RESUMO
Background Cerebral folate deficiency (CFD) syndrome is characterised by a low concentration of 5-methyltetrahydrofolate in cerebrospinal fluid, while folate levels in plasma and red blood cells are in the low normal range. Mutations in several folate pathway genes, including FOLR1 (folate receptor alpha, FRα), DHFR (dihydrofolate reductase) and PCFT (proton coupled folate transporter) have been previously identified in patients with CFD. Methods In an effort to identify causal mutations for CFD, we performed whole exome sequencing analysis on eight CFD trios and identified eight de novo mutations in seven trios. Results Notably, we found a de novo stop gain mutation in the capicua (CIC) gene. Using 48 sporadic CFD samples as a validation cohort, we identified three additional rare variants in CIC that are putatively deleterious mutations. Functional analysis indicates that CIC binds to an octameric sequence in the promoter regions of folate transport genes: FOLR1, PCFT and reduced folate carrier (Slc19A1; RFC1). The CIC nonsense variant (p.R353X) downregulated FOLR1 expression in HeLa cells as well as in the induced pluripotent stem cell (iPSCs) derived from the original CFD proband. Folate binding assay demonstrated that the p.R353X variant decreased cellular binding of folic acid in cells. Conclusion This study indicates that CIC loss of function variants can contribute to the genetic aetiology of CFD through regulating FOLR1 expression. Our study described the first mutations in a non-folate pathway gene that can contribute to the aetiology of CFD.
Assuntos
Cérebro/metabolismo , Receptor 1 de Folato/genética , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Mutação com Perda de Função , Doenças do Sistema Nervoso/líquido cefalorraquidiano , Proteínas Repressoras/genética , Tetra-Hidrofolatos/líquido cefalorraquidiano , Células Cultivadas , Regulação para Baixo , Feminino , Receptor 1 de Folato/deficiência , Deficiência de Ácido Fólico/genética , Células HEK293 , Humanos , Masculino , Doenças do Sistema Nervoso/genética , Distrofias Neuroaxonais , Linhagem , Análise de Sequência de DNAAssuntos
Caderinas/genética , Síndromes Epilépticas/tratamento farmacológico , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Leucovorina/farmacologia , Tetra-Hidrofolatos/líquido cefalorraquidiano , Complexo Vitamínico B/farmacologia , Criança , Síndromes Epilépticas/líquido cefalorraquidiano , Síndromes Epilépticas/genética , Feminino , Humanos , Leucovorina/administração & dosagem , Linhagem , Protocaderinas , Resultado do Tratamento , Complexo Vitamínico B/administração & dosagemRESUMO
BACKGROUND: Cerebral folate deficiency (CFD) is a neurological disease, hallmarked by remarkable low concentrations of 5-methyltetrahydrofolic acid (5-MTHF) in cerebrospinal fluid (CSF). The primary causes of CFD include the presence of folate receptor (FR) autoantibodies, defects of FR encoding gene FOLR1, mitochondrial diseases and congenital abnormalities in folate metabolism. CASE PRESENTATION: Here we first present a Chinese male CFD patient whose seizure onset at 2 years old with convulsive status epilepticus. Magnetic Resonance Imaging (MRI) revealed the development of encephalomalacia, laminar necrosis in multiple lobes of the brain and cerebellar atrophy. Whole Exome Sequencing (WES) uncovered a homozygous missense variant of c.524G > T (p.C175F) in FOLR1 gene. Further laboratory tests demonstrated the extremely low level of 5-MTHF in the CSF from this patient, which was attributed to cerebral folate transport deficiency. Following the intravenous and oral treatment of calcium folinate, the concentrations of 5-MTHF in CSF were recovered to the normal range and seizure symptoms were relieved as well. CONCLUSIONS: One novel variation of FOLR1 was firstly identified from a Chinese male patient with tonic-clonic seizures, developmental delay, and ataxia. The WES and laboratory results elucidated the etiology of the symptoms. Clinical outcomes were improved by early diagnosis and proper treatment.
Assuntos
Encefalomalacia/genética , Receptor 1 de Folato/genética , Deficiência de Ácido Fólico/genética , Convulsões/genética , Estado Epiléptico/genética , Idade de Início , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Criança , Encefalomalacia/líquido cefalorraquidiano , Encefalomalacia/diagnóstico por imagem , Encefalomalacia/tratamento farmacológico , Receptor 1 de Folato/deficiência , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/diagnóstico por imagem , Deficiência de Ácido Fólico/tratamento farmacológico , Homozigoto , Humanos , Leucovorina/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Convulsões/líquido cefalorraquidiano , Convulsões/diagnóstico por imagem , Convulsões/tratamento farmacológico , Estado Epiléptico/líquido cefalorraquidiano , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/tratamento farmacológico , Tetra-Hidrofolatos/líquido cefalorraquidiano , Sequenciamento do ExomaRESUMO
TITLE: Epilepsia dependiente de piridoxina por deficiencia en el gen PNPO.
Assuntos
Encefalopatias Metabólicas/genética , Cromossomos Humanos Par 17/genética , Epilepsia/genética , Hipóxia-Isquemia Encefálica/genética , Mutação de Sentido Incorreto , Piridoxaminafosfato Oxidase/deficiência , Convulsões/genética , Dissomia Uniparental , Adolescente , Epilepsia/líquido cefalorraquidiano , Epilepsia/tratamento farmacológico , Feminino , Humanos , Polimorfismo de Nucleotídeo Único , Piridoxaminafosfato Oxidase/genética , Piridoxina/uso terapêutico , Tetra-Hidrofolatos/líquido cefalorraquidianoRESUMO
Cerebral folate deficiency is typically defined as a deficiency of the major folate species 5-methyltetrahydrofolate in the cerebrospinal fluid (CSF) in the presence of normal peripheral total folate levels. However, it should be noted that cerebral folate deficiency is also often used to describe conditions where CSF 5-MTHF is low, in the presence of low or undefined peripheral folate levels. Known defects of folate transport are deficiency of the proton coupled folate transporter, associated with systemic as well as cerebral folate deficiency, and deficiency of the folate receptor alpha, leading to an isolated cerebral folate deficiency associated with intractable seizures, developmental delay and/or regression, progressive ataxia and choreoathetoid movement disorders. Inborn errors of folate metabolism include deficiencies of the enzymes methylenetetrahydrofolate reductase, dihydrofolate reductase and 5,10-methenyltetrahydrofolate synthetase. Cerebral folate deficiency is potentially a treatable condition and so prompt recognition of these inborn errors and initiation of appropriate therapy is of paramount importance. Secondary cerebral folate deficiency may be observed in other inherited metabolic diseases, including disorders of the mitochondrial oxidative phosphorylation system, serine deficiency, and pyridoxine dependent epilepsy. Other secondary causes of cerebral folate deficiency include the effects of drugs, immune response activation, toxic insults and oxidative stress. This review describes the absorption, transport and metabolism of folate within the body; analytical methods to measure folate species in blood, plasma and CSF; inherited and acquired causes of cerebral folate deficiency; and possible treatment options in those patients found to have cerebral folate deficiency.
Assuntos
Encefalopatias Metabólicas Congênitas/diagnóstico , Epilepsia/diagnóstico , Deficiência de Ácido Fólico/diagnóstico , Ácido Fólico/uso terapêutico , Tetra-Hidrofolatos/deficiência , Encéfalo/patologia , Encefalopatias Metabólicas Congênitas/líquido cefalorraquidiano , Encefalopatias Metabólicas Congênitas/tratamento farmacológico , Encefalopatias Metabólicas Congênitas/genética , Diagnóstico Diferencial , Epilepsia/líquido cefalorraquidiano , Epilepsia/tratamento farmacológico , Epilepsia/genética , Receptor 1 de Folato/genética , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/tratamento farmacológico , Deficiência de Ácido Fólico/genética , Humanos , Tetra-Hidrofolatos/líquido cefalorraquidianoRESUMO
OBJECTIVE: To describe the phenotype and the response to folinic acid supplementation of cerebral folate deficiency (CFD) in adults, a disorder diagnosed on low 5-methyltetrahydro-folate (5MTHF) in cerebrospinal fluid (CSF), which can correspond to a inherited disorder of folate metabolism (IDFM) or to a metabolic consequence of various neurological diseases. METHODS: We conducted a retrospective study on 224 adult patients with neurological symptoms who had a 5MTHF CSF dosage, collecting their neurologic and neuroimaging data. RESULTS: 69 patients had CFD (CSF 5MTHF levelâ¯<â¯41â¯nmol/L), 25 of them had severe CFD (sCFD; ≤25â¯nmol/L) with adult onset neurological symptoms in 41%. 56% of sCFD patients had an underlying identified neurologic disorder, mainly mitochondrial diseases, hepatic encephalopathy and primary brain calcifications (no identified IDFM), the others were classified as undiagnosed. sCFD patients presented most frequently pyramidal syndrome (75%), movement disorders (56%), cerebellar syndrome (50%) and intellectual disability (46%). MRI findings mostly showed white matter abnormalities (WMA; 32%) and calcifications (12%), and were normal in 23%. The clinico-radiological phenotype of sCFD patients was not clearly different from non CFD patients in terms of manifestations frequency. However, their neurological picture was more complex with a higher number of combined neurological symptoms (4.7±1.6 vs 3.4±1.7, pâ¯=â¯.01). In Magnetic Resonance Spectroscopy (MRS), Choline/Creatine (Cho/Cr) ratio was lower in sCFD patients (nâ¯=â¯7) compared to non-CFD patients (nâ¯=â¯73) (pâ¯=â¯.005), with good sensitivity (71%) and excellent specificity (92%). Among twenty-one CFD patients treated with folinic acid, nine had a sustained improvement, all with sCFD but one (50% of sCFD patients improved). In two undiagnosed patients with extremely low 5MTHF CSF values, MRI WMA and low Cho/Cr ratios, folinic acid treatment leaded to a dramatic clinical and radiological improvement. CONCLUSION: CSF 5MTHF dosage should be considered in patients with mitochondrial diseases, primary brain calcifications and unexplained complex neurological disorders especially if associated with WMA, since folinic acid supplementation in patients with sCFD is frequently efficient.
Assuntos
Doenças Cerebelares/complicações , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/genética , Mutação/genética , Proteínas/genética , Adolescente , Adulto , Idoso , Calcinose/diagnóstico por imagem , Calcinose/etiologia , Calcinose/genética , Doenças Cerebelares/líquido cefalorraquidiano , Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/genética , Criança , Pré-Escolar , Feminino , Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/diagnóstico por imagem , Seguimentos , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doenças Mitocondriais/diagnóstico por imagem , Doenças Mitocondriais/etiologia , Estudos Retrospectivos , Tetra-Hidrofolatos/líquido cefalorraquidiano , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Adulto JovemRESUMO
Folate metabolism in the brain is critically important and serves a number of vital roles in nucleotide synthesis, single carbon metabolism/methylation, amino acid metabolism, and mitochondrial translation. Genetic defects in almost every enzyme of folate metabolism have been reported to date, and most have neurological sequelae. We report 2 patients presenting with a neurometabolic disorder associated with biallelic variants in the MTHFS gene, encoding 5,10-methenyltetrahydrofolate synthetase. Both patients presented with microcephaly, short stature, severe global developmental delay, progressive spasticity, epilepsy, and cerebral hypomyelination. Baseline CSF 5-methyltetrahydrolate (5-MTHF) levels were in the low-normal range. The first patient was treated with folinic acid, which resulted in worsening cerebral folate deficiency. Treatment in this patient with a combination of oral L-5-methyltetrahydrofolate and intramuscular methylcobalamin was able to increase CSF 5-MTHF levels, was well tolerated over a 4â¯month period, and resulted in subjective mild improvements in functioning. Measurement of MTHFS enzyme activity in fibroblasts confirmed reduced activity. The direct substrate of the MTHFS reaction, 5-formyl-THF, was elevated 30-fold in patient fibroblasts compared to control, supporting the hypothesis that the pathophysiology of this disorder is a manifestation of toxicity from this metabolite.
Assuntos
Sistemas de Transporte de Aminoácidos Acídicos/deficiência , Antiporters/deficiência , Carbono-Nitrogênio Ligases/genética , Epilepsia/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Microcefalia/genética , Doenças Mitocondriais/genética , Transtornos Psicomotores/genética , Sistemas de Transporte de Aminoácidos Acídicos/líquido cefalorraquidiano , Sistemas de Transporte de Aminoácidos Acídicos/genética , Sistemas de Transporte de Aminoácidos Acídicos/metabolismo , Antiporters/líquido cefalorraquidiano , Antiporters/genética , Antiporters/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Carbono-Nitrogênio Ligases/líquido cefalorraquidiano , Carbono-Nitrogênio Ligases/deficiência , Carbono-Nitrogênio Ligases/metabolismo , Epilepsia/líquido cefalorraquidiano , Epilepsia/complicações , Epilepsia/patologia , Feminino , Receptor 1 de Folato/deficiência , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/líquido cefalorraquidiano , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/complicações , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/metabolismo , Humanos , Masculino , Doenças Metabólicas/líquido cefalorraquidiano , Doenças Metabólicas/complicações , Doenças Metabólicas/genética , Doenças Metabólicas/patologia , Microcefalia/líquido cefalorraquidiano , Microcefalia/complicações , Microcefalia/patologia , Doenças Mitocondriais/líquido cefalorraquidiano , Doenças Mitocondriais/complicações , Doenças Mitocondriais/metabolismo , Malformações do Sistema Nervoso/líquido cefalorraquidiano , Malformações do Sistema Nervoso/complicações , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/metabolismo , Distrofias Neuroaxonais , Transtornos Psicomotores/líquido cefalorraquidiano , Transtornos Psicomotores/complicações , Transtornos Psicomotores/metabolismo , Tetra-Hidrofolatos/líquido cefalorraquidiano , Tetra-Hidrofolatos/metabolismoRESUMO
Mitochondrial diseases are a group of genetic disorders leading to the dysfunction of mitochondrial energy metabolism pathways. We aimed to assess the clinical phenotype and the biochemical cerebrospinal fluid (CSF) biogenic amine profiles of patients with different diagnoses of genetic mitochondrial diseases. We recruited 29 patients with genetically confirmed mitochondrial diseases harboring mutations in either nuclear or mitochondrial DNA (mtDNA) genes. Signs and symptoms of impaired neurotransmission and neuroradiological data were recorded. CSF monoamines, pterins, and 5-methyltetrahydrofolate (5MTHF) concentrations were analyzed using high-performance liquid chromatography with electrochemical and fluorescence detection procedures. The mtDNA mutations were studied by Sanger sequencing, Southern blot, and real-time PCR, and nuclear DNA was assessed either by Sanger or next-generation sequencing. Five out of 29 cases showed predominant dopaminergic signs not attributable to basal ganglia involvement, harboring mutations in different nuclear genes. A chi-square test showed a statistically significant association between high homovanillic acid (HVA) values and low CSF 5-MTHF values (chi-square = 10.916; p = 0.001). Seven out of the eight patients with high CSF HVA values showed cerebral folate deficiency. Five of them harbored mtDNA deletions associated with Kearns-Sayre syndrome (KSS), one had a mitochondrial point mutation at the mtDNA ATPase6 gene, and one had a POLG mutation. In conclusion, dopamine deficiency clinical signs were present in some patients with mitochondrial diseases with different genetic backgrounds. High CSF HVA values, together with a severe cerebral folate deficiency, were observed in KSS patients and in other mtDNA mutation syndromes.
Assuntos
Aminas Biogênicas/líquido cefalorraquidiano , Ácido Homovanílico/líquido cefalorraquidiano , Doenças Mitocondriais/líquido cefalorraquidiano , Doenças Mitocondriais/diagnóstico , Pterinas/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , DNA Mitocondrial/genética , Humanos , Doenças Mitocondriais/genética , Mutação Puntual , Deleção de Sequência , Tetra-Hidrofolatos/deficiênciaRESUMO
BACKGROUND: In 2009, untargeted metabolomics led to the delineation of a new clinico-biological entity called cerebellar ataxia with elevated cerebrospinal free sialic acid, or CAFSA. In order to elucidate CAFSA, we applied sequentially targeted and untargeted omic approaches. METHODS AND RESULTS: First, we studied five of the six CAFSA patients initially described. Besides increased CSF free sialic acid concentrations, three patients presented with markedly decreased 5-methyltetrahydrofolate (5-MTHF) CSF concentrations. Exome sequencing identified a homozygous POLG mutation in two affected sisters, but failed to identify a causative gene in the three sporadic patients with high sialic acid but low 5-MTHF. Using targeted mass spectrometry, we confirmed that free sialic acid was increased in the CSF of a third known POLG-mutated patient. We then pursued pathophysiological analyses of CAFSA using mass spectrometry-based metabolomics on CSF from two sporadic CAFSA patients as well as 95 patients with an unexplained encephalopathy and 39 controls. This led to the identification of a common metabotype between the two initial CAFSA patients and three additional patients, including one patient with Kearns-Sayre syndrome. Metabolites of the CSF metabotype were positioned in a reconstruction of the human metabolic network, which highlighted the proximity of the metabotype with acetyl-CoA and carnitine, two key metabolites regulating mitochondrial energy homeostasis. CONCLUSION: Our genetic and metabolomics analyses suggest that CAFSA is a heterogeneous entity related to mitochondrial DNA alterations either through POLG mutations or a mechanism similar to what is observed in Kearns-Sayre syndrome.
Assuntos
Ataxia Cerebelar/diagnóstico , Genômica/métodos , Metabolômica/métodos , Ácido N-Acetilneuramínico/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , Adulto , Estudos de Casos e Controles , Ataxia Cerebelar/líquido cefalorraquidiano , Ataxia Cerebelar/genética , Ataxia Cerebelar/metabolismo , Análise Mutacional de DNA , DNA Polimerase gama/genética , DNA Mitocondrial/análise , Feminino , Humanos , Masculino , Espectrometria de Massas , Irmãos , Tetra-Hidrofolatos/análise , Sequenciamento do Exoma/métodosRESUMO
BACKGROUND: We describe a new method for simultaneous measurement of monoamine metabolites (3-O-methyldopa [3-OMD], 3-methoxy-4-hydroxyphenylethyleneglycol [MHPG], 5-hydroxyindoleacetic acid [5-HIAA], and homovanillic acid [HVA]) and 5-methyltetrahydrofolate (5-MTHF) and its use on cerebrospinal fluid (CSF) samples from pediatric patients. METHODS: Monoamine metabolites and 5-MTHF were measured by high-performance liquid chromatography with fluorescence detection. CSF samples were prospectively collected from children according to a standardized collection protocol in which the first 1-ml fraction was used for analysis. RESULTS: Monoamine metabolites and 5-MTHF were separated within 10min. They showed linearity from the limit of detection to 1024nmol/l. The limit of quantification of each metabolite was sufficiently low for the CSF sample assay. In 42 CSF samples after excluding cases with possibly altered neurotransmitter profiles, the concentrations of 3-OMD, MHPG, 5-HIAA, HVA, and 5-MTHF showed significant age dependence and their ranges were comparable with the reference values in the literature. The metabolite profiles of aromatic l-amino acid decarboxylase deficiency, Segawa disease, and folate receptor α defect by this method were compatible with those in the literature. CONCLUSIONS: This method is a simple means of measuring CSF monoamine metabolites and 5-MTHF, and is especially useful for laboratories not equipped with electrochemical detectors.
Assuntos
Di-Hidroxifenilalanina/análogos & derivados , Ácido Homovanílico/líquido cefalorraquidiano , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Metoxi-Hidroxifenilglicol/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , Descarboxilases de Aminoácido-L-Aromático/líquido cefalorraquidiano , Descarboxilases de Aminoácido-L-Aromático/deficiência , Cromatografia Líquida de Alta Pressão/métodos , Di-Hidroxifenilalanina/líquido cefalorraquidiano , Distúrbios Distônicos/líquido cefalorraquidiano , Fluorescência , Receptor 1 de Folato/líquido cefalorraquidiano , Receptor 1 de Folato/deficiência , Receptor 1 de Folato/genética , Humanos , Limite de Detecção , Distrofias Neuroaxonais/líquido cefalorraquidiano , Valores de Referência , Reprodutibilidade dos Testes , Tirosina/análogos & derivadosRESUMO
Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. The objective of this study was to investigate the relationships between cerebral amyloid production and both blood and cerebrospinal fluid (CSF) markers of the homocysteine metabolism. We assessed CSF concentrations of soluble APPα, soluble APPß, and amyloid ß1-42 (Aß1-42), as well as plasma levels of homocysteine (Hcys), total vitamin B12, and folate, and CSF concentrations of homocysteine (Hcys-CSF), 5-methyltetrahydrofolate (5-MTHF), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) in 59 subjects with normal cognition. Linear regression analyses were performed to assess associations between homocysteine metabolism parameters and amyloid production. The study was approved by the Ethical Committee of the University of Bonn. After controlling for age, gender, APOEe4 status, and albumin ratio (Qalb), higher Aß1-42 CSF levels were associated with high Hcys and low vitamin B12 plasma levels as well as with high Hcys, high SAH, and low 5-MTHF CSF levels. Higher CSF concentrations of sAPPα and sAPPß were associated with high SAH levels. The results suggest that disturbed homocysteine metabolism is related to increased CSF levels of sAPP forms and Aß1-42, and may contribute to the accumulation of amyloid pathology in the brain. Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. We found associations between CSF levels of soluble APP forms and Aß1-42, and markers of the homocysteine metabolism in both plasma and CSF in adults with normal cognition. Disturbed homocysteine metabolism may represent a target for preventive and early disease-modifying interventions in Alzheimer's disease.
Assuntos
Peptídeos beta-Amiloides/líquido cefalorraquidiano , Precursor de Proteína beta-Amiloide/líquido cefalorraquidiano , Homocisteína/metabolismo , Fragmentos de Peptídeos/líquido cefalorraquidiano , Adulto , Albuminas/metabolismo , Apolipoproteína E4/genética , Feminino , Ácido Fólico/líquido cefalorraquidiano , Voluntários Saudáveis , Homocisteína/sangue , Homocisteína/líquido cefalorraquidiano , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valores de Referência , S-Adenosilmetionina/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , Vitamina B 12/líquido cefalorraquidianoRESUMO
OBJECTIVE: To describe an assay of 5-methyltetrahydrofolate (5MTHF) in the cerebrospinal fluid (CSF) of children, to determine reference values, and to report the clinical significance of this assay in metabolic disorders affecting folate transport and metabolism. METHODS: CSF 5MTHF was determined by high-performance liquid chromatography with fluorescent detection in pediatric patients including one with FOLR1 gene mutation and one with methylenetetrahydrofolate reductase (MTHFR) deficiency. CSF total folate was measured using an automated analyzer. RESULTS: 5MTHF and total folate were determined in 188 and 93 CSF samples, respectively. CSF 5MTHF was high throughout the first six months of life and subsequently declined with age. Reference values of CSF 5MTHF and total folate were determined from 162 and 82 samples, respectively. The patient with FOLR1 gene mutation had extremely low CSF 5MTHF and total folate, though these values normalized after folinic acid supplementation. The patient with MTHFR deficiency had extremely low 5MTHF and moderately low total folate; these values were not associated and showed no significant change after folic acid supplementation. CONCLUSIONS: This 5MTHF assay is simple, rapid, sensitive, reliable, and cost-effective. It will aid in the diagnosis and therapeutic monitoring of metabolic disorders affecting folate transport and metabolism.
Assuntos
Ácido Fólico/metabolismo , Tetra-Hidrofolatos/líquido cefalorraquidiano , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Testes de Química Clínica/métodos , Suplementos Nutricionais , Receptor 1 de Folato/genética , Homocistinúria , Humanos , Lactente , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular , Transtornos Psicóticos , Valores de ReferênciaRESUMO
BACKGROUND: Cerebral folate transporter deficiency caused by FOLR-1 mutations has been described in 2009. This condition is characterized by a 5MTHF level <5 nmol/l in the CSF, along with regression of acquisition in the second year of life, ataxia, and refractory myoclonic epilepsy. Oral or intravenous folinic acid (5-formyltetrahydrofolate) treatment has been shown to improve clinical status. CASE PRESENTATION: We present the cases of two sisters with cerebral folate transport deficiency caused by mutation in the folate receptor 1 (FOLR1) gene (MIM *136430). Following recommendations, we administered oral folinic acid at 5 mg/kg/day, resulting in some initial clinical improvement, yet severe epilepsy persisted. During treatment, cerebrospinal fluid (CSF) analysis revealed normal 5-methyltetrahydrofolate (5MTHF) levels (60.1 nmol/l; normal range: 53-182 nmol/l). Epilepsy proved difficult to control and the younger patient exhibited neurological regression. We then administered high-dose folinic acid intravenously over 3 days (6 mg/kg/day for 24 h, then 12 mg/kg/day for 48 h), which significantly improved clinical status and epilepsy. CSF analysis revealed high 5MTHF levels following intravenous infusion (180 nmol/l). Treatment continued with monthly intravenous administrations of 20-25 mg/kg folinic acid. At 2 years post-treatment, clinical improvement was confirmed. CONCLUSIONS: This report illustrates that cerebral folate transporter deficiency caused by FOLR-1 mutations is a treatable condition and can potentially be cured by folinic acid treatment. As already reported, early effective treatment is known to improve outcomes in affected children. In our study, intravenous high-dose folinic acid infusions appeared to optimize clinical response.
Assuntos
Receptor 1 de Folato/deficiência , Leucovorina/administração & dosagem , Mutação , Distrofias Neuroaxonais/tratamento farmacológico , Criança , Pré-Escolar , Feminino , Receptor 1 de Folato/genética , Humanos , Infusões Intravenosas , Distrofias Neuroaxonais/genética , Irmãos , Tetra-Hidrofolatos/líquido cefalorraquidianoRESUMO
OBJECTIVE: To examine the association between cerebral folate deficiency and autism, this study examined CSF 5-methyltetrahydrofolate (5-MTHF) concentrations in a group of young children with autism, investigated the natural variation in CSF 5-MTHF over time, and assessed the relationship between CSF 5-MTHF and symptoms. METHODS: CSF was collected from 67 children with a diagnosis of DSM-IV-TR autistic disorder (age, mean ± SD 43 ± 11 months), with a second CSF sample obtained 1-3 years later on 31 of these subjects (time to follow-up, 30 ± 8 months). RESULTS: At time 1, 7% (5/67) of participants had 5-MTHF <40 nmol/L. At follow-up, 23% (7/31) of participants had 5-MTHF <40 nmol/L (only one of whom had been low at time 1). A moderate correlation with a very wide confidence interval (CI) was observed between time 1 and time 2 CSF 5-MTHF measurements (Pearson r[p] = 0.38 [0.04]; 95% CI 0.02-0.64). Neither the CSF 5-MTHF levels nor changes over time correlated with the clinical features of autism. CONCLUSIONS: CSF 5-MTHF levels vary significantly over time in an unpredictable fashion and do not show a significant relationship to typical clinical features of autism. Reduced CSF 5-MTHF levels are a nonspecific finding in autism. Our data do not support the use of lumbar puncture for assessment of CSF 5-MTHF in autism.
Assuntos
Transtorno Autístico/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , Transtorno Autístico/sangue , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Criança , Pré-Escolar , Ácido Fólico/sangue , Seguimentos , Humanos , Estudos Longitudinais , Testes Neuropsicológicos , Índice de Gravidade de DoençaRESUMO
We describe a simple stable isotope dilution method for accurate and precise measurement of cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5-MTHF) as a clinical diagnostic test. 5-MTHF is the main biologically active form of folic acid and is involved in regulation of homocysteine and DNA synthesis. Measurement of 5-MTHF in CSF provides diagnostic information regarding diseases affecting folate metabolism within the central nervous system, in particular inborn errors of folate metabolism. Determination of 5-MTHF in CSF (50 µL) was performed utilizing high performance liquid chromatography coupled with electrospray positive ionization tandem mass spectrometry (HPLC-ESI-MS/MS). 5-MTHF in CSF is determined by a 1:2 dilution with internal standard (5-MTHF-(13)C5) and injected directly onto the HPLC-ESI-MS/MS system. Each assay is quantified using a five-point standard curve (25-400 nM) and has an analytical measurement range of 3-1000 nM.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Tetra-Hidrofolatos/líquido cefalorraquidiano , Métodos Analíticos de Preparação de Amostras , Humanos , Estatística como AssuntoRESUMO
We describe neurotransmitter abnormalities in two patients with drug-resistant epilepsy resulting from deleterious de novo mutations in sodium channel genes. Whole exome sequencing identified a de novo SCN2A splice-site mutation (c.2379+1G>A, p.Glu717Gly.fs*30) resulting in deletion of exon 14, in a 10-year old male with early onset global developmental delay, intermittent ataxia, autism, hypotonia, epileptic encephalopathy and cerebral/cerebellar atrophy. In the cerebrospinal fluid both homovanillic acid and 5-hydroxyindoleacetic acid were significantly decreased; extensive biochemical and genetic investigations ruled out primary neurotransmitter deficiencies and other known inborn errors of metabolism. In an 8-year old female with an early onset intractable epileptic encephalopathy, developmental regression, and progressive cerebellar atrophy, a previously unreported de novo missense mutation was identified in SCN8A (c.5615G>A; p.Arg1872Gln), affecting a highly conserved residue located in the C-terminal of the Nav1.6 protein. Aside from decreased homovanillic acid and 5-hydroxyindoleacetic acid, 5-methyltetrahydrofolate was also found to be low. We hypothesize that these channelopathies cause abnormal synaptic mono-amine metabolite secretion/uptake via impaired vesicular release and imbalance in electrochemical ion gradients, which in turn aggravate the seizures. Treatment with oral 5-hydroxytryptophan, l-Dopa/Carbidopa, and a dopa agonist resulted in mild improvement of seizure control in the male case, most likely via dopamine and serotonin receptor activated signal transduction and modulation of glutamatergic, GABA-ergic and glycinergic neurotransmission. Neurotransmitter analysis in other sodium channelopathy patients will help validate our findings, potentially yielding novel treatment opportunities.
Assuntos
Canalopatias/metabolismo , Epilepsia Resistente a Medicamentos/metabolismo , Epilepsia/metabolismo , Mutação de Sentido Incorreto , Neurotransmissores/deficiência , Convulsões/etiologia , Transtorno Autístico/etiologia , Transtorno Autístico/genética , Canalopatias/tratamento farmacológico , Criança , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsia/tratamento farmacológico , Epilepsia/genética , Exoma , Feminino , Ácido Homovanílico/líquido cefalorraquidiano , Humanos , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Masculino , Hipotonia Muscular/etiologia , Hipotonia Muscular/genética , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.6/genética , Neurotransmissores/metabolismo , Receptores Dopaminérgicos/metabolismo , Convulsões/genética , Análise de Sequência de DNA , Canais de Sódio/deficiência , Canais de Sódio/genética , Tetra-Hidrofolatos/líquido cefalorraquidianoRESUMO
BACKGROUND: Cerebral folate deficiency (CFD) may be underdiagnosed, as it manifests with various non-specific neurological symptoms. The diagnosis of CFD requires a determination of 5-methyltetrahydrofolate (5MTHF) in the cerebrospinal fluid (CSF), which is available in a limited number of specialized laboratories. In clinical biochemistry laboratories, total folate (TF) determination in serum or plasma is routinely performed by automated analyzers. The aim of this study is to determine whether the automated assay of CSF TF is a helpful screening tool for CFD. METHODS: We analyzed CSF samples collected from 73 pediatric patients. We measured CSF TF, serum TF, and CSF 5MTHF in 73, 70, and 48 patients, respectively. The assay of 5MTHF was conducted by a newly developed system utilizing liquid chromatography-tandem mass spectrometry (LC-MS/MS). We investigated the correlation between TF and 5MTHF in the CSF. RESULTS: There was a strong positive correlation between CSF TF and 5MTHF (ρ=0.930, p<0.0001, n=48). Age was negatively correlated with CSF TF (ρ=-0.557, p<0.0001, n=51), serum TF (ρ=-0.457, p=0.0008, n=51), and CSF 5MTHF (ρ=-0.387, p=0.0263, n=33), but not with the CSF/serum TF ratio. CONCLUSIONS: The automated assay of CSF TF is helpful to estimate CSF 5MTHF. The CSF TF assay may have a significant impact on the early diagnosis of CFD, because clinicians have better access to it than the 5MTHF assay.
Assuntos
Deficiência de Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/diagnóstico , Ácido Fólico/líquido cefalorraquidiano , Tetra-Hidrofolatos/líquido cefalorraquidiano , Adolescente , Doenças Cerebelares/líquido cefalorraquidiano , Doenças Cerebelares/diagnóstico , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Diagnóstico Precoce , Humanos , Lactente , Valores de Referência , Espectrometria de Massas em TandemRESUMO
Folinic acid-responsive seizures (FARS) are a rare treatable cause of neonatal epilepsy. They have characteristic peaks on CSF monoamine metabolite analysis, and have mutations in the ALDH7A1 gene, characteristically found in pyridoxine-dependent epilepsy. There are case reports of patients presenting with seizures at a later age, and with folate deficiency due to different mechanisms with variable response to folinic acid supplementation. Here, we report 2 siblings who presented with global developmental delay and intractable seizures who responded clinically to folinic acid therapy. Their work-up included metabolic and genetic testing. The DNA sequencing was carried out for the ALDH7A1 gene, and the folate receptor 1 (FOLR1) gene. They had very low 5-methyltetrahydrofolate (5-MTHF) in CSF with no systemic folate deficiency and no characteristic peaks on neurotransmitter metabolite chromatogram. A novel mutation in the FOLR1 gene was found. The mutation in this gene is shown to affect CSF folate transport leading to cerebral folate deficiency. The response to treatment with folinic acid was dramatic with improvement in social interaction, mobility, and complete seizure control. We should consider the possibility of this treatable condition in appropriate clinical circumstances early, as diagnosis with favorable outcome depends on the specialized tests.
Assuntos
Encefalopatias Metabólicas Congênitas/tratamento farmacológico , Epilepsias Mioclônicas/tratamento farmacológico , Receptor 1 de Folato/genética , Deficiência de Ácido Fólico/tratamento farmacológico , Leucovorina/uso terapêutico , Mutação de Sentido Incorreto , Mutação Puntual , Atrofia , Encéfalo/patologia , Encefalopatias Metabólicas Congênitas/líquido cefalorraquidiano , Encefalopatias Metabólicas Congênitas/diagnóstico , Encefalopatias Metabólicas Congênitas/genética , Encefalopatias Metabólicas Congênitas/patologia , Transtornos Globais do Desenvolvimento Infantil/genética , Pré-Escolar , Consanguinidade , Deficiências do Desenvolvimento/genética , Diagnóstico Precoce , Eletroencefalografia , Epilepsias Mioclônicas/líquido cefalorraquidiano , Epilepsias Mioclônicas/diagnóstico , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/patologia , Feminino , Receptor 1 de Folato/deficiência , Deficiência de Ácido Fólico/líquido cefalorraquidiano , Deficiência de Ácido Fólico/diagnóstico , Deficiência de Ácido Fólico/genética , Humanos , Imageamento por Ressonância Magnética , Masculino , Piridoxina/uso terapêutico , Irmãos , Tetra-Hidrofolatos/líquido cefalorraquidianoRESUMO
Deficiency of 5-methyltetrahydrofolate (5-MTHF) in cerebrospinal fluid (CSF) is associated with a number of neurometabolic conditions including mitochondrial electron transport chain defects. Whilst failure of the active transport of 5-methyltetrahydrofolate (5-MTHF) into the CSF compartment has been proposed as a potential mechanism responsible for the 5-MTHF deficiency seen in mitochondrial disorders, it is becoming increasingly clear that other mechanisms are involved. Here, we have considered the role of oxidative stress as a contributing mechanism. Concerning, ascorbic acid (AA), we have established a CSF reference range (103-303µM) and demonstrated a significant positive correlation between 5-MTHF and AA. Furthermore, CSF itself was also shown to convey antioxidant properties towards 5-MTHF. However, this protection could be overcome by the introduction of a hydroxyl radical generating system. Using a neuronal model system, inhibition of mitochondrial complex I, by 58%, was associated with a 23% increase in superoxide generation and a significantly increased loss of 5-MTHF from the extracellular medium. Addition of AA (150µM) was able to prevent this increased 5-MTHF catabolism. We conclude that increased generation of reactive oxygen species and/or loss of CSF antioxidants are also factors to consider with regard to the development of a central 5-MTHF deficiency. Co-supplementation of AA together with appropriate folate replacement may be of therapeutic benefit.
Assuntos
Ácido Ascórbico/líquido cefalorraquidiano , Ácido Fólico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tetra-Hidrofolatos/líquido cefalorraquidiano , Adolescente , Adulto , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Adulto JovemRESUMO
Cerebral folate deficiency (CFD) syndrome is a neurodevelopmental disorder typically caused by folate receptor autoantibodies (FRAs) that interfere with folate transport across the blood-brain barrier. Autism spectrum disorders (ASDs) and improvements in ASD symptoms with leucovorin (folinic acid) treatment have been reported in some children with CFD. In children with ASD, the prevalence of FRAs and the response to leucovorin in FRA-positive children has not been systematically investigated. In this study, serum FRA concentrations were measured in 93 children with ASD and a high prevalence (75.3%) of FRAs was found. In 16 children, the concentration of blocking FRA significantly correlated with cerebrospinal fluid 5-methyltetrahydrofolate concentrations, which were below the normative mean in every case. Children with FRAs were treated with oral leucovorin calcium (2 mg kg(-1) per day; maximum 50 mg per day). Treatment response was measured and compared with a wait-list control group. Compared with controls, significantly higher improvement ratings were observed in treated children over a mean period of 4 months in verbal communication, receptive and expressive language, attention and stereotypical behavior. Approximately one-third of treated children demonstrated moderate to much improvement. The incidence of adverse effects was low. This study suggests that FRAs may be important in ASD and that FRA-positive children with ASD may benefit from leucovorin calcium treatment. Given these results, empirical treatment with leucovorin calcium may be a reasonable and non-invasive approach in FRA-positive children with ASD. Additional studies of folate receptor autoimmunity and leucovorin calcium treatment in children with ASD are warranted.