Methylenetetrahydrofolate reductase and psychiatric diseases

MicroRNA classification and discovery for major depressive disorder diagnosis: Towards a robust and interpretable machine learning approach

BACKGROUND

Major depressive disorder (MDD) is notably underdiagnosed and undertreated due to its complex nature and subjective diagnostic methods. Biomarker identification would help provide a clearer understanding of MDD aetiology. Although machine learning (ML) has been implemented in previous studies to study the alteration of microRNA (miRNA) levels in MDD cases, clinical translation has not been feasible due to the lack of interpretability (i.e. too many miRNAs for consideration) and stability.

METHODS

This study applied logistic regression (LR) model to the blood miRNA expression profile to differentiate patients with MDD (n = 60) from healthy controls (HCs, n = 60). Embedded (L1-regularised logistic regression) feature selector was utilised to extract clinically relevant miRNAs, and optimized for clinical application.

RESULTS

Patients with MDD could be differentiated from HCs with the area under the receiver operating characteristic curve (AUC) of 0.81 on testing data when all available miRNAs were considered (which served as a benchmark). Our LR model selected miRNAs up to 5 (known as LR-5 model) emerged as the best model because it achieved a moderate classification ability (AUC = 0.75), relatively high interpretability (feature number = 5) and stability (ϕ̂Z=0.55) compared to the benchmark. The top-ranking miRNAs identified by our model have demonstrated associations with MDD pathways involving cytokine signalling in the immune system, the reelin signalling pathway, programmed cell death and cellular responses to stress.

CONCLUSION

The LR-5 model, which is optimised based on ML design factors, may lead to a robust and clinically usable MDD diagnostic tool.

Homocysteine levels in first-episode patients with psychiatric disorders

A high homocysteine (Hcy) level is a risk factor for schizophrenia, depression, and bipolar disorder. However, the role of hyperhomocysteinemia as either an independent factor or an auxiliary contributor to specific psychiatric symptoms or disorders remains unclear. This study aimed to examine Hcy levels in first-episode inpatients with psychotic symptoms and various psychiatric diseases to elucidate the association between Hcy levels and psychiatric disorders. This study enrolled 191 patients (aged 18-40 years) with psychiatric disorders. Seventy-five patients were diagnosed with schizophrenia, 48 with acute and transient psychotic disorders, 36 with manic episodes with psychosis, 32 with major depressive episodes with psychosis, and 56 healthy controls. Serum Hcy levels were measured using the enzyme cycle method. A Hcy concentration level of > 15 μmol/L was defined as hyperhomocysteinemia. Hcy levels were significantly higher in first-episode patients with psychiatric disorders compared to healthy controls (5.99 ± 3.60 vs. 19.78 ± 16.61 vs. 15.50 ± 9.08 vs. 20.00 ± 11.33 vs. 16.22 ± 12.06, F = 12.778, P < 0.001). Hcy levels were significantly higher in males with schizophrenia, acute and transient psychotic disorder, and major depressive disorder but not in mania [schizophrenia, (t = -4.727, P < 0.001); acute and transient psychotic disorders, (t = -3.389, P = 0.001); major depressive episode with psychosis, (t = -3.796, P < 0.001); manic episodes with psychosis, (t = -1.684, P = 0.101)]. However, serum Hcy levels were not significantly different among the psychiatric disorder groups (F = 0.139, P = 0.968). Multivariate linear regression showed that males had an increased risk for homocysteinemia. (95% CI = 8.192-15.370, P < 0.001). These results suggest that first-episode patients with psychiatric disorders have higher Hcy levels than in the general population, and men are at greater risk for psychiatric disorders. In conclusion, elevated Hcy levels may contribute to the pathogenesis of first-episode patients with psychotic symptoms.

Genetics of ischemic stroke functional outcome

Ischemic stroke, which accounts for 87% of cerebrovascular accidents, is responsible for massive global burden both in terms of economic cost and personal hardship. Many stroke survivors face long-term disability-a phenotype associated with an increasing number of genetic variants. While clinical variables such as stroke severity greatly impact recovery, genetic polymorphisms linked to functional outcome may offer physicians a unique opportunity to deliver personalized care based on their patient's genetic makeup, leading to improved outcomes. A comprehensive catalogue of the variants at play is required for such an approach. In this review, we compile and describe the polymorphisms associated with outcome scores such as modified Rankin Scale and Barthel Index. Our search identified 74 known genetic polymorphisms spread across 48 features associated with various poststroke disability metrics. The known variants span diverse biological systems and are related to inflammation, vascular homeostasis, growth factors, metabolism, the p53 regulatory pathway, and mitochondrial variation. Understanding how these variants influence functional outcome may be helpful in maximizing poststroke recovery.

Discovery of Methylenetetrahydrofolate Reductase (MTHFR) Deficiency in Individuals With Common Psychiatric Comorbidities: A Retrospective Case Review

INTRODUCTION

A retrospective analysis was conducted of a data set collected in an outpatient behavioral health clinic to assess medication metabolism and methylenetetrahydrofolate reductase (MTHFR) and to see if there was a correlation with certain diagnoses and/or gender.

METHOD

The outpatient routine completed genetic testing on their patients and the test results were later collected through a third-party company, which completed the pharmacogenomic test analyzing genetic variations in DNA, medication metabolism, and an MTHFR deficiency.

RESULTS

This study reviewed 186 patients seen in an outpatient setting who were tested for an MTHFR deficiency and compared their psychiatric diagnoses and the number of failed medication attempts. Of those 186 patients, 77 had normal MTHFR enzyme function, 85 were found to have a moderate MTHFR deficiency, and 24 had a severe MTHFR deficiency. Those with a severe MTHFR deficiency had a higher number of medication trials as compared to those without the deficiency and there were overall more patients with a moderate MTHFR deficiency in this data set.

CONCLUSION

Currently, MTHFR deficiency is not commonly tested due to lack of insurance coverage and provider knowledge, and due to the cost of the test itself. Thus, the diagnosis can often be missed.

Effect of L-Methylfolate Supplementation on Sleep for Patients with Reduced Methylenetetrahydrofolate Reductase Activity

INTRODUCTION

Clinicians have limited options outside controlled substances to address sleep disturbance, which left untreated can negatively affect patient outcomes in cardiovascular health, mental health, immunologic function, and more. For some, genetic factors may influence sleep disturbances. L-methylfolate, the active form of folate, plays a critical role in regulation of monoamine neurotransmitters known to have significant impact on sleep regulation: dopamine, serotonin, norepinephrine. Single nucleotide polymorphisms of the enzyme methylene-tetrahydrofolate-reductase are common and can impact monoamine production. The goal of this study was to evaluate effects of L-methylfolate supplementation on sleep in a cohort with reduced methylene tetrahydrofolate reductase (MTHFR) activity.

METHODS

A retrospective cohort of patients being treated with L-methylfolate in a concierge medical clinic setting was studied. Patients presenting with sleep complaints were evaluated using the Patient-Reported Outcomes Measurement Information System at baseline. Patients with known MTHFR polymorphisms at either C667T and/or A1298C were recommended 5 mg of L-methylfolate daily and were reevaluated at 2 wks, at 4 wks, and at 8 wks of supplementation. Statistical comparisons were made utilizing ANOVA and T-test comparisons.

RESULTS

Ten were included in the final cohort: six male and four female, average age 43 ± 16 years. Beginning at wk 2, average sleep disturbance improved significantly by -6.94 points (p = 0.005) and by 8 wks, all patients had improvement with a -14.34 change in disturbance from baseline (p = 0.001).

CONCLUSION

Improvement in sleep disturbance was seen in both low and intermediate function phenotypes. L-methylfolate may be useful for improving sleep in patients with MTHFR polymorphism.

Folate Receptor Alpha Autoantibodies in the Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) Population

The folate receptor alpha autoantibodies (FRAAs) are associated with cerebral folate deficiency (CFD) and autism spectrum disorder (ASD). Both of these syndromes have overlapping characteristics with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) and Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS). Thus, we propose that the FRAAs may contribute to the symptomatology of PANS/PANDAS. To test this hypothesis, 1 mL of serum from 47 patients (age range = 6-18 years old) clinically diagnosed with PANS/PANDAS was sent to Vascular Strategies (Plymouth Meeting, PA, USA) for analysis of FRAAs. Moreover, 63.8% of PANS/PANDAS patients (male = 15; female = 15) were found to have either the blocking and/or blinding FRAAs, with 25 (83.3%; male = 14; female = 11) having binding FRAAs, two (6.7%; all female = 2) having blocking FRAAs, and 3 (10%; male = 1; female = 2) having both binding and blocking. Furthermore, surprisingly, ASD was associated with a 0.76 lower binding titer (p = 0.02), and severe tics were associated with a 0.90 higher binding titer (p = 0.01). A case of a FRAA-positive patient is provided to illustrate that a treatment plan including leucovorin can result in symptom improvement in patients with PANS/PANDAS who are FRAA-positive. These data, for the first time, demonstrate that PANS/PANDAS is associated with FRAAs and suggest folate metabolism abnormalities may contribute to PANS/PANDAS symptomatology. Further studies investigating the therapeutic nature of leucovorin in the treatment of PANS/PANDAS are needed. Such studies may open up an alternative, safe, and well-tolerated treatment for those with the PANS/PANDAS diagnosis.

The Implication of a Polymorphism in the Methylenetetrahydrofolate Reductase Gene in Homocysteine Metabolism and Related Civilisation Diseases

Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in the one-carbon cycle. This enzyme is essential for the metabolism of methionine, folate, and RNA, as well as for the production of proteins, DNA, and RNA. MTHFR catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to its active form, 5-methyltetrahydrofolate, a co-substrate for homocysteine remethylation to methionine. Numerous variants of the MTHFR gene have been recognised, among which the C677T variant is the most extensively studied. The C677T polymorphism, which results in the conversion of valine to alanine at codon 222, is associated with reduced activity and an increased thermolability of the enzyme. Impaired MTHFR efficiency is associated with increased levels of homocysteine, which can contribute to increased production of reactive oxygen species and the development of oxidative stress. Homocysteine is acknowledged as an independent risk factor for cardiovascular disease, while chronic inflammation serves as the common underlying factor among these issues. Many studies have been conducted to determine whether there is an association between the C677T polymorphism and an increased risk of cardiovascular disease, hypertension, diabetes, and overweight/obesity. There is substantial evidence supporting this association, although several studies have concluded that the polymorphism cannot be reliably used for prediction. This review examines the latest research on MTHFR polymorphisms and their correlation with cardiovascular disease, obesity, and epigenetic regulation.

Methylenetetrahydrofolate reductase polymorphisms in dental caries-induced pulp inflammation and regeneration of dentine-pulp complex: Future perspectives

Dental caries (DC)-induced pulp infections usually undergo the common endodontic treatment, root canal therapy (RCT). Endodontically treated teeth are devitalized, become brittle and susceptible for re-infection which eventually results in dental loss. These complications arise because the devitalized pulp losses its ability for innate homeostasis, repair and regeneration. Therefore, restoring the vitality, structure and function of the inflamed pulp and compromised dentin have become the focal points in regenerative endodontics. There are very few evidences, so far, that connect methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR-SNPs) and dental disorders. However, the primary consequences of MTHFR-SNPs, in terms of excessive homocysteine and folate deficiency, are well-known contributors to dental diseases. This article identifies the possible mechanisms by which MTHFR-SNP-carriers are susceptible for DC-induced pulp inflammation (PI); and discusses a cell-homing based strategy for in vivo transplantation in an orthotopic model to regenerate the functional dentine-pulp complex which includes dentinogenesis, neurogenesis and vasculogenesis, in the SNP-carriers.

Susceptibility to preoperative seizures in glioma patients with elevated homocysteine levels

OBJECTIVE

Seizures are a common clinical presentation in patients with glioma and substantially impact patients' quality of life. Hyperhomocysteinemia is defined as abnormally high serum levels of homocysteine (Hcy) and is reportedly linked to susceptibility to various nervous system diseases. However, it remains unclear whether and how hyperhomocysteinemia and its associated genetic polymorphisms promote seizures in glioma patients.

METHODS

We retrospectively reviewed all medical data from 127 patients with malignant gliomas, who underwent initial tumor resection by our team between July 2019 and June 2021 and had preoperative measurements of serum Hcy levels. According to whether they had at least one seizure before surgery, they were divided into the seizure and nonseizure groups. We also detected polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene and measured intratumoral Hcy levels in these patients.

RESULTS

Hyperhomocysteinemia was a susceptibility factor for preoperative seizures in glioma patients according to both univariate analyses (P < 0.001) and multivariate logistic regression analyses (OR 1.239, 95% CI 1.062-1.445, P = 0.007). Patients with the MTHFR C677T variant exhibited elevated serum Hcy levels (P = 0.027) and an increased prevalence of preoperative seizures (P = 0.019). Intratumoral Hcy levels were positively correlated with serum Hcy levels (R = 0.231, P = 0.046) and were elevated in patients with hyperhomocysteinemia (P = 0.031), the MTHFR C677T variant (P = 0.002) and preoperative seizures (P = 0.003). High intratumoral Hcy levels, rather than hyperhomocysteinemia or the MTHFR C677T variant, emerged as an independent risk factor for preoperative seizures (OR 1.303, 95% CI 1.015-1.673, P = 0.038). Furthermore, the effects of hyperhomocysteinemia on epileptic susceptibility were reduced to nonsignificance when intratumoral Hcy was controlled to the same level between groups.

SIGNIFICANCE

Glioma patients with hyperhomocysteinemia and the MTHFR C677T variant were susceptible to preoperative seizures, suggesting their potential as biomarkers for the management of seizures in glioma patients. The elevation of intratumoral Hcy is a possible mechanism underlying this susceptibility.

Bayesian nonparametric method for genetic dissection of brain activation region

Biological evidence indicewates that the brain atrophy can be involved at the onset of neuropathological pathways of Alzheimer's disease. However, there is lack of formal statistical methods to perform genetic dissection of brain activation phenotypes such as shape and intensity. To this end, we propose a Bayesian hierarchical model which consists of two levels of hierarchy. At level 1, we develop a Bayesian nonparametric level set (BNLS) model for studying the brain activation region shape. At level 2, we construct a regression model to select genetic variants that are strongly associated with the brain activation intensity, where a spike-and-slab prior and a Gaussian prior are chosen for feature selection. We develop efficient posterior computation algorithms based on the Markov chain Monte Carlo (MCMC) method. We demonstrate the advantages of the proposed method via extensive simulation studies and analyses of imaging genetics data in the Alzheimer's disease neuroimaging initiative (ADNI) study.

Folate and Its Significance in Depressive Disorders and Suicidality: A Comprehensive Narrative Review

Depressive disorders pose significant challenges to global public health, necessitating effective prevention and management strategies. Notably, the occurrence of suicide frequently coincides with depressive episodes. Suicide is as a paramount global health concern that demands efficacious preventive strategies. Current psychiatric approaches heavily rely on pharmacological interventions but have had limited success in addressing the global burden of mental health issues. Suboptimal nutrition, with its impact on the neuroendocrine system, has been implicated in the underlying pathology of depressive disorders. Folate, a group of water-soluble compounds, plays a crucial role in various central nervous system functions. Depressed individuals often exhibit low levels of serum and red blood cell folate. Multiple studies and systematic reviews have investigated the efficacy of folic acid and its derivative, L-methylfolate, which can cross the blood-brain barrier, as stand-alone or adjunct therapies for depression. Although findings have been mixed, the available evidence generally supports the use of these compounds in depressed individuals. Recent studies have established links between the one-carbon cycle, folate-homocysteine balance, immune system function, glutamate excitation via NMDA (N-methyl-D-aspartate) receptors, and gut microbiome eubiosis in mood regulation. These findings provide insights into the complex neurobiological mechanisms underlying the effects of folate and related compounds in depression. Through a comprehensive review of the existing literature, this study aims to advance our understanding of the therapeutic potential of folic acid and related compounds in depression treatment. It also seeks to explore their role in addressing suicidal tendencies and shed light on the neurobiological mechanisms involved, leveraging the latest discoveries in depression research.

Methylenetetrahydrofolate Reductase C677T (rs1801133) Polymorphism Is Associated with Bladder Cancer in Asian Population: Epigenetic Meta-Analysis as Precision Medicine Approach

The etiology of bladder cancer remains unclear. This study investigates the impact of gene polymorphisms, particularly methylenetetrahydrofolate reductase gene (MTHFR), on bladder cancer susceptibility, focusing on the rs1801133 single-nucleotide polymorphism (SNP). A meta-analysis was conducted after systematically reviewing the MTHFR gene literature, adhering to PRISMA guidelines and registering in PROSPERO (CRD42023423064). Seven studies were included, showing a significant association between the MTHFR C677T (rs1801133) polymorphism and bladder cancer susceptibility. Individuals with the T-allele or TT genotype had a higher likelihood of bladder cancer. In the Asian population, the overall analysis revealed an odds ratio (OR) of 1.15 (95% CI 1.03-1.30; p-value = 0.03) for T-allele versus C-allele and an OR of 1.34 (95% CI 1.04-1.72; p-value = 0.02) for TT genotype versus TC+CC genotype. The CC genotype, however, showed no significant association with bladder cancer. Notably, epigenetic findings displayed low sensitivity but high specificity, indicating reliable identified associations while potentially overlooking some epigenetic factors related to bladder cancer. In conclusion, the MTHFR T-allele and TT genotype were associated with increased bladder cancer risk in the Asian population. These insights into genetic factors influencing bladder cancer susceptibility could inform targeted prevention and treatment strategies. Further research is warranted to validate and expand these findings.

Recovery from (treatment-resistant) depression after lifestyle changes and micronutrient precision supplementation: a preliminary field study in patients

BACKGROUND AND PURPOSE

The incidence of depression is increasing, despite continued advances in psychological and pharmacological interventions. New treatment approaches are urgently needed. Here we assess the effects on depression of individualized micronutrient supplementation, in concert with a standard set of lifestyle changes.

METHODS

We conducted a small field-study with 17 participants in Austria. Patients with depression (n = 11) and healthy volunteers (n = 6) underwent laboratory serum analysis and filled out the DASS-21 and a questionnaire about their medical history and condition. The list of parameters to be tested in the serum analysis was derived from an expert heuristic compilation of factors known to influence depression, narrowed down to a workable list to be tested in this initial study. On the basis of the results, the participants (n = 17) received individualized recommendations for micronutrient supplementation, in collaboration with their treating physician. Participants followed the individual supplementation regime for two months, along with a standard set of lifestyle changes. After two months the laboratory serum analyses, the DASS-21, and the questionnaire were repeated.

RESULTS

All patients with micronutrient deficiencies were in the patient group; none of the healthy volunteers showed any micronutrient deficiencies. After two months of precision supplementation and lifestyle changes, all but one patient had recovered from their depression or had considerably improved. The one patient who didn't recover was the only one with a known trigger of their depression (trauma). Of 11 patients with depression, the trigger was unknown for the other ten.

CONCLUSIONS

These results have promising implications for further research, treatment, drug development, and public health. We propose that systematic screening of patients with symptoms of depression be developed for future research, medical care, and practice. Psychiatry and psychotherapy may see improved results once they no longer have to push against the underlying constraints of existing micronutrient deficiencies.

MTHFR Deficiency in Biological Siblings Diagnosed With Autism and Attention-Deficit Hyperactivity Disorder (ADHD): A Report of Two Cases

Methylenetetrahydrofolate reductase is a critical enzyme that has been associated with several complex psychiatric mental health illnesses. The enzyme can be detected by bloodwork or a cheek swab and, once identified as lacking in individuals, can be treated by over-the-counter supplementation with folate. Due to a provider's limited information and/or the cost to cover the test, the deficiency is not regularly tested for, and, therefore, is missed and not treated. There are very limited studies that demonstrate the benefits of supplements in conjunction with psychotropic medications. This study discusses the case of two biological siblings diagnosed with attention-deficit hyperactivity disorder and autism, who presented with this unique deficiency and had improvement of symptoms once starting the supplement with their traditional psychopharmacological treatment.

Correlation between methylenetetrahydrofolate reductase gene-specific methylation and recurrent spontaneous abortion

OBJECTIVE

To investigate the correlation between methylenetetrahydrofolate reductase (MTHFR) gene-specific methylation and recurrent spontaneous abortion (RSA).

METHODS

A total of 50 RSA patients who visited our hospital were recruited in the study group; 50 multiparous women who underwent physical examinations during the same period were enrolled in the control group. The levels of homocysteine, folic acid, and vitamin B12 and their MTHFR gene polymorphism and specific methylation were measured in both groups. The Logistic regression equation was used to analyze the correlation between MTHFR gene-specific methylation and RSA.

RESULTS

The methylated allele MM was not found in the control group, and the frequency in the study group was 1.19%. The frequency of the MU genotype in the study group 32.93% was higher than that in the control group 12.45%. The frequency of methylated alleles of CC and CT genotypes carrying MTHFR C677T polymorphism in the study group was higher than that in the control group (P < 0.05). There was no significant difference in the TT genotype between the two groups (P > 0.05). Multivariate Logistic regression analysis exhibited that patients with methylated alleles of CC genotype had a risk of RSA increased by 1.167 times, and the risk increased by 2.500 times in patients with methylated alleles of CT genotype (P < 0.05). 83.33% of RSA patients carrying methylated alleles affected hyperhomocysteinemia. In patients with elevated homocysteine levels, the risk of RSA caused by methylated allele was significantly increased by 7.321 times.

CONCLUSION

MTHFR gene-specific methylation can significantly increase the risk of RSA.

Therapeutic Potential of the Purinergic System in Major Depressive Disorder Associated with COVID-19

Neuroinflammation is closely related to the development of depression, since the latter is caused, among other factors, by inflammatory processes, mainly related to the activation of microglia and expression of specific genes, which occurs during the neuroinflammatory process. Thus, COVID-19 is an important risk factor for the development of depression, since in addition to generating the feeling of stress, which also increases the activity of the immune system, it is also the cause of pathological processes and physiological ones that lead to the development of neuroinflammation, microglial activation, gene expression dysfunction and decreased concentration of available serotonin. That said, drugs are being used to combat COVID-19 to reduce the oxidative stress presented in the disease. Thus, tramadol and fluoxetine are highlighted as drugs used, however, although they present some positive results, such as the reduction of pro-inflammatory cytokines, they are also associated with negative effects such as dependence, pulmonary, cardiac and brain impairment. From this, the purinergic system is highlighted in the literature as a possible therapeutic target. This is because its mechanisms are related to the regulation of microglia, astrocytes and the physiology of important neurotransmitters and hormones. Added to this, there is a modulation of inflammatory activity, especially with regard to the P2X7 receptors of this system. The latter is an important target for the treatment of depression and COVID-19, since positive results were obtained through the genetic exclusion of this receptor and the use of selective antagonists.

Paroxetine treatment in an animal model of depression improves sperm quality

Depression in mammals is known to be associated with poor reproductive capacity. In males, it has been associated with decreased efficiency of spermatogenesis as well as the production of spermatozoa of reduced structural and functional integrity. Although antidepressants are effective in correcting depressive states, there is controversy regarding their effectiveness in restoring male reproductive function. Here, using an animal model of depression induced by a forced swim test, we confirmed that depression is accompanied by impaired male reproductive function. We further show that administration of a conventional antidepressant of the serotonin reuptake inhibitor class (paroxetine) impairs male reproductive performance in terms of sperm production and quality when administered to healthy animals. Intriguingly, when paroxetine is administered to "depressed" animals, it resulted in a complete restoration of the animal's ability to produce sperm that appears to be as capable of meeting the parameters evaluated here as those of control animals. The one-carbon cycle (1CC) is one of the most important metabolic cycles that include the methionine and folate cycles and plays a major role in DNA synthesis, amino acids, and also the production of antioxidants. Our results show that depression affects the main components of this cycle and paroxetine on healthy mice increases homocysteine levels, decreases glycine and vitamin B12, while in depressed mice, it increases folate levels and decreases vitamin B12. Thus, paroxetine exerts negative impacts on male reproductive function when administered to healthy animals and it well correlate with the altered sperm parameters and functions of depressed animals, and its mechanism remains to be explored.

Association of homocysteine and polymorphism of methylenetetrahydrofolate reductase with early-onset post stroke depression

Background

Homocysteine (Hcy) has been indicated to be involved in pathophysiology of post stroke depression (PSD). There is a lack of research to study the relationship between Hcy metabolism genes and PSD. Our study aims to investigate the relationship among Hcy metabolism genes, Hcy, and early-onset PSD.

Materials and methods

We recruited 212 patients with stroke and collected their peripheral blood sample, clinical data, and laboratory test on admission. 12 single nucleotide polymorphisms (SNPs) in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), and methionine synthase (MTR) genes were genotyped by high-resolution melt analysis. PSD was diagnosed by DSM-V at 2 weeks after stroke. Binary logistic regression and haplotype analysis were used to examine the association between Hcy metabolism genes and PSD. Mediation analysis was performed to clarify whether the SNPs exerted their effect on PSD by affecting the Hcy level.

Results

81 patients were diagnosed with PSD, and the incidence rate was 38.2%. Hcy level in PSD group was significantly higher than it in non-PSD group (p = 0.019). MTHFR rs1801133 AA genotype an A allele were associated with an elevated risk of PSD after adjustment for some confounding factors (OR = 4.021, 95% CI: 1.459∼11.080, p = 0.007 for AA genotype; OR = 1.808, 95% CI: 1.172∼2.788, p = 0.007 for A allele). Furthermore, the effect of MTHFR rs1801133 AA genotype on PSD was mediated by Hcy (OR = 1.569, 95% CI: 0.013∼3.350, p < 0.05).

Conclusion

MTHFR rs1801133 and Hcy were associated with PSD, and MTHFR rs1801133 may exert an effect on PSD via mediating Hcy level. This offers a new perspective for treating PSD and understanding the mechanism of PSD.

Genetics, genomics, and diet interactions in obesity in the Latin American environment

Obesity is a chronic disease characterized by abnormal or excessive fat accumulation that could impact an individual's health; moreover, the World Health Organization (WHO) has declared obesity a global epidemic since 1997. In Latin America, in 2016, reports indicated that 24.2% of the adult population was obese. The environmental factor or specific behaviors like dietary intake or physical activity have a vital role in the development of a condition like obesity, but the interaction of genes could contribute to that predisposition. Hence, it is vital to understand the relationship between genes and disease. Indeed, genetics in nutrition studies the genetic variations and their effect on dietary response; while genomics in nutrition studies the role of nutrients in gene expression. The present review represents a compendium of the dietary behaviors in the Latin American environment and the interactions of genes with their single nucleotide polymorphisms (SNPs) associated with obesity, including the risk allele frequencies in the Latin American population. Additionally, a bibliographical selection of several studies has been included; these studies examined the impact that dietary patterns in Latin American environments have on the expression of numerous genes involved in obesity-associated metabolic pathways.

A meta-analysis on the susceptibility to the development of bladder cancer in the presence of DNMT3A, DNMT3B, and MTHFR gene polymorphisms

Background

The etiology of bladder cancer is not yet well known. In this study, we want to evaluate the effect of polymorphisms of genes that have an epigenetic effect (MTHFR, DNMT3A/B) on the susceptibility to develop bladder cancer (BC).

Methods

A systematic review was performed for MTHFR, DNMT3A, and DNMT3B, followed by a meta-analysis conducted for rs1801131, rs1801133, rs2274976, rs1550117, and rs1569686 SNPs. A sensitivity and a subgroup analysis were then used.

Results

20 studies were included, where no statistically significant association between any of the analyzed SNPs and the occurrence of BC was detected. Subgroup analysis revealed a statistically significant association in North African population with rs1801133: TT vs. TC + CC (P = 0.013; OR 95% CI = 0.52 [0.311–0.872]); TT vs.TC (P = 0.003; OR 95% CI = 0.448 [0.261–0.769]) and in North American population with rs1801131: CC vs. CA (P = 0.039; OR 95% CI = 0.71 [0.523–0.984]). A sensitivity analysis revealed that there is a statistically significant association between rs1801131 and the occurrence of BC (OR = 0.79, 95%CI [0.65–0.97]), (OR = 0.80, 95%CI [0.65–0.98]) and (OR = 0.78, 95%CI [0.63–0.96]) which correspond to CC vs. CA + AA; CC vs. CA; and CC vs. AA genetic models.

Conclusion

This is the first study to assess the effect of DNMTs on bladder cancer risk. No statistically significant association was found between polymorphisms of MTHFR, DNMT3A/B genes and bladder cancer development, except for the North African and the North American populations with rs1801133 and  rs1801131, respectively, with a protective effect of rs1801131 based on a sensitivity analysis.

The Roles of MTRR and MTHFR Gene Polymorphisms in Colorectal Cancer Survival

Background: Paradoxically epidemiological data illustrate a negative relationship between dietary folate intake and colorectal cancer (CRC) risk. The occurrence and progression of CRC may be influenced by variants in some key enzyme coding genes in the folate metabolic pathway. We investigated the correlation between genetic variants in methionine synthase reductase (MTRR) and methylenetetrahydrofolate reductase (MTHFR) and CRC survival. Methods: This study used data collected from the Newfoundland Familial Colorectal Cancer Study. A total of 532 patients diagnosed with CRC for the first time from 1999 to 2003 were enrolled, and their mortality were tracked until April 2010. DNA samples were genotyped by Illumina’s integrated quantum 1 million chip. Cox models were established to assess 33 tag single-nucleotide polymorphisms in MTRR and MTHFR in relation to overall survival (OS), disease-free survival (DFS) and CRC-specific survival. Results: The MTRR and MTHFR genes were associated with DFS and CRC-specific survival in CRC patients at the gene level. After multiple comparison adjustment, MTRR rs1801394 A (vs. G) allele was associated with increased DFS (p = 0.024), while MTHRT rs3737966 (G vs. A), rs4846049 (T vs. G), rs1476413 (A vs. G), rs1801131 (C vs. A), rs12121543 (A vs. C), rs1801133 (C vs. T), rs4846052 (T vs. C), rs2066471 (A vs. G) and rs7533315 (T vs. C) were related to worse CRC-specific survival. Additionally, significant interactions were seen among pre-diagnostic alcohol consumption with MTRR rs1801394, rs3776467, rs326124, rs162040, and rs3776455, with superior OS associated with those protective variant alleles limited to patients with alcohol consumption under the median. The MTHFR rs3737966 (G vs. A) allele seemed to be detrimental to CRC survival only among subjects with fruit intake below the median. Conclusions: Polymorphic variants in MTRR and MTHFR genes that code for key enzymes for folate metabolism may be associated with survival in patients with CRC. The gene-CRC outcome association seems modulated by alcohol drinking and fruit intake.

Association of H-Type Hypertension with miR-21, miR-29, and miR-199 in Kazahks of Xinjiang, China

Objective

This study aims to analyze the expressions of miR-21, miR-29, and miR-199 in the serum of the patients with H-type hypertension among Kazakhs. Then, we analyzed the effect of MTHFR 677C > T polymorphism on the association between the above miRNA and H-type hypertension.

Method

In this study, the expression of miR-21, miR-29, and miR-199 was quantitatively measured in 120 serum samples and then stratified according to the C677T polymorphism to analyze the relationship between target miRNAs and HHcy.

Results

The expression of miR-21/-29 in the hypertension group was higher than the normal group (P < 0.001). And the expression of miR-199 was higher in the hcy group than in the normal group (P < 0.001). In the CC and CT genotypes of MTHFR 677C > T, the expression of miR-21 was lower in the HHcy patients than in the normal individuals (P = 0.005 and P = 0.001) and miR-199 was significantly higher in the HHcy patients than in the normal ones (P = 0.002 and P = 0.048). No such difference was found in the TT genotype. Logistic regression analysis showed that after adjusting for sex, age, BMI, systolic blood pressure, diastolic blood pressure, and MTHFRC677 T gene polymorphism, miR-21 was negatively correlated with hcy (OR = 0.222, 95% CI (0.101–0.485), P < 0.001) and miR-199 was positively correlated with hcy (OR = 1.823,95%CI (1.272∼2.614), P = 0.001).

Conclusion

miR-21, miR-29, and miR-199 are associated with H-type hypertension in the Kazakhs, especially hyperhomocysteinemia. And these three miRNAs may serve as biomarkers to provide clues to the potential pathogenesis of H-type hypertension.

A retrospective examination of adjunctive L-methylfolate in children and adolescents with unipolar depression

BACKGROUND

Adjunctive l-methylfolate is commonly prescribed for children and adolescents with treatment-resistant mood disorders; however, the relationship between l-methylfolate augmentation across methylenetetrahydrofolate reductase (MTHFR) genotypes in youths with depressive symptoms is unclear.

METHODS

We retrospectively examined the electronic health records of patients (N = 412) with depressive symptoms associated with unipolar depressive disorders and their MTHFR C677T genotypes from 2013 to 2019. Patients were ≤18 years of age at the time of MTHFR pharmacogenetic testing. Treatment response was assessed with Clinical Global Impression-Improvement (CGI-I) score reported in the medical record.

RESULTS

Patients with an MTHFR C677T C/T or T/T genotype were more likely to be prescribed l-methylfolate when the clinician knew their MTHFR genotype (p < 0.0001, OR: 15.1, 95 % CI: [5.1, 44.2]), but not when the clinician did not know their genotype (p = 0.4, OR: 2.1, 95 % CI: [0.4, 11.4]). Change in baseline and endpoint CGI-I scores between patients with an MTHFR C677T variant who were prescribed and not prescribed l-methylfolate did not significantly differ (p = 0.39). Response rate was not associated with l-methylfolate prescription (p = 0.17) or l-methylfolate dose (p = 0.69).

LIMITATIONS

This was a retrospective study, which yielded a heterogeneous patient population and limited data availability (e.g., adherence). Patients are severely ill and may have a refractory illness that limits response to adjunctive l-methylfolate.

CONCLUSION

Clinicians prescribe l-methylfolate to children and adolescents with depressive symptoms associated with unipolar depressive disorders who have an MTHFR C677T variant, although augmentation may not be associated with treatment response, regardless of MTHFR genotype or dose.

Association between variants of MTHFR genes and psychiatric disorders: A meta-analysis

Background

Psychiatric disorders have seriously affected human life, one of the risk genes related to psychosis is the methylenetetrahydrofolatereductase (MTHFR) gene. This gene has a potential role in psychiatric disorders. Therefore, a meta-analysis is conducted to investigate the correlations between two prevalent MTHFR single nucleotide polymorphisms (SNPs), MTHFR C677T, A1298C, severe psychological disorders (schizophrenia, major depression, bipolar disorder).

Methods

A total of 81 published studies were screened and selected by a search of electronic databases up to April 2022. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association between MTHFR polymorphism and psychiatric disorders susceptibility by using random effect models.

Results

We found that MTHFR C677T polymorphism is significantly related to schizophrenia and major depression in the overall population. MTHFR C677T has been linked to an increased risk of bipolar disorder in the recessive model (TT vs. CT + CC). Ethnic subgroup analysis shows that schizophrenia and major depression significantly correlate with MTHFR C677T and A1298C in Asian populations but not Caucasians. Besides, schizophrenia is correlated substantially with MTHFR C677T in the African population. However, the MTHFR A1298C polymorphism is only marginally linked to major depression.

Conclusion

Findings of the current study revealed that MTHFR may contribute to the common pathogenesis of psychiatric diseases and that its variants may be essential in controlling the expression of psychosis-related genes. This study could help the researchers and health specialists in the early diagnosis and treatment of psychiatric disorders.

Association between MTHFR (677C>T and 1298A>C) polymorphisms and psychiatric disorder: A meta-analysis

Recent studies showed that genetic polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) is related to attention-deficit hyperactivity disorder (ADHD), bipolar disorder (BD) and schizophrenia (SCZ). However, no consistent conclusion has been determined. This meta-analysis aims to interrogate the relationship between MTHFR gene polymorphisms (677C>T and 1298A>C) and the occurrence of ADHD, BD and SCZ. We retrieved case-control studies that met the inclusion criteria from the PubMed database. Associations between MTHFR polymorphisms (677C>T and 1298A>C) and ADHD, BD and SCZ were measured by means of odds ratios (ORs) using a random effects model and 95% confidence intervals (CIs). Additionally, sensitivity analysis and publication bias were performed. After inclusion criteria were met, a total of five studies with ADHD including 434 cases and 670 controls, 18 studies with BD including 4167 cases and 5901 controls and 44 studies with SCZ including 16,098 cases and 19913 controls were finally included in our meta-analysis. Overall, our meta-analytical results provided evidence that the MTHFR 677C>T was associated with occurrence of BD and SCZ, while the 1298A>C polymorphism was related to ADHD and BD, and additionally the sensitivity analysis indicated these results were stable and reliable. This may provide useful information for relevant studies on the etiology of psychiatric disorders.

Associations of Two Common Polymorphisms in MTHFR Gene with Blood Lipids and Therapeutic Efficacy of Simvastatin

BACKGROUND AND PURPOSE

Cardio-cerebrovascular disease is an important public health challenge worldwide, and its complex etiology has not been elucidated fully. The study was to investigate the relationship between two common polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, baseline lipids and the lipid-lowering efficacy of simvastatin in a Chinese hyperlipidemic population.

METHODS

All participants were recruited from Anhui, China. By the extreme sampling method, we selected subjects with low response (n=108) and high response (n=106) based on their adjusted lipid-lowering response to simvastatin administrated for 8 consecutive weeks. Both MTHFR C677T and A1298C loci were genotyped by MALDI-TOF MS platform. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were measured at baseline and after 8 weeks of oral 20 mg/d tablet of simvastatin.

RESULTS

Patients with the 677TT genotype had significantly higher baseline TC, HDL-C, and change in HDL-C (ΔHDL-C) levels after treatment than those with 677CC+CT genotypes (β = 0.207, P = 0.045; β = 0.182, P = 0.026; and β = 0.16, P = 0.002, respectively). Patients with 1298AC+CC genotypes had significantly higher baseline LDL-C and change in LDL-C (ΔLDL-C) levels (β = 0.276, P =0.043; β = 0.359, P = 0.025, respectively) than those with 1298AA genotype. We found statistical interactions between the two SNPs in association with baseline HDL-C (P for interaction = 0.034), TC (P for interaction = 0.069), and TG (P for interaction = 0.034). Baseline TC (P = 0.027) and HDL-C (P = 0.046) and change in HDL-C (P = 0.019) were different among those with the MTHFR A-T haplotype compared with A-C.

CONCLUSIONS

Our major findings suggest that both MTHFR C677T and A1298C polymorphisms could be important genetic determinants of lipid traits and drug efficacy of simvastatin. This will contribute to a better understanding of strategies for personalized medication in Chinese patients with dyslipidemia.

Association of Fetal MTHFR C677T Polymorphism with Susceptibility to Neural Tube Defects: A Systematic Review and Update Meta-Analysis

Background MTHFR gene may be a key epigenetic regulation-related factor crucial during embryogenesis. We performed a meta-analysis to determine the association of fetal MTHFR C677T polymorphism with neural tube defects (NTDs).Methods A comprehensive literature search of the PubMed, Embase, and CNKI database was performed up to April 10, 2020.Results A total of 19 case-control studies with 2,228 NTDs cases and 4,220 controls were identified. Pooled data revealed that the fetal MTHFR C677T polymorphism was significantly highly correlated with development of NTDs in the overall population. Stratified analysis showed a significant association among Caucasians and Asians, but not in mixed populations. There was a significant association between the MTHFR C677T polymorphism and spina bifida risk. No publication bias was found under any genetic model.Conclusions Our pooled data support the fetal MTHFR C677T polymorphism association with risk of NTDs, especially among Caucasians and Asians.

A Study of the MTHFR Gene Prevalence in a Rural Tennessee Opioid Use Disorder Treatment Center Population

Background: Opioid Use Disorder (OUD) has been linked to dopamine and the neurological reward centers. Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in the production of many neurotransmitters such as dopamine. As such, MTHFR variants that lead to decreased production of neurotransmitters may play a role in OUD. However, lacunae exist for characterizing the prevalence of the MTHFR mutations in an OUD population. The objective of this study was to determine prevalence of the MTHFR gene mutations in a rural Tennessean population with OUD. Methods: This study was a retrospective cohort of individuals with OUD that evaluated the prevalence of MTHFR variants. Patients were categorized as normal, homozygous C677T, heterozygous C677T, homozygous A1298C, or heterozygous A1298C. The primary outcome was a qualitative comparison of the prevalence of each of the MTHFR variants in our cohort to the publicly reported MTHR polymorphism prevalence. Secondary outcomes include race and ethnicity differences as well as stimulant use differences for each of the variants. Results: A total of 232 patients undergoing care for opioid use disorder were included in the study. Of those included, 30 patients had a normal MTHFR allele and 202 had a variant MTHFR allele. Overall, the prevalence of any MTHFR variant was 87.1% (95% CI 82.6–91.4%). When comparing those with a normal MTHFR allele to those with any MTHFR variant, there was no difference in age, sex, race and ethnicity, or stimulant use. Conclusion: The overall prevalence of MTHFR variants in patients with opioid use disorders is high.

GABAA subunit single nucleotide polymorphisms show sex-specific association to alcohol consumption and mental distress in a Norwegian population-based sample

Little is known about genetic influences on the relationship between alcohol consumption and mental distress in the general population, where the majority report consumption and distress far below diagnostic thresholds. This study investigated single nucleotide polymorphisms (SNPs) from candidate gene studies on alcohol use disorder and depressive disorders, for association with alcohol consumption and with mental distress in a population-based sample from the Cohort of Norway (n = 1978, 49% women). The relationship between alcohol consumption and mental distress was further examined for genotype modification. There was a positive correlation between mental distress and alcohol consumption in men, as well as an association between SNPs and mental distress in men (GABRG1, GABRA2, DRD2, ANKK1, MTHFR) and women (CHRM2, MTHFR) and between SNPs and alcohol consumption in women (GABRA2, MTHFR). No modification by SNP genotype was found on the relationship between alcohol consumption and mental distress. The association between mental distress and GABRG1 in men remained significant after correcting for multiple comparisons. The results indicate that alcohol consumption and mental distress are associated in the general population even at levels below clinical thresholds and point to SNPs in genes related to GABAergic signalling for level of mental distress in men.

Association Between MTHFR rs17367504 Polymorphism and Major Depressive Disorder in Taiwan: Evidence for Effect Modification by Exercise Habits

BACKGROUND/AIM

Recent studies reported that folate supplementation has beneficial effects on major depression. The Methylenetetrahydrofolate reductase (MTHFR) enzyme is crucial in folate metabolism. This population-based study examined the association between MTHFR rs17367504 polymorphism and major depressive disorder based on exercise habits.

METHODS

Taiwan Biobank (TWB) provided demographic and genotype data between 2008 and 2015. The biobank participants were Taiwanese aged 30 to 70. Data on major depressive disorder (MDD) were obtained from the National Health Insurance Research Database (NHIRD).

RESULTS

A total of 636 individuals were identified with MDD, whereas 17,298 individuals were considered controls. The associations of MTHFR rs17367504 and exercise with MDD risk were estimated using logistic regression models. The distribution of MTHFR rs17367504 genotype frequencies differed significantly between the MDD and control groups. We found that, compared with the AA genotype, the GG genotype was associated with a significantly increased risk of MDD [adjusted odds ratio (aOR), 1.76; 95% confidence interval (CI), 1.05-2.94; p = 0.033]. We found an interaction (p = 0.04) between rs17367504 and exercise, a well-known protective factor for MDD. A substantial increase in the risk of MDD was found among those with GG genotypes who did not exercise (aOR, 2.93; 95% CI, 1.66-5.17; p < 0.001).

CONCLUSIONS

Our findings indicate that MDD is related to MTHFR rs17367504 and exercise, though the mechanisms remain to be determined.

Individuals with Bipolar Disorder Have a Higher Level of Homocysteine Than Major Depressive Disorder: A Retrospective Chart Review and Observational Study

PURPOSE

Previous studies suggest that homocysteine (Hcy) may be involved in the pathogenesis of bipolar disorder (BD) and major depressive disorder (MDD) by influencing glutamatergic transmission, inflammation, and other mechanisms. There are no established biomarkers to distinguish BD from MDD. This study aims to compare Hcy levels between BD and MDD.

PATIENTS AND METHODS

We collected medical records of patients aged 14-75 admitted to the hospital from January 1 to July 1, 2022 with a discharge diagnosis of MDD or BD, including all examinations of patients at admission (acute phase) and discharge (non-acute phase). We measured Hcy levels in healthy controls (HC).

RESULTS

The analysis included 104 patients with MDD, 103 patients with BD, and 80 HC. Hcy levels were higher in the MDD and BD group than in the HC group and higher in the BD group than in the MDD group, both in the acute and non-acute phases (all P < 0.05). There was no significant difference in Hcy levels between the psychotropic medication users and non-users in the BD or MDD group (all P > 0.05). Multivariate logistic regression analysis only for the MDD and BD group indicated that the likelihood of BD diagnosis was significantly associated with Hcy levels (in the acute phase: OR = 1.052, P = 0.016; in the non-acute phase: OR = 1.101, P < 0.001) after controlling for gender, age, and metabolic indicators.

CONCLUSION

Our study suggests that Hcy levels were elevated in MDD and BD patients and were higher in BD patients than in MDD patients, which provides evidence for a possible relationship between one-carbon metabolism and the pathogenesis of BD. Besides, Hcy may be one of the potential biomarkers to distinguish BD from MDD.

The Landscape of Clinical Implementation of Pharmacogenetic Testing in Central China: A Single-Center Study

Purpose

Pharmacogenetic testing is recognized as the major method for the individualized pharmacotherapy in clinical pharmacy practice, but information about the clinical implementation of pharmacogenetic testing in China is limited. The present study aimed to determine the situation of clinical implementation for pharmacogenetic testing in central China.

Methods

The study is conducted in the department of clinical pharmacy in The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China. We collected and analyzed pharmacogenetic testing results from November 1, 2013 to November 2, 2018 in our hospital, which were checked in the electronic medical record system. The main outcome measures were the number and type of pharmacogenetic testing across five years.

Results

A total of 47,265 (56.9% male, mean age = 51.5 years) pharmacogenetic testing results were obtained with an average annual rate of growth of 63.0% across five years. A 50.2% (23,748/47,265) of all the pharmacogenetic testing results were for the determination of cytochrome P450 2C19 (CYP2C19) *2, *3 genotypes, and 41.7% were for the methylene tetrahydrofolate reductase (MTHFR) C677T genotype. The number of departments performing the pharmacogenetic testing was 35, 63, 55, 52, 52 and 39 for 2013–2018, respectively, and the main top five departments were cardiology, psychiatry, ICU, cardiac surgery and intervention.

Conclusion

Clinical implementation of pharmacogenetic testing in China is growing rapidly, but the types and implementing departments of pharmacogenetic testing were limited. Our present study reported the real-world implementation modality of pharmacogenomic tests in China. It will help us to understand the testing of pharmacogenetics in China in order to promote the rational development of pharmacogenetics.

The potential use of folate and its derivatives in treating psychiatric disorders: A systematic review

OBJECTIVES

To examine the strengths and limitations of existing data to provide guidance for the use of folate supplements as treatment, with or without other psychotropic medications, in various psychiatric disorders. To identify area for further research in terms of the biosynthesis of mechanism of folate and genetic variants in metabolic pathway in human.

METHODS

A systematic review of published literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to assess whether folate supplements are beneficial in certain psychiatric disorders (depression, bipolar disorder, schizophrenia, autism spectrum disorder, and attention deficit hyperactivity disorder). Methodology of this review is registered with Prospero (Registration number CRD 42021266605).

DATA SOURCES

Eligible studies were identified using a systematic search of four electronic databases: Embase, Pubmed, PsycINFO, and Cochrane. The search strategy covered the time period from 1974 to August 16th, 2021. Therefore, this review examines randomized control trials or open-label trials completed during this period.

RESULTS

We identified 23 studies of folate supplements in various psychiatric disorders for critical review. Of these, 9 studies investigated the efficacy of folate supplements in major depressive disorders, 5 studies in schizophrenia, 6 studies in autism spectrum disorder, 2 studies in bipolar affective disorder and 1 study in attention deficit hyperactive disorder. The most consistent finding association of oral levomefolic acid or 5-methylfolate with improvement in clinical outcomes in mental health conditions as mentioned above, especially in major depressive disorder (including postpartum and post-menopausal depression), schizophrenia, autism spectrum disorder, attention deficit hyperactivity disorder and bipolar affective disorder. Folate supplements were well tolerated.

LIMITATION

Our results are not representative of all types of studies such as case reports or case series studies, nor are they representative of the studies conducted in languages that are not in English or not translated in English.

CONCLUSION

Increasing evidence from clinical trials consistently demonstrate folate supplements, especially levomefolic acid or 5-methylfolate, may improve clinical outcomes for certain psychiatric diseases, especially as an adjunct pharmacotherapy with minimal side effects.

Nutrigenetics and nutrigenomics-A personalized approach to nutrition

The prevalence of non-communicable diseases has been on an upward trajectory for some time and this puts an enormous burden on the healthcare expenditure. Lifestyle modifications including dietary interventions hold an immense promise to manage and prevent these diseases. Recent advances in genomic research provide evidence that focussing these efforts on individual variations in abilities to metabolize nutrients (nutrigenetics) and exploring the role of dietary compounds on gene expression (nutrigenomics and nutri-epigenomics) can lead to more meaningful personalized dietary strategies to promote optimal health. This chapter aims to provide examples on these gene-diet interactions at multiple levels to support the need of embedding targeted dietary interventions as a way forward to prevent, avoid and manage diseases.

Association between high BMI and high homocysteine levels in Chinese patients with bipolar disorder

BACKGROUND

Bipolar disorder (BD) has been associated with an increased prevalence of weight gain and abnormally elevated plasma homocysteine (Hcy) levels. However, the relationship between BMI and Hcy in BD patients has not been investigated. This study aimed to explore this relationship in Chinese patients with BD.

METHODS

Plasma Hcy levels, socio-demographic parameters, clinical and anthropometric data were collected from 195 BD inpatients and 84 healthy controls. The level of plasma Hcy was determined by high-performance liquid chromatography. Body mass index (BMI) was calculated by body weight divided by the square of the height. The participants were divided into a high BMI group and a low BMI group using 24 kg/m² as a threshold.

RESULTS

The prevalence of high BMI was slightly elevated in BD patients in comparison to healthy controls. Patients with elevated BMI had significantly higher Hcy levels than patients with low BMI. Hcy level was an independent contributor of the occurrence of high BMI in BD patients. The level of Hcy was positively correlated with BMI in BD patients. In addition, depressive episodes of BD were positively correlated with the prevalence of high BMI and married BD patients were more likely to have high BMI levels.

CONCLUSIONS

There is a close relationship between BMI and plasma Hcy levels in patients with BD, suggesting that Hcy may be an important indicator for BD-induced weight gain. This finding provides a new avenue for weight management of BD patients and to help avoid the potential risk of cardiovascular diseases.

Key considerations in the pharmacological management of treatment-resistant depression

Introduction: Treatment-resistant depression (TRD) is a complex, multifactorial, and biologically heterogeneous disorder with debilitating outcomes. Understanding individual reasons why patients do not respond to treatment is necessary for improving clinical recommendations regarding medication regimens, augmentation strategies, and alternative treatments.Areas covered: This manuscript reviews evidence-based treatment strategies for the clinical management of TRD. Current developments in the field and potential future recommendations for personalized treatment of TRD are also discussed.Expert opinion: Treatment guidelines for TRD are limited by the heterogeneous nature of the disorder. Furthermore, current strategies reflect this heterogeneity by emphasizing disease characteristics as well as drug trial response or failure. Developing robust biomarkers that could one day be integrated into clinical practice has the potential to advance specific treatment targets and ultimately improve treatment and remission outcomes.

Lead (Pb) and neurodevelopment: A review on exposure and biomarkers of effect (BDNF, HDL) and susceptibility

Lead (Pb) is a ubiquitous environmental pollutant and a potent toxic compound. Humans are exposed to Pb through inhalation, ingestion, and skin contact via food, water, tobacco smoke, air, dust, and soil. Pb accumulates in bones, brain, liver and kidney. Fetal exposure occurs via transplacental transmission. The most critical health effects are developmental neurotoxicity in infants and cardiovascular effects and nephrotoxicity in adults. Pb exposure has been steadily decreasing over the past decades, but there are few recent exposure data from the general European population; moreover, no safe Pb limit has been set. Sensitive biomarkers of exposure, effect and susceptibility, that reliably and timely indicate Pb-associated toxicity are required to assess human exposure-health relationships in a situation of low to moderate exposure. Therefore, a systematic literature review based on PubMed entries published before July 2019 that addressed Pb exposure and biomarkers of effect and susceptibility, neurodevelopmental toxicity, epigenetic modifications, and transcriptomics was conducted. Finally included were 58 original papers on Pb exposure and 17 studies on biomarkers. The biomarkers that are linked to Pb exposure and neurodevelopment were grouped into effect biomarkers (serum brain-derived neurotrophic factor (BDNF) and serum/saliva cortisol), susceptibility markers (epigenetic markers and gene sequence variants) and other biomarkers (serum high-density lipoprotein (HDL), maternal iron (Fe) and calcium (Ca) status). Serum BDNF and plasma HDL are potential candidates to be further validated as effect markers for routine use in HBM studies of Pb, complemented by markers of Fe and Ca status to also address nutritional interactions related to neurodevelopmental disorders. For several markers, a causal relationship with Pb-induced neurodevelopmental toxicity is likely. Results on BDNF are discussed in relation to Adverse Outcome Pathway (AOP) 13 ("Chronic binding of antagonist to N-methyl-D-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities") of the AOP-Wiki. Further studies are needed to validate sensitive, reliable, and timely effect biomarkers, especially for low to moderate Pb exposure scenarios.

Associations between methylenetetrahydrofolate reductase polymorphisms and hepatocellular carcinoma risk: An update meta-analysis and trial sequential analysis

AIM

To evaluate the associations between the methylenetetrahydrofolate reductase (MTHFR) single-nucleotide polymorphisms (SNPs) and hepatocellular carcinoma (HCC) with meta-analysis and trial sequential analysis.

METHODS

PubMed, Embase, the Google Scholar, Wan fang database, VIP database, and China National Knowledge Infrastructure were extensively searched before April 2021. Odds ratios (ORs) and 95% confidence interval (95% CI) were calculated. Review Manager Version 5.3, STATA version 12.0 and TSA 0.9.5.10 Beta software were used.

RESULTS

Nineteen studies with 6941 HCC patients and 9436 controls were finally included. The MTHFR rs1801133 (C677T) SNP was associated with increased HCC risk under heterozygote genetic model (OR = 1.10, 95% CI = [1.01, 1.20]). For Subgroup analysis, increased risks of HCC were detected in Mongoloid, Chinese. For MTHFR rs1801131 (A1298C) SNP, increased risk of HCC was only observed in Caucasians (allelic: OR = 1.86, 95% CI = [1.49, 2.31]; homozygote: OR = 3.39, 95% CI = [2.18, 5.27]), interesting decreased risk was detected in Mongoloid (recessive: OR = 0.30, 95% CI = [0.15, 0.58]; homozygote: OR = 0.41, 95% CI = [0.24, 0.72]). Sensitivity analysis indicated stability in our results. Publication bias was not detected based on Begg test and Egger test. Trial sequential analysis indicated further studies to confirm the associations in MTHFR C677T polymorphism.

CONCLUSION

The MTHFR rs1801133 SNP was associated with an increased risk of HCC in Mongoloid population especially in Chinese. Increased HCC risk is also observed in Caucasian population for the MTHFR rs1801131 SNP, and decreased risk of HCC is remarkably discovered in Mongoloid and Chinese subgroups, which need further validation.

When should a psychiatrist remember to test homocysteine levels? - a literature review

Introduction: Homocysteine is an endogenous sulfur amino acid, formed as a result of biochemical changes in methionine. The normal concentration of homocysteine in healthy people is within the range of 5 - 15 µmol / l, and values above 15 µmol / l are referred to as hyperhomocysteinemia. Moreover, it has been shown that the level of homocysteine may be associated with the occurrence of mental disorders. The aim of this article was to search for a relationship between the level of this amino acid and the incidence and prognosis of bipolar disorder, depression, anxiety disorders, schizophrenia or Alzheimer’s disease.

Material and method: For the review of the literature, available articles from the PubMed database and Google Scholar were used under the following keywords: homocysteine, depression, bipolar disorder, schizophrenia, Alzheimer’s disease in the period from 1992 to 2021.

Results: The research conducted so far shows that there is a significant correlation between elevated levels of homocysteine and the above-mentioned mental disorders.

Conclusion: In order to prevent the consequences of the increased level of homocysteine, its concentration in blood serum should be monitored periodically and appropriate treatment should be implemented in case of abnormal results. It is important to educate patients about the consequences of hyperhomocysteinemia i.a. atherosclerosis, stroke, ischemic heart disease, osteoporosis, neural tube defects, mental disorders and neurodegenerative diseases. It should be also established a strategy to lower the level of this amino acid through lifestyle changes, as well as the supply of folic acid, vitamins B12, B6, B2, N-acetylcysteine and betaine.

The role of BDNF exon I region methylation in the treatment of depression with sertraline and its clinical diagnostic value

Background

Brain‐derived neurotrophic factor (BDNF) is considered to be one of the best candidate genes for depression. However, whether sertraline treatment affects the methylation level of this gene remains unknown.

Methods

Fifty‐three patients with depression and 51 healthy controls were included in the study. The methylation level of BDNF exon I was determined in blood samples from these subjects. The Hamilton Depression Scale was used to evaluate the depression status of patients. Single nucleotide polymorphism detection was used for genotyping, and a receiver operating characteristic (ROC) curve was used to evaluate the predictive value of the methylation level of this locus in patients with depression.

Results

There was a significant difference in the methylation level of BDNF exon I between the control and depression groups. No effect of sertraline monotherapy on BDNF methylation was found in subjects with depression. Moreover, no interaction was found between BDNF genotype and the per cent methylation of BDNF exon I. However, methylation at this site was positively correlated with diurnal variation and retardation scores. Blood homocysteine concentrations were significantly reduced by sertraline treatment. No influence of genotype on serum BDNF concentration was found in subjects with depression. The ROC curve showed that methylation of BDNF exon I may be used to distinguish patients from healthy people, to a certain extent.

Conclusion

Methylation of BDNF exon I may be used as a biomarker of depression and may be a therapeutic target for previously untreated depression.

The combination of methylenehydrofolate reductase C677T polymorphism screening and gastrointestinal tumor markers detection may be an early screening method for gastrointestinal cancer related to helicobacter pylori infection

Methyltetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism, and its single nucleotide polymorphism (SNP) site C677T may be associated with gastrointestinal cancer. However, the relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers carcinoma embryonic antigen (CEA), carbohydrate antigen 199 (CA199) and carbohydrate antigen 724 (CA724) in Helicobacter pylori (H. pylori) infection is not specified. This study aims to identify the association between MTHFR C677T polymorphism and gastrointestinal tumor markers (CEA, CA199 and CA724) in H. pylori infection. The relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers in 58 patients with H. pylori infection and 94 non-infected patients was studied. We found that TT genotype was a susceptibility factor of H. pylori infection, which was also associated with increased CEA and CA724 levels. Moreover, there was a negative additive interaction between MTHFR gene C677T polymorphism and CEA levels in H.pylori infection. Meanwhile, there were significant differences in CEA levels between MTHFR C677T polymorphism and H.pylori infection. The presence of T allele led to a decrease in CEA levels when ¹³C urea breath test (¹³C-UBT) was positive, while the presence of T allele led to an increase in CEA levels when ¹³C-UBT was negative. Therefore, we suggest that healthy people should take MTHFR C677T polymorphism screening, combined with ¹³C-UBT and gastrointestinal tumor markers detection, which can screen out the susceptible population of H. pylori, and help to detect gastrointestinal cancer in the early stage.

A New Look on an Old Issue: Comprehensive Review of Neurotransmitter Studies in Cerebrospinal Fluid of Patients with Schizophrenia and Antipsychotic Effect on Monoamine's Metabolism

Neurotransmitters metabolism has a key role in the physiopathology of schizophrenia as demonstrated by studies measuring monoamine metabolites in patient’s cerebrospinal fluid (CSF) since the beginning of the antipsychotic use. This comprehensive review aims to understand the anomalies of CSF monoamines in schizophrenia and their correlation with clinical and paraclinical features. We also review the influence of antipsychotic treatment on CSF monoamines and discuss the connection with metabolic and inflammatory processes. Studies comparing CSF homovanillic acid (HVA) levels between patients and controls are miscellaneous, due to the heterogeneity of samples studies. However, low HVA is associated with more positive symptoms and a poorer outcome and negatively correlated with brain ventricle size. Based on humans and animals’ studies, antipsychotic treatments increase HVA during the first week of administration and decrease progressively over the time with a fall-off after withdrawal. 5‐hydroxyindolacetic acetic acid levels do not seem to be different in the patient’s CSF compared to controls. Considering metabolic co-factors of neurotrans-mitters synthesis, there is evidence supporting an increase of kynurenic acid in the CSF of patients with schizophrenia. Few studies explore folate metabolism in CSF. Literature also emphasizes the relationship between folate metabolism, inflammation and monoamine’s metabolism. Those results suggest that the CSF monoamines could be correlated with schizophrenia symptoms and treatment outcome. However, further studies, exploring the role of CSF monoamines as biomarkers of disease severity and response to treatment are needed. They should assess the antipsychotic prescription, inflammatory markers and folate metabolism as potential confounding factors.

Exploring the Role of Nutraceuticals in Major Depressive Disorder (MDD): Rationale, State of the Art and Future Prospects

Major depressive disorder (MDD) is a complex and common disorder, with many factors involved in its onset and development. The clinical management of this condition is frequently based on the use of some pharmacological antidepressant agents, together with psychotherapy and other alternatives in most severe cases. However, an important percentage of depressed patients fail to respond to the use of conventional therapies. This has created the urgency of finding novel approaches to help in the clinical management of those individuals. Nutraceuticals are natural compounds contained in food with proven benefits either in health promotion or disease prevention and therapy. A growing interest and economical sources are being placed in the development and understanding of multiple nutraceutical products. Here, we summarize some of the most relevant nutraceutical agents evaluated in preclinical and clinical models of depression. In addition, we will also explore less frequent but interest nutraceutical products which are starting to be tested, also evaluating future roads to cover in order to maximize the benefits of nutraceuticals in MDD.

Relationship between MTHFR gene polymorphism and susceptibility to bronchial asthma and glucocorticoid efficacy in children

OBJECTIVES

To study the association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism with susceptibility to bronchial asthma and glucocorticoid (GC) efficacy in children.

METHODS

A total of 173 children with bronchial asthma who were hospitalized between June 2018 and December 2020 were selected as the observation group. The children received aerosol inhalation of GC for three consecutive months. A total of 178 healthy children who underwent physical examination during the same period were selected as the control group. PCR was used to detect the genotypes of the MTHFR C677T for the two groups. The differences in genotype distribution between the two groups were analyzed. Children with different genotypes in the observation group were compared in terms of immunoglobulin E (IgE), interleukin-8 (IL-8), leukotriene B4 (LTB4), lung function, and clinical outcome before and after treatment.

RESULTS

TT genotype and T allele were significantly more frequent in the observation group than in the control group (P<0.001). TT/CT genotypes and T allele were independent risk factors for bronchial asthma (OR=6.615 and 7.055 respectively; P<0.001). After GC treatment, the children with CC, CT or TT genotypes experienced significantly decreased levels of IgE, IL-8, and LTB4 and significantly increased forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio (P<0.001). The children with TT genotype showed significantly lower levels of IL-8 and LTB4 than those with CC genotype, a significantly lower level of LTB4 than those with CT genotype, significantly higher FVC than those with CT genotype, and a significantly higher FEV1/FVC ratio than those with CC genotype (P<0.05). The children with TT genotype had better GC efficacy compared with those with CC genotype (P<0.05). TT genotype was an independent factor for good GC efficacy (OR=2.111, P=0.018).

CONCLUSIONS

MTHFR gene polymorphism is associated with asthma susceptibility and GC efficacy in children. Children carrying TT/CT genotypes have a higher risk of developing asthma, and those with TT genotype are more sensitive to GC treatment.

Genetics and Epigenetics of One-Carbon Metabolism Pathway in Autism Spectrum Disorder: A Sex-Specific Brain Epigenome?

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition affecting behavior and communication, presenting with extremely different clinical phenotypes and features. ASD etiology is composite and multifaceted with several causes and risk factors responsible for different individual disease pathophysiological processes and clinical phenotypes. From a genetic and epigenetic side, several candidate genes have been reported as potentially linked to ASD, which can be detected in about 10–25% of patients. Folate gene polymorphisms have been previously associated with other psychiatric and neurodegenerative diseases, mainly focused on gene variants in the DHFR gene (5q14.1; rs70991108, 19bp ins/del), MTHFR gene (1p36.22; rs1801133, C677T and rs1801131, A1298C), and CBS gene (21q22.3; rs876657421, 844ins68). Of note, their roles have been scarcely investigated from a sex/gender viewpoint, though ASD is characterized by a strong sex gap in onset-risk and progression. The aim of the present review is to point out the molecular mechanisms related to intracellular folate recycling affecting in turn remethylation and transsulfuration pathways having potential effects on ASD. Brain epigenome during fetal life necessarily reflects the sex-dependent different imprint of the genome-environment interactions which effects are difficult to decrypt. We here will focus on the DHFR, MTHFR and CBS gene-triad by dissecting their roles in a sex-oriented view, primarily to bring new perspectives in ASD epigenetics.

Mechanisms Underlying the Comorbidity of Schizophrenia and Type 2 Diabetes Mellitus

The mortality rate of patients with schizophrenia is high, and life expectancy is shorter by 10 to 20 years. Metabolic abnormalities including type 2 diabetes mellitus (T2DM) are among the main reasons. The prevalence of T2DM in patients with schizophrenia may be epidemiologically frequent because antipsychotics induce weight gain as a side effect and the cognitive dysfunction of patients with schizophrenia relates to a disordered lifestyle, poor diet, and low socioeconomic status. Apart from these common risk factors and risk factors unique to schizophrenia, accumulating evidence suggests the existence of common susceptibility genes between schizophrenia and T2DM. Functional proteins translated from common genetic susceptibility genes are known to regulate neuronal development in the brain and insulin in the pancreas through several common cascades. In this review, we discuss common susceptibility genes, functional cascades, and the relationship between schizophrenia and T2DM. Many genetic and epidemiological studies have reliably associated the comorbidity of schizophrenia and T2DM, and it is probably safe to think that common cascades and mechanisms suspected from common genes' functions are related to the onset of both schizophrenia and T2DM. On the other hand, even when genetic analyses are performed on a relatively large number of comorbid patients, the results are sometimes inconsistent, and susceptibility genes may carry only a low or moderate risk. We anticipate future directions in this field.

The Effects of Polymorphisms in One-carbon Metabolism Genes on Manifestation of Ichthyosis Vulgaris

BACKGROUND: Ichthyosis vulgaris is the most common type of Mendelian disorders of cornification, caused by loss-of-function mutations in the gene encoding epidermal protein filaggrin (FLG), namely R501X and 2282del4. FLG 2282del4 mutation in heterozygotes is incompletely penetrant. Polymorphisms in one-carbon metabolism genes could be associated with clinical manifestation of ichthyosis vulgaris. AIM: The purpose of the present study was to analyze the effects of MTHFR, MTR and MTRR polymorphisms in patients with ichthyosis vulgaris. METHODS: 31 patients with ichthyosis vulgaris, 7 their FLG heterozygous relatives without symptoms of disorder, and 150 healthy controls were enrolled in study. FLG null mutations —R501X (rs61816761) and 2282del4 (rs558269137) — and one-carbon metabolism gene polymorphisms — MTHFR C677T (rs1801133), MTHFR A1298C (rs1801131), MTR A2756G (rs1805087) and MTRR A66G (rs1801394) — were analyzed by a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. RESULTS: Among patients with ichthyosis, heterozygous for FLG 2282del4 mutation, the distributions of genotypes for folate metabolism genes were: MTHFR C677T CC:CT:TT —29.4%:70.6%:0.0%; MTHFR A1298C AA:AC:CC — 52.9%:47.1%:0.0%; MTR A2756G AA:AG:GG — 70.3%:23.5%:5.9%; MTRR A66G AA:AG:GG — 23.4%:52.9%:23.5%. The frequencies of MTR 2756AA and MTRR 66GG genotypes were 1.4–1.6 times higher in affected individuals heterozygous for 2282del4 than in patients with other FLG genotypes. In affected 2282del4 heterozygotes, the frequency of MTR 2756AA genotype was 1.6 times greater than in healthy controls (p<0.01). The strongest association was found between MTHFR 677CT/MTHFR 1298AA/MTR 2756AA/MTRR 66AG genotype and ichthyosis — OR=11.23 (95% CI 2.51−50.21, p=0.002). CONCLUSIONS: Various genotypes of one-carbon metabolism genes increase the risk of ichthyosis in heterozygotes for the FLG 2282del4 mutation (OR 2.799‑11.231). The most probable predisposing genotype is 677CT/1298AA/2756AA+AG/66AG.

Comparison of inflammatory, nutrient, and neurohormonal indicators in patients with schizophrenia, bipolar disorder and major depressive disorder

Psychiatric disorders are severe, debilitating conditions with unknown etiology and are commonly misdiagnosed, when based solely on clinical interviews, because of overlapping symptoms and similar familial patterns. Until now, no valid and objective biomarkers have been used to diagnose and differentiate between psychiatric disorders. We compared clinically tested serum indicators in terms of inflammation (C-reactive protein, complement proteins C3 and C4, and serum Immunoglobulins A, M, and G), nutrients (homocysteine, folate, and vitamin B12), and neurohormones (adrenocorticotropic hormone and cortisol) in patients with schizophrenia (SCZ, n = 1659), bipolar disorder (BD, n = 1901), and major depressive disorder (MDD, n = 1521) to investigate potential biomarkers. A receiver operating characteristic (ROC) curve was used to analyze the diagnostic potential of these analytes. We found that compared with MDD, serum levels of C-reactive protein, C3, C4, and homocysteine were higher in SCZ and BD groups, and folate and vitamin B12 were lower in SCZ and BD groups. In contrast with BD, adrenocorticotropic hormone and cortisol increased in patients with MDD. Although ROC analysis suggested that they were not able to effectively distinguish between the three, these biological indicators showed different patterns in the three disorders. As such, more specific biomarkers should be explored in the future.