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Kho J, Polak U, Jiang MM, Odom JD, Hunter JV, Ali SM, Burrage LC, Nagamani SC, Pautler RG, Thompson HP, Urayama A, Jin Z, Lee B. Argininosuccinate lyase deficiency causes blood-brain barrier disruption via nitric oxide-mediated dysregulation of claudin expression. JCI Insight 2023; 8:e168475. [PMID: 37490345 PMCID: PMC10544197 DOI: 10.1172/jci.insight.168475] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 07/19/2023] [Indexed: 07/27/2023] Open
Abstract
Nitric oxide (NO) is a critical signaling molecule that has been implicated in the pathogenesis of neurocognitive diseases. Both excessive and insufficient NO production have been linked to pathology. Previously, we have shown that argininosuccinate lyase deficiency (ASLD) is a novel model system to investigate cell-autonomous, nitric oxide synthase-dependent NO deficiency. Humans with ASLD are at increased risk for developing hyperammonemia due to a block in ureagenesis. However, natural history studies have shown that individuals with ASLD have multisystem disease including neurocognitive deficits that can be independent of ammonia. Here, using ASLD as a model of NO deficiency, we investigated the effects of NO on brain endothelial cells in vitro and the blood-brain barrier (BBB) in vivo. Knockdown of ASL in human brain microvascular endothelial cells (HBMECs) led to decreased transendothelial electrical resistance, indicative of increased cell permeability. Mechanistically, treatment with an NO donor or inhibition of Claudin-1 improved barrier integrity in ASL-deficient HBMECs. Furthermore, in vivo assessment of a hypomorphic mouse model of ASLD showed increased BBB leakage, which was partially rescued by NO supplementation. Our results suggest that ASL-mediated NO synthesis is required for proper maintenance of brain microvascular endothelial cell functions as well as BBB integrity.
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Affiliation(s)
- Jordan Kho
- Department of Molecular and Human Genetics and
| | | | | | | | - Jill V. Hunter
- Department of Radiology, Baylor College of Medicine, Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
| | | | - Lindsay C. Burrage
- Department of Molecular and Human Genetics and
- Texas Children’s Hospital, Houston, Texas, USA
| | - Sandesh C.S. Nagamani
- Department of Molecular and Human Genetics and
- Texas Children’s Hospital, Houston, Texas, USA
| | - Robia G. Pautler
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, USA
| | - Hannah P. Thompson
- Department of Neurology, University of Texas Health Science Center, Houston, Texas, USA
| | - Akihiko Urayama
- Department of Neurology, University of Texas Health Science Center, Houston, Texas, USA
| | - Zixue Jin
- Department of Molecular and Human Genetics and
| | - Brendan Lee
- Department of Molecular and Human Genetics and
- Texas Children’s Hospital, Houston, Texas, USA
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2
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Neuroimaging findings of inborn errors of metabolism: urea cycle disorders, aminoacidopathies, and organic acidopathies. Jpn J Radiol 2023:10.1007/s11604-023-01396-0. [PMID: 36729192 PMCID: PMC9893193 DOI: 10.1007/s11604-023-01396-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/23/2023] [Indexed: 02/03/2023]
Abstract
Although there are many types of inborn errors of metabolism (IEMs) affecting the central nervous system, also referred to as neurometabolic disorders, individual cases are rare, and their diagnosis is often challenging. However, early diagnosis is mandatory to initiate therapy and prevent permanent long-term neurological impairment or death. The clinical course of IEMs is very diverse, with some diseases progressing to acute encephalopathy following infection or fasting while others lead to subacute or slowly progressive encephalopathy. The diagnosis of IEMs relies on biochemical and genetic tests, but neuroimaging studies also provide important clues to the correct diagnosis and enable the conditions to be distinguished from other, more common causes of encephalopathy, such as hypoxia-ischemia. Proton magnetic resonance spectroscopy (1H-MRS) is a powerful, non-invasive method of assessing neurological abnormalities at the microscopic level and can measure in vivo brain metabolites. The present review discusses neuroimaging findings, including those of 1H-MRS, of IEMs focusing on intoxication disorders such as urea cycle disorders, aminoacidopathies, and organic acidopathies, which can result in acute life-threatening metabolic decompensation or crisis.
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3
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Khoja S, Liu XB, Truong B, Nitzahn M, Lambert J, Eliav A, Nasser E, Randolph E, Burke KE, White R, Zhu X, Martini PG, Nissim I, Cederbaum SD, Lipshutz GS. Intermittent lipid nanoparticle mRNA administration prevents cortical dysmyelination associated with arginase deficiency. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 28:859-874. [PMID: 35694211 PMCID: PMC9156989 DOI: 10.1016/j.omtn.2022.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 04/22/2022] [Indexed: 11/28/2022]
Abstract
Arginase deficiency is associated with prominent neuromotor features, including spastic diplegia, clonus, and hyperreflexia; intellectual disability and progressive neurological decline are other signs. In a constitutive murine model, we recently described leukodystrophy as a significant component of the central nervous system features of arginase deficiency. In the present studies, we sought to examine if the administration of a lipid nanoparticle carrying human ARG1 mRNA to constitutive knockout mice could prevent abnormalities in myelination associated with arginase deficiency. Imaging of the cingulum, striatum, and cervical segments of the corticospinal tract revealed a drastic reduction of myelinated axons; signs of degenerating axons were also present with thin myelin layers. Lipid nanoparticle/ARG1 mRNA administration resulted in both light and electron microscopic evidence of a dramatic recovery of myelin density compared with age-matched controls; oligodendrocytes were seen to be extending processes to wrap many axons. Abnormally thin myelin layers, when myelination was present, were resolved with intermittent mRNA administration, indicative of not only a greater density of myelinated axons but also an increase in the thickness of the myelin sheath. In conclusion, lipid nanoparticle/ARG1 mRNA administration in arginase deficiency prevents the associated leukodystrophy and restores normal oligodendrocyte function.
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Affiliation(s)
- Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Xiao-Bo Liu
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Brian Truong
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Matthew Nitzahn
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Jenna Lambert
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Adam Eliav
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Eram Nasser
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Emma Randolph
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | | | - Rebecca White
- Moderna Inc., 200 Technology Square, Cambridge, MA 02139, USA
| | - Xuling Zhu
- Moderna Inc., 200 Technology Square, Cambridge, MA 02139, USA
| | | | - Itzhak Nissim
- Division of Metabolism and Human Genetics, The Children Hospital of Philadelphia and The Department of Biochemistry and Biophysics, Perlman School of Medicine, Philadelphia, PA 19104, USA
| | - Stephen D. Cederbaum
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Intellectual and Developmental Disabilities Research Center at UCLA, Los Angeles, CA 90095, USA
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Gerald S. Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
- Intellectual and Developmental Disabilities Research Center 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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4
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Whitehead MT, Lai LM, Blüml S. Clinical 1H MRS in childhood neurometabolic diseases — part 2: MRS signatures. Neuroradiology 2022; 64:1111-1126. [DOI: 10.1007/s00234-022-02918-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/10/2022] [Indexed: 12/23/2022]
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Sen K, Anderson AA, Whitehead MT, Gropman AL. Review of Multi-Modal Imaging in Urea Cycle Disorders: The Old, the New, the Borrowed, and the Blue. Front Neurol 2021; 12:632307. [PMID: 33995244 PMCID: PMC8113618 DOI: 10.3389/fneur.2021.632307] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/26/2021] [Indexed: 12/16/2022] Open
Abstract
The urea cycle disorders (UCD) are rare genetic disorder due to a deficiency of one of six enzymes or two transport proteins that act to remove waste nitrogen in form of ammonia from the body. In this review, we focus on neuroimaging studies in OTCD and Arginase deficiency, two of the UCD we have extensively studied. Ornithine transcarbamylase deficiency (OTCD) is the most common of these, and X-linked. Hyperammonemia (HA) in OTCD is due to deficient protein handling. Cognitive impairments and neurobehavioral disorders have emerged as the major sequelae in Arginase deficiency and OTCD, especially in relation to executive function and working memory, impacting pre-frontal cortex (PFC). Clinical management focuses on neuroprotection from HA, as well as neurotoxicity from other known and yet unclassified metabolites. Prevention and mitigation of neurological injury is a major challenge and research focus. Given the impact of HA on neurocognitive function of UCD, neuroimaging modalities, especially multi-modality imaging platforms, can bring a wealth of information to understand the neurocognitive function and biomarkers. Such information can further improve clinical decision making, and result in better therapeutic interventions. In vivo investigations of the affected brain using multimodal neuroimaging combined with clinical and behavioral phenotyping hold promise. MR Spectroscopy has already proven as a tool to study biochemical aberrations such as elevated glutamine surrounding HA as well as to diagnose partial UCD. Functional Near Infrared Spectroscopy (fNIRS), which assesses local changes in cerebral hemodynamic levels of cortical regions, is emerging as a non-invasive technique and will serve as a surrogate to fMRI with better portability. Here we review two decades of our research using non-invasive imaging and how it has contributed to an understanding of the cognitive effects of this group of genetic conditions.
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Affiliation(s)
- Kuntal Sen
- Division of Neurogenetics and Neurodevelopmental Pediatrics, Department of Neurology, Children's National Hospital, George Washington University School of Medicine, Washington, DC, United States
| | - Afrouz A Anderson
- Department of Research, Focus Foundation, Crofton, MD, United States
| | - Matthew T Whitehead
- Department of Radiology, Children's National Hospital, George Washington University School of Medicine, Washington, DC, United States
| | - Andrea L Gropman
- Division of Neurogenetics and Neurodevelopmental Pediatrics, Department of Neurology, Children's National Hospital, George Washington University School of Medicine, Washington, DC, United States
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Richmond CR, Ballantyne LL, de Guzman AE, Nieman BJ, Funk CD, Ghasemlou N. Arginase-1 deficiency in neural cells does not contribute to neurodevelopment or functional outcomes after sciatic nerve injury. Neurochem Int 2021; 145:104984. [PMID: 33561495 DOI: 10.1016/j.neuint.2021.104984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 01/13/2021] [Accepted: 02/02/2021] [Indexed: 10/22/2022]
Abstract
Arginase-1 (Arg1) is an enzyme controlling the final step of the urea cycle, with highest expression in the liver and lower expression in the lungs, pancreas, kidney, and some blood cells. Arg1 deficiency is an inherited urea cycle disorder presenting with neurological dysfunction including spastic diplegia, intellectual and growth retardation, and encephalopathy. The contribution of Arg1 expression in the central and peripheral nervous system to the development of neurological phenotypes remains largely unknown. Previous studies have shown prominent arginase-1 expression in the nervous system and post-peripheral nerve injury in mice, but very low levels in the naïve state. To investigate neurobiological roles of Arg1, we created a conditional neural (n)Arg1 knockout (KO) mouse strain, with expression eliminated in neuronal and glial precursors, and compared them to littermate controls. Long-term analysis did not reveal any major differences in blood amino acid levels, body weight, or stride gait cycle from 8 to 26-weeks of age. Brain structure measured by magnetic resonance imaging at 16-weeks of age observed only a significant decrease in the volume of the mammillary bodies. We also assessed whether nArg1, which is expressed by sensory neurons after injury, may play a role in regeneration following sciatic nerve crush. Only subtle differences were observed in locomotor and sensory recovery between nArg1 KO and control mice. These results suggest that arginase-1 expression in central and peripheral neural cells does not contribute substantially to the phenotypes of this urea cycle disorder, nor is it likely crucial for post-injury regeneration in this mouse model.
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Affiliation(s)
- Christopher R Richmond
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Laurel L Ballantyne
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - A Elizabeth de Guzman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5T 3H7, Canada
| | - Brian J Nieman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5T 3H7, Canada; Ontario Institute for Cancer Research, Ontario, M5G 0A3, Canada
| | - Colin D Funk
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
| | - Nader Ghasemlou
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, K7L 3N6, Canada; Department of Anesthesiology & Perioperative Medicine, Queen's University, Kingston, Ontario, K7L 3N6, Canada; Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
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7
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Sin YY, Baron G, Schulze A, Funk CD. Arginase-1 deficiency. J Mol Med (Berl) 2015; 93:1287-96. [PMID: 26467175 DOI: 10.1007/s00109-015-1354-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/14/2015] [Accepted: 10/01/2015] [Indexed: 12/13/2022]
Abstract
Arginase-1 (ARG1) deficiency is a rare autosomal recessive disorder that affects the liver-based urea cycle, leading to impaired ureagenesis. This genetic disorder is caused by 40+ mutations found fairly uniformly spread throughout the ARG1 gene, resulting in partial or complete loss of enzyme function, which catalyzes the hydrolysis of arginine to ornithine and urea. ARG1-deficient patients exhibit hyperargininemia with spastic paraparesis, progressive neurological and intellectual impairment, persistent growth retardation, and infrequent episodes of hyperammonemia, a clinical pattern that differs strikingly from other urea cycle disorders. This review briefly highlights the current understanding of the etiology and pathophysiology of ARG1 deficiency derived from clinical case reports and therapeutic strategies stretching over several decades and reports on several exciting new developments regarding the pathophysiology of the disorder using ARG1 global and inducible knockout mouse models. Gene transfer studies in these mice are revealing potential therapeutic options that can be exploited in the future. However, caution is advised in extrapolating results since the lethal disease phenotype in mice is much more severe than in humans indicating that the mouse models may not precisely recapitulate human disease etiology. Finally, some of the functions and implications of ARG1 in non-urea cycle activities are considered. Lingering questions and future areas to be addressed relating to the clinical manifestations of ARG1 deficiency in liver and brain are also presented. Hopefully, this review will spark invigorated research efforts that lead to treatments with better clinical outcomes.
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Affiliation(s)
- Yuan Yan Sin
- Department of Biomedical and Molecular Sciences, Queen's University, 433 Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada
| | - Garrett Baron
- Department of Biomedical and Molecular Sciences, Queen's University, 433 Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada
| | - Andreas Schulze
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada.,Genetics and Genome Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
| | - Colin D Funk
- Department of Biomedical and Molecular Sciences, Queen's University, 433 Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada.
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8
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Hyperargininemia due to arginase I deficiency: the original patients and their natural history, and a review of the literature. Amino Acids 2015; 47:1751-62. [DOI: 10.1007/s00726-015-2032-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 06/13/2015] [Indexed: 12/30/2022]
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9
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Hoffmann GF, Kölker S. Defects in amino acid catabolism and the urea cycle. HANDBOOK OF CLINICAL NEUROLOGY 2013; 113:1755-1773. [PMID: 23622399 DOI: 10.1016/b978-0-444-59565-2.00046-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Symptoms in patients with defects in amino acid catabolism and the urea cycle usually develop because of intoxication of accumulating metabolites. The cumulative prevalence of these disorders is considerable (at least>1:2000 newborns). Timely and correct intervention during the initial presentation and during later episodes is most important. Evaluation of metabolic parameters should be performed on an emergency basis in every patient with symptoms of unexplained metabolic crisis, intoxication, and/or unexplained encephalopathy. A substantial number of patients develop acute encephalopathy or chronic and fluctuating progressive neurological disease. The so-called cerebral organic acid disorders present with (progressive) neurological symptoms: ataxia, myoclonus, extrapyramidal symptoms, and "metabolic stroke." Important diagnostic clues, such as white matter abnormalities, cortical or cerebellar atrophy, and injury of the basal ganglia can be derived from cranial magnetic resonance imaging (MRI). Long-term neurological disease is common, particularly in untreated patients, and the manifestations are varied, the most frequent being (1) mental defect, (2) epilepsy, and (3) movement disorders. Successful treatment strategies are becoming increasingly available. They mostly require an experienced interdisciplinary team including a neuropediatrician and/or later on a neurologist.
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Affiliation(s)
- Georg F Hoffmann
- Department of General Pediatrics, University Children's Hospital Heidelberg, Heidelberg, Germany.
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10
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Carvalho DR, Farage L, Martins BJAF, Brum JM, Speck-Martins CE, Pratesi R. Brain MRI and Magnetic Resonance Spectroscopy Findings in Patients with Hyperargininemia. J Neuroimaging 2012; 24:155-60. [DOI: 10.1111/j.1552-6569.2012.00739.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/22/2012] [Accepted: 05/28/2012] [Indexed: 11/27/2022] Open
Affiliation(s)
| | - Luciano Farage
- School of Medicine; Brasilia University; Brasilia DF Brazil
| | | | - Jaime M Brum
- SARAH Network of Rehabilitation Hospitals; Brasilia DF Brazil
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11
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Jain-Ghai S, Nagamani SCS, Blaser S, Siriwardena K, Feigenbaum A. Arginase I deficiency: severe infantile presentation with hyperammonemia: more common than reported? Mol Genet Metab 2011; 104:107-11. [PMID: 21802329 PMCID: PMC3171515 DOI: 10.1016/j.ymgme.2011.06.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 06/29/2011] [Accepted: 06/29/2011] [Indexed: 11/21/2022]
Abstract
Enzyme defects of the urea cycle typically present with significant hyperammonemia and its associated toxicity, in the first few months of life. However, arginase I (ARG1) deficiency, a rare autosomal recessive disorder, has classically been the exception. ARG1 deficiency usually presents later in life with spasticity, seizures, failure to thrive and developmental regression. Neonatal and early infantile presentation of ARG1 deficiency with severe hyperammonemia remains rare and only six such cases have been described. We report a severely affected infant with ARG1 deficiency who presented at 6 weeks of age with lethargy, poor feeding and severe encephalopathy caused by hyperammonemia. The clinical and biochemical features of the proband and six other previously reported cases with neonatal or infantile-onset presentation of ARG1 deficiency with hyperammonemia are reviewed. In addition, the clinical spectrum of seven previously unpublished patients with later onset ARG1 deficiency, who also experienced recurrent hyperammonemia, is presented. Several biochemical abnormalities have been postulated to play a role in the pathogenesis of the neurological changes in ARG1 deficiency including hyperargininemia, elevated guanidino compounds and elevated glutamine levels, as well as the hyperammonemia. The index case demonstrated many of these. The cases reviewed here suggest a genotype/phenotype correlation and advocate for the addition of arginine as a primary target in newborn screening programs.
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Affiliation(s)
- Shailly Jain-Ghai
- Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G1X8.
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12
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Segawa Y, Matsufuji M, Itokazu N, Utsunomiya H, Watanabe Y, Yoshino M, Takashima S. A long-term survival case of arginase deficiency with severe multicystic white matter and compound mutations. Brain Dev 2011; 33:45-8. [PMID: 20456883 DOI: 10.1016/j.braindev.2010.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 02/01/2010] [Accepted: 03/05/2010] [Indexed: 11/19/2022]
Abstract
Neuropathology and neuroimaging of long-term survival cases of arginase deficiency are rarely reported. The magnetic resonance imaging (MRI) of our case showed severe multicystic white matter lesions with cortical atrophy, which were more severe compared with previous reports. In this patient, low-protein diet successfully reduced hyperammonemia, but hyperargininemia persisted. These severe neurological and MRI findings may be explained by a compound heterozygote, inheriting both of severe mutant alleles from her parents.
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Affiliation(s)
- Yoshie Segawa
- Yanagawa Institute for Developmental Disabilities, Fukuoka, Japan
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13
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Hendriksz CJ. Inborn errors of metabolism for the diagnostic radiologist. Pediatr Radiol 2009; 39:211-20. [PMID: 19082997 DOI: 10.1007/s00247-008-1072-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 09/28/2008] [Accepted: 10/06/2008] [Indexed: 11/24/2022]
Abstract
Inherited metabolic disorders are becoming more important with the increasing availability of diagnostic methods and therapies for these conditions. The radiologist has become an important link in making the diagnosis or collaborating with the specialist centre to diagnose these disorders and monitor effects of therapy. The modes of presentation, disease-specific groups, classic radiological features and investigations are explored in this article to try and give the general radiologist some crucial background knowledge. The following presentations are covered: acute intoxication, hypoglycaemia, developmental delay and storage features. Specific groups of disorders covered are the abnormalities of intermediary metabolism, disorders of fatty acid oxidation and ketogenesis, mitochondrial disorders, lysosomal storage disorders, and, briefly, other groups such as peroxisomal disorders, disorders of glycosylation, and creatine synthesis disorders. New advances and the demands for monitoring are also briefly explored.
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Affiliation(s)
- Chris J Hendriksz
- Department of Clinical Inherited Metabolic Disorders, Birmingham Children's Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham, B4 6NH, UK.
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14
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Enns GM. Neurologic damage and neurocognitive dysfunction in urea cycle disorders. Semin Pediatr Neurol 2008; 15:132-9. [PMID: 18708004 DOI: 10.1016/j.spen.2008.05.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although the survival of patients who have urea cycle disorders has improved with the use of modalities such as alternative pathway therapy and hemodialysis, neurologic outcome is suboptimal. Patients often manifest with a variety of neurologic abnormalities, including cerebral edema, seizures, cognitive impairment, and psychiatric illness. Current hypotheses of the pathogenesis underlying brain dysfunction in these patients have focused on several lines of investigation, including the role of glutamine in causing cerebral edema, mitochondrial dysfunction leading to energy failure and the production of free radicals, and altered neurotransmitter metabolism. Advances in understanding the pathogenetic mechanisms underlying brain impairment in urea cycle disorders may lead to the development of therapies designed to interfere with the molecular cascade that ultimately leads to cerebral edema and other brain pathological findings.
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Affiliation(s)
- Gregory M Enns
- Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, CA 94305, USA.
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