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1.
Am J Hum Genet ; 108(7): 1283-1300, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34214447

RESUMO

Most rare clinical missense variants cannot currently be classified as pathogenic or benign. Deficiency in human 5,10-methylenetetrahydrofolate reductase (MTHFR), the most common inherited disorder of folate metabolism, is caused primarily by rare missense variants. Further complicating variant interpretation, variant impacts often depend on environment. An important example of this phenomenon is the MTHFR variant p.Ala222Val (c.665C>T), which is carried by half of all humans and has a phenotypic impact that depends on dietary folate. Here we describe the results of 98,336 variant functional-impact assays, covering nearly all possible MTHFR amino acid substitutions in four folinate environments, each in the presence and absence of p.Ala222Val. The resulting atlas of MTHFR variant effects reveals many complex dependencies on both folinate and p.Ala222Val. MTHFR atlas scores can distinguish pathogenic from benign variants and, among individuals with severe MTHFR deficiency, correlate with age of disease onset. Providing a powerful tool for understanding structure-function relationships, the atlas suggests a role for a disordered loop in retaining cofactor at the active site and identifies variants that enable escape of inhibition by S-adenosylmethionine. Thus, a model based on eight MTHFR variant effect maps illustrates how shifting landscapes of environment- and genetic-background-dependent missense variation can inform our clinical, structural, and functional understanding of MTHFR deficiency.


Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Mutação de Sentido Incorreto , Substituição de Aminoácidos , Análise Mutacional de DNA , Diploide , Biblioteca Gênica , Genótipo , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/fisiologia , Saccharomyces cerevisiae/genética
2.
Mol Nutr Food Res ; 65(14): e2100197, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34010503

RESUMO

SCOPE: Many pregnant women have higher folic acid (FA) intake due to food fortification and increased vitamin use. It is reported that diets containing five-fold higher FA than recommended for mice (5xFASD) during pregnancy resulted in methylenetetrahydrofolate reductase (MTHFR) deficiency and altered choline/methyl metabolism, with neurobehavioral abnormalities in newborns. The goal is to determine whether these changes have their origins in the placenta during embryonic development. METHODS AND RESULTS: Female mice are fed control diet or 5xFASD for a month before mating and maintained on these diets until embryonic day 17.5. 5xFASD led to pseudo-MTHFR deficiency in maternal liver and altered choline/methyl metabolites in maternal plasma (increased methyltetrahydrofolate and decreased betaine). Methylation potential (S-adenosylmethionine:S-adenosylhomocysteine ratio) and glycerophosphocholine are decreased in placenta and embryonic liver. Folic acid supplemented diet results in sex-specific transcriptome profiles in placenta, with validation of dietary expression changes of 29 genes involved in angiogenesis, receptor biology or neurodevelopment, and altered methylation of the serotonin receptor 2A gene. CONCLUSION: Moderate increases in folate intake during pregnancy result in placental metabolic and gene expression changes, particularly in angiogenesis, which may contribute to abnormal behavior in pups. These results are relevant for determining a safe upper limit for folate intake during pregnancy.

3.
J Nutr Biochem ; 88: 108554, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33220403

RESUMO

Food fortification with folic acid and increased use of vitamin supplements have raised concerns about high folic acid intake. We previously showed that high folic acid intake was associated with hepatic degeneration, decreased levels of methylenetetrahydrofolate reductase (MTHFR), lower methylation potential, and perturbations of lipid metabolism. MTHFR synthesizes the folate derivative for methylation reactions. In this study, we assessed the possibility that high folic acid diets, fed to wild-type and Mthfr+/- mice, could alter DNA methylation and/or deregulate hepatic cholesterol homeostasis. Digital restriction enzyme analysis of methylation in liver revealed DNA hypomethylation of a CpG in the lipolysis-stimulated lipoprotein receptor (Lsr) gene, which is involved in hepatic uptake of cholesterol. Pyrosequencing confirmed this methylation change and identified hypomethylation of several neighboring CpG dinucleotides. Lsr expression was increased and correlated negatively with DNA methylation and plasma cholesterol. A putative binding site for E2F1 was identified. ChIP-qPCR confirmed reduced E2F1 binding when methylation at this site was altered, suggesting that it could be involved in increasing Lsr expression. Expression of genes in cholesterol synthesis, transport or turnover (Abcg5, Abcg8, Abcc2, Cyp46a1, and Hmgcs1) was perturbed by high folic acid intake. We also observed increased hepatic cholesterol and increased expression of genes such as Sirt1, which might be involved in a rescue response to restore cholesterol homeostasis. Our work suggests that high folic acid consumption disturbs cholesterol homeostasis in liver. This finding may have particular relevance for MTHFR-deficient individuals, who represent ~10% of many populations.

4.
Nutrients ; 12(6)2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32521649

RESUMO

Fifteen to 20% of pregnant women may exceed the recommended intake of folic acid (FA) by more than four-fold. This excess could compromise neurocognitive and motor development in offspring. Here, we explored the impact of an FA-supplemented diet (5× FASD, containing five-fold higher FA than recommended) during pregnancy on brain function in murine offspring, and elucidated mechanistic changes. We placed female C57BL/6 mice for one month on control diets or 5× FASD before mating. Diets were maintained throughout pregnancy and lactation. Behavioural tests were conducted on 3-week-old pups. Pups and mothers were sacrificed at weaning. Brains and livers were collected to examine choline/methyl metabolites and immunoreactive methylenetetrahydrofolate reductase (MTHFR). 5× FASD led to hyperactivity-like behavior and memory impairment in 3-week-old pups of both sexes. Reduced MTHFR protein in the livers of FASD mothers and male pups resulted in choline/methyl metabolite disruptions in offspring liver (decreased betaine) and brain (decreased glycerophosphocholine and sphingomyelin in male pups, and decreased phosphatidylcholine in both sexes). These results indicate that moderate folate supplementation downregulates MTHFR and alters choline/methyl metabolism, contributing to neurobehavioral alterations. Our findings support the negative impact of high FA on brain development, and may lead to improved guidelines on optimal folate levels during pregnancy.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Ácido Fólico/efeitos adversos , Fígado/metabolismo , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Recomendações Nutricionais , Caracteres Sexuais , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Troca Materno-Fetal , Transtornos da Memória/induzido quimicamente , Camundongos Endogâmicos C57BL , Fosfatidilcolinas/metabolismo , Gravidez , Esfingomielinas/metabolismo
5.
Mol Neurobiol ; 56(6): 4175-4191, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30288696

RESUMO

Folate is an important B vitamin required for methylation reactions, nucleotide and neurotransmitter synthesis, and maintenance of homocysteine at nontoxic levels. Its metabolism is tightly linked to that of choline, a precursor to acetylcholine and membrane phospholipids. Low folate intake and genetic variants in folate metabolism, such as the methylenetetrahydrofolate reductase (MTHFR) 677 C>T polymorphism, have been suggested to impact brain function and increase the risk for cognitive decline and late-onset Alzheimer's disease. Our study aimed to assess the impact of genetic and nutritional disturbances in folate metabolism, and their potential interaction, on features of cognitive decline and brain biochemistry in a mouse model. Wild-type and Mthfr+/- mice, a model for the MTHFR 677 C>T polymorphism, were fed control or folate-deficient diets from weaning until 8 and 10 months of age. We observed short-term memory impairment measured by the novel object paradigm, altered transcriptional levels of synaptic markers and epigenetic enzymes, as well as impaired choline metabolism due to the Mthfr+/- genotype in cortex or hippocampus. We also detected changes in mRNA levels of Presenillin-1, neurotrophic factors, one-carbon metabolic and epigenetic enzymes, as well as reduced levels of S-adenosylmethionine and acetylcholine, due to the folate-deficient diet. These findings shed further insights into the mechanisms by which genetic and dietary folate metabolic disturbances increase the risk for cognitive decline and suggest that these mechanisms are distinct.


Assuntos
Envelhecimento/patologia , Encéfalo/patologia , Dieta , Ácido Fólico/metabolismo , Homocistinúria/complicações , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/complicações , Peptídeos beta-Amiloides/metabolismo , Animais , Ansiedade/complicações , Ansiedade/fisiopatologia , Encéfalo/fisiopatologia , Sobrevivência Celular , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Colina/metabolismo , Ilhas de CpG/genética , Metilação de DNA/genética , Epigênese Genética , Ácido Glutâmico/metabolismo , Homocistinúria/fisiopatologia , Fígado/metabolismo , Masculino , Transtornos da Memória/complicações , Transtornos da Memória/fisiopatologia , Memória de Curto Prazo , Metilação , Camundongos Endogâmicos BALB C , Espasticidade Muscular/fisiopatologia , Fatores de Crescimento Neural/metabolismo , Neurônios/patologia , Fosfolipídeos/metabolismo , Transtornos Psicóticos/complicações , Transtornos Psicóticos/fisiopatologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , S-Adenosilmetionina/metabolismo , Transmissão Sináptica
6.
Mol Nutr Food Res ; 63(3): e1801001, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30408316

RESUMO

SCOPE: Dietary and genetic folate disturbances can lead to nonalcoholic fatty liver disease (NAFLD). A common variant in methylenetetrahydrofolate reductase (MTHFR 677C→T) causes mild MTHFR deficiency with lower 5-methyltetrahydrofolate for methylation reactions. The goal is to determine whether mild murine MTHFR deficiency contributes to NAFLD-related effects. METHODS AND RESULTS: Wild-type and Mthfr+/- mice, a model for the human variant, are fed control (CD) or high-fat (HFAT) diets for 8 weeks. On both diets, MTHFR deficiency results in decreased S-adenosylmethionine, increased S-adenosylhomocysteine, and decreased betaine with reduced methylation capacity, and changes in expression of several inflammatory or anti-inflammatory mediators (Saa1, Apoa1, and Pon1). On CD, MTHFR deficiency leads to microvesicular steatosis with expression changes in lipid regulators Xbp1s and Cyp7a1. The combination of MTHFR deficiency and HFAT exacerbates changes in inflammatory mediators and introduces additional effects on inflammation (Saa2) and lipid metabolism (Nr1h4, Srebf1c, Ppara, and Crot). These effects are consistent with increased expression of pro-inflammatory HDL precursors and greater lipid accumulation. MTHFR deficiency may enhance liver injury through alterations in methylation capacity, inflammatory response, and lipid metabolism. CONCLUSION: Individuals with the MTHFR variant may be at increased risk for liver disease and related complications, particularly when consuming high-fat diets.


Assuntos
Homocistinúria/metabolismo , Inflamação/etiologia , Metabolismo dos Lipídeos , Fígado/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/metabolismo , Tecido Adiposo/metabolismo , Animais , Glicemia/análise , Fígado Gorduroso/etiologia , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , Transtornos Psicóticos/metabolismo
7.
J Nutr ; 148(4): 501-509, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659962

RESUMO

Background: Suboptimal folate intake, a risk factor for birth defects, is common even in areas with folate fortification. A polymorphism in methylenetetrahydrofolate dehydrogenase 1 (MTHFD1), R653Q (MTHFD1 c.1958 G > A), has also been associated with increased birth defect risk, likely through reduced purine synthesis. Objective: We aimed to determine if the interaction of MTHFD1 synthetase deficiency and low folate intake increases developmental abnormalities in a mouse model for MTHFD1 R653Q. Methods: Female Mthfd1S+/+ and Mthfd1S+/- mice were fed control or low-folate diets (2 and 0.3 mg folic acid/kg diet, respectively) before mating and during pregnancy. Embryos and placentas were examined for anomalies at embryonic day 10.5. Maternal 1-carbon metabolites were measured in plasma and liver. Results: Delays and defects doubled in litters of Mthfd1S+/- females fed low-folate diets compared to wild-type females fed either diet, or Mthfd1S+/- females fed control diets [P values (defects): diet 0.003, maternal genotype 0.012, diet × maternal genotype 0.014]. These adverse outcomes were associated with placental dysmorphology. Intrauterine growth restriction was increased by embryonic Mthfd1S+/- genotype, folate deficiency, and interaction of maternal Mthfd1S+/- genotype with folate deficiency (P values: embryonic genotype 0.045, diet 0.0081, diet × maternal genotype 0.0019). Despite a 50% increase in methylenetetrahydrofolate reductase expression in low-folate maternal liver (P diet = 0.0007), methyltetrahydrofolate concentration decreased 70% (P diet <0.0001) and homocysteine concentration doubled in plasma (P diet = 0.0001); S-adenosylmethionine decreased 40% and S-adenosylhomocysteine increased 20% in low-folate maternal liver (P diet = 0.002 and 0.0002, respectively). Conclusions: MTHFD1 synthetase-deficient mice are more sensitive to low folate intake than wild-type mice during pregnancy. Reduced purine synthesis due to synthetase deficiency and altered methylation potential due to low folate may increase pregnancy complications. Further studies and individualized intake recommendations may be required for women homozygous for the MTHFD1 R653Q variant.


Assuntos
Anormalidades Congênitas/etiologia , Deficiência de Ácido Fólico/complicações , Ácido Fólico/administração & dosagem , Formiato-Tetra-Hidrofolato Ligase/deficiência , Genótipo , Meteniltetra-Hidrofolato Cicloidrolase/deficiência , Metilenotetra-Hidrofolato Desidrogenase (NADP)/deficiência , Enzimas Multifuncionais/deficiência , Polimorfismo Genético , Complicações na Gravidez/etiologia , Animais , Metilação de DNA , Dieta , Modelos Animais de Doenças , Feminino , Desenvolvimento Fetal , Retardo do Crescimento Fetal/etiologia , Ácido Fólico/sangue , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/genética , Deficiência de Ácido Fólico/metabolismo , Formiato-Tetra-Hidrofolato Ligase/genética , Formiato-Tetra-Hidrofolato Ligase/metabolismo , Ligases , Fígado/metabolismo , Meteniltetra-Hidrofolato Cicloidrolase/genética , Meteniltetra-Hidrofolato Cicloidrolase/metabolismo , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Enzimas Multifuncionais/genética , Enzimas Multifuncionais/metabolismo , Placenta , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/genética , Complicações na Gravidez/metabolismo , Prenhez , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Tetra-Hidrofolatos/sangue
8.
Hum Mol Genet ; 27(7): 1123-1135, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29360980

RESUMO

Supplementation with high doses of folic acid, an important mediator of one-carbon transfers for DNA methylation, is used clinically to improve sperm parameters in infertile men. We recently detected an unexpected loss of DNA methylation in the sperm of idiopathic infertile men after 6 months of daily supplementation with 5 mg folic acid (>10× the daily recommended intake-DRI), exacerbated in men homozygous for a common variant in the gene encoding an important enzyme in folate metabolism, methylenetetrahydrofolate reductase (MTHFR 677C>T). To investigate the epigenomic impact and mechanism underlying effects of folic acid on male germ cells, wild-type and heterozygote mice for a targeted inactivation of the Mthfr gene were fed high-dose folic acid (10× the DRI) or control diets (CDs) for 6 months. No changes were detected in general health, sperm counts or methylation of imprinted genes. Reduced representation bisulfite sequencing revealed sperm DNA hypomethylation in Mthfr+/- mice on the 10× diets. Wild-type mice demonstrated sperm hypomethylation only with a very high dose (20×) of folic acid for 12 months. Testicular MTHFR protein levels decreased significantly in wild-type mice on the 20× diet but not in those on the 10× diet, suggesting a possible role for MTHFR deficiency in sperm DNA hypomethylation. In-depth analysis of the folic acid-exposed sperm DNA methylome suggested mouse/human susceptibility of sequences with potential importance to germ cell and embryo development. Our data provide evidence for a similar cross-species response to high dose folic acid supplementation, of sperm DNA hypomethylation, and implicate MTHFR downregulation as a possible mechanism.


Assuntos
Metilação de DNA/efeitos dos fármacos , DNA/metabolismo , Ácido Fólico/farmacologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espermatozoides/metabolismo , Testículo/metabolismo , Animais , DNA/genética , Metilação de DNA/genética , Masculino , Camundongos , Camundongos Knockout , Espermatozoides/citologia , Testículo/citologia
9.
Hum Mol Genet ; 26(5): 888-900, 2017 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-28069796

RESUMO

Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid.


Assuntos
Ácido Fólico/efeitos adversos , Homocistinúria/genética , Memória de Curto Prazo/efeitos dos fármacos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/genética , Acetilcolina/genética , Acetilcolina/metabolismo , Animais , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Dieta/efeitos adversos , Feminino , Ácido Fólico/administração & dosagem , Homocistinúria/induzido quimicamente , Homocistinúria/patologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/fisiopatologia , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Camundongos , Espasticidade Muscular/induzido quimicamente , Espasticidade Muscular/patologia , Gravidez , Transtornos Psicóticos/genética , Transtornos Psicóticos/patologia
10.
Mol Carcinog ; 56(3): 1030-1040, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27597531

RESUMO

The common R653Q variant (∼20% homozygosity in Caucasians) in the synthetase domain of the folate-metabolizing enzyme MTHFD1 reduces purine synthesis. Although this variant does not appear to affect risk for colorectal cancer, we questioned whether it would affect growth of colorectal tumors. We induced tumor formation in a mouse model for MTHFD1-synthetase deficiency (Mthfd1S+/- ) using combined administration of azoxymethane (AOM) and dextran sodium sulfate (DSS) in male and female wild-type and Mthfd1S+/- mice. Tumor size was significantly smaller in MthfdS+/- mice, particularly in males. A reduction in the proliferation of MthfdS+/- mouse embryonic fibroblast cell lines, compared with wild-type lines, was also observed. Tumor number was not influenced by genotype. The amount of inflammation observed within tumors from male Mthfd1S+/- mice was lower than that in wild-type mice. Gene expression analysis in tumor adjacent normal (pre-neoplastic) tissue identified several genes involved in proliferation (Fosb, Fos, Ptk6, Esr2, Atf3) and inflammation (Atf3, Saa1, TNF-α) that were downregulated in MthfdS+/- males. In females, MthfdS+/- genotype was not associated with these gene expression changes, or with differences in tumor inflammation. These findings suggest that the mechanisms directing tumor growth differ significantly between males and females. We suggest that restriction of purine synthesis, reduced expression of genes involved in proliferation, and/or reduced inflammation lead to slower tumor growth in MTHFD1-synthetase deficiency. These findings may have implications for CRC tumor growth and prognosis in individuals with the R653Q variant. © 2016 Wiley Periodicals, Inc.


Assuntos
Aminoidrolases/deficiência , Neoplasias Colorretais/patologia , Formiato-Tetra-Hidrofolato Ligase/deficiência , Meteniltetra-Hidrofolato Cicloidrolase/deficiência , Metilenotetra-Hidrofolato Desidrogenase (NADP)/deficiência , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Antígenos de Histocompatibilidade Menor/genética , Complexos Multienzimáticos/deficiência , Enzimas Multifuncionais/deficiência , Polimorfismo de Nucleotídeo Único , Animais , Azoximetano/efeitos adversos , Proliferação de Células , Células Cultivadas , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/genética , Sulfato de Dextrana/efeitos adversos , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos
11.
Am J Clin Nutr ; 104(5): 1459-1469, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27707701

RESUMO

BACKGROUND: Moderately high folic acid intake in pregnant women has led to concerns about deleterious effects on the mother and fetus. Common polymorphisms in folate genes, such as methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase (MTHFD1) R653Q, may modulate the effects of elevated folic acid intake. OBJECTIVES: We investigated the effects of moderate folic acid supplementation on reproductive outcomes and assessed the potential interaction of the supplemented diet with MTHFD1-synthetase (Mthfd1S) deficiency in mice, which is a model for the R653Q variant. DESIGN: Female Mthfd1S+/+ and Mthfd1S+/- mice were fed a folic acid-supplemented diet (FASD) (5-fold higher than recommended) or control diets before mating and during pregnancy. Embryos and placentas were assessed for developmental defects at embryonic day 10.5 (E10.5). Maternal folate and choline metabolites and gene expression in folate-related pathways were examined. RESULTS: The combination of FASD and maternal MTHFD1-synthetase deficiency led to a greater incidence of defects in E10.5 embryos (diet × maternal genotype, P = 0.0016; diet × embryonic genotype, P = 0.054). The methylenetetrahydrofolate reductase (MTHFR) protein and methylation potential [ratio of S-adenosylmethionine (major methyl donor):S-adenosylhomocysteine) were reduced in maternal liver. Although 5-methyltetrahydrofolate (methylTHF) was higher in maternal circulation, the methylation potential was lower in embryos. The presence of developmental delays and defects in Mthfd1S+/- embryos was associated with placental defects (P = 0.003). The labyrinth layer failed to form properly in the majority of abnormal placentas, which compromised the integration of the maternal and fetal circulation and presumably the transfer of methylTHF and other nutrients. CONCLUSIONS: Moderately higher folate intake and MTHFD1-synthetase deficiency in pregnant mice result in a lower methylation potential in maternal liver and embryos and a greater incidence of defects in embryos. Although maternal circulating methylTHF was higher, it may not have reached the embryos because of abnormal placental development; abnormal placentas were observed predominantly in abnormally developed embryos. These findings have implications for women with high folate intakes, particularly if they are polymorphic for MTHFD1 R653Q.


Assuntos
Aminoidrolases/deficiência , Aminoidrolases/genética , Ácido Fólico/farmacologia , Formiato-Tetra-Hidrofolato Ligase/deficiência , Formiato-Tetra-Hidrofolato Ligase/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/deficiência , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Complexos Multienzimáticos/deficiência , Complexos Multienzimáticos/genética , Placenta/anormalidades , Placenta/enzimologia , Polimorfismo de Nucleotídeo Único , Aminoidrolases/metabolismo , Animais , Colina/farmacologia , Suplementos Nutricionais , Embrião de Mamíferos/enzimologia , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Formiato-Tetra-Hidrofolato Ligase/metabolismo , Modelos Logísticos , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Transgênicos , Complexos Multienzimáticos/metabolismo , Gravidez , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo
12.
Mamm Genome ; 27(3-4): 122-34, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26951114

RESUMO

Polymorphisms and decreased activity of methylenetetrahydrofolate reductase (MTHFR) are linked to disease, including cancer. However, epigenetic regulation has not been thoroughly studied. Our goal was to generate DNA methylation profiles of murine/human MTHFR gene regions and examine methylation in brain and liver tumors. Pyrosequencing in four murine tissues revealed minimal DNA methylation in the CpG island. Higher methylation was seen in liver or intestine in the CpG island shore 5' to the upstream translational start site or in another region 3' to the downstream start site. In the latter region, there was negative correlation between expression and methylation. Three orthologous regions were investigated in human MTHFR, as well as a fourth region between the two translation start sites. We found significantly increased methylation in three regions (not the CpG island) in pediatric astrocytomas compared with control brain, with decreased expression in tumors. Methylation in hepatic carcinomas was also increased in the three regions compared with normal liver, but the difference was significant for only one CpG. This work, the first overview of the Mthfr/MTHFR epigenetic landscape, suggests regulation through methylation in some regions, demonstrates increased methylation/decreased expression in pediatric astrocytomas, and should serve as a resource for future epigenetic studies.


Assuntos
Neoplasias Encefálicas/etiologia , Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica , Metilação de DNA , Dieta , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Animais , Sequência de Bases , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/genética , Ilhas de CpG , Modelos Animais de Doenças , Epigênese Genética , Feminino , Expressão Gênica , Loci Gênicos , Humanos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Baço/metabolismo
13.
Exp Eye Res ; 145: 164-172, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-26646559

RESUMO

Mutations in crumb homologue 1 (CRB1) in humans are associated with Leber's congenital amaurosis (LCA) and retinitis pigmentosa (RP). There is no clear genotype-phenotype correlation for human CRB1 mutations in RP and LCA. The high variability in clinical features observed in CRB1 mutations suggests that environmental factors or genetic modifiers influence severity of CRB1 related retinopathies. Retinal degeneration 8 (rd8) is a spontaneous mutation in the Crb1 gene (Crb1(rdr/rd8)). Crb1(rdr/rd8) mice present with focal disruption in the outer retina manifesting as white spots on fundus examination. Mild retinal dysfunction with decreased b-wave amplitude has been reported in Crb1(rdr/rd8) mice at 18 months. Methylene tetrahydrofolate reductase (MTHFR) is a crucial enzyme of homocysteine metabolism. MTHFR mutations are prevalent in humans and are linked to a broad spectrum of disorders including cardiovascular and neurodegenerative diseases. We recently reported the retinal phenotype in Mthfr-deficient (Mthfr(+/-)) heterozygous mice. At 24 weeks the mice showed decreased RGC function, thinner nerve fiber layer, focal areas of vascular leakage and 20% fewer cells in the ganglion cell layer (GCL). Considering the variability in CRB1-related retinopathies and the high occurrence of human MTHFR mutations we evaluated whether Mthfr deficiency influences rd8 retinal phenotype. Mthfr heterozygous mice with rd8 mutations (Mthfr(+/-)(rd8/rd8)) and Crb(rd8/rd8) mice (Mthfr(+/+rd8/rd8)) mice were subjected to comprehensive retinal evaluation using ERG, fundoscopy, fluorescein angiography (FA), morphometric and retinal flat mount immunostaining analyses of isolectin-B4 at 8-54 wks. Assessment of retinal function revealed a significant decrease in the a-, b- and c-wave amplitudes in Mthfr(+/-)(rd8/rd8) mice at 52 wks. Fundoscopic evaluation demonstrated the presence of signature rd8 spots in Mthfr(+/+rd8/rd8) mice and an increase in the extent of these rd8 spots in Mthfr(+/-)(rd8/rd8) mice at 24 weeks and beyond. FA revealed marked vascular leakage, ischemia and vascular tortuosity in Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal dysplasia was observed in ∼14-33% Mthfr(+/-)(rd8/rd8) mice by morphometric analysis. This was accompanied by a ∼20% reduction in cells of the GCL of Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal flat mount immunostaining with isolectin-B4 showed neovascularization and loss of blood vessel integrity in Mthfr(+/-)(rd8/rd8) mice in contrast to mild vasculopathy in Mthfr(+/+rd8/rd8) mice. Taken together, our data support an earlier onset and worsened retinal phenotype when Mthfr and rd8 mutations coexist. Our study sets the stage for future studies to investigate the role of MTHFR deficiency in human CRB1 retinopathies.


Assuntos
Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Proteínas do Tecido Nervoso/genética , Retina/metabolismo , Degeneração Retiniana/metabolismo , Células Ganglionares da Retina/metabolismo , Animais , DNA/genética , Análise Mutacional de DNA , Modelos Animais de Doenças , Angiofluoresceinografia , Fundo de Olho , Estudos de Associação Genética , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Proteínas do Tecido Nervoso/metabolismo , Fenótipo , Retina/patologia , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Células Ganglionares da Retina/patologia
14.
PLoS One ; 10(11): e0143738, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26599510

RESUMO

Malaria is a significant global health issue, with nearly 200 million cases in 2013 alone. Parasites obtain folate from the host or synthesize it de novo. Folate consumption has increased in many populations, prompting concerns regarding potential deleterious consequences of higher intake. The impact of high dietary folate on the host's immune function and response to malaria has not been examined. Our goal was to determine whether high dietary folate would affect response to malarial infection in a murine model of cerebral malaria. Mice were fed control diets (CD, recommended folate level for rodents) or folic acid-supplemented diets (FASD, 10x recommended level) for 5 weeks before infection with Plasmodium berghei ANKA. Survival, parasitemia, numbers of immune cells and other infection parameters were assessed. FASD mice had reduced survival (p<0.01, Cox proportional hazards) and higher parasitemia (p< 0.01, joint model of parasitemia and survival) compared with CD mice. FASD mice had lower numbers of splenocytes, total T cells, and lower numbers of specific T and NK cell sub-populations, compared with CD mice (p<0.05, linear mixed effects). Increased brain TNFα immunoreactive protein (p<0.01, t-test) and increased liver Abca1 mRNA (p<0.01, t-test), a modulator of TNFα, were observed in FASD mice; these variables correlated positively (rs = 0.63, p = 0.01). Bcl-xl/Bak mRNA was increased in liver of FASD mice (p<0.01, t-test), suggesting reduced apoptotic potential. We conclude that high dietary folate increases parasite replication, disturbs the immune response and reduces resistance to malaria in mice. These findings have relevance for malaria-endemic regions, when considering anti-folate anti-malarials, food fortification or vitamin supplementation programs.


Assuntos
Antimaláricos/uso terapêutico , Ácido Fólico/efeitos adversos , Malária/tratamento farmacológico , Plasmodium berghei/patogenicidade , Animais , Malária Cerebral/tratamento farmacológico , Camundongos , Parasitemia/tratamento farmacológico , Plasmodium berghei/efeitos dos fármacos , Modelos de Riscos Proporcionais , Linfócitos T/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
15.
Birth Defects Res A Clin Mol Teratol ; 103(12): 1031-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26408344

RESUMO

BACKGROUND: A single nucleotide polymorphism (SNP) in the synthetase domain of the trifunctional folate-dependent enzyme MTHFD1 (c.1958G>A, R653Q) has been linked to adverse pregnancy outcomes, neural tube defects, and possibly congenital heart defects. Maternal folate deficiency may also modify the risk associated with these disorders. We recently established a mouse model with a mild deficiency of 10-formyltetrahydrofolate synthetase activity in MTHFD1 (Mthfd1S(+/-) mice) to investigate disorders associated with SNPs in this gene. The effect of synthetase deficiency on embryonic heart development has not yet been examined. METHODS: Female Mthfd1S(+/+) and (+/-) mice were placed on control and folate-deficient diets for 6 weeks before mating to Mthfd1S(+/-) males. Embryos and placentae were collected at embryonic day 14.5. Embryos were evaluated for congenital heart defects by histological examination. RESULTS: Embryonic Mthfd1S(+/-) genotype was associated with an increased incidence of heart defects, primarily ventricular septal defects. Other markers of embryonic development (crown-rump length, embryonic weight, embryonic delay, placental weight, and thickness of the ventricular myocardium) were not affected by embryonic genotype. Maternal genotype and diet did not have a significant effect on these outcomes. CONCLUSION: Deficiency of the MTHFD1 10-formyltetrahydrofolate synthetase activity in embryos is associated with increased incidence of congenital heart defects.


Assuntos
Aminoidrolases/genética , Modelos Animais de Doenças , Formiato-Tetra-Hidrofolato Ligase/genética , Cardiopatias Congênitas/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Complexos Multienzimáticos/genética , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout
16.
Cell Metab ; 21(6): 905-17, 2015 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-26039453

RESUMO

Heritable epigenetic factors can contribute to complex disease etiology. Here we examine the contribution of DNA methylation to complex traits that are precursors to heart disease, diabetes, and osteoporosis. We profiled DNA methylation in the liver using bisulfite sequencing in 90 mouse inbred strains, genome-wide expression levels, proteomics, metabolomics, and 68 clinical traits and performed epigenome-wide association studies (EWAS). We found associations with numerous clinical traits including bone density, insulin resistance, expression, and protein and metabolite levels. A large proportion of associations were unique to EWAS and were not identified using GWAS. Methylation levels were regulated by genetics largely in cis, but we also found evidence of trans regulation, and we demonstrate that genetic variation in the methionine synthase reductase gene Mtrr affects methylation of hundreds of CpGs throughout the genome. Our results indicate that natural variation in methylation levels contributes to the etiology of complex clinical traits.


Assuntos
Ilhas de CpG/fisiologia , Metilação de DNA/fisiologia , Epigenômica , Fígado/metabolismo , Locos de Características Quantitativas/fisiologia , Animais , Estudo de Associação Genômica Ampla , Camundongos , Especificidade da Espécie
17.
Invest Ophthalmol Vis Sci ; 56(4): 2684-95, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25766590

RESUMO

PURPOSE: Methylenetetrahydrofolate reductase (Mthfr) is a key enzyme in homocysteine-methionine metabolism. We investigated Mthfr expression in retina and asked whether mild hyperhomocysteinemia, due to Mthfr deficiency, alters retinal neurovascular structure and function. METHODS: Expression of Mthfr was investigated at the gene and protein level using quantitative (q) RT-PCR, in situ hybridization, immunoblotting, and immunohistochemistry (IHC). The Mthfr+/+ and Mthfr+/- mice were subjected to comprehensive evaluation using ERG, funduscopy, fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), HPLC, and morphometric and IHC analysis of glial fibrillary acidic protein (GFAP) at 8 to 24 weeks. RESULTS: Gene and protein analyses disclosed widespread retinal expression of Mthfr. Electroretinography (ERG) revealed a significant decrease in positive scotopic threshold response in retinas of Mthfr+/- mice at 24 weeks. Fundus examination in mice from both groups was normal; FA revealed areas of focal vascular leakage in 20% of Mthfr+/- mice at 12 to 16 weeks and 60% by 24 weeks. The SD-OCT revealed a significant decrease in nerve fiber layer (NFL) thickness at 24 weeks in Mthfr+/- compared to Mthfr+/+ mice. There was a 2-fold elevation in retinal hcy at 24 weeks in Mthfr+/- mice by HPLC and IHC. Morphometric analysis revealed an approximately 20% reduction in cells in the ganglion cell layer of Mthfr+/- mice at 24 weeks. The IHC indicated significantly increased GFAP labeling suggestive of Müller cell activation. CONCLUSIONS: Mildly hyperhomocysteinemic Mthfr+/- mice demonstrate reduced ganglion cell function, thinner NFL, and mild vasculopathy by 24 weeks. The retinal phenotype is similar to that of hyperhomocysteinemic mice with deficiency of cystathionine-ß-synthase (Cbs) reported earlier. The data support the hypothesis that hyperhomocysteinemia may be causative in certain retinal neurovasculopathies.


Assuntos
DNA/genética , Regulação da Expressão Gênica , Homocistinúria/patologia , Hiper-Homocisteinemia/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Espasticidade Muscular/patologia , Células Ganglionares da Retina/patologia , Animais , Modelos Animais de Doenças , Eletrorretinografia , Angiofluoresceinografia , Fundo de Olho , Homocistinúria/genética , Homocistinúria/metabolismo , Hiper-Homocisteinemia/genética , Hiper-Homocisteinemia/metabolismo , Immunoblotting , Imuno-Histoquímica , Metilenotetra-Hidrofolato Redutase (NADPH2)/biossíntese , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Transgênicos , Espasticidade Muscular/genética , Espasticidade Muscular/metabolismo , Transtornos Psicóticos/genética , Transtornos Psicóticos/metabolismo , Transtornos Psicóticos/patologia , Reação em Cadeia da Polimerase em Tempo Real , Tomografia de Coerência Óptica
18.
Am J Clin Nutr ; 101(3): 646-58, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25733650

RESUMO

BACKGROUND: Increased consumption of folic acid is prevalent, leading to concerns about negative consequences. The effects of folic acid on the liver, the primary organ for folate metabolism, are largely unknown. Methylenetetrahydrofolate reductase (MTHFR) provides methyl donors for S-adenosylmethionine (SAM) synthesis and methylation reactions. OBJECTIVE: Our goal was to investigate the impact of high folic acid intake on liver disease and methyl metabolism. DESIGN: Folic acid-supplemented diet (FASD, 10-fold higher than recommended) and control diet were fed to male Mthfr(+/+) and Mthfr(+/-) mice for 6 mo to assess gene-nutrient interactions. Liver pathology, folate and choline metabolites, and gene expression in folate and lipid pathways were examined. RESULTS: Liver and spleen weights were higher and hematologic profiles were altered in FASD-fed mice. Liver histology revealed unusually large, degenerating cells in FASD Mthfr(+/-) mice, consistent with nonalcoholic fatty liver disease. High folic acid inhibited MTHFR activity in vitro, and MTHFR protein was reduced in FASD-fed mice. 5-Methyltetrahydrofolate, SAM, and SAM/S-adenosylhomocysteine ratios were lower in FASD and Mthfr(+/-) livers. Choline metabolites, including phosphatidylcholine, were reduced due to genotype and/or diet in an attempt to restore methylation capacity through choline/betaine-dependent SAM synthesis. Expression changes in genes of one-carbon and lipid metabolism were particularly significant in FASD Mthfr(+/-) mice. The latter changes, which included higher nuclear sterol regulatory element-binding protein 1, higher Srepb2 messenger RNA (mRNA), lower farnesoid X receptor (Nr1h4) mRNA, and lower Cyp7a1 mRNA, would lead to greater lipogenesis and reduced cholesterol catabolism into bile. CONCLUSIONS: We suggest that high folic acid consumption reduces MTHFR protein and activity levels, creating a pseudo-MTHFR deficiency. This deficiency results in hepatocyte degeneration, suggesting a 2-hit mechanism whereby mutant hepatocytes cannot accommodate the lipid disturbances and altered membrane integrity arising from changes in phospholipid/lipid metabolism. These preliminary findings may have clinical implications for individuals consuming high-dose folic acid supplements, particularly those who are MTHFR deficient.


Assuntos
Suplementos Nutricionais/envenenamento , Inibidores Enzimáticos/envenenamento , Ácido Fólico/envenenamento , Homocistinúria/etiologia , Metabolismo dos Lipídeos , Fígado/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/etiologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Animais , Regulação da Expressão Gênica , Heterozigoto , Homocistinúria/metabolismo , Homocistinúria/patologia , Homocistinúria/fisiopatologia , Lipogênese , Fígado/patologia , Fígado/fisiopatologia , Masculino , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/antagonistas & inibidores , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Mutantes , Espasticidade Muscular/metabolismo , Espasticidade Muscular/patologia , Espasticidade Muscular/fisiopatologia , Mutação , Tamanho do Órgão , Transtornos Psicóticos/etiologia , Transtornos Psicóticos/metabolismo , Transtornos Psicóticos/patologia , Transtornos Psicóticos/fisiopatologia , Organismos Livres de Patógenos Específicos
19.
Proteomics ; 14(21-22): 2558-65, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25081070

RESUMO

Colorectal cancer risk is increased when dietary folate intake is low, with or without a deficiency in methylenetetrahydrofolate reductase (MTHFR). We have observed that intestinal tumors are induced in mice fed low-folate diets, and that tumor incidence is increased when these mice also have MTHFR deficiency. This study was undertaken to identify differentially expressed proteins in conditions favoring initial steps of murine carcinogenesis in normal preneoplastic intestine. We compared the proteome of BALB/c normal intestine in Mthfr(+/+) mice fed control diets for 1 year (low susceptibility to tumorigenesis) with the proteome of Mthfr(+/-) animals fed low folate diets (higher tumor susceptibility). Our data suggest that the NuRD complex, KRAS-related proteins, the protein synthetic machinery, and fatty acid-related metabolic proteins are upregulated in the early stages of tumorigenesis. These proteins may serve as biomarkers or targets for colorectal cancer diagnosis or therapy.


Assuntos
Carcinogênese/metabolismo , Ácido Fólico/metabolismo , Homocistinúria/complicações , Neoplasias Intestinais/etiologia , Neoplasias Intestinais/metabolismo , Intestinos/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/complicações , Proteoma/metabolismo , Animais , Carcinogênese/patologia , Dieta , Modelos Animais de Doenças , Feminino , Mucosa Intestinal/metabolismo , Neoplasias Intestinais/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteômica , Transtornos Psicóticos/complicações
20.
JAMA Neurol ; 71(7): 901-4, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24797679

RESUMO

IMPORTANCE: Hereditary spastic paraplegia is a highly heterogeneous group of neurogenetic disorders with pure and complicated clinical phenotypes. No treatment is available for these disorders. We identified 2 unrelated families, each with 2 siblings with severe methylenetetrahydrofolate reductase (MTHFR) deficiency manifesting a complicated form of adult-onset hereditary spastic paraparesis partially responsive to betaine therapy. OBSERVATIONS: Both pairs of siblings presented with a similar combination of progressive spastic paraparesis and polyneuropathy, variably associated with behavioral changes, cognitive impairment, psychosis, seizures, and leukoencephalopathy, beginning between the ages of 29 and 50 years. By the time of diagnosis a decade later, 3 patients were ambulatory and 1 was bedridden. Investigations have revealed severe hyperhomocysteinemia and hypomethioninemia, reduced fibroblast MTHFR enzymatic activity (18%-52% of control participants), and 3 novel pathogenic MTHFR mutations, 2 as compound heterozygotes in one family and 1 as a homozygous mutation in the other family. Treatment with betaine produced a rapid decline of homocysteine by 50% to 70% in all 4 patients and, over 9 to 15 years, improved the conditions of the 3 ambulatory patients. CONCLUSIONS AND RELEVANCE: Although severe MTHFR deficiency is a rare cause of complicated spastic paraparesis in adults, it should be considered in select patients because of the potential therapeutic benefit of betaine supplementation.


Assuntos
Betaína/farmacologia , Homocistinúria/genética , Lipotrópicos/farmacologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/genética , Índice de Gravidade de Doença , Paraplegia Espástica Hereditária/etiologia , Paraplegia Espástica Hereditária/genética , Adulto , Idade de Início , Idoso , Feminino , Homocistinúria/classificação , Humanos , Imageamento por Ressonância Magnética , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/classificação , Metilenotetra-Hidrofolato Redutase (NADPH2)/efeitos dos fármacos , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Pessoa de Meia-Idade , Espasticidade Muscular/classificação , Estudos Prospectivos , Transtornos Psicóticos/classificação , Transtornos Psicóticos/genética , Paraplegia Espástica Hereditária/tratamento farmacológico , Resultado do Tratamento
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