1
|
Biswas A, Malhotra M, Mankad K, Carney O, D'Arco F, Muthusamy K, Sudhakar SV. Clinico-radiological phenotyping and diagnostic pathways in childhood neurometabolic disorders-a practical introductory guide. Transl Pediatr 2021; 10:1201-1230. [PMID: 34012862 PMCID: PMC8107844 DOI: 10.21037/tp-20-335] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Inborn errors of metabolism (IEM) although individually rare, together constitute a significant proportion of childhood neurological disorders. Majority of these disorders occur due to deficiency of an enzyme in a specific metabolic pathway, leading to damage by accumulation of a toxic substrate or deficiency of an essential metabolite. Early diagnosis is crucial in many of these conditions to prevent or minimise brain damage. Whilst many of the neuroimaging features are nonspecific, certain disorders demonstrate specific patterns due to selective vulnerability of different structures to different insults. Along with clinical and biochemical profile, neuroimaging thus plays a pivotal role in differentiating metabolic disorders from other causes, in providing a differential diagnosis or suggesting a metabolic pathway derangement, and on occasion also helps make a specific diagnosis. This allows initiation of targeted metabolic and genetic work up and treatment. Familiarity with the clinical features, relevant biochemical features and neuroimaging findings of common metabolic disorders to facilitate a prompt diagnosis cannot thus be overemphasized. In this article, we describe the latest classification scheme, the clinical and biochemical clues and common radiological patterns. The diagnostic algorithm followed in daily practice after clinico-radiological phenotyping is alluded to and illustrated by clinical vignettes. Focused sections on neonatal metabolic disorders and mitochondrial disorders are also provided. The purpose of this article is to provide a brief overview and serve as a practical primer to clinical and radiological phenotypes and diagnostic aspects of IEM.
Collapse
Affiliation(s)
- Asthik Biswas
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada
| | - Mukul Malhotra
- Department of Neurology, Christian Medical College, Vellore, India
| | - Kshitij Mankad
- Neuroradiology Unit, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Olivia Carney
- Neuroradiology Unit, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Felice D'Arco
- Neuroradiology Unit, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | | | - Sniya Valsa Sudhakar
- Neuroradiology Unit, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
2
|
Reddy N, Calloni SF, Vernon HJ, Boltshauser E, Huisman TAGM, Soares BP. Neuroimaging Findings of Organic Acidemias and Aminoacidopathies. Radiographics 2018; 38:912-931. [PMID: 29757724 DOI: 10.1148/rg.2018170042] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although individual cases of inherited metabolic disorders are rare, overall they account for a substantial number of disorders affecting the central nervous system. Organic acidemias and aminoacidopathies include a variety of inborn errors of metabolism that are caused by defects in the intermediary metabolic pathways of carbohydrates, amino acids, and fatty acid oxidation. These defects can lead to the abnormal accumulation of organic acids and amino acids in multiple organs, including the brain. Early diagnosis is mandatory to initiate therapy and prevent permanent long-term neurologic impairments or death. Neuroimaging findings can be nonspecific, and metabolism- and genetics-based laboratory investigations are needed to confirm the diagnosis. However, neuroimaging has a key role in guiding the diagnostic workup. The findings at conventional and advanced magnetic resonance imaging may suggest the correct diagnosis, help narrow the differential diagnosis, and consequently facilitate early initiation of targeted metabolism- and genetics-based laboratory investigations and treatment. Neuroimaging may be especially helpful for distinguishing organic acidemias and aminoacidopathies from other more common diseases with similar manifestations, such as hypoxic-ischemic injury and neonatal sepsis. Therefore, it is important that radiologists, neuroradiologists, pediatric neuroradiologists, and clinicians are familiar with the neuroimaging findings of organic acidemias and aminoacidopathies. ©RSNA, 2018.
Collapse
Affiliation(s)
- Nihaal Reddy
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Sonia F Calloni
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Hilary J Vernon
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Eugen Boltshauser
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Thierry A G M Huisman
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Bruno P Soares
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| |
Collapse
|
3
|
Wani NA, Qureshi UA, Jehangir M, Ahmad K, Hussain Z. Atypical MR lenticular signal change in infantile isovaleric acidemia. Indian J Radiol Imaging 2016; 26:131-4. [PMID: 27081237 PMCID: PMC4813063 DOI: 10.4103/0971-3026.178362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Isovaleric acidemia (IVA) is an inborn error of branched chain amino acid metabolism that may manifest as acute neonatal metabolic acidosis or as chronic intermittent form with developmental delay or recurrent episodes of acute metabolic acidosis. Early diagnosis is the key to prevent morbidity and mortality. Brain imaging abnormalities are rarely described in IVA. We report a case of chronic intermittent IVA with acute presentation in a 4-month-old infant who presented with acute metabolic acidosis. Brain magnetic resonance imaging (MRI) revealed symmetric signal intensity changes in bilateral lentiform nuclei with an unreported T1-weighted (T1W) symmetric hyperintense ring-like appearance in bilateral putamen.
Collapse
Affiliation(s)
- Nisar A Wani
- Department of Pediatric Radiology, Government Medical College, Srinagar, Jammu and Kashmir, India
| | - Umer Amin Qureshi
- Department of Pediatrics, Government Medical College, Srinagar, Jammu and Kashmir, India
| | - Majid Jehangir
- Department of Radiology, Government Medical College, Srinagar, Jammu and Kashmir, India
| | - Kaiser Ahmad
- Department of Pediatrics, Government Medical College, Srinagar, Jammu and Kashmir, India
| | - Zahid Hussain
- Department of Pediatrics, Government Medical College, Srinagar, Jammu and Kashmir, India
| |
Collapse
|
4
|
Kasapkara CS, Ezgu FS, Okur I, Tumer L, Biberoglu G, Hasanoglu A. N-carbamylglutamate treatment for acute neonatal hyperammonemia in isovaleric acidemia. Eur J Pediatr 2011; 170:799-801. [PMID: 21207059 DOI: 10.1007/s00431-010-1362-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Accepted: 11/22/2010] [Indexed: 01/20/2023]
Abstract
Hyperammonemia occurs mainly in patients with branched-chain organic acidemias such as propionic, methylmalonic, and isovaleric acidemias. Its pathophysiological process is mainly via the competitive inhibition of N-acetylglutamate synthetase. Oral carglumic acid (N-carbamylglutamate) administration can correct hyperammonemia in neonates with propionic and methylmalonic acidemias, thus avoiding dialysis therapy. Isovaleric acidemia is an autosomal recessive disease of leucine metabolism due to deficiency of isovaleryl-CoA dehydrogenase. For the first time, we report a neonate with isovaleric acidemia, whose plasma ammonia concentration dropped dramatically after one oral load of carglumic acid. This experience suggests that carglumic acid could be considered for acute hyperammonemia resulting from isovaleric acidemia. However, trials with more patients are needed.
Collapse
Affiliation(s)
- Cigdem Seher Kasapkara
- Department of Pediatric Nutrition and Metabolism, Gazi University Medical School, Besevler, Ankara, 06500, Turkey.
| | | | | | | | | | | |
Collapse
|
6
|
Solano AF, Leipnitz G, De Bortoli GM, Seminotti B, Amaral AU, Fernandes CG, Latini AS, Dutra-Filho CS, Wajner M. Induction of oxidative stress by the metabolites accumulating in isovaleric acidemia in brain cortex of young rats. Free Radic Res 2008; 42:707-15. [PMID: 18661426 DOI: 10.1080/10715760802311179] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The present work investigated the in vitro effects of isovaleric acid (IVA) and isovalerylglycine (IVG), which accumulate in isovaleric acidemia (IVAcidemia), on important parameters of oxidative stress in supernatants and mitochondrial preparations from brain of 30-day-old rats. IVG, but not IVA, significantly increased TBA-RS and chemiluminescence values in cortical supernatants. Furthermore, the addition of free radical scavengers fully prevented IVG-induced increase of TBA-RS. IVG also decreased GSH concentrations, whereas IVA did not modify this parameter in brain supernatants. Furthermore, IVG did not alter lipid peroxidation or GSH concentrations in mitochondrial preparations, indicating that the generation of oxidants by IVG was dependent on cytosolic mechanisms. On the other hand, IVA significantly induced carbonyl formation both in supernatants and purified mitochondrial preparations from rat brain, with no effect observed for IVG. Therefore, it is presumed that oxidative damage may be at least in part involved in the pathophysiology of the neuropathology of IVAcidemia.
Collapse
Affiliation(s)
- Alexandre F Solano
- Departamento de Bioquimica, Instituto de Ciencias Basicas da Saude, UFRGS, Porto Alegre, RS, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Vockley J, Ensenauer R. Isovaleric acidemia: new aspects of genetic and phenotypic heterogeneity. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2006; 142C:95-103. [PMID: 16602101 PMCID: PMC2652706 DOI: 10.1002/ajmg.c.30089] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Isovaleric acidemia (IVA) is an autosomal recessive inborn error of leucine metabolism caused by a deficiency of the mitochondrial enzyme isovaleryl-CoA dehydrogenase (IVD) resulting in the accumulation of derivatives of isovaleryl-CoA. It was the first organic acidemia recognized in humans and can cause significant morbidity and mortality. Early diagnosis and treatment with a protein restricted diet and supplementation with carnitine and glycine are effective in promoting normal development in severely affected individuals. Both intra- and interfamilial variability have been recognized. Initially, two phenotypes with either an acute neonatal or a chronic intermittent presentation were described. More recently, a third group of individuals with mild biochemical abnormalities who can be asymptomatic have been identified through newborn screening of blood spots by tandem mass spectrometry. IVD is a flavoenzyme that catalyzes the conversion of isovaleryl-CoA to 3-methylcrotonyl-CoA and transfers electrons to the electron transfer flavoprotein. Human IVD has been purified from tissue and recombinant sources and its biochemical and physical properties have been extensively studied. Molecular analysis of the IVD gene from patients with IVA has allowed characterization of different types of mutations in this gene. One missense mutation, 932C>T (A282V), is particularly common in patients identified through newborn screening with mild metabolite elevations and who have remained asymptomatic to date. This mutation leads to a partially active enzyme with altered catalytic properties; however, its effects on clinical outcome and the necessity of therapy are still unknown. A better understanding of the heterogeneity of this disease and the relevance of genotype/phenotype correlations to clinical management of patients are among the challenges remaining in the study of this disorder in the coming years.
Collapse
Affiliation(s)
- Jerry Vockley
- Department of Pediatrics, University of Pittsburgh School of Medicine, Children's Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15238, USA.
| | | |
Collapse
|