This review summarises progress in the research of homocystinuria (HCU) in the past three decades. HCU due to cystathionine β-synthase (CBS) was discovered in 1962, and Prof. Jan Peter Kraus summarised developments in the field in the first-ever Komrower lecture in 1993. In the past three decades, significant advancements have been achieved in the biology of CBS, including gene organisation, tissue expression, 3D structures, and regulatory mechanisms. Renewed interest in CBS arose in the late 1990s when this enzyme was implicated in biogenesis of H2S. Advancements in genetic and biochemical techniques enabled the identification of several hundreds of pathogenic CBS variants and the misfolding of missense mutations as a common mechanism. Several cellular, invertebrate and murine HCU models allowed us to gain insights into functional and metabolic pathophysiology of the disease. Establishing the E-HOD consortium and patient networks, HCU Network Australia and HCU Network America, offered new possibilities for acquiring clinical data in registries and data on patients' quality of life. A recent analysis of data from the E-HOD registry showed that the clinical variability of HCU is broad, extending from severe childhood disease to milder (late) adulthood forms, which typically respond to pyridoxine. Pyridoxine responsiveness appears to be the key factor determining the clinical course of HCU. Increased awareness about HCU played a role in developing novel therapies, such as gene therapy, correction of misfolding by chaperones, removal of methionine from the gut and enzyme therapies that decrease homocysteine or methionine in the circulation.

• MeSH
• cystathionin-beta-synthasa * genetika   MeSH
• dějiny 21. století MeSH
• fenotyp * MeSH
• homocystinurie * genetika   MeSH
• lidé MeSH
• mutace MeSH
• zvířata MeSH
• Check Tag
• dějiny 21. století MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

BACKGROUND: Cystathionine β-synthase (CBS)-deficient homocystinuria (HCU) is an inherited disorder of sulfur amino acid metabolism with varying severity and organ complications, and a limited knowledge about underlying pathophysiological processes. Here we aimed at getting an in-depth insight into disease mechanisms using a transgenic mouse model of HCU (I278T). METHODS: We assessed metabolic, proteomic and sphingolipidomic changes, and mitochondrial function in tissues and body fluids of I278T mice and WT controls. Furthermore, we evaluated the efficacy of methionine-restricted diet (MRD) in I278T mice. RESULTS: In WT mice, we observed a distinct tissue/body fluid compartmentalization of metabolites with up to six-orders of magnitude differences in concentrations among various organs. The I278T mice exhibited the anticipated metabolic imbalance with signs of an increased production of hydrogen sulfide and disturbed persulfidation of free aminothiols. HCU resulted in a significant dysregulation of liver proteome affecting biological oxidations, conjugation of compounds, and metabolism of amino acids, vitamins, cofactors and lipids. Liver sphingolipidomics indicated upregulation of the pro-proliferative sphingosine-1-phosphate signaling pathway. Liver mitochondrial function of HCU mice did not seem to be impaired compared to controls. MRD in I278T mice improved metabolic balance in all tissues and substantially reduced dysregulation of liver proteome. CONCLUSION: The study highlights distinct tissue compartmentalization of sulfur-related metabolites in normal mice, extensive metabolome, proteome and sphingolipidome disruptions in I278T mice, and the efficacy of MRD to alleviate some of the HCU-related biochemical abnormalities.

• MeSH
• cystathionin-beta-synthasa * metabolismus   nedostatek   genetika   MeSH
• homocystinurie * metabolismus   genetika   MeSH
• játra * metabolismus   MeSH
• lipidomika metody   MeSH
• metabolomika * metody   MeSH
• mitochondrie metabolismus   MeSH
• modely nemocí na zvířatech * MeSH
• myši transgenní * MeSH
• myši MeSH
• proteom metabolismus   MeSH
• proteomika * metody   MeSH
• sfingolipidy * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Cystathionine beta-synthase (CBS)-deficient homocystinuria (HCU) is the most common inborn error of sulfur amino acid metabolism. The pyridoxine non-responsive form of the disease manifests itself by massively increasing plasma and tissue concentrations of homocysteine, a toxic intermediate of methionine metabolism that is thought to be the major cause of clinical complications including skeletal deformities, connective tissue defects, thromboembolism and cognitive impairment. The current standard of care involves significant dietary interventions that, despite being effective, often adversely affect quality of life of HCU patients, leading to poor adherence to therapy and inadequate biochemical control with clinical complications. In recent years, the unmet need for better therapeutic options has resulted in development of novel enzyme and gene therapies and exploration of pharmacological approaches to rescue CBS folding defects caused by missense pathogenic mutations. Here, we review scientific evidence and current state of affairs in development of recent approaches to treat HCU.

• MeSH
• cystathionin-beta-synthasa genetika   metabolismus   MeSH
• homocystinurie * farmakoterapie   genetika   metabolismus   MeSH
• kvalita života MeSH
• lidé MeSH
• missense mutace MeSH
• tromboembolie * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH

Elevated total plasma homocysteine (hyperhomocysteinemia) is a marker of cardiovascular, thrombotic, and neuropsychological disease. It has multiple causes, including the common nutritional vitamin B12 or folate deficiency. However, some rare but treatable, inborn errors of metabolism (IEM) characterized by hyperhomocysteinemia can be missed due to variable presentations and the lack of awareness. The aim of this study is to identify undiagnosed IEM in adults with significantly elevated homocysteine using key existing clinical data points, then IEM specific treatment can be offered to improve outcome. We conducted a retrospective study with data mining and chart review of patients with plasma total homocysteine >30 μmol/L over a two-year period. We offer biochemical and genetic testing to patients with significant hyperhomocysteinemia without a clear explanation to diagnose IEM. We identified 22 subjects with significant hyperhomocysteinemia but no clear explanation. Subsequently, we offered genetic testing to seven patients and diagnosed one patient with classic homocystinuria due to cystathionine beta-synthase deficiency. With treatment, she lowered her plasma homocysteine and improved her health. This study stresses the importance of a thorough investigation of hyperhomocysteinemia in adults to identify rare but treatable IEM. We propose a metabolic evaluation algorithm for elevated homocysteine levels.

• MeSH
• dospělí MeSH
• homocystein MeSH
• homocystinurie * diagnóza   genetika   MeSH
• hyperhomocysteinemie * diagnóza   genetika   MeSH
• kyselina listová MeSH
• lidé MeSH
• retrospektivní studie MeSH
• vitamin B 12 terapeutické užití   MeSH
• vrozené poruchy metabolismu * diagnóza   genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

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.

• MeSH
• homocystein MeSH
• homocystinurie * diagnóza   farmakoterapie   MeSH
• kohortové studie MeSH
• lidé MeSH
• methylentetrahydrofolátreduktasa (NADPH2) nedostatek   genetika   MeSH
• novorozenec MeSH
• psychotické poruchy MeSH
• retrospektivní studie MeSH
• svalová spasticita diagnóza   MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

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.

• MeSH
• betain škodlivé účinky   MeSH
• cystathionin-beta-synthasa MeSH
• homocystein MeSH
• homocystinurie * farmakoterapie   MeSH
• lidé MeSH
• methylentetrahydrofolátreduktasa (NADPH2) nedostatek   genetika   MeSH
• psychotické poruchy * MeSH
• svalová spasticita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH

Úvod: Dědičně podmíněné poruchy metabolismu (DPM) aminokyselin (AMK), organických kyselin (OA) a cyklu močoviny (UCD) představují heterogenní skupinu 135 různých onemocnění způsobených porušenou syntézou, transportem či odbouráváním AMK, OA a amoniaku. Jednotlivá onemocnění jsou vzácná, ale celkový výskyt v populaci je 1 : 3000–4000. Metodika: Práce shrnuje klinické, diagnostické a terapeutické aspekty nejčastějších DPM-AMK, OA a UCD. Osm nemocí je součástí laboratorního novorozeneckého screeningu, diagnostika ostatních DPM závisí na klinickém podezření, stanovení amoniaku v krvi a rychlé indikaci selektivního metabolického screeningu. Výsledky: DPM-AMK, OA a UCD se klinicky projevují akutním nebo subakutním rozvratem metabolismu s metabolickou alkalózou nebo acidózou a následným postižením funkcí jater, ledvin a/nebo mozku nebo pomalu progredujícím postižením CNS se zpomalením vývoje a poruchou kognitivních funkcí. Do první skupiny patří OA, tyrosinemie typu 1, leucinóza a UCD, které se projevují hromaděním toxických metabolitů vznikajících při degradaci aminokyselin. Do druhé skupiny patří fenylketonurie a homocystinurie, u které se přidružuje i postižení očí, kostí a/nebo tromboembolické příhody. Závěr: Adekvátní terapie závisí na včasné diagnostice. U pacientů s akutním postižením mozku, například při těžké hyperamonemii, se používají eliminační metody. U pacientů s pomaleji progredujícím onemocněním se uplatňuje celoživotní nízkobílkovinná dieta suplementovaná potravinami pro zvláštní lékařské účely, vitaminoterapie a chaperonová terapie podporující aktivity postižených enzymů a snaha blokovat či aktivovat alternativní metabolické dráhy. Zvyšuje se počet onemocnění, u kterých se používá enzymová substituční terapie či transplantace jater nebo ledvin. Nově probíhají trialy s genovou terapií.

Introduction: Inborn errors of amino acid (AA), organic acid (OA) metabolism and disorders of the urea cycle (UCD) represent a heterogeneous group of 135 different diseases caused by impaired synthesis, transport or degradation of AA, OA and ammonia. Individual diseases are rare, but the overall incidence in the population is 1:3000–4000. Methodology: The work summarizes the clinical, diagnostic and therapeutic aspects of the most common inborn errors of AA, OA metabolism and UCD. Eight diseases are part of laboratory neonatal screening, diagnosis of other IEMs depends on clinical suspicion, determination of ammonia in the blood and rapid indication of selective metabolic screening. Results: Inborn errors of AA, OA metabolism and UCD are clinically manifested by acute or subacute metabolic disruption with metabolic alkalosis or acidosis and subsequent hepatic, renal and / or cerebral impairment or slowly progressive brain impairment with developmental delay and cognitive decline. The first group includes OA, tyrosinemia type 1, leucinosis and UCD, which are manifested by the accumulation of toxic metabolites arising from amino acid degradation. The second group includes phenylketonuria and homocystinuria, which are associated with eye, bone and / or thromboembolic events. Conclusion: Adequate therapy depends on early diagnosis. Elimination methods are used in patients with acute brain involvement, such as severe hyperammonaemia. In patients with chronic disease, a lifelong low-protein diet supplemented with foods for special medical purposes, vitamin therapy and chaperone therapy supporting the activities of affected enzymes and efforts to block or activate alternative metabolic pathways are used. The number of diseases in which enzyme replacement therapy or liver or kidney transplantation is used is increasing. Trials with gene therapy are underway.

• MeSH
• dítě MeSH
• fenylketonurie diagnóza   terapie   MeSH
• homocystinurie diagnóza   terapie   MeSH
• lidé MeSH
• neketotická hyperglycinemie diagnóza   terapie   MeSH
• nemoc s močí javorového sirupu diagnóza   terapie   MeSH
• tyrosinemie diagnóza   terapie   MeSH
• vrozené poruchy metabolismu aminokyselin * diagnóza   terapie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

Cystathionine β-synthase (CBS) deficiency has a wide clinical spectrum, ranging from neurodevelopmental problems, lens dislocation and marfanoid features in early childhood to adult onset disease with predominantly thromboembolic complications. We have analysed clinical and laboratory data at the time of diagnosis in 328 patients with CBS deficiency from the E-HOD (European network and registry for Homocystinurias and methylation Defects) registry. We developed comprehensive criteria to classify patients into four groups of pyridoxine responsivity: non-responders (NR), partial, full and extreme responders (PR, FR and ER, respectively). All groups showed overlapping concentrations of plasma total homocysteine while pyridoxine responsiveness inversely correlated with plasma/serum methionine concentrations. The FR and ER groups had a later age of onset and diagnosis and a longer diagnostic delay than NR and PR patients. Lens dislocation was common in all groups except ER but the age of dislocation increased with increasing responsiveness. Developmental delay was commonest in the NR group while no ER patient had cognitive impairment. Thromboembolism was the commonest presenting feature in ER patients, whereas it was least likely at presentation in the NR group. This probably is due to the differences in ages at presentation: all groups had a similar number of thromboembolic events per 1000 patient-years. Clinical severity of CBS deficiency depends on the degree of pyridoxine responsiveness. Therefore, a standardised pyridoxine-responsiveness test in newly diagnosed patients and a critical review of previous assessments is indispensable to ensure adequate therapy and to prevent or reduce long-term complications.

• MeSH
• cystathionin-beta-synthasa nedostatek   MeSH
• dítě MeSH
• dospělí MeSH
• fenotyp MeSH
• homocystinurie diagnóza   farmakoterapie   enzymologie   MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• methionin krev   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• opožděná diagnóza MeSH
• předškolní dítě MeSH
• pyridoxin terapeutické užití   MeSH
• registrace MeSH
• senioři MeSH
• stupeň závažnosti nemoci MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

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.

• MeSH
• dítě MeSH
• dospělí MeSH
• epilepsie diagnóza   patologie   MeSH
• homocystinurie diagnóza   patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mentální retardace diagnóza   patologie   MeSH
• methylentetrahydrofolátreduktasa (NADPH2) nedostatek   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• opožděná diagnóza MeSH
• psychotické poruchy diagnóza   patologie   MeSH
• retrospektivní studie MeSH
• svalová spasticita diagnóza   patologie   MeSH
• věk při počátku nemoci MeSH
• záchvaty diagnóza   patologie   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

Metabolic syndrome-a risk factor for arteriosclerosis and diabetes type 2- is one of the major population health burdens while homocystinurias are rare genetic disorders complicated also by vascular disease. These seemingly unrelated conditions, however, have been both linked to disturbed metabolism of sulfur compounds including cysteine and hydrogen sulfide. We will use targeted metabolomics approach for determination of compounds related to cysteine metabolism (including markers of hydrogen sulfide synthesis and catabolism) in plasma samples obtained from patients with homocystinurias, obese patients and controls, and in cultured human cells; to get further insight into organ-specific changes we will complement research in humans by studying tissues from animal models. This project will elucidate the role of cysteine and hydrogen sulfide in selected diseases and will facilitate development of novel personalized approaches to treat metabolic syndrome or its components, and to ameliorate complications in homocystinurias by targeting specific parts of relevant metabolic pathways.

Metabolický syndrom je rizikový faktor pro atherosklerózu a diabetes 2.typu a patří mezi populačně významné stavy, naproti tomu homocystinurie s postižením cévního systému patří mezi vzácné genetické nemoci. U obou těchto zdánlivě nesouvisejících chorob však byly nalezeny změny v metabolismu cysteinu i sirovodíku. Ve studii použijeme metody cílené metabolomiky pro stanovení látek souvisejících s metabolismem cysteinu (včetně látek odrážejících syntézu a katabolismus sirovodíku) ve vzorcích plasmy získaných od pacientů s homocystinuriemi, obézních pacientů a kontrol, a dále v kultivovaných lidských buňkách. Pro porozumění orgánově specifickým změnám doplníme výzkum na humánních vzorcích studiem tkání u zvířecích modelů. Řešení tohoto projektu objasní detailně úlohu cysteinu a sirovodíku u dvou skupin nemocí a umožní tak vývoj nových postupů personalizované medicíny zacílených na určitá místa metabolických drah; tyto postupy budou využitelné při léčbě metabolického syndromu či jeho komponent a pro zmírnění komplikací u pacientů s homocystinuriemi.

• MeSH
• cystein metabolismus   MeSH
• homocystinurie etiologie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• metabolický syndrom etiologie   metabolismus   MeSH
• metabolomika MeSH
• modely nemocí na zvířatech MeSH
• sulfan metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• vnitřní lékařství
• neurologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR