenomenon and comorbid diagnosis with genetic polymorphism of MTHFR C677 T mutation.
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PMID:Effectiveness of add-on l-methylfolate therapy in a complex psychiatric illness with MTHFR C677 T genetic polymorphism. 2752 Aug 98

Previous studies suggest that elevated total homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which correlates with plasma total homocysteine levels, are risk factors for schizophrenia (SCZ). Recently, a large genome-wide association study (GWAS) of plasma total homocysteine levels in individuals of European ancestry identified many single-nucleotide polymorphisms (SNPs) (n=13,974). The primary purpose of this study was to examine the association between these plasma total homocysteine-related SNPs and SCZ in the Japanese population. First, we investigated associations between six SNPs and plasma total homocysteine levels in non-psychiatric subjects in the Japanese population (n=1030). Then, we evaluated the cumulative effects of three SNPs on SCZ risk by calculating the Genotype Risk Score (GRS) (1120 cases, 2643 controls). Of the six SNPs examined, we replicated similar associations with the European GWAS at four loci (CENPQ, CPS1, MTHFR, and MUT). GRS based on three SNPs (CENPQ, CPS1, and MTHFR) was significantly associated with SCZ. Our findings suggest that common polygenic variations, which are associated with the plasma total homocysteine levels, may contribute to the risk of SCZ.
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PMID:Cumulative effect of the plasma total homocysteine-related genetic variants on schizophrenia risk. 2781 Feb 29


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