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Häberle J, Siri B, Dionisi-Vici C. Quo vadis ureagenesis disorders? A journey from 90 years ago into the future. J Inherit Metab Dis 2024. [PMID: 38837457 DOI: 10.1002/jimd.12763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/30/2024] [Accepted: 05/14/2024] [Indexed: 06/07/2024]
Abstract
The pathway of ammonia disposal in the mammalian organism has been described in 1932 as a metabolic cycle present in the liver in different compartments. In 1958, the first human disorder affecting this pathway was described as a genetic condition leading to cognitive impairment and constant abnormalities of amino acid metabolism. Since then, defects in all enzymes and transporters of the urea cycle have been described, referring to them as primary urea cycle disorders causing primary hyperammonemia. In addition, there is a still increasing list of conditions that impact on the function of the urea cycle by various mechanisms, hereby leading to secondary hyperammonemia. Despite great advances in understanding the molecular background and the biochemical specificities of both primary and secondary hyperammonemias, there remain many open questions: we do not fully understand the pathophysiology in many of the conditions; we do not always understand the highly variable clinical course of affected patients; we clearly appreciate the need for novel and improved diagnostic and therapeutic approaches. This study does look back to the beginning of the urea cycle (hi)story, briefly describes the journey through past decades, hereby illustrating advancements and knowledge gaps, and gives examples for the extremely broad perspective imminent to some of the defects of ureagenesis and allied conditions.
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Affiliation(s)
- Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Barbara Siri
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - Carlo Dionisi-Vici
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
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2
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Makris G, Veit L, Rüfenacht V, Klassa S, Zürcher N, Matsumoto S, Poms M, Häberle J. Expression and function of the urea cycle in widely-used hepatic cellular models. J Inherit Metab Dis 2024. [PMID: 38192032 DOI: 10.1002/jimd.12701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 01/10/2024]
Abstract
The group of rare metabolic defects termed urea cycle disorders (UCDs) occur within the ammonia elimination pathway and lead to significant neurocognitive sequelae for patients surviving decompensation episodes. Besides orthotopic liver transplantation, curative options are lacking for UCDs, with dietary management being the gold clinical standard. Novel therapeutic approaches are essential for UCDs; however, such effort presupposes preclinical testing in cellular models that effectively capture disease manifestation. Several cellular and animal models exist and aim to recapitulate the broad phenotypic spectrum of UCDs; however, the majority of those lack extensive molecular and biochemical characterization. The development of cellular models is emerging since animal models are extremely time and cost consuming, and subject to ethical considerations, including the 3R principle that endorses animal welfare over unchecked preclinical testing. The aim of this study was to compare the extent of expression and functionality of the urea cycle in two commercial hepatoma-derived cell lines, induced pluripotent stem cell hepatocytes (iPSC-Heps), primary human hepatocytes (PHHs) and human liver cell preparations. Using immunoblotting, immunocytochemistry, and stable isotope tracing of the urea cycle metabolites, we identified that the hepatoma-derived, 2-week differentiated HepaRG cells are urea cycle proficient and behave as cellular alternatives to PHHs. Furthermore, HepaRG cells were superior to iPSC-Heps, which are known to exhibit batch-to-batch variabilities in terms of hepatic maturity and enzyme expression. Finally, HepG2 cells lack the urea cycle enzymes ornithine transcarbamylase and arginase 1, the transporter ORNT1, which limits their suitability as model for the study of UCDs.
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Affiliation(s)
- Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
- Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Lara Veit
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Sven Klassa
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Nadia Zürcher
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Shirou Matsumoto
- Department of Pediatrics, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Martin Poms
- Division of Clinical Chemistry and Biochemistry, University Children's Hospital Zurich, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
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3
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Zarante Bahamón AM, Navarro Marroquin S, Suarez-Obando F, Ramón Gómez JL. Recomendaciones de manejo de la hiperamonemia en neonatos. UNIVERSITAS MÉDICA 2023. [DOI: 10.11144/javeriana.umed63-4.rmhn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
La hiperamonemia se define como el aumento de las concentraciones de amonio en el plasma, de forma aguda o crónica. Frecuentemente, se presenta en diversos tipos de errores innatos del metabolismo, enfermedades que deben diagnosticarse y manejarse de manera inmediata y adecuada, debido a que el retraso en su manejo genera secuelas neurológicas graves y permanentes, así como desenlaces fatales. El objetivo del artículo es aportar herramientas al clínico para la sospecha, el abordaje diagnóstico y el manejo del recién nacido con hiperamonemia primaria, teniendo en cuenta la correlación entre fisiopatología, etiología, aproximación clínica y de laboratorio, así como recomendaciones de manejo farmacológico y no farmacológico.
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4
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Scharping M, Brennenstuhl H, Garbade SF, Wild B, Posset R, Zielonka M, Kölker S, Haun MW, Opladen T. Unmet Needs of Parents of Children with Urea Cycle Disorders. CHILDREN 2022; 9:children9050712. [PMID: 35626889 PMCID: PMC9140128 DOI: 10.3390/children9050712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 12/26/2022]
Abstract
(1) Background: Phenotypic diversity and long-term health outcomes of individuals with urea cycle disorders (UCDs) have been described in detail. However, there is limited information on the burden on affected families. (2) Methods: To evaluate the family burden in parents with children suffering from UCDs, we used validated questionnaires. Socio-demographic characteristics were evaluated, and an adapted version of the Parental Need Scale for Rare Diseases questionnaire was used. The survey was conducted in families of UCD patients cared for at the University Children’s Hospital Heidelberg. (3) Results: From April to November 2021, 59 participants were interviewed (mothers n = 34, fathers n = 25). The affected patients most frequently suffered from ornithine transcarbamylase deficiency (OTC-D) (female n = 12, male n = 12), followed by argininosuccinate synthetase deficiency (ASS-D, n = 13) and argininosuccinate lyase deficiency (ASL-D, n = 8). About one-third of the participants were “dissatisfied” or “extremely dissatisfied” with health professionals’ disease knowledge. In addition, 30% of the participants reported a medium or high need for “additional information on the development of their children”, and 44% reported a medium or high need “for information on available services”. A majority of 68% reported a need for additional support regarding services such as support groups (42%) or psychological counseling (29%). (4) Conclusions: Our study indicates that there is an unmet need for sufficient information about the development of children with UCDs, as well as for information about available support services for families with UCD patients. Furthermore, the results highlight the importance of establishing or improving family-centered care approaches. This pilot study may serve as a template for the assessment of the family burden associated with other inherited metabolic diseases.
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Affiliation(s)
- Mara Scharping
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Heiko Brennenstuhl
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Sven F. Garbade
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Beate Wild
- Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, 69120 Heidelberg, Germany; (B.W.); (M.W.H.)
| | - Roland Posset
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Matthias Zielonka
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Stefan Kölker
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
| | - Markus W. Haun
- Department of General Internal Medicine and Psychosomatics, University Hospital Heidelberg, 69120 Heidelberg, Germany; (B.W.); (M.W.H.)
| | - Thomas Opladen
- Division of Child Neurology and Metabolic Medicine, Centre for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany; (M.S.); (H.B.); (S.F.G.); (R.P.); (M.Z.); (S.K.)
- Correspondence:
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5
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Eminoğlu FT, Öncül Ü, Kahveci F, Okulu E, Kraja E, Köse E, Kendirli T. Characteristics of continuous venovenous hemodiafiltration in the acute treatment of inherited metabolic disorders. Pediatr Nephrol 2022; 37:1387-1397. [PMID: 34693482 PMCID: PMC8542505 DOI: 10.1007/s00467-021-05329-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/02/2021] [Accepted: 10/04/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Continuous kidney replacement therapies (CKRT) have been reported to be an effective approach to removing toxic metabolites in inborn errors of metabolism (IEM). The present study evaluates efficiency and complications of CKRT in children with IEM. METHODS Patients diagnosed with IEM who underwent CKRT in pediatric and neonatal intensive care units were analyzed. CKRT were initiated in patients with persistently high blood ammonia levels (≥ 500 μmol/L), blood ammonia levels > 250 μmol/L in the presence of moderate encephalopathy, high blood leucine levels (≥ 1500 μmol/L), and blood leucine levels < 1500 μmol/L in the presence of deteriorating neurological status or persistent metabolic acidosis. RESULTS Of 22 patients enrolled, nine (40.9%) Maple syrup urine disease (MSUD), eight (36.4%) urea cycle disorders (UCD), and five (22.7%) organic acidemias (OA). Median age was 72.3 [9.9-1040.8] days. In total, 28 dialysis sessions were analyzed [16 (57.1%) continuous venovenous hemodialysis, and 12 (42.9%) continuous venovenous hemodiafiltration]. A significant decrease was noted in leucine levels (from 1608.4 ± 885.3 to 314.6 ± 109.9 µmol/L) of patients with MSUD, while ammonia levels were significantly decreased in patients with UCD and OA (from 1279.9 ± 612.1 to 85.1 ± 21.6 µmol/L). The most frequent complications of CKRT were thrombocytopenia (60.7%), hypotension (53.6%), and hypocalcemia (42.9%). Median age of patients with hypotension treated with vasoactive medications was significantly lower than median age of those with normal blood pressure. CONCLUSION CKRT is a reliable approach for effective and rapid removal of toxic metabolites in children with IEM, and CKRT modalities can be safely used and are well-tolerated in infants.
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Affiliation(s)
- Fatma Tuba Eminoğlu
- Department of Pediatric Metabolism, Faculty of Medicine, Ankara University, Ankara, Turkey.
| | - Ümmühan Öncül
- Department of Pediatric Metabolism, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Fevzi Kahveci
- Department of Pediatric Intensive Care Unit, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Emel Okulu
- Department of Neonatology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Elvis Kraja
- Department of Neonatology, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Engin Köse
- Department of Pediatric Metabolism, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Tanıl Kendirli
- Department of Pediatric Intensive Care Unit, Faculty of Medicine, Ankara University, Ankara, Turkey
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6
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Nitzahn M, Truong B, Khoja S, Vega-Crespo A, Le C, Eliav A, Makris G, Pyle AD, Häberle J, Lipshutz GS. CRISPR-Mediated Genomic Addition to CPS1 Deficient iPSCs is Insufficient to Restore Nitrogen Homeostasis. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2021; 94:545-557. [PMID: 34970092 PMCID: PMC8686786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CPS1 deficiency is an inborn error of metabolism caused by loss-of-function mutations in the CPS1 gene, catalyzing the initial reaction of the urea cycle. Deficiency typically leads to toxic levels of plasma ammonia, cerebral edema, coma, and death, with the only curative treatment being liver transplantation; due to limited donor availability and the invasiveness and complications of the procedure, however, alternative therapies are needed. Induced pluripotent stem cells offer an alternative cell source to partial or whole liver grafts that theoretically would not require immune suppression regimens and additionally are amenable to genetic modifications. Here, we genetically modified CPS1 deficient patient-derived stem cells to constitutively express human codon optimized CPS1 from the AAVS1 safe harbor site. While edited stem cells efficiently differentiated to hepatocyte-like cells, they failed to metabolize ammonia more efficiently than their unedited counterparts. This unexpected result appears to have arisen in part due to transgene promoter methylation, and thus transcriptional silencing, in undifferentiated cells, impacting their capacity to restore the complete urea cycle function upon differentiation. As pluripotent stem cell strategies are being expanded widely for potential cell therapies, these results highlight the need for strict quality control and functional analysis to ensure the integrity of cell products.
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Affiliation(s)
- Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of
Medicine at UCLA, Los Angeles, CA, USA,Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA
| | - Brian Truong
- Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA,Department of Molecular and Medical Pharmacology, David
Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Suhail Khoja
- Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA
| | - Agustin Vega-Crespo
- Department of Molecular and Medical Pharmacology, David
Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Colleen Le
- Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA
| | - Adam Eliav
- Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA
| | - Georgios Makris
- Division of Metabolism and Children’s Research Center,
University Children’s Hospital Zurich, Switzerland
| | - April D. Pyle
- Department of Microbiology, Immunology, and Molecular
Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Eli and Edythe Broad Stem Cell Center, David Geffen
School of Medicine at UCLA, Los Angeles, CA, USA
| | - Johannes Häberle
- Division of Metabolism and Children’s Research Center,
University Children’s Hospital Zurich, Switzerland
| | - Gerald S. Lipshutz
- Molecular Biology Institute, David Geffen School of
Medicine at UCLA, Los Angeles, CA, USA,Department of Surgery, David Geffen School of Medicine
at UCLA, Los Angeles, CA, USA,Department of Molecular and Medical Pharmacology, David
Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Psychiatry, David Geffen School of
Medicine at UCLA, Los Angeles, CA, USA,Intellectual and Developmental Disabilities Research
Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Semel Institute for Neuroscience, David Geffen School
of Medicine at UCLA, Los Angeles, CA, USA,To whom all correspondence should be addressed:
Gerald S. Lipshutz, David Geffen School of Medicine at UCLA, Los Angeles, CA
90095-7054;
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7
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Oltman SP, Rogers EE, Baer RJ, Jasper EA, Anderson JG, Steurer MA, Pantell MS, Petersen MA, Partridge JC, Karasek D, Ross KM, Feuer SK, Franck LS, Rand L, Dagle JM, Ryckman KK, Jelliffe-Pawlowski LL. Newborn metabolic vulnerability profile identifies preterm infants at risk for mortality and morbidity. Pediatr Res 2021; 89:1405-1413. [PMID: 33003189 PMCID: PMC8061535 DOI: 10.1038/s41390-020-01148-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 01/09/2023]
Abstract
BACKGROUND Identifying preterm infants at risk for mortality or major morbidity traditionally relies on gestational age, birth weight, and other clinical characteristics that offer underwhelming utility. We sought to determine whether a newborn metabolic vulnerability profile at birth can be used to evaluate risk for neonatal mortality and major morbidity in preterm infants. METHODS This was a population-based retrospective cohort study of preterm infants born between 2005 and 2011 in California. We created a newborn metabolic vulnerability profile wherein maternal/infant characteristics along with routine newborn screening metabolites were evaluated for their association with neonatal mortality or major morbidity. RESULTS Nine thousand six hundred and thirty-nine (9.2%) preterm infants experienced mortality or at least one complication. Six characteristics and 19 metabolites were included in the final metabolic vulnerability model. The model demonstrated exceptional performance for the composite outcome of mortality or any major morbidity (AUC 0.923 (95% CI: 0.917-0.929). Performance was maintained across mortality and morbidity subgroups (AUCs 0.893-0.979). CONCLUSIONS Metabolites measured as part of routine newborn screening can be used to create a metabolic vulnerability profile. These findings lay the foundation for targeted clinical monitoring and further investigation of biological pathways that may increase the risk of neonatal death or major complications in infants born preterm. IMPACT We built a newborn metabolic vulnerability profile that could identify preterm infants at risk for major morbidity and mortality. Identifying high-risk infants by this method is novel to the field and outperforms models currently in use that rely primarily on infant characteristics. Utilizing the newborn metabolic vulnerability profile for precision clinical monitoring and targeted investigation of etiologic pathways could lead to reductions in the incidence and severity of major morbidities associated with preterm birth.
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Affiliation(s)
- Scott P. Oltman
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California
| | - Elizabeth E. Rogers
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Rebecca J. Baer
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Pediatrics, University of California San Diego, La Jolla, CA
| | | | - James G. Anderson
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Martina A. Steurer
- Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California,Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Matthew S. Pantell
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Mark A. Petersen
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - J. Colin Partridge
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Deborah Karasek
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Obstetrics, Gynecology, & Reproductive Sciences, University of California San Francisco, San Francisco, California
| | - Kharah M. Ross
- Owerko Centre, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Alberta
| | - Sky K. Feuer
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Obstetrics, Gynecology, & Reproductive Sciences, University of California San Francisco, San Francisco, California
| | - Linda S. Franck
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,School of Nursing, University of California San Francisco, San Francisco California
| | - Larry Rand
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Obstetrics, Gynecology, & Reproductive Sciences, University of California San Francisco, San Francisco, California
| | - John M. Dagle
- Department of Pediatric, University of Iowa, Iowa City, IA
| | - Kelli K. Ryckman
- Department of Epidemiology, University of Iowa, Iowa City, IA,Department of Pediatric, University of Iowa, Iowa City, IA
| | - Laura L. Jelliffe-Pawlowski
- California Preterm Birth Initiative, University of California San Francisco, San Francisco, California,Department of Epidemiology & Biostatistics, University of California San Francisco, San Francisco, California
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8
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Ranchin B, Plaisant F, Demède D, Guillebon J, Javouhey E, Bacchetta J. Review: Neonatal dialysis is technically feasible but ethical and global issues need to be addressed. Acta Paediatr 2021; 110:781-788. [PMID: 33373057 DOI: 10.1111/apa.15539] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/28/2022]
Abstract
AIM Our aim was to look at the technical, ethical and global issues related to neonatal dialysis. METHODS We performed a PubMed research on manuscripts published from March 2010 to March 2020 and retrospectively reviewed all neonates who received dialysis in our French paediatric and neonatal intensive care units from April 2009 to March 2019. RESULTS Dialysis is performed on neonates with pre-existing renal diseases, acute kidney injuries or inborn errors of metabolism. It is required in 0.5%-1% of neonates admitted to the neonatal intensive care units. Peritoneal dialysis and extracorporeal blood purification are both feasible, with more complications, but the results are close to those obtained in older infants, at least in children without multi-organ dysfunction. Novel haemodialysis machines are being evaluated. Ethical issues are a major concern. Multidisciplinary teams should consider associated comorbidities, risks of permanent end-stage renal disease and provide parents with full and neutral information. These should drive decisions about whether dialysis is in child's best interests. CONCLUSION Neonatal dialysis is technically feasible, but ethically challenging, and short-term and long-term data remain limited. Prospective studies and dialysis registries would improve global management and quality of life of these patients at risk of chronic kidney disease.
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Affiliation(s)
- Bruno Ranchin
- Centre de Référence des Maladies Rénales Rares Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
| | - Franck Plaisant
- Service de Néonatologie et réanimation néonatale Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
| | - Delphine Demède
- Service de Chirurgie Pédiatrique Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
| | - Jean‐Marie Guillebon
- Centre de Référence des Maladies Rénales Rares Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
| | - Etienne Javouhey
- Service de Réanimation pédiatrique Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
- Faculté de Médecine Lyon Est Université de Lyon Lyon France
| | - Justine Bacchetta
- Centre de Référence des Maladies Rénales Rares Hôpital Femme Mère Enfant Hospices Civils de Lyon Bron France
- Faculté de Médecine Lyon Est Université de Lyon Lyon France
- INSERM UMR 1033 Faculté de Médecine Lyon Est Université de Lyon Lyon France
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9
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Bernal AC, Tubio MC, Crespo C, Eiroa HD. Clinical and Genetic Characterization and Biochemical Correlation at Presentation in 48 Patients Diagnosed with Urea Cycle Disorders at the Hospital Juan P Garrahan, Argentina. JOURNAL OF INBORN ERRORS OF METABOLISM AND SCREENING 2021. [DOI: 10.1590/2326-4594-jiems-2020-0026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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10
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Makris G, Lauber M, Rüfenacht V, Gemperle C, Diez-Fernandez C, Caldovic L, Froese DS, Häberle J. Clinical and structural insights into potential dominant negative triggers of proximal urea cycle disorders. Biochimie 2020; 183:89-99. [PMID: 33309754 DOI: 10.1016/j.biochi.2020.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 12/31/2022]
Abstract
Despite biochemical and genetic testing being the golden standards for identification of proximal urea cycle disorders (UCDs), genotype-phenotype correlations are often unclear. Co-occurring partial defects affecting more than one gene have not been demonstrated so far in proximal UCDs. Here, we analyzed the mutational spectrum of 557 suspected proximal UCD individuals. We probed oligomerizing forms of NAGS, CPS1 and OTC, and evaluated the surface exposure of residues mutated in heterozygously affected individuals. BN-PAGE and gel-filtration chromatography were employed to discover protein-protein interactions within recombinant enzymes. From a total of 281 confirmed patients, only 15 were identified as "heterozygous-only" candidates (i.e. single defective allele). Within these cases, the only missense variants to potentially qualify as dominant negative triggers were CPS1 p.Gly401Arg and NAGS p.Thr181Ala and p.Tyr512Cys, as assessed by residue oligomerization capacity and surface exposure. However, all three candidates seem to participate in critical intramolecular functions, thus, unlikely to facilitate protein-protein interactions. This interpretation is further supported by BN-PAGE and gel-filtration analyses revealing no multiprotein proximal urea cycle complex formation. Collectively, genetic analysis, structural considerations and in vitro experiments point against a prominent role of dominant negative effects in human proximal UCDs.
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Affiliation(s)
- Georgios Makris
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Matthias Lauber
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Véronique Rüfenacht
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Corinne Gemperle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Carmen Diez-Fernandez
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland; Nextech Invest, Bahnhofstrasse 18, 8001, Zurich, Switzerland
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Hospital, Washington, DC, USA
| | - D Sean Froese
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
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Nitzahn M, Lipshutz GS. CPS1: Looking at an ancient enzyme in a modern light. Mol Genet Metab 2020; 131:289-298. [PMID: 33317798 PMCID: PMC7738762 DOI: 10.1016/j.ymgme.2020.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/02/2020] [Accepted: 10/03/2020] [Indexed: 02/06/2023]
Abstract
The mammalian urea cycle (UC) is responsible for siphoning catabolic waste nitrogen into urea for excretion. Disruptions of the functions of any of the enzymes or transporters lead to elevated ammonia and neurological injury. Carbamoyl phosphate synthetase 1 (CPS1) is the first and rate-limiting UC enzyme responsible for the direct incorporation of ammonia into UC intermediates. Symptoms in CPS1 deficiency are typically the most severe of all UC disorders, and current clinical management is insufficient to prevent the associated morbidities and high mortality. With recent advances in basic and translational studies of CPS1, appreciation for this enzyme's essential role in the UC has been broadened to include systemic metabolic regulation during homeostasis and disease. Here, we review recent advances in CPS1 biology and contextualize them around the role of CPS1 in health and disease.
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Affiliation(s)
- Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gerald S Lipshutz
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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12
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Considering Proximal Urea Cycle Disorders in Expanded Newborn Screening. Int J Neonatal Screen 2020; 6:ijns6040077. [PMID: 33124615 PMCID: PMC7712149 DOI: 10.3390/ijns6040077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/20/2020] [Accepted: 09/29/2020] [Indexed: 02/06/2023] Open
Abstract
Proximal urea cycle disorders (PUCDs) have adverse outcomes such as intellectual disability and death, which may benefit from newborn screening (NBS) through early detection and prevention with early treatment. Ornithine transcarbamylase deficiency (OTCD) and carbamoyl phosphate synthetase 1 deficiency (CPS1D) are screened in six and eight states in the United States. We analyzed current evidence to see if it supports inclusion of PUCDs in the NBS panels based upon prevention potential, medical, diagnostic, treatment, and public health rationales. A literature review was performed in PubMed using MESH terms for OTCD, CPS1D, and NAGSD. A systematic review was performed in the hallmark of NBS inclusion criteria. We reviewed 31 articles. Molecular and biochemical diagnosis is available to provide diagnostic evidence. Untreated PUCDs have a significant burden with considerable developmental delay and mortality that may improve with early treatment. Tandem mass spectrometry can be used for NBS for PUCDs; however, citrulline and glutamine alone are not specific. Medical treatments currently available for PUCDs meet existing medical, diagnostic, treatment, and public health rationales. Improvement in NBS algorithms to increase sensitivity and specificity will allow earlier diagnosis and treatment to potentially improve disability and mortality rates.
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13
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Ames EG, Luckritz KE, Ahmad A. A retrospective review of outcomes in the treatment of hyperammonemia with renal replacement therapy due to inborn errors of metabolism. Pediatr Nephrol 2020; 35:1761-1769. [PMID: 32232638 DOI: 10.1007/s00467-020-04533-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/08/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Outcomes for severe hyperammonemia treated with renal replacement therapy (RRT) reported in the literature vary widely. This has created differing recommendations regarding when RRT is beneficial for hyperammonemic patients. METHODS To evaluate our institution's experience with RRT in pediatric patients with inborn errors of metabolism (IEMs) and potential prognostic indicators of a better or worse outcome, we performed a retrospective chart review of patients who received RRT for hyperammonemia. Our cohort included 19 patients with confirmed IEMs who received RRT between 2000 and 2017. Descriptive statistics are presented as medians with interquartile ranges with appropriate statistical testing assuming unequal variance. RESULTS There were 16 males (84%) and 3 females (16%) identified for inclusion in this study. There were 9 survivors (47%) and 10 non-survivors (53%). The average age of survivors was 67 months (age range from 3 days to 15.6 years). The average age of non-survivors was 1.8 months (age range from 2 days to 18.7 months). Peak ammonia, ammonia on admission, and at RRT initiation were higher in non-survivors compared with survivors. Higher ammonia levels and no change in ammonia between admission and RRT initiation were associated with an increased risk of mortality. CONCLUSIONS Hyperammonemia affects two distinct patient populations; neonates with markedly elevated ammonia levels on presentation and older children who often have established IEM diagnoses and require RRT after failing nitrogen-scavenging therapy. Our experience demonstrates no significant change in mortality associated with neonatal hyperammonemia, which remains high despite improvements in RRT and intensive care.
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Affiliation(s)
- Elizabeth G Ames
- Division of Pediatric Genetics, Metabolism, and Genomic Medicine, Department of Pediatrics, University of Michigan, D5240 Medical Professional Building, 1500 E. Medical Center Dr, Ann Arbor, MI, 48109, USA.
| | - Kera E Luckritz
- Division of Pediatric Nephrology, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Ayesha Ahmad
- Division of Pediatric Genetics, Metabolism, and Genomic Medicine, Department of Pediatrics, University of Michigan, D5240 Medical Professional Building, 1500 E. Medical Center Dr, Ann Arbor, MI, 48109, USA
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14
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Matoori S, Forster V, Agostoni V, Bettschart-Wolfensberger R, Bektas RN, Thöny B, Häberle J, Leroux JC, Kabbaj M. Preclinical evaluation of liposome-supported peritoneal dialysis for the treatment of hyperammonemic crises. J Control Release 2020; 328:503-513. [PMID: 32860926 DOI: 10.1016/j.jconrel.2020.08.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/07/2020] [Accepted: 08/20/2020] [Indexed: 12/19/2022]
Abstract
Liposome-supported peritoneal dialysis (LSPD) with transmembrane pH-gradient liposomes was previously shown to enhance ammonia removal in cirrhotic rats and holds promise for the treatment of hyperammonemic crises-associated disorders. The main objective of this work was to conduct the preclinical evaluation of LSPD in terms of pharmacokinetics, ammonia uptake, and toxicology to seek regulatory approval for a first-in-human study. The formulation containing citric acid-loaded liposomes was administered intraperitoneally at two different doses once daily for ten days to healthy minipigs. It was also tested in a domestic pig model of hyperammonemia. The pharmacokinetics of citric acid and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine was linear following intraperitoneal administration of medium and high dose. There was no systemic accumulation following daily doses over ten days. The systemic exposure to phospholipids remained low. Furthermore, the liposome-containing peritoneal fluid contained significantly higher ammonia levels than the liposome-free control, demonstrating efficient ammonia sequestration in the peritoneal space. This was indeed confirmed by the ability of LSPD to decrease plasmatic ammonia levels in artificially induced hyperammonemic pigs. LSPD was well tolerated, and no complement activation-related pseudoallergy reactions were observed. The safety profile, the linear pharmacokinetics of citric acid following repeated administrations of LSPD as well as the linear dose-dependent ammonia sequestration in the peritoneal space provide a strong basis for the clinical investigation of LSPD.
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Affiliation(s)
- Simon Matoori
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland; John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | | | - Valentina Agostoni
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Regula Bettschart-Wolfensberger
- Department of Clinical Diagnostics and Services, Section of Anaesthesiology, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
| | - Rima Nadine Bektas
- Department of Clinical Diagnostics and Services, Section of Anaesthesiology, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
| | - Beat Thöny
- Division of Metabolism, University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism, University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.
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15
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Alhashem AM, Salih RM, Al-Aqeel AI, Mohamed S. Peripheral venous route for administration of ammonul infusion for treatment of acute hyperammonemia. An experience from a tertiary center in Saudi Arabia. Saudi Med J 2020; 41:98-101. [PMID: 31915802 PMCID: PMC7001061 DOI: 10.15537/smj.2020.1.24760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objectives: To determine the local effects of peripheral Ammonul infusion on the skin and the subcutaneous tissues. Methods: This retrospective study was conducted at Prince Sultan Military Medical City, Riyadh, Saudi Arabia. All children <16 years of age admitted between December 2015 and October 2018 with hyperammonemia and received Ammonul infusion for treatment were recruited. Results: Twenty-one patients received the Ammonul infusion. They were admitted 58 times with acute hyperammonemia during the study period, with an average of 2.8 admissions per patient. The mean age of the included patients was 49.5 months. The most frequent underlying diagnoses were propionic acidemia (n=9), urea cycle disorders (n=5), and intrinsic liver disease (n=3). All participants received Ammonul through peripheral lines except 3 who received it through central lines. No extravasation, burns, or other local side effects were observed in this cohort. Conclusion: This data indicate that the use of Ammonul through a peripheral venous route appears to be safe and not associated with infusion-related local adverse effects.
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Affiliation(s)
- Amal M Alhashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Kingdom of Saudi Arabia. E-mail.
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16
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Nguyen HH, Khanh Nguyen N, Dung Vu C, Thu Huong Nguyen T, Nguyen NL. Late-Onset Ornithine Transcarbamylase Deficiency and Variable Phenotypes in Vietnamese Females With OTC Mutations. Front Pediatr 2020; 8:321. [PMID: 32793520 PMCID: PMC7390877 DOI: 10.3389/fped.2020.00321] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022] Open
Abstract
Background: Ornithine transcarbamylase deficiency (OTCD) is an X- linked recessive disorder and the most common error of the urea cycle, caused by the mutations in the OTC gene. Due to X-inactivation, 15-20% of female carriers present symptoms of OTCD at late onset. Early diagnosis of OTCD by molecular analysis in females is highly desirable. The aim of the study was to identify the mutations in two unrelated Vietnamese girls suspected with OTCD and the carriers in their families for definitive diagnosis and proper counseling. Case Presentation: Two patients presented with an acute encephalopathy at the first admission. Biochemical tests revealed hyperammonemia, hyperlactatemia, elevated glutamine level, elevated transaminase, elevated urinary orotic and uracil acid levels, and disorder of prothrombin time. Brain magnetic resonance imaging indicated cerebral edema. Based on the clinical and laboratory results, the two patients were diagnosed with urea cycle disorders. Therefore, the two patients were managed by stopping feeding, with infused glucose, l-carnitine, l-arginine, and sodium benzoate, and with hemofiltration. The two patients were alert and recovered with normal blood ammonia levels after 72 h of treatment. The family history of patient 1 showed that her brother died at 4 days of age due to a coma and dyspnea, while her parents were asymptomatic. Variable phenotypes were observed in three generations of the patient 2's family, including asymptomatic (mother), affected female adults dying at the first symptom (grandmother and aunt), and affected males dying in the first week of life (uncle, cousin, and siblings). Whole-exome sequencing showed two mutations in the OTC gene, including one novel missense mutation, c.365A>T, in the patient 1 and one previously reported splicing mutation, c.717+1G>A, in the patient 2. The two mutations are evaluated as likely pathogenic and pathogenic, respectively, according to the recommendations of the American College of Medical Genetics and Genomics (ACMG). Genetic analyses in the families indicated the mothers were heterozygous. Conclusion: Clinical, biochemical, and molecular findings accurately diagnosed the two patients with late-onset OTCD. Our results explained the genetic causes and proposed the risk in the patients' families, which could be useful for genetic counseling and monitoring in prenatal diagnosis.
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Affiliation(s)
- Huy-Hoang Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Ngoc Khanh Nguyen
- Department of Endocrinology, Metabolism and Genetic, Center for Rare Diseases and Newborn Screening, Vietnam National Hospital of Pediatrics, Hanoi, Vietnam
| | - Chi Dung Vu
- Department of Endocrinology, Metabolism and Genetic, Center for Rare Diseases and Newborn Screening, Vietnam National Hospital of Pediatrics, Hanoi, Vietnam
| | - Thi Thu Huong Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
| | - Ngoc-Lan Nguyen
- Institute of Genome Research, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam.,Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam
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Häberle J, Burlina A, Chakrapani A, Dixon M, Karall D, Lindner M, Mandel H, Martinelli D, Pintos-Morell G, Santer R, Skouma A, Servais A, Tal G, Rubio V, Huemer M, Dionisi-Vici C. Suggested guidelines for the diagnosis and management of urea cycle disorders: First revision. J Inherit Metab Dis 2019; 42:1192-1230. [PMID: 30982989 DOI: 10.1002/jimd.12100] [Citation(s) in RCA: 241] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 02/06/2023]
Abstract
In 2012, we published guidelines summarizing and evaluating late 2011 evidence for diagnosis and therapy of urea cycle disorders (UCDs). With 1:35 000 estimated incidence, UCDs cause hyperammonemia of neonatal (~50%) or late onset that can lead to intellectual disability or death, even while effective therapies do exist. In the 7 years that have elapsed since the first guideline was published, abundant novel information has accumulated, experience on newborn screening for some UCDs has widened, a novel hyperammonemia-causing genetic disorder has been reported, glycerol phenylbutyrate has been introduced as a treatment, and novel promising therapeutic avenues (including gene therapy) have been opened. Several factors including the impact of the first edition of these guidelines (frequently read and quoted) may have increased awareness among health professionals and patient families. However, under-recognition and delayed diagnosis of UCDs still appear widespread. It was therefore necessary to revise the original guidelines to ensure an up-to-date frame of reference for professionals and patients as well as for awareness campaigns. This was accomplished by keeping the original spirit of providing a trans-European consensus based on robust evidence (scored with GRADE methodology), involving professionals on UCDs from nine countries in preparing this consensus. We believe this revised guideline, which has been reviewed by several societies that are involved in the management of UCDs, will have a positive impact on the outcomes of patients by establishing common standards, and spreading and harmonizing good practices. It may also promote the identification of knowledge voids to be filled by future research.
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Affiliation(s)
- Johannes Häberle
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
| | - Alberto Burlina
- Division of Inborn Metabolic Disease, Department of Pediatrics, University Hospital Padua, Padova, Italy
| | - Anupam Chakrapani
- Department of Metabolic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Marjorie Dixon
- Dietetics, Great Ormond Street Hospital for Children, NHS Trust, London, UK
| | - Daniela Karall
- Clinic for Pediatrics, Division of Inherited Metabolic Disorders, Medical University of Innsbruck, Innsbruck, Austria
| | - Martin Lindner
- University Children's Hospital, Frankfurt am Main, Germany
| | - Hanna Mandel
- Institute of Human Genetics and metabolic disorders, Western Galilee Medical Center, Nahariya, Israel
| | - Diego Martinelli
- Division of Metabolism, Bambino Gesù Children's Hospital, Rome, Italy
| | - Guillem Pintos-Morell
- Centre for Rare Diseases, University Hospital Vall d'Hebron, Barcelona, Spain
- CIBERER_GCV08, Research Institute IGTP, Barcelona, Spain
- Universitat Autònoma de Barcelona, Barcelona, Spain
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anastasia Skouma
- Institute of Child Health, Agia Sofia Children's Hospital, Athens, Greece
| | - Aude Servais
- Service de Néphrologie et maladies métaboliques adulte Hôpital Necker 149, Paris, France
| | - Galit Tal
- The Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
| | - Vicente Rubio
- Instituto de Biomedicina de Valencia (IBV-CSIC), Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER), Valencia, Spain
| | - Martina Huemer
- University Children's Hospital Zurich and Children's Research Centre, Zurich, Switzerland
- Department of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
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18
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Enns GM, Porter MH, Francis-Sedlak M, Burdett A, Vockley J. Perspectives on urea cycle disorder management: Results of a clinician survey. Mol Genet Metab 2019; 128:102-108. [PMID: 31377149 DOI: 10.1016/j.ymgme.2019.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/12/2019] [Accepted: 07/16/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND/AIMS Urea cycle disorders (UCDs) are rare inborn errors of urea synthesis. US and European consensus statements on the diagnosis and treatment of UCDs were last published in 2001 and 2019, respectively. Recommendations are based primarily on case reports and expert opinion and there is limited agreement or consistency related to long-term management approaches. A clinician survey was conducted to assess current real-world practices and perspectives on challenges and unmet needs. METHODS A 14-item multiple-choice survey was administered to physicians in 2017. Clinicians who reported actively managing at least 1 patient with UCD were eligible to participate. Descriptive statistics were calculated for each survey item (frequencies for categorical variables; means, standard deviations, medians, and ranges for continuous variables). RESULTS Sixty-six US clinicians completed the survey (65 geneticists; 1 pediatric neurologist). Over 90% of responders agreed or strongly agreed that even modest elevations in ammonia could cause physiological and functional brain damage; >80% of respondents agreed that asymptomatic UCD patients are at risk of brain damage over time due to mild/subclinical elevations in ammonia. Eighty-six percent of clinicians agreed or strongly agreed with recommending genetic testing for female relatives when a patient is diagnosed with ornithine transcarbamylase deficiency. Ninety-four percent of respondents agreed that patients have better disease control when they are more adherent to their UCD therapy. Nearly 90% indicated that clinicians and patients would benefit from updated UCD management guidance. More than half (53%) of respondents rated the symptoms of UCDs as extremely or very burdensome to the everyday lives of patients and their families; only 8% rated UCD symptoms as slightly or not at all burdensome. The majority of clinicians agreed (48%) or strongly agreed (32%) that caring for a child or family member with a UCD has a negative impact on the quality of life and/or health of family members/guardians (e.g. stress, relationships, ability to work). CONCLUSIONS This self-reported survey suggests a need for updated and expanded clinical guidance on the long-term treatment and management of UCD patients.
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Affiliation(s)
- Gregory M Enns
- Stanford University, School of Medicine, Stanford, CA, USA.
| | | | | | | | - Jerry Vockley
- University of Pittsburgh, School of Medicine, Graduate School of Public Health, Pittsburgh, PA, USA
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19
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Porta F, Peruzzi L, Bonaudo R, Pieretti S, Busso M, Cocchi E, Conio A, Pagliardini V, Spada M. Differential response to renal replacement therapy in neonatal‐onset inborn errors of metabolism. Nephrology (Carlton) 2018; 23:957-961. [DOI: 10.1111/nep.13409] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2018] [Indexed: 11/26/2022]
Affiliation(s)
- Francesco Porta
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Licia Peruzzi
- Departments of NephrologyDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Roberto Bonaudo
- Departments of NephrologyDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Silvia Pieretti
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Marta Busso
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Enrico Cocchi
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Alessandra Conio
- Departments of Anesthesia and Intensive CareDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Veronica Pagliardini
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
| | - Marco Spada
- Departments of PediatricsDialysis and Transplantation Unit, Città della Salute e della Scienza, Regina Margherita Children's Hospital Torino Italy
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