Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
J Inherit Metab Dis ; 47(2): 327-339, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38112342

RESUMO

Cerebellar atrophy is a characteristic sign of late-onset Tay-Sachs disease (LOTS). Other structural neuroimaging abnormalities are inconsistently reported. Our study aimed to perform a detailed whole-brain analysis and quantitatively characterize morphometric changes in LOTS patients. Fourteen patients (8 M/6F) with LOTS from three centers were included in this retrospective study. For morphometric brain analyses, we used deformation-based morphometry, voxel-based morphometry, surface-based morphometry, and spatially unbiased cerebellar atlas template. The quantitative whole-brain morphometric analysis confirmed the finding of profound pontocerebellar atrophy with most affected cerebellar lobules V and VI in LOTS patients. Additionally, the atrophy of structures mainly involved in motor control, including bilateral ventral and lateral thalamic nuclei, primary motor and sensory cortex, supplementary motor area, and white matter regions containing corticospinal tract, was present. The atrophy of the right amygdala, hippocampus, and regions of occipital, parietal and temporal white matter was also observed in LOTS patients in contrast with controls (p < 0.05, FWE corrected). Patients with dysarthria and those initially presenting with ataxia had more severe cerebellar atrophy. Our results show predominant impairment of cerebellar regions responsible for speech and hand motor function in LOTS patients. Widespread morphological changes of motor cortical and subcortical regions and tracts in white matter indicate abnormalities in central motor circuits likely coresponsible for impaired speech and motor function.


Assuntos
Doença de Tay-Sachs , Substância Branca , Humanos , Doença de Tay-Sachs/patologia , Substância Branca/diagnóstico por imagem , Estudos Retrospectivos , Imageamento por Ressonância Magnética , Encéfalo/patologia , Atrofia/patologia
2.
Arthritis Res Ther ; 25(1): 234, 2023 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-38042879

RESUMO

BACKGROUND: Currently, it is not possible to predict whether patients with hyperuricemia (HUA) will develop gout and how this progression may be affected by urate-lowering treatment (ULT). Our study aimed to evaluate differences in plasma lipidome between patients with asymptomatic HUA detected ≤ 40 years (HUA ≤ 40) and > 40 years, gout patients with disease onset ≤ 40 years (Gout ≤ 40) and > 40 years, and normouricemic healthy controls (HC). METHODS: Plasma samples were collected from 94 asymptomatic HUA (77% HUA ≤ 40) subjects, 196 gout patients (59% Gout ≤ 40), and 53 HC. A comprehensive targeted lipidomic analysis was performed to semi-quantify 608 lipids in plasma. Univariate and multivariate statistics and advanced visualizations were applied. RESULTS: Both HUA and gout patients showed alterations in lipid profiles with the most significant upregulation of phosphatidylethanolamines and downregulation of lysophosphatidylcholine plasmalogens/plasmanyls. More profound changes were observed in HUA ≤ 40 and Gout ≤ 40 without ULT. Multivariate statistics differentiated HUA ≤ 40 and Gout ≤ 40 groups from HC with an overall accuracy of > 95%. CONCLUSION: Alterations in the lipidome of HUA and Gout patients show a significant impact on lipid metabolism. The most significant glycerophospholipid dysregulation was found in HUA ≤ 40 and Gout ≤ 40 patients, together with a correction of this imbalance with ULT.


Assuntos
Gota , Hiperuricemia , Humanos , Hiperuricemia/diagnóstico , Hiperuricemia/tratamento farmacológico , Ácido Úrico , Lipidômica , Gota/diagnóstico , Gota/tratamento farmacológico , Supressores da Gota/uso terapêutico
3.
Genet Med ; 25(11): 100944, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37493040

RESUMO

PURPOSE: Zellweger spectrum disorders (ZSDs) are known as autosomal recessive disorders caused by defective peroxisome biogenesis due to bi-allelic pathogenic variants in any of at least 13 different PEX genes. Here, we report 2 unrelated patients who present with an autosomal dominant ZSD. METHODS: We performed biochemical and genetic studies in blood and skin fibroblasts of the patients and demonstrated the pathogenicity of the identified PEX14 variants by functional cell studies. RESULTS: We identified 2 different single heterozygous de novo variants in the PEX14 genes of 2 patients diagnosed with ZSD. Both variants cause messenger RNA mis-splicing, leading to stable expression of similar C-terminally truncated PEX14 proteins. Functional studies indicated that the truncated PEX14 proteins lost their function in peroxisomal matrix protein import and cause increased degradation of peroxisomes, ie, pexophagy, thus exerting a dominant-negative effect on peroxisome functioning. Inhibition of pexophagy by different autophagy inhibitors or genetic knockdown of the peroxisomal autophagy receptor NBR1 resulted in restoration of peroxisomal functions in the patients' fibroblasts. CONCLUSION: Our finding of an autosomal dominant ZSD expands the genetic repertoire of ZSDs. Our study underscores that single heterozygous variants should not be ignored as possible genetic cause of diseases with an established autosomal recessive mode of inheritance.


Assuntos
Síndrome de Zellweger , Humanos , Alelos , Peroxissomos/genética , Peroxissomos/metabolismo , Transporte Proteico/fisiologia , Proteínas/genética , Síndrome de Zellweger/genética
4.
Mol Neurobiol ; 60(4): 2024-2035, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36598650

RESUMO

The present study aimed to elucidate the effect of sulforaphane (a natural isothiocyanate) on oxidative stress and mitochondrial dysfunction during and at selected periods following status epilepticus (SE) induced in immature 12-day-old rats by Li-pilocarpine. Dihydroethidium was employed for the detection of superoxide anions, immunoblot analyses for 3-nitrotyrosine (3-NT) and 4-hydroxynonenal (4-HNE) levels and respiratory chain complex I activity for evaluation of mitochondrial function. Sulforaphane was given i.p. in two doses (5 mg/kg each), at PD 10 and PD 11, respectively. The findings of the present study indicate that both the acute phase of SE and the early period of epileptogenesis (1 week and 3 weeks following SE induction) are associated with oxidative stress (documented by the enhanced superoxide anion production and the increased levels of 3-NT and 4-HNE) and the persisting deficiency of complex I activity. Pretreatment with sulforaphane either completely prevented or significantly reduced markers of both oxidative stress and mitochondrial dysfunction. Since sulforaphane had no direct anti-seizure effect, the findings suggest that the ability of sulforaphane to activate Nrf2 is most likely responsible for the observed protective effect. Nrf2-ARE signaling pathway can be considered a promising target for novel therapies of epilepsy, particularly when new compounds, possessing inhibitory activity against protein-protein interaction between Nrf2 and its repressor protein Keap1, with less "off-target" effects and, importantly, with an optimal permeability and bioavailability properties, become available commercially.


Assuntos
Fator 2 Relacionado a NF-E2 , Estado Epiléptico , Ratos , Animais , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Isotiocianatos/farmacologia , Sulfóxidos/metabolismo , Sulfóxidos/farmacologia , Estado Epiléptico/metabolismo , Superóxidos/metabolismo , Mitocôndrias/metabolismo
5.
Redox Biol ; 58: 102517, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36306676

RESUMO

Regulation of H2S homeostasis in humans is poorly understood. Therefore, we assessed the importance of individual enzymes in synthesis and catabolism of H2S by studying patients with respective genetic defects. We analyzed sulfur compounds (including bioavailable sulfide) in 37 untreated or insufficiently treated patients with seven ultrarare enzyme deficiencies and compared them to 63 controls. Surprisingly, we observed that patients with severe deficiency in cystathionine ß-synthase (CBS) or cystathionine γ-lyase (CSE) - the enzymes primarily responsible for H2S synthesis - exhibited increased and normal levels of bioavailable sulfide, respectively. However, an approximately 21-fold increase of urinary homolanthionine in CBS deficiency strongly suggests that lacking CBS activity is compensated for by an increase in CSE-dependent H2S synthesis from accumulating homocysteine, which suggests a control of H2S homeostasis in vivo. In deficiency of sulfide:quinone oxidoreductase - the first enzyme in mitochondrial H2S oxidation - we found normal H2S concentrations in a symptomatic patient and his asymptomatic sibling, and elevated levels in an asymptomatic sibling, challenging the requirement for this enzyme in catabolizing H2S under physiological conditions. Patients with ethylmalonic encephalopathy and sulfite oxidase/molybdenum cofactor deficiencies exhibited massive accumulation of thiosulfate and sulfite with formation of large amounts of S-sulfocysteine and S-sulfohomocysteine, increased renal losses of sulfur compounds and concomitant strong reduction in plasma total cysteine. Our results demonstrate the value of a comprehensive assessment of sulfur compounds in severe disorders of homocysteine/cysteine metabolism and provide evidence for redundancy and compensatory mechanisms in the maintenance of H2S homeostasis.


Assuntos
Sulfeto de Hidrogênio , Humanos , Sulfeto de Hidrogênio/metabolismo , Cisteína , Sulfetos/metabolismo , Homeostase , Enxofre , Homocisteína
6.
J Inherit Metab Dis ; 45(4): 848-861, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35460084

RESUMO

MTHFR deficiency is a severe inborn error of metabolism leading to impairment of the remethylation of homocysteine to methionine. Neonatal and early-onset patients mostly exhibit a life-threatening acute neurologic deterioration. Furthermore, data on early-onset patients' long-term outcomes are scarce. The aims of this study were (1) to study and describe the clinical and laboratory parameters of early-onset MTHFR-deficient patients (i.e., ≤3 months of age) and (2) to identify predictive factors for severe neurodevelopmental outcomes in a cohort with early and late onset MTHFR-deficient patients. To this end, we conducted a retrospective, multicentric, international cohort study on 72 patients with MTHFR deficiency from 32 international metabolic centres. Characteristics of the 32 patients with early-onset MTHFR deficiency were described at time of diagnosis and at the last follow-up visit. Logistic regression analysis was used to identify predictive factors of severe neurodevelopmental outcome in a broader set of patients with early and non-early-onset MTHFR deficiency. The majority of early-onset MTHFR-deficient patients (n = 32) exhibited neurologic symptoms (76%) and feeding difficulties (70%) at time of diagnosis. At the last follow-up visit (median follow-up time of 8.1 years), 76% of treated early-onset patients (n = 29) exhibited a severe neurodevelopmental outcome. Among the whole study population of 64 patients, pre-symptomatic diagnosis was independently associated with a significantly better neurodevelopmental outcome (adjusted OR 0.004, [0.002-0.232]; p = 0.003). This study provides evidence for benefits of pre-symptomatic diagnosis and appropriate therapeutic management, highlighting the need for systematic newborn screening for MTHFR deficiency and pre-symptomatic treatment that may improve outcome.


Assuntos
Homocistinúria , Estudos de Coortes , Homocisteína , Homocistinúria/diagnóstico , Homocistinúria/tratamento farmacológico , Humanos , Recém-Nascido , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Espasticidade Muscular/diagnóstico , Transtornos Psicóticos , Estudos Retrospectivos
7.
J Inherit Metab Dis ; 45(4): 719-733, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35358327

RESUMO

Patient registries for rare diseases enable systematic data collection and can also be used to facilitate postauthorization safety studies (PASS) for orphan drugs. This study evaluates the PASS for betaine anhydrous (Cystadane), conducted as public private partnership (PPP) between the European network and registry for homocystinurias and methylation defects and the marketing authorization holder (MAH). Data were prospectively collected, 2013-2016, in a noninterventional, international, multicenter, registry study. Putative adverse and severe adverse events were reported to the MAH's pharmacovigilance. In total, 130 individuals with vitamin B6 nonresponsive (N = 54) and partially responsive (N = 7) cystathionine beta-synthase (CBS) deficiency, as well as 5,10-methylenetetrahydrofolate reductase (MTHFR; N = 21) deficiency and cobalamin C (N = 48) disease were included. Median (range) duration of treatment with betaine anhydrous was 6.8 (0-9.8) years. The prescribed betaine dose exceeded the recommended maximum (6 g/day) in 49% of individuals older than 10 years because of continued dose adaptation to weight; however, with disease-specific differences (minimum: 31% in B6 nonresponsive CBS deficiency, maximum: 67% in MTHFR deficiency). Despite dose escalation no new or potential risk was identified. Combined disease-specific treatment decreased mean ± SD total plasma homocysteine concentrations from 203 ± 116 to 81 ± 51 µmol/L (p < 0.0001), except in MTHFR deficiency. Recommendations for betaine anhydrous dosage were revised for individuals ≥ 10 years. PPPs between MAH and international scientific consortia can be considered a reliable model for implementing a PASS, reutilizing well-established structures and avoiding data duplication and fragmentation.


Assuntos
Homocistinúria , Transtornos Psicóticos , Betaína/efeitos adversos , Cistationina beta-Sintase , Homocisteína , Homocistinúria/tratamento farmacológico , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Espasticidade Muscular
8.
Nutrients ; 13(9)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34578803

RESUMO

Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD/MTPD) and medium chain acyl-CoA dehydrogenase deficiency (MCADD) were included in the expanded neonatal screening program (ENBS) in Czechia in 2009, allowing for the presymptomatic diagnosis and nutritional management of these patients. The aim of our study was to assess the nationwide impact of ENBS on clinical outcome. This retrospective study analysed acute events and chronic complications and their severity in pre-ENBS and post-ENBS cohorts. In total, 28 children (12 before, 16 after ENBS) were diagnosed with LCHADD/MTPD (incidence 0.8/100,000 before and 1.2/100,000 after ENBS). In the subgroup detected by ENBS, a significantly longer interval from birth to first acute encephalopathy was observed. In addition, improvement in neuropathy and cardiomyopathy (although statistically non-significant) was demonstrated in the post-ENBS subgroup. In the MCADD cohort, we included 69 patients (15 before, 54 after ENBS). The estimated incidence rose from 0.7/100,000 before to 4.3/100,000 after ENBS. We confirmed a significant decrease in the number of episodes of acute encephalopathy and lower proportion of intellectual disability after ENBS (p < 0.0001). The genotype-phenotype correlations suggest a new association between homozygosity for the c.1528C > G variant and more severe heart involvement in LCHADD patients.


Assuntos
Acil-CoA Desidrogenase/deficiência , Cardiomiopatias/dietoterapia , Cardiomiopatias/diagnóstico , Erros Inatos do Metabolismo Lipídico/dietoterapia , Erros Inatos do Metabolismo Lipídico/diagnóstico , Miopatias Mitocondriais/dietoterapia , Miopatias Mitocondriais/diagnóstico , Proteína Mitocondrial Trifuncional/deficiência , Triagem Neonatal/métodos , Doenças do Sistema Nervoso/dietoterapia , Doenças do Sistema Nervoso/diagnóstico , Rabdomiólise/dietoterapia , Rabdomiólise/diagnóstico , 3-Hidroxiacil-CoA Desidrogenases/deficiência , Cardiomiopatias/epidemiologia , Carnitina/análogos & derivados , Carnitina/sangue , Criança , Pré-Escolar , República Tcheca/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Erros Inatos do Metabolismo Lipídico/epidemiologia , Masculino , Erros Inatos do Metabolismo/diagnóstico , Miopatias Mitocondriais/epidemiologia , Doenças do Sistema Nervoso/epidemiologia , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Rabdomiólise/epidemiologia , Índice de Gravidade de Doença
9.
Front Neurosci ; 15: 634378, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746702

RESUMO

The aim of the present study was to elucidate the effect of resveratrol (natural polyphenol) on seizure activity, production of ROS, brain damage and mitochondrial function in the early phase of status epilepticus (SE), induced in immature 12 day-old rats by substances of a different mechanism of action (Li-pilocarpine, DL-homocysteic acid, 4-amino pyridine, and kainate). Seizure activity, production of superoxide anion, brain damage and mitochondrial function were assessed by EEG recordings, hydroethidium method, FluoroJadeB staining and Complex I activity measurement. A marked decrease of complex I activity associated with the acute phase of SE in immature brain was significantly attenuated by resveratrol, given i.p. in two or three doses (25 mg/kg each), 30 min before, 30 or 30 and 60 min after the induction of SE. Increased O2 .- production was completely normalized, brain damage partially attenuated. Since resveratrol did not influence seizure activity itself (latency, intensity, frequency), the mechanism of protection is likely due to its antioxidative properties. The findings have a clinical relevance, suggesting that clinically available substances with antioxidant properties might provide a high benefit as an add-on therapy during the acute phase of SE, influencing also mechanisms involved in the development of epilepsy.

10.
Int J Mol Sci ; 22(4)2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33669292

RESUMO

The ABCG2 gene is a well-established hyperuricemia/gout risk locus encoding a urate transporter that plays a crucial role in renal and intestinal urate excretion. Hitherto, p.Q141K-a common variant of ABCG2 exhibiting approximately one half the cellular function compared to the wild-type-has been reportedly associated with early-onset gout in some populations. However, compared with adult-onset gout, little clinical information is available regarding the association of other uricemia-associated genetic variations with early-onset gout; the latent involvement of ABCG2 in the development of this disease requires further evidence. We describe a representative case of familial pediatric-onset hyperuricemia and early-onset gout associated with a dysfunctional ABCG2, i.e., a clinical history of three generations of one Czech family with biochemical and molecular genetic findings. Hyperuricemia was defined as serum uric acid (SUA) concentrations 420 µmol/L for men or 360 µmol/L for women and children under 15 years on two measurements, performed at least four weeks apart. The proband was a 12-year-old girl of Roma ethnicity, whose SUA concentrations were 397-405 µmol/L. Sequencing analyses focusing on the coding region of ABCG2 identified two rare mutations-c.393G>T (p.M131I) and c.706C>T (p.R236X). Segregation analysis revealed a plausible link between these mutations and hyperuricemia and the gout phenotype in family relatives. Functional studies revealed that p.M131I and p.R236X were functionally deficient and null, respectively. Our findings illustrate why genetic factors affecting ABCG2 function should be routinely considered in clinical practice as part of a hyperuricemia/gout diagnosis, especially in pediatric-onset patients with a strong family history.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Gota/complicações , Gota/genética , Hiperuricemia/complicações , Hiperuricemia/genética , Proteínas de Neoplasias/genética , Transportadores de Ânions Orgânicos/genética , Polimorfismo de Nucleotídeo Único , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Adulto , Criança , República Tcheca , Feminino , Predisposição Genética para Doença , Células HEK293 , Humanos , Hiperuricemia/sangue , Masculino , Mutação , Proteínas de Neoplasias/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Linhagem , Fenótipo , Transfecção , Ácido Úrico/sangue
11.
J Inherit Metab Dis ; 44(3): 777-786, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33089527

RESUMO

5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency usually presents as a severe neonatal disease. This study aimed to characterize natural history, biological and molecular data, and response to treatment of patients with late-onset MTHFR deficiency. The patients were identified through the European Network and Registry for Homocystinuria and Methylation Defects and the Adult group of the French Society for Inherited Metabolic Diseases; data were retrospectively colleted. To identify juvenile to adult-onset forms of the disease, we included patients with a diagnosis established after the age of 10 years. We included 14 patients (median age at diagnosis: 32 years; range: 11-54). At onset (median age: 20 years; range 9-38), they presented with walking difficulties (n = 8), cognitive decline (n = 3) and/or seizures (n = 3), sometimes associated with mild mental retardation (n = 6). During the disease course, symptoms were almost exclusively neurological with cognitive dysfunction (93%), gait disorders (86%), epilepsy (71%), psychiatric symptoms (57%), polyneuropathy (43%), and visual deficit (43%). Mean diagnostic delay was 14 years. Vascular events were observed in 28% and obesity in 36% of the patients. One patient remained asymptomatic at the age of 55 years. Upon treatment, median total homocysteine decreased (from 183 µmol/L, range 69-266, to 90 µmol/L, range 20-142) and symptoms improved (n = 9) or stabilized (n = 4). Missense pathogenic variants in the C-terminal regulatory domain of the protein were over-represented compared to early-onset cases. Residual MTHFR enzymatic activity in skin fibroblasts (n = 4) was rather high (17%-58%). This series of patients with late-onset MTHFR deficiency underlines the still unmet need of a prompt diagnosis of this treatable disease.


Assuntos
Homocistinúria/diagnóstico , Homocistinúria/patologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/diagnóstico , Espasticidade Muscular/patologia , Adolescente , Adulto , Idade de Início , Criança , Diagnóstico Tardio , Epilepsia/diagnóstico , Epilepsia/patologia , Feminino , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/patologia , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/patologia , Estudos Retrospectivos , Convulsões/diagnóstico , Convulsões/patologia , Adulto Jovem
12.
J Neuropathol Exp Neurol ; 79(10): 1065-1071, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827029

RESUMO

Neuronal intranuclear inclusion disease (NIID) is a progressive neurodegenerative disorder categorized into 3 phenotypic variants: infantile, juvenile, and adult. Four recent reports have linked NIID to CGG expansions in the NOTCH2NLC gene in adult NIID (aNIID) and several juvenile patients. Infantile NIID (iNIID) is an extremely rare neuropediatric condition. We present a 7-year-old male patient with severe progressive neurodegenerative disease that included cerebellar symptoms with cerebellar atrophy on brain MRI, psychomotor developmental regression, pseudobulbar syndrome, and polyneuropathy. The diagnosis of iNIID was established through a postmortem neuropathology work-up. We performed long-read sequencing of the critical NOTCH2NLC repeat motif and found no expansion in the patient. We also re-evaluated an antemortem skin biopsy that was collected when the patient was 2 years and 8 months old and did not identify the intranuclear inclusions. In our report, we highlight that the 2 methods (skin biopsy and CGG expansion testing in NOTCH2NLC) used to identify aNIID patients may provide negative results in iNIID patients.


Assuntos
Doenças Neurodegenerativas/diagnóstico , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Receptor Notch2/genética , Biópsia , Encéfalo/patologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/patologia , Masculino , Pele/patologia , Medula Espinal/patologia , Repetições de Trinucleotídeos/genética
16.
Genome Med ; 12(1): 13, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000841

RESUMO

BACKGROUND: For the majority of rare clinical missense variants, pathogenicity status cannot currently be classified. Classical homocystinuria, characterized by elevated homocysteine in plasma and urine, is caused by variants in the cystathionine beta-synthase (CBS) gene, most of which are rare. With early detection, existing therapies are highly effective. METHODS: Damaging CBS variants can be detected based on their failure to restore growth in yeast cells lacking the yeast ortholog CYS4. This assay has only been applied reactively, after first observing a variant in patients. Using saturation codon-mutagenesis, en masse growth selection, and sequencing, we generated a comprehensive, proactive map of CBS missense variant function. RESULTS: Our CBS variant effect map far exceeds the performance of computational predictors of disease variants. Map scores correlated strongly with both disease severity (Spearman's ϱ = 0.9) and human clinical response to vitamin B6 (ϱ = 0.93). CONCLUSIONS: We demonstrate that highly multiplexed cell-based assays can yield proactive maps of variant function and patient response to therapy, even for rare variants not previously seen in the clinic.


Assuntos
Cistationina beta-Sintase/genética , Teste de Complementação Genética/métodos , Testes Genéticos/métodos , Homocistinúria/genética , Mutação de Sentido Incorreto , Cistationina beta-Sintase/metabolismo , Genótipo , Humanos , Fenótipo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética
17.
Arthritis Res Ther ; 21(1): 77, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30894219

RESUMO

BACKGROUND: ABCG2 is a high-capacity urate transporter that plays a crucial role in renal urate overload and extra-renal urate underexcretion. Previous studies have suggested an association between hyperuricemia and gout susceptibility relative to dysfunctional ABCG2 variants, with rs2231142 (Q141K) being the most common. In this study, we analyzed the ABCG2 gene in a hyperuricemia and gout cohort focusing on patients with pediatric-onset, i.e., before 18 years of age. METHOD: The cohort was recruited from the Czech Republic (n = 234) and consisted of 58 primary hyperuricemia and 176 gout patients, with a focus on pediatric-onset patients (n = 31, 17 hyperuricemia/14 gouts); 115 normouricemic controls were used for comparison. We amplified, sequenced, and analyzed 15 ABCG2 exons. The chi-square goodness-of-fit test was used to compare minor allele frequencies (MAF), and the log-rank test was used to compare empirical distribution functions. RESULTS: In the pediatric-onset cohort, two common (p.V12M, p.Q141K) and three very rare (p.K360del, p.T421A, p.T434M) allelic ABCG2 variants were detected. The MAF of p.Q141K was 38.7% compared to adult-onset MAF 21.2% (OR = 2.4, P = 0.005), to the normouricemic controls cohort MAF 8.5% (OR = 6.8, P <  0.0001), and to the European population MAF 9.4% (OR = 5.7, P <  0.0001). The MAF was greatly elevated not only among pediatric-onset gout patients (42.9%) but also among patients with hyperuricemia (35.3%). Most (74%) of the pediatric-onset patients had affected family members (61% were first-degree relatives). CONCLUSION: Our results show that genetic factors affecting ABCG2 function should be routinely considered in a hyperuricemia/gout diagnosis, especially in pediatric-onset patients. Genotyping of ABCG2 is essential for risk estimation of gout/hyperuricemia in patients with very early-onset and/or a family history.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Predisposição Genética para Doença/genética , Gota/genética , Hiperuricemia/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Alopurinol/uso terapêutico , Criança , Pré-Escolar , Estudos de Coortes , República Tcheca , Febuxostat/uso terapêutico , Feminino , Frequência do Gene , Genótipo , Gota/diagnóstico , Gota/tratamento farmacológico , Supressores da Gota/uso terapêutico , Humanos , Hiperuricemia/diagnóstico , Hiperuricemia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
J Inherit Metab Dis ; 42(2): 333-352, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30773687

RESUMO

AIM: To explore the clinical presentation, course, treatment and impact of early treatment in patients with remethylation disorders from the European Network and Registry for Homocystinurias and Methylation Defects (E-HOD) international web-based registry. RESULTS: This review comprises 238 patients (cobalamin C defect n = 161; methylenetetrahydrofolate reductase deficiency n = 50; cobalamin G defect n = 11; cobalamin E defect n = 10; cobalamin D defect n = 5; and cobalamin J defect n = 1) from 47 centres for whom the E-HOD registry includes, as a minimum, data on medical history and enrolment visit. The duration of observation was 127 patient years. In 181 clinically diagnosed patients, the median age at presentation was 30 days (range 1 day to 42 years) and the median age at diagnosis was 3.7 months (range 3 days to 56 years). Seventy-five percent of pre-clinically diagnosed patients with cobalamin C disease became symptomatic within the first 15 days of life. Total homocysteine (tHcy), amino acids and urinary methylmalonic acid (MMA) were the most frequently assessed disease markers; confirmatory diagnostics were mainly molecular genetic studies. Remethylation disorders are multisystem diseases dominated by neurological and eye disease and failure to thrive. In this cohort, mortality, thromboembolic, psychiatric and renal disease were rarer than reported elsewhere. Early treatment correlates with lower overall morbidity but is less effective in preventing eye disease and cognitive impairment. The wide variation in treatment hampers the evaluation of particular therapeutic modalities. CONCLUSION: Treatment improves the clinical course of remethylation disorders and reduces morbidity, especially if started early, but neurocognitive and eye symptoms are less responsive. Current treatment is highly variable. This study has the inevitable limitations of a retrospective, registry-based design.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/terapia , Homocistinúria/metabolismo , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Espasticidade Muscular/metabolismo , Vitamina B 12/metabolismo , Adolescente , Adulto , Idade de Início , Criança , Pré-Escolar , Estudos Transversais , Progressão da Doença , Europa (Continente) , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Metilação , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Ácido Metilmalônico/urina , Fenótipo , Gravidez , Transtornos Psicóticos/metabolismo , Sistema de Registros , Estudos Retrospectivos , Adulto Jovem
19.
Br J Pharmacol ; 176(4): 594-606, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30341787

RESUMO

BACKGROUND AND PURPOSE: Homocystinurias are rare genetic defects characterized by altered fluxes of sulfur compounds including homocysteine and cysteine. We explored whether the severely perturbed sulfur amino acid metabolism in patients with homocystinurias affects the metabolism of hydrogen sulfide. EXPERIMENTAL APPROACH: We studied 10 treated patients with a block in the conversion of homocysteine to cysteine due to cystathionine ß-synthase deficiency (CBSD) and six treated patients with remethylation defects (RMD) and an enhanced flux of sulfur metabolites via transsulfuration. Control groups for CBSD and RMD patients consisted of 22 patients with phenylketonuria on a low-protein diet and of 12 healthy controls respectively. Plasma and urine concentrations of selected sulfur compounds were analysed by HPLC and LC-MS/MS. KEY RESULTS: Patients with CBSD exhibited plasma concentrations of monobromobimane-detected sulfide similar to appropriate controls. Urinary homolanthionine and thiosulfate in CBSD were increased significantly 1.9 and 3 times suggesting higher hydrogen sulfide synthesis by γ-cystathionase and detoxification respectively. Surprisingly, patients with RMD had significantly lower plasma sulfide levels (53 and 64% of controls) with lower sulfite concentrations, and higher taurine and thiosulfate levels suggesting enhanced cysteine oxidation and hydrogen sulfide catabolism respectively. CONCLUSION AND IMPLICATIONS: The results from this study suggest that severe inherited defects in sulfur amino acid metabolism may be accompanied by only moderately perturbed hydrogen sulfide metabolism and lends support to the hypothesis that enzymes in the transsulfuration pathway may not be the major contributors to the endogenous hydrogen sulfide pool. LINKED ARTICLES: This article is part of a themed section on Chemical Biology of Reactive Sulfur Species. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.4/issuetoc.


Assuntos
Homocistinúria/metabolismo , Compostos de Enxofre/metabolismo , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Homocistinúria/sangue , Homocistinúria/urina , Humanos , Lactente , Masculino , Compostos de Enxofre/sangue , Compostos de Enxofre/urina , Adulto Jovem
20.
Int J Neonatal Screen ; 5(3): 35, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33072994

RESUMO

Appropriate and timely education about newborn screening (NBS) helps to foster benefits such as prompt follow up, to promote parents' autonomy via informed consent and minimize the harms such as reducing the impact of NBS false-positive results. The aim of this study was to ascertain how mothers are informed about NBS in the Czech Republic and to identify the variables associated with awareness about NBS. The questionnaires evaluating awareness and its determinants were mailed to a random sample of 3000 mothers 3 months post-delivery. The overall response rate was 42%. We analysed 1100 questionnaires and observed that better awareness about NBS was significantly associated with age, parity, number of information sources, child health status, size of maternity hospital and an obstetrician as the source of prenatally obtained information. Although the majority of mothers (77%) in our study recalled being informed by a physician or nurse in the neonatal ward, results have revealed that over 40% of participants did not have sufficient awareness about the principal aspects of NBS. Several measures including seminars for healthcare providers and the development and distribution of new educational materials were adopted to improve parental education about NBS in the Czech Republic.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...