1
|
Jolfayi AG, Naderi N, Ghasemi S, Salmanipour A, Adimi S, Maleki M, Kalayinia S. A novel pathogenic variant in the carnitine transporter gene, SLC22A5, in association with metabolic carnitine deficiency and cardiomyopathy features. BMC Cardiovasc Disord 2024; 24:1. [PMID: 38166572 PMCID: PMC10763261 DOI: 10.1186/s12872-023-03676-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/15/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Primary carnitine deficiency (PCD) denotes low carnitine levels with an autosomal recessive pattern of inheritance. Cardiomyopathy is the most common cardiac symptom in patients with PCD, and early diagnosis can prevent complications. Next-generation sequencing can identify genetic variants attributable to PCD efficiently. OBJECTIVE We aimed to detect the genetic cause of the early manifestations of hypertrophic cardiomyopathy and metabolic abnormalities in an Iranian family. METHODS We herein describe an 8-year-old boy with symptoms of weakness and lethargy diagnosed with PCD through clinical evaluations, lab tests, echocardiography, and cardiac magnetic resonance imaging. The candidate variant was confirmed through whole-exome sequencing, polymerase chain reaction, and direct Sanger sequencing. The binding efficacy of normal and mutant protein-ligand complexes were evaluated via structural modeling and docking studies. RESULTS Clinical evaluations, echocardiography, and cardiac magnetic resonance imaging findings revealed hypertrophic cardiomyopathy as a clinical presentation of PCD. Whole-exome sequencing identified a new homozygous variant, SLC22A5 (NM_003060.4), c.821G > A: p.Trp274Ter, associated with carnitine transport. Docking analysis highlighted the impact of the variant on carnitine transport, further indicating its potential role in PCD development. CONCLUSIONS The c.821G > A: p.Trp274Ter variant in SLC22A5 potentially acted as a pathogenic factor by reducing the binding affinity of organic carnitine transporter type 2 proteins for carnitine. So, the c.821G > A variant may be associated with carnitine deficiency, metabolic abnormalities, and cardiomyopathic characteristics.
Collapse
Affiliation(s)
- Amir Ghaffari Jolfayi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Niloofar Naderi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Serwa Ghasemi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Salmanipour
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sara Adimi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Maleki
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
2
|
Siri B, Olivieri G, Lepri FR, Poms M, Goffredo BM, Commone A, Novelli A, Häberle J, Dionisi-Vici C. Father-to-daughter transmission in late-onset OTC deficiency: an underestimated mechanism of inheritance of an X-linked disease. Orphanet J Rare Dis 2024; 19:3. [PMID: 38167094 PMCID: PMC10763478 DOI: 10.1186/s13023-023-02997-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Ornithine Transcarbamylase Deficiency (OTCD) is an X-linked urea cycle disorder characterized by acute hyperammonemic episodes. Hemizygous males are usually affected by a severe/fatal neonatal-onset form or, less frequently, by a late-onset form with milder disease course, depending on the residual enzymatic activity. Hyperammonemia can occur any time during life and patients could remain non- or mis-diagnosed due to unspecific symptoms. In heterozygous females, clinical presentation varies based on the extent of X chromosome inactivation. Maternal transmission in X-linked disease is the rule, but in late-onset OTCD, due to the milder phenotype of affected males, paternal transmission to the females is possible. So far, father-to-daughter transmission of OTCD has been reported only in 4 Japanese families. RESULTS We identified in 2 Caucasian families, paternal transmission of late-onset OTCD with severe/fatal outcome in affected males and 1 heterozygous female. Furthermore, we have reassessed the pedigrees of other published reports in 7 additional families with evidence of father-to-daughter inheritance of OTCD, identifying and listing the family members for which this transmission occurred. CONCLUSIONS Our study highlights how the diagnosis and pedigree analysis of late-onset OTCD may represent a real challenge for clinicians. Therefore, the occurrence of paternal transmission in OTCD should not be underestimated, due to the relevant implications for disease inheritance and risk of recurrence.
Collapse
Affiliation(s)
- Barbara Siri
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.
- Department of Paediatrics, Città della Salute e della Scienza, OIRM, University of Turin, Turin, Italy.
| | - Giorgia Olivieri
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| | - Francesca Romana Lepri
- Translational Cytogenomics Research Unit, Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Martin Poms
- Division of Clinical Chemistry and Biochemistry and Children's Research Center, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Bianca Maria Goffredo
- Division of Metabolism and Metabolic Diseases Research Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Anna Commone
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| | - Antonio Novelli
- Translational Cytogenomics Research Unit, Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Carlo Dionisi-Vici
- Division of Metabolic Diseases and Hepatology, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| |
Collapse
|
3
|
Seidl MJ, Scharre S, Posset R, Druck AC, Epp F, Okun JG, Dimitrov B, Hoffmann GF, Kölker S, Zielonka M. ASS1 deficiency is associated with impaired neuronal differentiation in zebrafish larvae. Mol Genet Metab 2024; 141:108097. [PMID: 38113552 DOI: 10.1016/j.ymgme.2023.108097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/21/2023]
Abstract
Citrullinemia type 1 (CTLN1) is a rare autosomal recessive urea cycle disorder caused by deficiency of the cytosolic enzyme argininosuccinate synthetase 1 (ASS1) due to pathogenic variants in the ASS1 gene located on chromosome 9q34.11. Even though hyperammenomia is considered the major pathomechanistic factor for neurological impairment and cognitive dysfunction, a relevant subset of individuals presents with a neurodegenerative course in the absence of hyperammonemic decompensations. Here we show, that ASS1 deficiency induced by antisense-mediated knockdown of the zebrafish ASS1 homologue is associated with defective neuronal differentiation ultimately causing neuronal cell loss and consecutively decreased brain size in zebrafish larvae in vivo. Whereas ASS1-deficient zebrafish larvae are characterized by markedly elevated concentrations of citrulline - the biochemical hallmark of CTLN1, accumulation of L-citrulline, hyperammonemia or therewith associated secondary metabolic alterations did not account for the observed phenotype. Intriguingly, coinjection of the human ASS1 mRNA not only normalized citrulline concentration but also reversed the morphological cerebral phenotype and restored brain size, confirming conserved functional properties of ASS1 across species. The results of the present study imply a novel, potentially non-enzymatic (moonlighting) function of the ASS1 protein in neurodevelopment.
Collapse
Affiliation(s)
- Marie J Seidl
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Svenja Scharre
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Roland Posset
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ann-Catrin Druck
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Friederike Epp
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jürgen G Okun
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Bianca Dimitrov
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Georg F Hoffmann
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Kölker
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Zielonka
- Heidelberg University, Medical Faculty Heidelberg, and Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany; Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany.
| |
Collapse
|
4
|
Safran A, Proskorovski-Ohayon R, Eskin-Schwartz M, Yogev Y, Drabkin M, Eremenko E, Aharoni S, Freund O, Jean MM, Agam N, Hadar N, Loewenthal N, Staretz-Chacham O, Birk OS. Hyperinsulinism/hyperammonemia syndrome caused by biallelic SLC25A36 mutation. J Inherit Metab Dis 2023; 46:744-755. [PMID: 36695547 DOI: 10.1002/jimd.12594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 01/06/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023]
Abstract
Hyperinsulinism/hyperammonemia (HI/HA) syndrome has been known to be caused by dominant gain-of-function mutations in GLUD1, encoding the mitochondrial enzyme glutamate dehydrogenase. Pathogenic GLUD1 mutations enhance enzymatic activity by reducing its sensitivity to allosteric inhibition by GTP. Two recent independent studies showed that a similar HI/HA phenotype can be caused by biallelic mutations in SLC25A36, encoding pyrimidine nucleotide carrier 2 (PNC2), a mitochondrial nucleotide carrier that transports pyrimidine and guanine nucleotides across the inner mitochondrial membrane: one study reported a single case caused by a homozygous truncating mutation in SLC25A36 resulting in lack of expression of SLC25A36 in patients' fibroblasts. A second study described two siblings with a splice site mutation in SLC25A36, causing reduction of mitochondrial GTP content, putatively leading to hyperactivation of glutamate dehydrogenase. In an independent study, through combined linkage analysis and exome sequencing, we demonstrate in four individuals of two Bedouin Israeli related families the same disease-causing SLC25A36 (NM_018155.3) c.284 + 3A > T homozygous splice-site mutation found in the two siblings. We demonstrate that the mutation, while causing skipping of exon 3, does not abrogate expression of mRNA and protein of the mutant SLC25A36 in patients' blood and fibroblasts. Affected individuals had hyperinsulinism, hyperammonemia, borderline low birth weight, tonic-clonic seizures commencing around 6 months of age, yet normal intellect and no significant other morbidities. Chronic constipation, hypothyroidism, and developmental delay previously described in a single patient were not found. We thus verify that biallelic SLC25A36 mutations indeed cause HI/HA syndrome and clearly delineate the disease phenotype.
Collapse
Affiliation(s)
- Amit Safran
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Regina Proskorovski-Ohayon
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Marina Eskin-Schwartz
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
- Genetics Institute, Soroka Medical Center, Beer Sheva, Israel
| | - Yuval Yogev
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Max Drabkin
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Ekaterina Eremenko
- Department of Life Sciences and Shraga Segal Department of Microbiology, Immunology and Genetics, National Institute of Biotechnology in the Negev, Zlotowski Neuroscience Center and the Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University, Beer Sheva, Israel
| | - Sarit Aharoni
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Ofek Freund
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Matan M Jean
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Nadav Agam
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Noam Hadar
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
| | - Neta Loewenthal
- Pediatric Endocrinology Unit, Pediatric Division, Soroka Medical Center, Beer Sheva, Israel
- Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel
| | - Orna Staretz-Chacham
- Faculty of Health Sciences, Ben Gurion University, Beer Sheva, Israel
- Pediatric Metabolic Clinic, Pediatric Division, Soroka Medical Center, Ben-Gurion University, Beer Sheva, Israel
| | - Ohad S Birk
- Morris Kahn Laboratory of Human Genetics at the Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University, Beer Sheva, Israel
- Genetics Institute, Soroka Medical Center, Beer Sheva, Israel
| |
Collapse
|
5
|
Lo RS, Cromie GA, Tang M, Teng K, Owens K, Sirr A, Kutz JN, Morizono H, Caldovic L, Ah Mew N, Gropman A, Dudley AM. The functional impact of 1,570 individual amino acid substitutions in human OTC. Am J Hum Genet 2023; 110:863-879. [PMID: 37146589 PMCID: PMC10183466 DOI: 10.1016/j.ajhg.2023.03.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/30/2023] [Indexed: 05/07/2023] Open
Abstract
Deleterious mutations in the X-linked gene encoding ornithine transcarbamylase (OTC) cause the most common urea cycle disorder, OTC deficiency. This rare but highly actionable disease can present with severe neonatal onset in males or with later onset in either sex. Individuals with neonatal onset appear normal at birth but rapidly develop hyperammonemia, which can progress to cerebral edema, coma, and death, outcomes ameliorated by rapid diagnosis and treatment. Here, we develop a high-throughput functional assay for human OTC and individually measure the impact of 1,570 variants, 84% of all SNV-accessible missense mutations. Comparison to existing clinical significance calls, demonstrated that our assay distinguishes known benign from pathogenic variants and variants with neonatal onset from late-onset disease presentation. This functional stratification allowed us to identify score ranges corresponding to clinically relevant levels of impairment of OTC activity. Examining the results of our assay in the context of protein structure further allowed us to identify a 13 amino acid domain, the SMG loop, whose function appears to be required in human cells but not in yeast. Finally, inclusion of our data as PS3 evidence under the current ACMG guidelines, in a pilot reclassification of 34 variants with complete loss of activity, would change the classification of 22 from variants of unknown significance to clinically actionable likely pathogenic variants. These results illustrate how large-scale functional assays are especially powerful when applied to rare genetic diseases.
Collapse
Affiliation(s)
- Russell S Lo
- Pacific Northwest Research Institute, Seattle, WA, USA
| | | | - Michelle Tang
- Pacific Northwest Research Institute, Seattle, WA, USA
| | - Kevin Teng
- Pacific Northwest Research Institute, Seattle, WA, USA
| | - Katherine Owens
- Pacific Northwest Research Institute, Seattle, WA, USA; Department of Applied Mathematics, University of Washington, Seattle, WA, USA
| | - Amy Sirr
- Pacific Northwest Research Institute, Seattle, WA, USA
| | - J Nathan Kutz
- Department of Applied Mathematics, University of Washington, Seattle, WA, USA
| | - Hiroki Morizono
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, DC, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
| | - Ljubica Caldovic
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, DC, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
| | - Nicholas Ah Mew
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, DC, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
| | - Andrea Gropman
- Center for Genetic Medicine Research, Children's National Research Institute, Children's National Hospital, Washington, DC, USA; Department of Genomics and Precision Medicine, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA; Department of Neurology, Division of Neurogenetics and Neurodevelopmental Disabilities, Children's National Hospital, Washington, DC, USA; Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC, USA
| | | |
Collapse
|
6
|
Boodhansingh KE, Rosenfeld E, Lord K, Adzick NS, Bhatti T, Ganguly A, De Leon DD, Stanley CA. Mosaic GLUD1 Mutations Associated with Hyperinsulinism Hyperammonemia Syndrome. Horm Res Paediatr 2022; 95:492-498. [PMID: 35952631 PMCID: PMC9671865 DOI: 10.1159/000526203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/20/2022] [Indexed: 01/07/2023] Open
Abstract
INTRODUCTION The hyperinsulinemia-hyperammonemia syndrome (HIHA) is the second most common cause of congenital hyperinsulinism and is caused by activating heterozygous missense mutations in GLUD1. In the majority of HIHA cases, the GLUD1 mutation is found to be de novo. We have identified 3 patients in whom clinical evaluation was suggestive of HIHA but with negative mutation analysis in peripheral blood DNA for GLUD1 as well as other known HI genes. METHODS We performed next-generation sequencing (NGS) on peripheral blood DNA from two children with clinical features of HIHA in order to look for mosaic mutations in GLUD1. Pancreas tissue was also available in one of these cases for NGS. In addition, NGS was performed on peripheral blood DNA from a woman with a history of HI in infancy whose child had HIHA due to a presumed de novo GLUD1 mutation. RESULTS Mosaic GLUD1 mutations were identified in these 3 cases at percent mosaicism ranging from 2.7% to 10.4% in peripheral blood. In one case with pancreas tissue available, the mosaic GLUD1 mutation was present at 17.9% and 28.9% in different sections of the pancreas. Two unique GLUD1 mutations were identified in these cases, both of which have been previously reported (c.1493c>t/p.Ser445Leu and c.820c>t/p.Arg221Cys). CONCLUSION The results suggest that low-level mosaic mutations in known HI genes may be the underlying molecular mechanism in some children with HI who have negative genetic testing in peripheral blood DNA.
Collapse
Affiliation(s)
- Kara E. Boodhansingh
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Elizabeth Rosenfeld
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katherine Lord
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - N. Scott Adzick
- Department of Surgery, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tricia Bhatti
- Department of Pathology, The Children's Hospital of Philadelphia, and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Arupa Ganguly
- Department of Genetics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Diva D. De Leon
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Charles A. Stanley
- Division of Endocrinology and Diabetes, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
7
|
Crefcoeur LL, Visser G, Ferdinandusse S, Wijburg FA, Langeveld M, Sjouke B. Clinical characteristics of primary carnitine deficiency: A structured review using a case-by-case approach. J Inherit Metab Dis 2022; 45:386-405. [PMID: 34997761 PMCID: PMC9305179 DOI: 10.1002/jimd.12475] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/03/2022] [Accepted: 01/05/2022] [Indexed: 11/24/2022]
Abstract
A broad spectrum of signs and symptoms has been attributed to primary carnitine deficiency (PCD) since its first description in 1973. Advances in diagnostic procedures have improved diagnostic accuracy and the introduction of PCD in newborn screening (NBS) programs has led to the identification of an increasing number of PCD patients, including mothers of screened newborns, who may show a different phenotype compared to clinically diagnosed patients. To elucidate the spectrum of signs and symptoms in PCD patients, we performed a structured literature review. Using a case-by-case approach, clinical characteristics, diagnostic data, and mode of patient identification were recorded. Signs and symptoms were categorized by organ involvement. In total, 166 articles were included, reporting data on 757 individual patients. In almost 20% (N = 136) of the cases, the diagnosis was based solely on low carnitine concentration which we considered an uncertain diagnosis of PCD. The remaining 621 cases had a diagnosis based on genetic and/or functional (ie, carnitine transporter activity) test results. In these 621 cases, cardiac symptoms (predominantly cardiomyopathy) were the most prevalent (23.8%). Neurological (7.1%), hepatic (8.4%), and metabolic (9.2%) symptoms occurred mainly in early childhood. Adult onset of symptoms occurred in 16 of 194 adult patients, of whom 6 (3.1%) patients suffered a severe event without any preceding symptom (five cardiac events and one coma). In conclusion, symptoms in PCD predominantly develop in early childhood. Most newborns and mothers of newborns detected through NBS remain asymptomatic. However, though rarely, severe complications do occur in both groups.
Collapse
Affiliation(s)
- Loek L. Crefcoeur
- Department of Metabolic Diseases, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtThe Netherlands
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC location Academic Medical CenterUniversity of Amsterdam, Amsterdam Gastroenterology and MetabolismAmsterdamThe Netherlands
| | - Gepke Visser
- Department of Metabolic Diseases, Wilhelmina Children's HospitalUniversity Medical Center UtrechtUtrechtThe Netherlands
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC location Academic Medical CenterUniversity of Amsterdam, Amsterdam Gastroenterology and MetabolismAmsterdamThe Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC location Academic Medical CenterUniversity of Amsterdam, Amsterdam Gastroenterology and MetabolismAmsterdamThe Netherlands
| | - Frits A. Wijburg
- Emma's Children's Hospital, Amsterdam UMC location Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Mirjam Langeveld
- Department of Endocrinology and Metabolism, Amsterdam UMC location Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Barbara Sjouke
- Department of Endocrinology and Metabolism, Amsterdam UMC location Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| |
Collapse
|
8
|
Ishikawa R, Sugimoto T, Abe T, Ohno N, Tazuma T, Giga M, Naito H, Kono T, Nomura E, Hara K, Yorifuji T, Yamawaki T. A 36-year-old Man with Repeated Short-term Transient Hyperammonemia and Impaired Consciousness with a Confirmed Carbamoyl Phosphate Synthase 1 Gene Monoallelic Mutation. Intern Med 2022; 61:1387-1392. [PMID: 34670888 PMCID: PMC9152872 DOI: 10.2169/internalmedicine.7961-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A 36-year-old man experienced severely impaired consciousness twice after drinking because of hyperammonemia. No abnormal blood tests were found other than ammonia levels. However, magnetic resonance imaging (MRI) showed atrophy of the brain parenchyma. One the second occasion, the patient suffered severe impairment of consciousness, and because of seizures and glossoptosis, mechanical ventilation was started. Urea cycle disorders (UCDs) were assumed to be involved. Genetic testing revealed a monoallelic mutation of the carbamoyl phosphate synthase 1 (CPS1) gene. When transient hyperammonemia of unknown cause occurs repeatedly in adults, an active investigation for UCDs should be conducted.
Collapse
Affiliation(s)
- Ruoyi Ishikawa
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Takamichi Sugimoto
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Takafumi Abe
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Narumi Ohno
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Taku Tazuma
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Mayumi Giga
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Hiroyuki Naito
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Tomoyuki Kono
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Eiichi Nomura
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| | - Keiichi Hara
- Department of Pediatrics and Institute for Clinical Research, NHO Kure Medical Center, Japan
| | - Tohru Yorifuji
- Division of Pediatric Endocrinology and Metabolism, Osaka City General Hospital, Japan
| | - Takemori Yamawaki
- Department of Neurology, Hiroshima City Hiroshima Citizens Hospital, Japan
| |
Collapse
|
9
|
Shahroor MA, Lasorsa FM, Porcelli V, Dweikat I, Di Noia MA, Gur M, Agostino G, Shaag A, Rinaldi T, Gasparre G, Guerra F, Castegna A, Todisco S, Abu-Libdeh B, Elpeleg O, Palmieri L. PNC2 (SLC25A36) Deficiency Associated With the Hyperinsulinism/Hyperammonemia Syndrome. J Clin Endocrinol Metab 2022; 107:1346-1356. [PMID: 34971397 DOI: 10.1210/clinem/dgab932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT The hyperinsulinism/hyperammonemia (HI/HA) syndrome, the second-most common form of congenital hyperinsulinism, has been associated with dominant mutations in GLUD1, coding for the mitochondrial enzyme glutamate dehydrogenase, that increase enzyme activity by reducing its sensitivity to allosteric inhibition by GTP. OBJECTIVE To identify the underlying genetic etiology in 2 siblings who presented with the biochemical features of HI/HA syndrome but did not carry pathogenic variants in GLUD1, and to determine the functional impact of the newly identified mutation. METHODS The patients were investigated by whole exome sequencing. Yeast complementation studies and biochemical assays on the recombinant mutated protein were performed. The consequences of stable slc25a36 silencing in HeLa cells were also investigated. RESULTS A homozygous splice site variant was identified in solute carrier family 25, member 36 (SLC25A36), encoding the pyrimidine nucleotide carrier 2 (PNC2), a mitochondrial nucleotide carrier that transports pyrimidine as well as guanine nucleotides across the inner mitochondrial membrane. The mutation leads to a 26-aa in-frame deletion in the first repeat domain of the protein, which abolishes transport activity. Furthermore, knockdown of slc25a36 expression in HeLa cells caused a marked reduction in the mitochondrial GTP content, which likely leads to a hyperactivation of glutamate dehydrogenase in our patients. CONCLUSION We report for the first time a mutation in PNC2/SLC25A36 leading to HI/HA and provide functional evidence of the molecular mechanism responsible for this phenotype. Our findings underscore the importance of mitochondrial nucleotide metabolism and expand the role of mitochondrial transporters in insulin secretion.
Collapse
Affiliation(s)
- Maher A Shahroor
- Department of Pediatrics and Genetics, Al Makassed Hospital and Al-Quds University, 95908 Jerusalem, Palestine
- Department of Neonatology, Sunnybrook Health Sciences Center, University of Toronto, M4N 3M5 Toronto, Canada
| | - Francesco M Lasorsa
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, 70125 Bari, Italy
| | - Vito Porcelli
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
| | - Imad Dweikat
- Metabolic Unit, An-Najah National University, P467 Nablus, Palestine
| | - Maria Antonietta Di Noia
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
| | - Michal Gur
- Department of Genetics, Hadassah, Hebrew University Medical Center, 91120 Jerusalem, Israel
| | - Giulia Agostino
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
| | - Avraham Shaag
- Department of Genetics, Hadassah, Hebrew University Medical Center, 91120 Jerusalem, Israel
| | - Teresa Rinaldi
- Pasteur Institute-Cenci Bolognetti Foundation, Department of Biology and Biotechnology "Charles Darwin", University of Rome La Sapienza, 00185 Rome, Italy
| | - Giuseppe Gasparre
- Department of Medical and Surgical Sciences (DIMEC), Unit of Medical Genetics and Center for Applied Biomedical Research (CRBA), University of Bologna, 40138 Bologna, Italy
| | - Flora Guerra
- Department of Medical and Surgical Sciences (DIMEC), Unit of Medical Genetics and Center for Applied Biomedical Research (CRBA), University of Bologna, 40138 Bologna, Italy
| | - Alessandra Castegna
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, 70125 Bari, Italy
| | - Simona Todisco
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
| | - Bassam Abu-Libdeh
- Department of Pediatrics and Genetics, Al Makassed Hospital and Al-Quds University, 95908 Jerusalem, Palestine
| | - Orly Elpeleg
- Department of Genetics, Hadassah, Hebrew University Medical Center, 91120 Jerusalem, Israel
| | - Luigi Palmieri
- Laboratory of Biochemistry and Molecular Biology, Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, 70125 Bari, Italy
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, 70125 Bari, Italy
| |
Collapse
|
10
|
Hoshino Y, Kodaira M, Matsuno A, Kaneko T, Fukuyama T, Takano K, Yazaki M, Sekijima Y. Reversible Leukoencephalopathy in a Man with Childhood-onset Hyperornithinemia-Hyperammonemia-Homocitrullinuria Syndrome. Intern Med 2022; 61:553-557. [PMID: 34433721 PMCID: PMC8907781 DOI: 10.2169/internalmedicine.7843-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A 49-year-old Japanese man had shown developmental delay, learning difficulties, epilepsy, and slowly progressive gait disturbance in elementary school. At 46 years old, he experienced repeated drowsiness with or without generalized convulsions, and hyperammonemia was detected. Brain magnetic resonance imaging detected multiple cerebral white matter lesions. An electroencephalogram showed diffuse slow basic activities with 2- to 3-Hz δ waves. Genetic tests confirmed a diagnosis of hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome. Leukoencephalopathy was resolved following the administration of L-arginine and lactulose with a decrease in plasma ammonia levels and glutamine-glutamate peak on magnetic resonance spectroscopy. Leukoencephalopathy in HHH syndrome may be reversible with the resolution of hyperammonemia-induced glutamine toxicity.
Collapse
Affiliation(s)
- Yumi Hoshino
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Japan
| | - Minori Kodaira
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Japan
| | - Atsuhiro Matsuno
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Japan
| | - Tomoki Kaneko
- Department of Radiology, Shinshu University School of Medicine, Japan
| | | | - Kyoko Takano
- Center for Medical Genetics, Shinshu University Hospital, Japan
| | - Masahide Yazaki
- Institute for Biomedical Sciences, Shinshu University, Japan
| | - Yoshiki Sekijima
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Japan
- Institute for Biomedical Sciences, Shinshu University, Japan
| |
Collapse
|
11
|
Zhao C, Wang Y, Yang H, Wang S, Tang MC, Cyr D, Parente F, Allard P, Waters P, Furtos A, Yang G, Mitchell GA. Propionic acidemia in mice: Liver acyl-CoA levels and clinical course. Mol Genet Metab 2022; 135:47-55. [PMID: 34896004 DOI: 10.1016/j.ymgme.2021.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 11/20/2021] [Accepted: 11/21/2021] [Indexed: 12/11/2022]
Abstract
Propionic acidemia (PA) is a severe autosomal recessive metabolic disease caused by deficiency of propionyl-CoA carboxylase (PCC). We studied PA transgenic (Pat) mice that lack endogenous PCC but express a hypoactive human PCCA cDNA, permitting their survival. Pat cohorts followed from 3 to 20 weeks of age showed growth failure and lethal crises of lethargy and hyperammonemia, commoner in males (27/50, 54%) than in females (11/52, 21%) and occurring mainly in Pat mice with the most severe growth deficiency. Groups of Pat mice were studied under basal conditions (P-Ba mice) and during acute crises (P-Ac). Plasma acylcarnitines in P-Ba mice, compared to controls, showed markedly elevated C3- and low C2-carnitine, with a further decrease in C2-carnitine in P-Ac mice. These clinical and biochemical findings resemble those of human PA patients. Liver acyl-CoA measurements showed that propionyl-CoA was a minor species in controls (propionyl-CoA/acetyl-CoA ratio, 0.09). In contrast, in P-Ba liver the ratio was 1.4 and in P-Ac liver, 13, with concurrent reductions of the levels of acetyl-CoA and other acyl-CoAs. Plasma ammonia levels in control, P-Ba and P-Ac mice were 109 ± 10, 311 ± 48 and 551 ± 61 μmol/L respectively. Four-week administration to Pat mice, of carglumate (N-carbamyl-L-glutamic acid), an analogue of N-carbamylglutamate, the product of the only acyl-CoA-requiring reaction directly related to the urea cycle, was associated with increased food consumption, improved growth and absence of fatal crises. Pat mice showed many similarities to human PA patients and provide a useful model for studying tissue pathophysiology and treatment outcomes.
Collapse
Affiliation(s)
- Chen Zhao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China; Medical Genetics Service, Department of Pediatrics and Research Center, CHU Sainte-Justine and Université de Montréal, Montreal, Quebec, Canada
| | - Youlin Wang
- Medical Genetics Service, Department of Pediatrics and Research Center, CHU Sainte-Justine and Université de Montréal, Montreal, Quebec, Canada
| | - Hao Yang
- Medical Genetics Service, Department of Pediatrics and Research Center, CHU Sainte-Justine and Université de Montréal, Montreal, Quebec, Canada
| | - Shupei Wang
- Medical Genetics Service, Department of Pediatrics and Research Center, CHU Sainte-Justine and Université de Montréal, Montreal, Quebec, Canada
| | | | - Denis Cyr
- Medical Genetics Service, Department of Laboratory Medicine, CHU Sherbrooke and Department of Pediatrics, Université de Sherbrooke, Quebec, Canada
| | - Fabienne Parente
- Biochemical Genetics Laboratory, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Pierre Allard
- Biochemical Genetics Laboratory, CHU Sainte-Justine, Montreal, Quebec, Canada
| | - Paula Waters
- Medical Genetics Service, Department of Laboratory Medicine, CHU Sherbrooke and Department of Pediatrics, Université de Sherbrooke, Quebec, Canada
| | - Alexandra Furtos
- Département de Chimie, Université de Montréal, Montreal, Quebec, Canada
| | - Gongshe Yang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A & F University, Yangling, Shaanxi, China.
| | - Grant A Mitchell
- Medical Genetics Service, Department of Pediatrics and Research Center, CHU Sainte-Justine and Université de Montréal, Montreal, Quebec, Canada.
| |
Collapse
|
12
|
Lipiński P, Greczan M, Piekutowska-Abramczuk D, Jurkiewicz E, Bakuła A, Socha P, Jankowska I, Rokicki D, Tylki-Szymańska A. NBAS deficiency due to biallelic c.2809C > G variant presenting with recurrent acute liver failure with severe hyperammonemia, acquired microcephaly and progressive brain atrophy. Metab Brain Dis 2021; 36:2169-2172. [PMID: 34427841 PMCID: PMC8437862 DOI: 10.1007/s11011-021-00827-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 08/14/2021] [Indexed: 12/04/2022]
Abstract
Biallelic pathogenic variants in the neuroblastoma amplified sequence (NBAS) gene were firstly (2015) identified as a cause of fever-triggered recurrent acute liver failure (RALF). Since then, some patients with NBAS deficiency presenting with neurologic features, including a motor delay, intellectual disability, muscular hypotonia and a mild brain atrophy, have been reported. Here, we describe a case of pediatric patient diagnosed with NBAS deficiency due to a homozygous c.2809C > G, p.(Pro937Ala) variant presenting with RALF with severe hyperammonemia, acquired microcephaly and progressive brain atrophy. Not reported in the literature findings include severe hyperammonemia during ALF episode, and neurologic features in the form of acquired progressive microcephaly with brain atrophy. The latter raises the hypothesis about a primary neurologic phenotype in NBAS deficiency.
Collapse
Affiliation(s)
- Patryk Lipiński
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, al. Dzieci Polskich 20, 04-730, Warsaw, Poland.
| | - Milena Greczan
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | | | - Elżbieta Jurkiewicz
- Department of Diagnostic Imaging, The Children's Memorial Health Institute, Warsaw, Poland
| | - Agnieszka Bakuła
- Department of Gastroenterology, Hepatology, Feeding Disorders and Pediatrics, Children's Memorial Health Institute, Warsaw, Poland
| | - Piotr Socha
- Department of Gastroenterology, Hepatology, Feeding Disorders and Pediatrics, Children's Memorial Health Institute, Warsaw, Poland
| | - Irena Jankowska
- Department of Gastroenterology, Hepatology, Feeding Disorders and Pediatrics, Children's Memorial Health Institute, Warsaw, Poland
| | - Dariusz Rokicki
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| | - Anna Tylki-Szymańska
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children's Memorial Health Institute, al. Dzieci Polskich 20, 04-730, Warsaw, Poland
| |
Collapse
|
13
|
Durer S, Durer C, Hoilat GJ. Adult-onset ornithine transcarbamylase deficiency as a rare cause of fatal hyperammonaemia. Lancet 2021; 398:e11. [PMID: 34454677 DOI: 10.1016/s0140-6736(21)01606-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/25/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Seren Durer
- Department of Internal Medicine, State University of New York Upstate Medical University Hospital, Syracuse, NY, USA.
| | - Ceren Durer
- Department of Internal Medicine, State University of New York Upstate Medical University Hospital, Syracuse, NY, USA
| | - Gilles Jadd Hoilat
- Department of Internal Medicine, State University of New York Upstate Medical University Hospital, Syracuse, NY, USA
| |
Collapse
|
14
|
Welch N, Singh SS, Kumar A, Dhruba SR, Mishra S, Sekar J, Bellar A, Attaway AH, Chelluboyina A, Willard BB, Li L, Huo Z, Karnik SS, Esser K, Longworth MS, Shah YM, Davuluri G, Pal R, Dasarathy S. Integrated multiomics analysis identifies molecular landscape perturbations during hyperammonemia in skeletal muscle and myotubes. J Biol Chem 2021; 297:101023. [PMID: 34343564 PMCID: PMC8424232 DOI: 10.1016/j.jbc.2021.101023] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/16/2021] [Accepted: 07/28/2021] [Indexed: 12/27/2022] Open
Abstract
Ammonia is a cytotoxic molecule generated during normal cellular functions. Dysregulated ammonia metabolism, which is evident in many chronic diseases such as liver cirrhosis, heart failure, and chronic obstructive pulmonary disease, initiates a hyperammonemic stress response in tissues including skeletal muscle and in myotubes. Perturbations in levels of specific regulatory molecules have been reported, but the global responses to hyperammonemia are unclear. In this study, we used a multiomics approach to vertically integrate unbiased data generated using an assay for transposase-accessible chromatin with high-throughput sequencing, RNA-Seq, and proteomics. We then horizontally integrated these data across different models of hyperammonemia, including myotubes and mouse and human muscle tissues. Changes in chromatin accessibility and/or expression of genes resulted in distinct clusters of temporal molecular changes including transient, persistent, and delayed responses during hyperammonemia in myotubes. Known responses to hyperammonemia, including mitochondrial and oxidative dysfunction, protein homeostasis disruption, and oxidative stress pathway activation, were enriched in our datasets. During hyperammonemia, pathways that impact skeletal muscle structure and function that were consistently enriched were those that contribute to mitochondrial dysfunction, oxidative stress, and senescence. We made several novel observations, including an enrichment in antiapoptotic B-cell leukemia/lymphoma 2 family protein expression, increased calcium flux, and increased protein glycosylation in myotubes and muscle tissue upon hyperammonemia. Critical molecules in these pathways were validated experimentally. Human skeletal muscle from patients with cirrhosis displayed similar responses, establishing translational relevance. These data demonstrate complex molecular interactions during adaptive and maladaptive responses during the cellular stress response to hyperammonemia.
Collapse
Affiliation(s)
- Nicole Welch
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA; Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA
| | - Shashi Shekhar Singh
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Avinash Kumar
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Saugato Rahman Dhruba
- Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas, USA
| | - Saurabh Mishra
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jinendiran Sekar
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Annette Bellar
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Amy H Attaway
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA; Department of Pulmonary Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Aruna Chelluboyina
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Belinda B Willard
- Proteomics Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ling Li
- Proteomics Research Core Services, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Zhiguang Huo
- Department of Biostatistics, College of Public Health and Health Profession, University of Florida, Gainesville, Florida, USA
| | - Sadashiva S Karnik
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Karyn Esser
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Michelle S Longworth
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Yatrik M Shah
- Department of Molecular & Integrative Physiology and Department of Gastroenterology, University of Michigan, Ann Arbor, Michigan, USA
| | - Gangarao Davuluri
- Integrated Physiology and Molecular Metabolism, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Ranadip Pal
- Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas, USA.
| | - Srinivasan Dasarathy
- Department of Inflammation & Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA; Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, Ohio, USA.
| |
Collapse
|
15
|
Arnold GL, Yester J, McCracken E, Feingold BD, Vockley J. Successful orthotopic heart transplantation in CPTII deficiency. Mol Genet Metab 2021; 133:182-184. [PMID: 34020866 PMCID: PMC8899800 DOI: 10.1016/j.ymgme.2021.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 11/23/2022]
Abstract
Carnitine palmitoyl transferase II (CPT II) catalyzes the release of activated long-chain fatty acids from acylcarnitines into mitochondria for subsequent fatty acid oxidation. Depending on residual enzyme activity, deficiency of this enzyme leads to a spectrum of symptoms from early onset hypoglycemia, hyperammonemia, cardiomyopathy and death to onset of recurrent rhabdomyolysis in adolescents and young adults. We present a case of successful orthotopic heart transplantation in a patient with severe infantile onset cardiomyopathy due to CPT II deficiency identified through newborn screening. Excellent cardiac function is preserved 12 years post-transplantation; however, the patient has developed intermittent episodes of hyperammonemia and rhabdomyolysis later in childhood and early adolescence readily resolved with intravenous glucose. Successful heart transplant in this patient demonstrates the feasibility of this management option in patients with even severe forms of long chain fatty acid oxidation disorders.
Collapse
|
16
|
Nagamani SCS, Ali S, Izem R, Schady D, Masand P, Shneider BL, Leung DH, Burrage LC. Biomarkers for liver disease in urea cycle disorders. Mol Genet Metab 2021; 133:148-156. [PMID: 33846069 PMCID: PMC8195846 DOI: 10.1016/j.ymgme.2021.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/03/2021] [Accepted: 04/04/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND Urea cycle disorders (UCDs) are among the most common inborn errors of liver metabolism. As therapies for hyperammonemia associated with urea cycle dysfunction have improved, chronic complications, such as liver disease, have become increasingly apparent in individuals with UCDs. Liver disease in UCDs may be associated with hepatic inflammation, hepatic fibrosis, portal hypertension, liver cancer and even liver failure. However, except for monitoring serum aminotransferases, there are no clear guidelines for screening and/or monitoring individuals with UCDs for liver disease. Thus, we systematically evaluated the potential utility of several non-invasive biomarkers for liver fibrosis in UCDs. METHODS We evaluated grey-scale ultrasonography, liver stiffness obtained from shear wave elastography (SWE), and various serum biomarkers for hepatic fibrosis and necroinflammation, in a cohort of 28 children and adults with various UCDs. RESULTS Overall, we demonstrate a high burden of liver disease in our participants with 46% of participants having abnormal grey-scale ultrasound pattern of the liver parenchyma, and 52% of individuals having increased liver stiffness. The analysis of serum biomarkers revealed that 32% of participants had elevated FibroTest™ score, a marker for hepatic fibrosis, and 25% of participants had increased ActiTest™ score, a marker for necroinflammation. Interestingly, liver stiffness did not correlate with ultrasound appearance or FibroTest™. CONCLUSION Overall, our results demonstrate the high overall burden of liver disease in UCDs and highlights the need for further studies exploring new tools for identifying and monitoring individuals with UCDs who are at risk for this complication. TRIAL REGISTRATION This study has been registered in ClinicalTrials.gov (NCT03721367).
Collapse
MESH Headings
- Adolescent
- Adult
- Argininosuccinate Lyase/blood
- Biomarkers/blood
- Child
- Child, Preschool
- Elasticity Imaging Techniques
- Female
- Genetic Diseases, Inborn/blood
- Genetic Diseases, Inborn/diagnostic imaging
- Genetic Diseases, Inborn/genetics
- Genetic Diseases, Inborn/pathology
- Humans
- Hyperammonemia/blood
- Hyperammonemia/genetics
- Hyperammonemia/metabolism
- Hyperammonemia/pathology
- Liver/diagnostic imaging
- Liver/pathology
- Liver Cirrhosis/blood
- Liver Cirrhosis/diagnostic imaging
- Liver Cirrhosis/genetics
- Liver Cirrhosis/pathology
- Liver Diseases/blood
- Liver Diseases/genetics
- Liver Diseases/metabolism
- Liver Diseases/pathology
- Male
- Metabolism, Inborn Errors/genetics
- Middle Aged
- Ultrasonography
- Urea Cycle Disorders, Inborn/blood
- Urea Cycle Disorders, Inborn/genetics
- Urea Cycle Disorders, Inborn/metabolism
- Urea Cycle Disorders, Inborn/pathology
- Young Adult
Collapse
Affiliation(s)
- Sandesh C S Nagamani
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA
| | - Saima Ali
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Rima Izem
- Division of Biostatistics and Study Methodology, Children's National Research Institute, Silver Spring, MD, USA; Department of Pediatrics, George Washington University, Washington, DC, USA; Department of Epidemiology, George Washington University, Washington, DC, USA
| | - Deborah Schady
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Prakash Masand
- Texas Children's Hospital, Houston, TX, USA; Edward B. Singleton Department of Radiology, Texas Children's Hospital, Houston, TX 77030, USA
| | - Benjamin L Shneider
- Section of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Pediatric Gastroenterology, Hepatology, and Nutrition, Texas Children's Hospital, Houston, TX, USA
| | - Daniel H Leung
- Section of Pediatric Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA; Pediatric Gastroenterology, Hepatology, and Nutrition, Texas Children's Hospital, Houston, TX, USA
| | - Lindsay C Burrage
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA; Texas Children's Hospital, Houston, TX, USA.
| |
Collapse
|
17
|
Mikkelsen ACD, Thomsen KL, Vilstrup H, Aamann L, Jones H, Mookerjee RP, Hamilton-Dutoit S, Frystyk J, Aagaard NK. Potassium deficiency decreases the capacity for urea synthesis and markedly increases ammonia in rats. Am J Physiol Gastrointest Liver Physiol 2021; 320:G474-G483. [PMID: 33404376 DOI: 10.1152/ajpgi.00136.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 12/07/2020] [Indexed: 01/31/2023]
Abstract
Our study provides novel findings of experimental hypokalemia reducing urea cycle functionality and thereby severely increasing plasma ammonia. This is pathophysiologically interesting because plasma ammonia increases during hypokalemia by a hitherto unknown mechanism, which may be particular important in relation to the unexplained link between hypokalemia and hepatic encephalopathy. Potassium deficiency decreases gene expression, protein synthesis, and growth. The urea cycle maintains body nitrogen homeostasis including removal of toxic ammonia. Hyperammonemia is an obligatory trait of liver failure, increasing the risk for hepatic encephalopathy, and hypokalemia is reported to increase ammonia. We aimed to clarify the effects of experimental hypokalemia on the in vivo capacity of the urea cycle, on the genes of the enzymes involved, and on ammonia concentrations. Female Wistar rats were fed a potassium-free diet for 13 days. Half of the rats were then potassium repleted. Both groups were compared with pair- and free-fed controls. The following were measured: in vivo capacity of urea-nitrogen synthesis (CUNS); gene expression (mRNA) of urea cycle enzymes; plasma potassium, sodium, and ammonia; intracellular potassium, sodium, and magnesium in liver, kidney, and muscle tissues; and liver sodium/potassium pumps. Liver histology was assessed. The diet induced hypokalemia of 1.9 ± 0.4 mmol/L. Compared with pair-fed controls, the in vivo CUNS was reduced by 34% (P < 0.01), gene expression of argininosuccinate synthetase 1 (ASS1) was decreased by 33% (P < 0.05), and plasma ammonia concentrations were eightfold elevated (P < 0.001). Kidney and muscle tissue potassium contents were markedly decreased but unchanged in liver tissue. Protein expressions of liver sodium/potassium pumps were unchanged. Repletion of potassium reverted all the changes. Hypokalemia decreased the capacity for urea synthesis via gene effects. The intervention led to marked hyperammonemia, quantitatively explainable by the compromised urea cycle. Our findings motivate clinical studies of patients with liver disease.
Collapse
Affiliation(s)
| | - Karen Louise Thomsen
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, United Kingdom
| | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Luise Aamann
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Helen Jones
- UCL Institute of Liver and Digestive Health, University College London, London, United Kingdom
| | - Rajeshwar P Mookerjee
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
- UCL Institute of Liver and Digestive Health, University College London, London, United Kingdom
| | | | - Jan Frystyk
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Kristian Aagaard
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| |
Collapse
|
18
|
Posset R, Kölker S, Gleich F, Okun JG, Gropman AL, Nagamani SCS, Scharre S, Probst J, Walter ME, Hoffmann GF, Garbade SF, Zielonka M. Severity-adjusted evaluation of newborn screening on the metabolic disease course in individuals with cytosolic urea cycle disorders. Mol Genet Metab 2020; 131:390-397. [PMID: 33288448 PMCID: PMC8315358 DOI: 10.1016/j.ymgme.2020.10.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVE The implementation of newborn screening (NBS) programs for citrullinemia type 1 (CTLN1) and argininosuccinic aciduria (ASA) is subject to controversial debate. The aim of this study was to assess the impact of NBS on the metabolic disease course and clinical outcome of affected individuals. METHODS In 115 individuals with CTLN1 and ASA, we compared the severity of the initial hyperammonemic episode (HAE) and the frequency of (subsequent) HAEs with the mode of diagnosis. Based on a recently established functional disease prediction model, individuals were stratified according to their predicted severe or attenuated phenotype. RESULTS Individuals with predicted attenuated forms of CTLN1 and ASA were overrepresented in the NBS group, while those with a predicted severe phenotype were underrepresented compared to individuals identified after the manifestation of symptoms (SX). Identification by NBS was associated with reduced severity of the initial HAE both in individuals with predicted severe and attenuated phenotypes, while it was not associated with lower frequency of (subsequent) HAEs. Similar results were obtained when including some patients diagnosed presymptomatically (i.e. prenatal testing, and high-risk family screening) in this analysis. CONCLUSION Since one of the major challenges of NBS outcome studies is the potential overrepresentation of individuals with predicted attenuated phenotypes in NBS cohorts, severity-adjusted evaluation of screened and unscreened individuals is important to avoid overestimation of the NBS effect. NBS enables the attenuation of the initial HAE but does not affect the frequency of subsequent metabolic decompensations in individuals with CTLN1 and ASA. Future long-term studies will need to evaluate the clinical impact of this finding, especially with regard to mortality, as well as cognitive outcome and quality of life of survivors.
Collapse
Affiliation(s)
- Roland Posset
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Stefan Kölker
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Florian Gleich
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Jürgen G Okun
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Andrea L Gropman
- Children's National Health System and The George Washington School of Medicine, Washington, DC, USA
| | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Svenja Scharre
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Joris Probst
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Magdalena E Walter
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Georg F Hoffmann
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Sven F Garbade
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Matthias Zielonka
- Center for Pediatric and Adolescent Medicine, Division of Pediatric Neurology and Metabolic Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany; Heidelberg Research Center for Molecular Medicine (HRCMM), Heidelberg, Germany.
| |
Collapse
|
19
|
Zhou X, Teng Y, Lin-Peng S, Li Z, Wu L, Liang D. Biochemical and genetic characteristics of 40 neonates with carnitine deficiency. Zhong Nan Da Xue Xue Bao Yi Xue Ban 2020; 45:1164-1171. [PMID: 33268576 DOI: 10.11817/j.issn.1672-7347.2020.190241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
OBJECTIVES Primary carnitine deficiency (PCD) is a rare fatty acid metabolism disorder that can cause neonatal death. This study aims to analyze carnitine levels and detect SLC22A5 gene in newborns with carnitine deficiency, to provide a basis for early diagnosis of PCD, and to explore the relationship between carnitine in blood and SLC22A5 genotype. METHODS A total of 40 neonates with low free carnitine (C0<10 μmol/L) in blood were the subjects of the study. SLC22A5 gene was detected by Sanger sequencing to analyze the value of carnitine, the results of gene test and their relationship. RESULTS A total of 15 variants of SLC22A5 gene were detected, including 11 pathogenic or likely pathogenic variants and 4 variants of uncertain significance. There were 5 new mutations: c.288delG (p.G96fsX33), c.744_745insTCG (p.M258_L259insS), c.752A>G (p.Y251C), c.495 C>A (p.R165E), and c.1298T>C (p.M433T). We found 14 PCD patients including 2 homozygous mutations and 12 heterozygous mutations, 14 with 1 mutation, and 12 with no mutation among 40 children. The C0 concentration of children with SLC22A5 gene homozygous or complex heterozygous mutations was (4.95±1.62) μmol/L in the initial screening, and (3.90±1.33) μmol/L in the second screening. The C0 concentration of children with no mutation was (7.04±2.05) μmol/L in the initial screening, and (8.02±2.87) μmol/L in the second screening. There were significant differences between children with homozygous or compound heterozygous mutations and with no mutation in C0 concentration of the initial and the second screening (both P<0.05), as well as between children with truncated mutation and with untruncated mutation in C0 concentration of the initial screening (P=0.022). CONCLUSIONS There are 5 new mutations which enriched the mutation spectrum of SLC22A5 gene. C0<5 μmol/L is highly correlated with SLC22A5 gene homozygous or compound heterozygous mutations. Children with truncated mutation may have lower C0 concentration than that with untruncated mutation in the initial screening.
Collapse
Affiliation(s)
- Xiaoqiang Zhou
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078.
- Department of Medical Genetics, Second Xiangya Hospital, Central South University, Changsha 410011.
| | - Yanling Teng
- Hunan Jiahui Genetic Specialist Hospital, Changsha 410078, China
| | - Siyuan Lin-Peng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078
| | - Zhuo Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078
| | - Lingqian Wu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078
- Hunan Jiahui Genetic Specialist Hospital, Changsha 410078, China
| | - Desheng Liang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078.
- Hunan Jiahui Genetic Specialist Hospital, Changsha 410078, China.
| |
Collapse
|
20
|
Brandt A, Agarwal N, Giri D, Yung Z, Didi M, Senniappan S. Hyperinsulinism hyperammonaemia (HI/HA) syndrome due to GLUD1 mutation: phenotypic variations ranging from late presentation to spontaneous resolution. J Pediatr Endocrinol Metab 2020; 33:675-679. [PMID: 32229669 DOI: 10.1515/jpem-2019-0416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 02/06/2020] [Indexed: 12/16/2022]
Abstract
Background The hyperinsulinism/hyperammonaemia (HI/HA) syndrome is the second most common cause of hyperinsulinaemic hypoglycaemia, caused by activating mutations in GLUD1. In this article, we report a series of three unrelated patients with HI/HA syndrome who demonstrated variable phenotypes, ranging from delayed presentation to spontaneous resolution of hypoglycaemia, thereby expanding the current knowledge and understanding of GLUD1 mutations. Case presentation This paper is a retrospective analysis of patients with HI/HA syndrome who demonstrated a variable disease course. Patient 1 presented with hypoglycaemic seizures at the age of 7 months and was diagnosed with HI/HA syndrome. Patient 2, a 5-year-old boy, on anti-convulsants since 8 months of age, was diagnosed with HI/HA at the age of 4 years. Patient 3, an 11-year-old girl with a history of transient neonatal hypoglycaemia, was diagnosed with HI/HA at the age of 12 months following evaluation for absence seizures. Patients 1 and 2 had raised ammonia levels, whilst patient 3 had normal ammonia level. The genetic analysis in all three patients confirmed GLUD1 mutation. Good glycaemic control was observed in all following diazoxide treatment. All patients have learning difficulties. Patient 1 demonstrated spontaneous resolution of hypoglycaemia at the age of 8 years, enabling discontinuation of diazoxide. Conclusions The cases highlight the diagnostic challenges in HI/HA syndrome due to a highly variable presentation. Knowledge of variable phenotypes would enable early diagnosis, thereby decreasing the risk of long-term neurological damage. Spontaneous resolution of hyperinsulinism could occur, and it is important to consider a trial off diazoxide therapy especially if the patients are on a small dose of diazoxide.
Collapse
Affiliation(s)
- Agnieszka Brandt
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Neha Agarwal
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Dinesh Giri
- Department of Paediatric Endocrinology, Bristol Royal Hospital for Children, Bristol, UK
| | - Zoe Yung
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Mohammad Didi
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Senthil Senniappan
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
- Consultant Paediatric Endocrinologist and Honorary Senior Lecturer, Alder Hey Children's NHS Foundation Trust, Liverpool L12 2AP, UK
| |
Collapse
|
21
|
Wang S, Leng J, Diao C, Wang Y, Zheng R. Genetic characteristics and follow-up of patients with fatty acid β-oxidation disorders through expanded newborn screening in a Northern Chinese population. J Pediatr Endocrinol Metab 2020; 33:683-690. [PMID: 32447334 DOI: 10.1515/jpem-2019-0551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 03/16/2020] [Indexed: 12/22/2022]
Abstract
Background Fatty acid β-oxidation disorders (FAODs) include more than 15 distinct disorders and have a wide variety of symptoms, usually not evident between episodes of acute decompensation. After the introduction of newborn screening (NBS) using tandem mass spectrometry (MS/MS), early identification of FAODs has become feasible. We analyzed the MS/MS results in Tianjin, China during a six-year period to evaluate the incidence, disease spectrum, and genetic characteristics of FAODs. Methods We analyzed the MS/MS results for screening FAODs from May 2013 to December 2018 in Tianjin, China. Infants with positive screening results were confirmed through next-generation sequencing and validated by Sanger sequencing. Results A total of 220,443 infants were screened and 25 FAODs patients were identified (1:8,817). Primary carnitine deficiency (PCD) with an incidence rate up to 1:20,040 was the most common disorder among all FAODs. Recurrent mutations of relatively common diseases, like PCD and short-chain acyl-CoA dehydrogenase deficiency (SCADD), were identified. During the follow-up, two patients suffered from sudden death due to carnitine palmitoyl transferase-Ⅱ deficiency (CPT Ⅱ) and very-long-chain acyl-CoA dehydrogenase deficiency (VLCAD). Conclusion Our data indicated that FAODs are relatively common in Tianjin and may even cause infant death in certain cases. The elucidated disease spectrum and genetic backgrounds elucidated in this study may contribute to the treatment and prenatal genetic counseling of FAODs.
Collapse
Affiliation(s)
- Shuting Wang
- Pediatric Department, Tianjin Medical University General Hospital, Tianjin, PR China
- Tianjin Women and Children's Health Center, Tianjin, PR China
| | - Junhong Leng
- Tianjin Women and Children's Health Center, Tianjin, PR China
| | - Chengming Diao
- Tianjin Women and Children's Health Center, Tianjin, PR China
| | - Yuan Wang
- Tianjin Medical Laboratory, BGI-Tianjin, BGI-Shenzhen, Tianjin, PR China
- Binhai Genomics Institute, BGI-Tianjin, BGI-Shenzhen, Tianjin, PR China
| | - Rongxiu Zheng
- Pediatric Department, Tianjin Medical University General Hospital, 154 Anshan Road, Heping District, 300052, Tianjin, PR China
| |
Collapse
|
22
|
Verbeeten KC, Lamhonwah AM, Bulman D, Faghfoury H, Chakraborty P, Tein I, Geraghty MT. Carnitine uptake defect due to a 5'UTR mutation in a pedigree with false positives and false negatives on Newborn screening. Mol Genet Metab 2020; 129:213-218. [PMID: 31864849 DOI: 10.1016/j.ymgme.2019.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/23/2019] [Accepted: 12/08/2019] [Indexed: 11/22/2022]
Abstract
Carnitine Uptake Defect (CUD) is an autosomal recessive disorder due to mutations in the SLC22A5 gene. Classically patients present in infancy with profound muscle weakness and cardiomyopathy with characteristic EKG findings. Later presentations include recurrent hypoketotic hypoglycemia, proximal limb girdle myopathy,and/or recurrent muscle pain. Newborn screening detects most of these clinical variants but in addition has identified maternal CUD often in asymptomatic women. We describe a family ascertained through 3 newborn screening (NBS) positive infants found to be unaffected themselves but in whom the mothers (sisters) were affected. There were also two affected children born to an affected male and his heterozygous wife who were false negatives on NBS but had increased fractional excretion of free carnitine in the urine. Analysis on a Next Generation Sequencing panel specifically designed to fully cover newborn screening disease targets showed a homozygous change in the five probands (SLC22A5; NM_003060:c.-149G > A; p.?). The mutation segregates with the CUD within the family. It is in the 5' UTR and has a frequency within the gnomAd database of 0.001198. Plasma carnitine was decreased and fractional excretion of free carnitine was increased in all affected individuals. Functional carnitine uptake studies in cultured skin fibroblasts of one proband showed carnitine uptake at the 5 μM concentration to be 6% of controls. Relative expression of OCTN2 mRNA to beta-actin mRNA by qRT-PCR was increased in a proband relative to controls by a factor of 465-fold. Western blotting revealed a 120 kDa protein band, as well as a weaker 240 kDa band in the proband, the significance of which is unknown at this time.
Collapse
Affiliation(s)
| | - Anne-Marie Lamhonwah
- University of Toronto, Toronto, ON, Canada; Dept. of Pediatrics, Laboratory Medicine and Pathobiology, University of Toronto, Canada; Genetics and Genome Biology Program, Hospital for Sick Children, University of Toronto, Canada
| | - Dennis Bulman
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada
| | | | - P Chakraborty
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada
| | - Ingrid Tein
- University of Toronto, Toronto, ON, Canada; Dept. of Pediatrics, Laboratory Medicine and Pathobiology, University of Toronto, Canada; Genetics and Genome Biology Program, Hospital for Sick Children, University of Toronto, Canada
| | - Michael T Geraghty
- University of Ottawa, Ottawa, ON, Canada; Newborn Screening Ontario, Canada; Children's Hospital of Eastern Ontario, Canada.
| |
Collapse
|
23
|
Rasmussen J, Dunø M, Lund AM, Steuerwald U, Hansen SH, Joensen HD, Køber L, Nielsen OW. Increased risk of sudden death in untreated primary carnitine deficiency. J Inherit Metab Dis 2020; 43:290-296. [PMID: 31373028 DOI: 10.1002/jimd.12158] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 07/17/2019] [Accepted: 07/29/2019] [Indexed: 12/22/2022]
Abstract
Primary carnitine deficiency (PCD) affects fatty acid oxidation and is associated with cardiomyopathy and cardiac arrhythmia, but the risk of sudden death in PCD is unknown. The Faroe Islands have a high prevalence of PCD, 1:300. This study systematically investigated a possible association between untreated PCD and sudden death in young Faroese subjects. We investigated all medico-legal cases of sudden death between 1979 and 2012 among subjects below the age of 45. Stored biomaterial was examined with molecular genetic analysis to reveal PCD. We compared the prevalence of PCD among sudden death cases with that of the background population (0.23%) to calculate the odds ratio (OR) for sudden death with PCD. Biomaterial was available and genetically analyzed from 53 of 65 sudden death cases (82%) in the Faroe Islands. Six (one male and five females) of the 53 cases were homozygous for the PCD related c.95A>G mutation-a prevalence of 11.3% (95% CI 5%-23%) and an OR of 54.3 (95% CI 21-138, P < .0001) for the association between sudden death and untreated PCD. Only 11 of the 53 sudden death cases were women-of whom five were homozygous for the c.95A>G mutation (45.5%) yielding an OR of 348.8 (95% CI 94-1287, P < .0001) for the association between sudden death and untreated PCD in females. This study showed a strong association between sudden death and untreated PCD, especially in females.
Collapse
Affiliation(s)
- Jan Rasmussen
- Department of Internal Medicine, National Hospital, Torshavn, Faroe Islands
- Department of Cardiology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Morten Dunø
- Department of Clinical Genetics, Centre for Inherited metabolic Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Allan M Lund
- Department of Clinical Genetics, Centre for Inherited metabolic Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Ulrike Steuerwald
- Department of Occupational and Public Health, Faroese National Health System, Torshavn, Faroe Islands
| | - Steen-Holger Hansen
- Section of Forensic Pathology, Department of Forensic Medicine, University of Copenhagen, Copenhagen, Denmark
| | | | - Lars Køber
- Department of Cardiology, Rigshospitalet University Hospital, Copenhagen, Denmark
| | - Olav W Nielsen
- Department of Cardiology, Bispebjerg University Hospital, Copenhagen, Denmark
| |
Collapse
|
24
|
Li X, Zhu X, Jia C, Ni M, Li Y, Zhang L, Zhao D. [Clinical and genetic characteristics of primary carnitine deficiency identified by neonatal screening]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2019; 36:1167-1170. [PMID: 31813139 DOI: 10.3760/cma.j.issn.1003-9406.2019.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OBJECTIVE To study the prevalence, clinical and genetic characteristics of primary carnitine deficiency (PCD). METHODS From January 2013 to December 2017, 720 667 newborns and their mothers were tested for PCD by tandem mass spectrometry. Potential mutations of carnitine transporter gene SLC22A5 among suspected PCD patients were analyzed. Dietary guidance and L-carnitine supplementation were provided to the parents. Growth and intelligence development were surveyed during follow-up. RESULTS In total 21 neonates and 6 mothers were diagnosed with PCD, which yielded an incidence of 1 in 34 317. Eighteen SLC22A5 mutations were detected, which included 4 novel mutations, namely c.1484T>C, c.394-1G>T, c.431T>C and c.265-266insGGCTCGCCACC. Eighteen patients were found to carry compound heterozygous mutations and 3 have carried homozygous SLC22A5 mutations. Three mothers carried compound heterozygous mutations and 2 carried homozygous mutations. Common mutations included c.1400C>G (42.3%), c.760C>T (11.5%) and c.51C>G (7.7%). During the 8-42 month follow-up, neonates with PCD showed no clinical symptoms but normal growth. Blood level of free carnitine was raised in all mothers after the treatment. CONCLUSION The incidence of neonatal PCD in Henan is 1 in 34 317, with the most common mutation being c.1400C>G. Above finding has enriched the spectrum of SLC22A5 gene mutations.
Collapse
Affiliation(s)
- Xiaole Li
- Department of Neonatal Screening, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China.
| | | | | | | | | | | | | |
Collapse
|
25
|
Soria LR, Nitzahn M, Angelis AD, Khoja S, Attanasio S, Annunziata P, Palmer DJ, Ng P, Lipshutz GS, Brunetti-Pierri N. Hepatic glutamine synthetase augmentation enhances ammonia detoxification. J Inherit Metab Dis 2019; 42:1128-1135. [PMID: 30724386 PMCID: PMC6684872 DOI: 10.1002/jimd.12070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/28/2019] [Indexed: 12/18/2022]
Abstract
The urea cycle and glutamine synthetase (GS) are the two main pathways for waste nitrogen removal and their deficiency results in hyperammonemia. Here, we investigated the efficacy of liver-specific GS overexpression for therapy of hyperammonemia. To achieve hepatic GS overexpression, we generated a helper-dependent adenoviral (HDAd) vector expressing the murine GS under the control of a liver-specific expression cassette (HDAd-GS). Compared to mice injected with a control vector expressing an unrelated reporter gene (HDAd-alpha-fetoprotein), wild-type mice with increased hepatic GS showed reduced blood ammonia levels and a concomitant increase of blood glutamine after intraperitoneal injections of ammonium chloride, whereas blood urea was unaffected. Moreover, injection of HDAd-GS reduced blood ammonia levels at baseline and protected against acute hyperammonemia following ammonia challenge in a mouse model with conditional hepatic deficiency of carbamoyl phosphate synthetase 1 (Cps1), the initial and rate-limiting step of ureagenesis. In summary, we found that upregulation of hepatic GS reduced hyperammonemia in wild-type and Cps1-deficient mice, thus confirming a key role of GS in ammonia detoxification. These results suggest that hepatic GS augmentation therapy has potential for treatment of both primary and secondary forms of hyperammonemia.
Collapse
Affiliation(s)
| | - Matthew Nitzahn
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, United States
- Molecular Biology Institute at UCLA, Los Angeles, United States
| | | | - Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, United States
- Molecular Biology Institute at UCLA, Los Angeles, United States
| | | | | | - Donna J. Palmer
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Philip Ng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Gerald S. Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, United States
- Molecular Biology Institute at UCLA, Los Angeles, United States
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
- Department of Translational Medicine, Federico II University, Naples, Italy
| |
Collapse
|
26
|
Allegri G, Deplazes S, Rimann N, Causton B, Scherer T, Leff JW, Diez-Fernandez C, Klimovskaia A, Fingerhut R, Krijt J, Kožich V, Nuoffer JM, Grisch-Chan HM, Thöny B, Häberle J. Comprehensive characterization of ureagenesis in the spf ash mouse, a model of human ornithine transcarbamylase deficiency, reveals age-dependency of ammonia detoxification. J Inherit Metab Dis 2019; 42:1064-1076. [PMID: 30714172 DOI: 10.1002/jimd.12068] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/30/2019] [Indexed: 12/24/2022]
Abstract
The most common ureagenesis defect is X-linked ornithine transcarbamylase (OTC) deficiency which is a main target for novel therapeutic interventions. The spf ash mouse model carries a variant (c.386G>A, p.Arg129His) that is also found in patients. Male spf ash mice have a mild biochemical phenotype with low OTC activity (5%-10% of wild-type), resulting in elevated urinary orotic acid but no hyperammonemia. We recently established a dried blood spot method for in vivo quantification of ureagenesis by Gas chromatography-mass spectrometry (GC-MS) using stable isotopes. Here, we applied this assay to wild-type and spf ash mice to assess ureagenesis at different ages. Unexpectedly, we found an age-dependency with a higher capacity for ammonia detoxification in young mice after weaning. A parallel pattern was observed for carbamoylphosphate synthetase 1 and OTC enzyme expression and activities, which may act as pacemaker of this ammonia detoxification pathway. Moreover, high ureagenesis in younger mice was accompanied by elevated periportal expression of hepatic glutamine synthetase, another main enzyme required for ammonia detoxification. These observations led us to perform a more extensive analysis of the spf ash mouse in comparison to the wild-type, including characterization of the corresponding metabolites, enzyme activities in the liver and plasma and the gut microbiota. In conclusion, the comprehensive enzymatic and metabolic analysis of ureagenesis performed in the presented depth was only possible in animals. Our findings suggest such analyses being essential when using the mouse as a model and revealed age-dependent activity of ammonia detoxification.
Collapse
Affiliation(s)
- Gabriella Allegri
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | - Sereina Deplazes
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | - Nicole Rimann
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | | | - Tanja Scherer
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | | | - Carmen Diez-Fernandez
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | - Anna Klimovskaia
- Institute for Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Ralph Fingerhut
- Swiss Newborn Screening Laboratory, University Children's Hospital, Zurich, Switzerland
| | - Jakub Krijt
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Viktor Kožich
- Department of Pediatrics and Adolescent Medicine, Charles University-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Jean-Marc Nuoffer
- Department of Clinical Chemistry, Inselspital Bern, Bern, Switzerland
| | - Hiu M Grisch-Chan
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | - Beat Thöny
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center (CRC), University Children's Hospital Zurich, Zurich, Switzerland
| |
Collapse
|
27
|
Khoja S, Nitzahn M, Truong B, Lambert J, Willis B, Allegri G, Rüfenacht V, Häberle J, Lipshutz GS. A constitutive knockout of murine carbamoyl phosphate synthetase 1 results in death with marked hyperglutaminemia and hyperammonemia. J Inherit Metab Dis 2019; 42:1044-1053. [PMID: 30835861 PMCID: PMC6728231 DOI: 10.1002/jimd.12048] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/31/2018] [Indexed: 12/25/2022]
Abstract
The enzyme carbamoyl phosphate synthetase 1 (CPS1; EC 6.3.4.16) forms carbamoyl phosphate from bicarbonate, ammonia, and adenosine triphosphate (ATP) and is activated allosterically by N-acetylglutamate. The neonatal presentation of bi-allelic mutations of CPS1 results in hyperammonemia with reduced citrulline and is reported as the most challenging nitrogen metabolism disorder to treat. As therapeutic interventions are limited, patients often develop neurological injury or die from hyperammonemia. Survivors remain vulnerable to nitrogen overload, being at risk for repetitive neurological injury. With transgenic technology, our lab developed a constitutive Cps1 mutant mouse and reports its characterization herein. Within 24 hours of birth, all Cps1 -/- mice developed hyperammonemia and expired. No CPS1 protein by Western blot or immunostaining was detected in livers nor was Cps1 mRNA present. CPS1 enzymatic activity was markedly decreased in knockout livers and reduced in Cps1+/- mice. Plasma analysis found markedly reduced citrulline and arginine and markedly increased glutamine and alanine, both intermolecular carriers of nitrogen, along with elevated ammonia, taurine, and lysine. Derangements in multiple other amino acids were also detected. While hepatic amino acids also demonstrated markedly reduced citrulline, arginine, while decreased, was not statistically significant; alanine and lysine were markedly increased while glutamine was trending towards significance. In conclusion we have determined that this constitutive neonatal mouse model of CPS1 deficiency replicates the neonatal human phenotype and demonstrates the key biochemical features of the disorder. These mice will be integral for addressing the challenges of developing new therapeutic approaches for this, at present, poorly treated disorder.
Collapse
Affiliation(s)
- Suhail Khoja
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Matthew Nitzahn
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Brian Truong
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Jenna Lambert
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Brandon Willis
- Mouse Biology Program, University of California, Davis, California
| | - Gabriella Allegri
- 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
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Gerald S Lipshutz
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, California
- Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, California
- Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, California
- Intellectual and Developmental Disabilities Research Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, California
- Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, California
| |
Collapse
|
28
|
Baruteau J, Diez-Fernandez C, Lerner S, Ranucci G, Gissen P, Dionisi-Vici C, Nagamani S, Erez A, Häberle J. Argininosuccinic aciduria: Recent pathophysiological insights and therapeutic prospects. J Inherit Metab Dis 2019; 42:1147-1161. [PMID: 30723942 DOI: 10.1002/jimd.12047] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 12/20/2018] [Indexed: 12/30/2022]
Abstract
The first patients affected by argininosuccinic aciduria (ASA) were reported 60 years ago. The clinical presentation was initially described as similar to other urea cycle defects, but increasing evidence has shown overtime an atypical systemic phenotype with a paradoxical observation, that is, a higher rate of neurological complications contrasting with a lower rate of hyperammonaemic episodes. The disappointing long-term clinical outcomes of many of the patients have challenged the current standard of care and therapeutic strategy, which aims to normalize plasma ammonia and arginine levels. Interrogations have raised about the benefit of newborn screening or liver transplantation on the neurological phenotype. Over the last decade, novel discoveries enabled by the generation of new transgenic argininosuccinate lyase (ASL)-deficient mouse models have been achieved, such as, a better understanding of ASL and its close interaction with nitric oxide metabolism, ASL physiological role outside the liver, and the pathophysiological role of oxidative/nitrosative stress or excessive arginine treatment. Here, we present a collaborative review, which highlights these recent discoveries and novel emerging concepts about ASL role in human physiology, ASA clinical phenotype and geographic prevalence, limits of current standard of care and newborn screening, pathophysiology of the disease, and emerging novel therapies. We propose recommendations for monitoring of ASA patients. Ongoing research aims to better understand the underlying pathogenic mechanisms of the systemic disease to design novel therapies.
Collapse
Affiliation(s)
- Julien Baruteau
- UCL Great Ormond Street Institute of Child Health, NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Carmen Diez-Fernandez
- Division of Metabolism and Children Research Centre (CRC), University Children's Hospital, Zurich, Switzerland
| | - Shaul Lerner
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israël
| | - Giusy Ranucci
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Paul Gissen
- UCL Great Ormond Street Institute of Child Health, NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Metabolic Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Sandesh Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israël
| | - Johannes Häberle
- Division of Metabolism and Children Research Centre (CRC), University Children's Hospital, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP) and Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
| |
Collapse
|
29
|
Abstract
Carnitine plays essential roles in intermediary metabolism. In non-vegetarians, most of carnitine sources (~75%) are obtained from diet whereas endogenous synthesis accounts for around 25%. Renal carnitine reabsorption along with dietary intake and endogenous production maintain carnitine homeostasis. The precursors for carnitine biosynthesis are lysine and methionine. The biosynthetic pathway involves four enzymes: 6-N-trimethyllysine dioxygenase (TMLD), 3-hydroxy-6-N-trimethyllysine aldolase (HTMLA), 4-N-trimethylaminobutyraldehyde dehydrogenase (TMABADH), and γ-butyrobetaine dioxygenase (BBD). OCTN2 (organic cation/carnitine transporter novel type 2) transports carnitine into the cells. One of the major functions of carnitine is shuttling long-chain fatty acids across the mitochondrial membrane from the cytosol into the mitochondrial matrix for β-oxidation. This transport is achieved by mitochondrial carnitine–acylcarnitine cycle, which consists of three enzymes: carnitine palmitoyltransferase I (CPT I), carnitine-acylcarnitine translocase (CACT), and carnitine palmitoyltransferase II (CPT II). Carnitine inborn errors of metabolism could result from defects in carnitine biosynthesis, carnitine transport, or mitochondrial carnitine–acylcarnitine cycle. The presentation of these disorders is variable but common findings include hypoketotic hypoglycemia, cardio(myopathy), and liver disease. In this review, the metabolism and homeostasis of carnitine are discussed. Then we present details of different inborn errors of carnitine metabolism, including clinical presentation, diagnosis, and treatment options. At the end, we discuss some of the causes of secondary carnitine deficiency.
Collapse
Affiliation(s)
- Mohammed Almannai
- Section of Medical Genetics, Children's Hospital, King Fahad Medical City, Riyadh 11525, Saudi Arabia.
| | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh 11426, Saudi Arabia.
- King Abdullah International Medical Research Center (KAIMRC), Riyadh 11426, Saudi Arabia.
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia.
| | - Ayman W El-Hattab
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, UAE.
| |
Collapse
|
30
|
Kumar V, Athreya R, Achuta SK, Sundarraju S. Case 3: An Unusual Case of Transient Neonatal Encephalopathy. Neoreviews 2019; 20:e472-e474. [PMID: 31371557 DOI: 10.1542/neo.20-8-e472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Vijay Kumar
- Department of Neonatology, Rainbow Children's Hospital, Marathahalli, Bengaluru, India
| | - Rajath Athreya
- Department of Neonatology, Rainbow Children's Hospital, Marathahalli, Bengaluru, India
| | - Sushma Kalyan Achuta
- Department of Neonatology, Rainbow Children's Hospital, Marathahalli, Bengaluru, India
| | - Sahana Sundarraju
- Department of Neonatology, Rainbow Children's Hospital, Marathahalli, Bengaluru, India
| |
Collapse
|
31
|
Staretz-Chacham O, Wormser O, Manor E, Birk OS, Ferreira CR. TMEM70 deficiency: Novel mutation and hypercitrullinemia during metabolic decompensation. Am J Med Genet A 2019; 179:1293-1298. [PMID: 30950220 PMCID: PMC10515609 DOI: 10.1002/ajmg.a.61138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/06/2019] [Accepted: 03/09/2019] [Indexed: 09/24/2023]
Abstract
Respiratory chain disorders comprise a heterogeneous group of diseases that are the result of mutations in nuclear or mitochondrial genes. TMEM70 encodes a nuclear protein involved in the assembly of respiratory chain complex V. Although mutations in various genes can result in isolated complex V deficiency; TMEM70 mutations represent the most common reported etiology. TMEM70 deficiency is known to cause a syndrome of neonatal mitochondrial encephalocardiomyopathy, accompanied by elevated lactate and hyperammonemia. Elevated citrulline has been reported previously in different inborn errors of metabolism, although uncommonly associated with TMEMT70 deficiency. We present a series of two siblings diagnosed with TMEM70 deficiency, and describe hypercitrullinemia during decompensation as a new finding in this condition. The cause of hyperammonemia in TMEM70 deficiency was previously assumed to be related to carbamoyl phosphate synthase 1 deficiency, but our finding of hypercitrullinemia rules out this possibility. We thus propose a different etiology for the hyperammonemia seen in these patients.
Collapse
Affiliation(s)
- Orna Staretz-Chacham
- Metabolic Clinic, Pediatric Division, Soroka University Medical Center, Ben Gurion University, Beer Sheva, Israel
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
- Shraga Segal Department of Microbiology, Immunology and Genetics, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Esther Manor
- Shraga Segal Department of Microbiology, Immunology and Genetics, Ben Gurion University of the Negev, Beer Sheva, Israel
- Genetics Institute, Soroka University Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
- Shraga Segal Department of Microbiology, Immunology and Genetics, Ben Gurion University of the Negev, Beer Sheva, Israel
- Genetics Institute, Soroka University Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
32
|
Silverstein S, Veerapandiyan A, Hayes-Rosen C, Ming X, Kornitzer J. A novel intronic homozygous mutation in the AMT gene of a patient with nonketotic hyperglycinemia and hyperammonemia. Metab Brain Dis 2019; 34:373-376. [PMID: 30350008 DOI: 10.1007/s11011-018-0317-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/12/2018] [Indexed: 10/28/2022]
Abstract
Nonketotic Hyperglycinemia is an autosomal recessive disorder characterized by defects in the mitochondrial glycine cleavage system. Most patients present soon after birth with seizures and hypotonia, and infants that survive the newborn period often have profound intellectual disability and intractable seizures. Here we present a case report of a 4-year-old girl with NKH as well as hyperammonemia, an uncommon finding in NKH. Genetic analysis found a previously unreported homozygous mutation (c.878-1 G > A) in the AMT gene. Maximum Entropy Principle modeling predicted that this mutation most likely breaks the splice site at the border of intron 7 and exon 8 of the AMT gene. Treatment with L-Arginine significantly reduced both the proband's glycine and ammonia levels, in turn aiding in control of seizures and mental status. This is the first time the use of L-Arginine is reported to successfully treat elevated glycine levels.
Collapse
Affiliation(s)
- Sarah Silverstein
- Department of Neurology, Rutgers University-New Jersey Medical School, 90 Bergen Street, DOC 8100, Newark, NJ, 07103, USA
| | - Aravindhan Veerapandiyan
- Department of Pediatrics, Division of Neurology, Arkansas Children's Hospital, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Caroline Hayes-Rosen
- Department of Neurology, Rutgers University-New Jersey Medical School, 90 Bergen Street, DOC 8100, Newark, NJ, 07103, USA
| | - Xue Ming
- Department of Neurology, Rutgers University-New Jersey Medical School, 90 Bergen Street, DOC 8100, Newark, NJ, 07103, USA
| | - Jeffrey Kornitzer
- Department of Neurology, Rutgers University-New Jersey Medical School, 90 Bergen Street, DOC 8100, Newark, NJ, 07103, USA.
| |
Collapse
|
33
|
Madsen KL, Preisler N, Rasmussen J, Hedermann G, Olesen JH, Lund AM, Vissing J. L-Carnitine Improves Skeletal Muscle Fat Oxidation in Primary Carnitine Deficiency. J Clin Endocrinol Metab 2018; 103:4580-4588. [PMID: 30219858 DOI: 10.1210/jc.2018-00953] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/10/2018] [Indexed: 12/30/2022]
Abstract
CONTEXT Primary carnitine deficiency (PCD) is an inborn error of fatty acid metabolism. Patients with PCD are risk for sudden heart failure upon fasting or illness if they are not treated with daily l-carnitine. OBJECTIVE To investigate energy metabolism during exercise in patients with PCD with and without l-carnitine treatment. DESIGN Interventional study. SETTING Hospital exercise laboratories and department of cardiology. PARTICIPANTS Eight adults with PCD who were homozygous for the c.95A>G (p.N32S) mutation and 10 healthy age- and sex-matched controls. INTERVENTION Four-day pause in l-carnitine treatment. MAIN OUTCOME MEASURES Total fatty acid and palmitate oxidation rates during 1-hour submaximal cycle ergometer exercise assessed with stable isotope method (U13C-palmitate and 2H2-d-glucose) and indirect calorimetry with and without l-carnitine. RESULTS Total fatty acid oxidation rate was higher in patients with l-carnitine treatment during exercise than without treatment [12.3 (SD, 3.7) vs 8.5 (SD, 4.6) µmol × kg-1 × min-1; P = 0.008]. However, the fatty acid oxidation rate was still lower in patients treated with l-carnitine than in the healthy controls [29.5 (SD, 10.1) µmol × kg-1 × min-1; P < 0.001] and in the l-carnitine group without treatment it was less than one third of that in the healthy controls (P < 0.001). In line with this, the palmitate oxidation rates during exercise were lower in the no-treatment period [144 (SD, 66) µmol × kg-1 × min-1] than during treatment [204 (SD, 84) µmol × kg-1 × min-1; P = 0.004) . CONCLUSIONS The results indicate that patients with PCD have limited fat oxidation during exercise. l-Carnitine treatment in asymptomatic patients with PCD may not only prevent cardiac complications but also boost skeletal muscle fat metabolism during exercise.
Collapse
Affiliation(s)
- Karen Lindhardt Madsen
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Nicolai Preisler
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Jan Rasmussen
- Department of Internal Medicine, The National Hospital of the Faroe Islands, Tórshavn, Faroe Islands
| | - Gitte Hedermann
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| | - Jess Have Olesen
- Centre for Inherited Metabolic Diseases, Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark
| | - Allan Meldgaard Lund
- Centre for Inherited Metabolic Diseases, Department of Clinical Genetics, Rigshospitalet, Copenhagen, Denmark
| | - John Vissing
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
34
|
Ashley SN, Nordin JML, Buza EL, Greig JA, Wilson JM. Adeno-associated viral gene therapy corrects a mouse model of argininosuccinic aciduria. Mol Genet Metab 2018; 125:241-250. [PMID: 30253962 DOI: 10.1016/j.ymgme.2018.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 08/26/2018] [Accepted: 08/27/2018] [Indexed: 12/11/2022]
Abstract
Argininosuccinic aciduria (ASA) is the second most common genetic disorder affecting the urea cycle. The disease is caused by deleterious mutations in the gene encoding argininosuccinate lyase (ASL); total loss of ASL activity results in severe neonatal onset of the disease, which is characterized by hyperammonemia within a few days of birth that can rapidly progress to coma and death. The long-term complications of ASA, such as hypertension and neurocognitive deficits, appear to be resistant to the current treatment options of dietary restriction, arginine supplementation, and nitrogen scavenging drugs. Treatment-resistant disease is currently being managed by orthotopic liver transplant, which shows variable improvement and requires lifetime immunosuppression. Here, we developed a gene therapy strategy for ASA aimed at alleviating the symptoms associated with urea cycle disruption by providing stable expression of ASL protein in the liver. We designed a codon-optimized human ASL gene packaged within adeno-associated virus serotype 8 (AAV8) as a vector for targeted delivery to the liver. To evaluate the therapeutic efficacy of this approach, we utilized a murine hypomorphic model of ASA. Neonatal administration of AAV8 via the temporal facial vein extended survival in ASA hypomorphic mice, although not to wild-type levels. Intravenous injection into adolescent hypomorphic mice led to increased survival and body weight and correction of metabolites associated with the disease. Our results demonstrate that AAV8 gene therapy is a viable approach for the treatment of ASA.
Collapse
Affiliation(s)
- Scott N Ashley
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jayme M L Nordin
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth L Buza
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jenny A Greig
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - James M Wilson
- Gene Therapy Program, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
35
|
Baruteau J, Perocheau DP, Hanley J, Lorvellec M, Rocha-Ferreira E, Karda R, Ng J, Suff N, Diaz JA, Rahim AA, Hughes MP, Banushi B, Prunty H, Hristova M, Ridout DA, Virasami A, Heales S, Howe SJ, Buckley SMK, Mills PB, Gissen P, Waddington SN. Argininosuccinic aciduria fosters neuronal nitrosative stress reversed by Asl gene transfer. Nat Commun 2018; 9:3505. [PMID: 30158522 PMCID: PMC6115417 DOI: 10.1038/s41467-018-05972-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/06/2018] [Indexed: 12/26/2022] Open
Abstract
Argininosuccinate lyase (ASL) belongs to the hepatic urea cycle detoxifying ammonia, and the citrulline-nitric oxide (NO) cycle producing NO. ASL-deficient patients present argininosuccinic aciduria characterised by hyperammonaemia, multiorgan disease and neurocognitive impairment despite treatment aiming to normalise ammonaemia without considering NO imbalance. Here we show that cerebral disease in argininosuccinic aciduria involves neuronal oxidative/nitrosative stress independent of hyperammonaemia. Intravenous injection of AAV8 vector into adult or neonatal ASL-deficient mice demonstrates long-term correction of the hepatic urea cycle and the cerebral citrulline-NO cycle, respectively. Cerebral disease persists if ammonaemia only is normalised but is dramatically reduced after correction of both ammonaemia and neuronal ASL activity. This correlates with behavioural improvement and reduced cortical cell death. Thus, neuronal oxidative/nitrosative stress is a distinct pathophysiological mechanism from hyperammonaemia. Disease amelioration by simultaneous brain and liver gene transfer with one vector, to treat both metabolic pathways, provides new hope for hepatocerebral metabolic diseases.
Collapse
Affiliation(s)
- Julien Baruteau
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | - Dany P Perocheau
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Joanna Hanley
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Maëlle Lorvellec
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Eridan Rocha-Ferreira
- Perinatal Brain Repair Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Rajvinder Karda
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Joanne Ng
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
- Neurology Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Natalie Suff
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Juan Antinao Diaz
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Ahad A Rahim
- Department of Pharmacology, School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Michael P Hughes
- Department of Pharmacology, School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, UK
| | - Blerida Banushi
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Helen Prunty
- Department of Paediatric Laboratory Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Mariya Hristova
- Perinatal Brain Repair Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Deborah A Ridout
- Population, Policy and Practice Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1E, UK
| | - Alex Virasami
- Histopathology Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Simon Heales
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
- Department of Paediatric Laboratory Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
| | - Stewen J Howe
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Suzanne M K Buckley
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK
| | - Philippa B Mills
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | - Paul Gissen
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London, WC1N 3JH, UK
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Simon N Waddington
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London, WC1E 6HX, UK.
- Wits/SAMRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa.
| |
Collapse
|
36
|
Khoja S, Nitzahn M, Hermann K, Truong B, Borzone R, Willis B, Rudd M, Palmer DJ, Ng P, Brunetti-Pierri N, Lipshutz GS. Conditional disruption of hepatic carbamoyl phosphate synthetase 1 in mice results in hyperammonemia without orotic aciduria and can be corrected by liver-directed gene therapy. Mol Genet Metab 2018; 124:243-253. [PMID: 29801986 PMCID: PMC6076338 DOI: 10.1016/j.ymgme.2018.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/02/2018] [Accepted: 04/02/2018] [Indexed: 02/06/2023]
Abstract
Carbamoyl phosphate synthetase 1 (CPS1) is a urea cycle enzyme that forms carbamoyl phosphate from bicarbonate, ammonia and ATP. Bi-allelic mutations of the CPS1 gene result in a urea cycle disorder presenting with hyperammonemia, often with reduced citrulline, and without orotic aciduria. CPS1 deficiency is particularly challenging to treat and lack of early recognition typically results in early neonatal death. Therapeutic interventions have limited efficacy and most patients develop long-term neurologic sequelae. Using transgenic techniques, we generated a conditional Cps1 knockout mouse. By loxP/Cre recombinase technology, deletion of the Cps1 locus was achieved in adult transgenic animals using a Cre recombinase-expressing adeno-associated viral vector. Within four weeks from vector injection, all animals developed hyperammonemia without orotic aciduria and died. Minimal CPS1 protein was detectable in livers. To investigate the efficacy of gene therapy for CPS deficiency following knock-down of hepatic endogenous CPS1 expression, we injected these mice with a helper-dependent adenoviral vector (HDAd) expressing the large murine CPS1 cDNA under control of the phosphoenolpyruvate carboxykinase promoter. Liver-directed HDAd-mediated gene therapy resulted in survival, normalization of plasma ammonia and glutamine, and 13% of normal Cps1 expression. A gender difference in survival suggests that female mice may require higher hepatic CPS1 expression. We conclude that this conditional murine model recapitulates the clinical and biochemical phenotype detected in human patients with CPS1 deficiency and will be useful to investigate ammonia-mediated neurotoxicity and for the development of cell- and gene-based therapeutic approaches.
Collapse
Affiliation(s)
- Suhail Khoja
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | - Matt Nitzahn
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | - Kip Hermann
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | - Brian Truong
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | | | - Brandon Willis
- Mouse Biology Program (MBP), University of California, Davis, United States
| | - Mitchell Rudd
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | - Donna J Palmer
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Philip Ng
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine, Naples, Italy; Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Gerald S Lipshutz
- Departments of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Intellectual and Developmental Disabilities Research Center at UCLA, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States; Semel Institute for Neuroscience, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States.
| |
Collapse
|
37
|
Abstract
The adult endocrinologist may be asked to consult on a patient for unexplained biochemical disturbances that could be caused by an underlying inborn error of metabolism. A genetic disorder is generally less likely to be the cause as these disorders are individually rare, however inborn errors of metabolism are collectively not infrequent and important to consider as they may be treatable and tragic outcomes avoided. Hyperammonemia or lactic acidosis are most often secondary markers of an acquired primary disease process, but they may be a clue to the presence of a genetic disorder. Herein is presented an approach to the differential diagnosis of elevated ammonia and lactate, and a brief discussion of management for when an inborn error is diagnosed.
Collapse
Affiliation(s)
- Michel Tchan
- Department of Genetic Medicine, Westmead Hospital, Westmead, NSW, Australia.
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
| |
Collapse
|
38
|
Wilnai Y, Blumenfeld YJ, Cusmano K, Hintz SR, Alcorn D, Benitz WE, Berquist WE, Bernstein JA, Castillo RO, Concepcion W, Cowan TM, Cox KL, Lyell DJ, Esquivel CO, Homeyer M, Hudgins L, Hurwitz M, Palma JP, Schelley S, Akula VP, Summar ML, Enns GM. Prenatal treatment of ornithine transcarbamylase deficiency. Mol Genet Metab 2018; 123:297-300. [PMID: 29396029 DOI: 10.1016/j.ymgme.2018.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 01/13/2018] [Indexed: 12/31/2022]
Abstract
PURPOSE OF STUDY Patients with neonatal urea cycle defects (UCDs) typically experience severe hyperammonemia during the first days of life, which results in serious neurological injury or death. Long-term prognosis despite optimal pharmacological and dietary therapy is still poor. The combination of intravenous sodium phenylacetate and sodium benzoate (Ammonul®) can eliminate nitrogen waste independent of the urea cycle. We report attempts to improve outcomes for males with severe ornithine transcarbamylase deficiency (OTCD), a severe X-linked condition, via prenatal intravenous administration of Ammonul and arginine to heterozygous carrier females of OTCD during labor. METHODS USED Two heterozygote OTCD mothers carrying male fetuses with a prenatal diagnosis of OTCD received intravenous Ammonul, arginine and dextrose-containing fluids shortly before birth. Maintenance Ammonul and arginine infusions and high-caloric enteral nutrition were started immediately after birth. Ammonul metabolites were measured in umbilical cord blood and the blood of the newborn immediately after delivery. Serial ammonia and biochemical analyses were performed following delivery. SUMMARY OF RESULTS Therapeutic concentrations of Ammonul metabolites were detected in umbilical cord and neonatal blood samples. Plasma ammonia and glutamine levels in the postnatal period were within the normal range. Peak ammonia levels in the first 24-48h were 53mcmol/l and 62mcmol/l respectively. The boys did not experience neurological sequelae secondary to hyperammonemia and received liver transplantation at ages 3months and 5months. The patients show normal development at ages 7 and 3years. CONCLUSION Prenatal treatment of mothers who harbor severe OTCD mutations and carry affected male fetuses with intravenous Ammonul and arginine, followed by immediate institution of maintenance infusions after delivery, results in therapeutic levels of benzoate and phenylacetate in the newborn at delivery and, in conjunction with high-caloric enteral nutrition, prevents acute hyperammonemia and neurological decompensation. Following initial medical management, early liver transplantation may improve developmental outcome.
Collapse
Affiliation(s)
- Yael Wilnai
- Department of Pediatrics, Stanford University, CA, USA
| | - Yair J Blumenfeld
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA
| | - Kristina Cusmano
- Department of Genetics and Metabolism, Children's National Medical Center, Washington, DC, USA
| | - Susan R Hintz
- Department of Pediatrics, Stanford University, CA, USA
| | | | | | | | | | - Ricardo O Castillo
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Stanford University, CA, USA
| | - Waldo Concepcion
- Division of Abdominal Transplantation, Stanford University, CA, USA
| | - Tina M Cowan
- Department of Pathology, Stanford University, CA, USA
| | - Kenneth L Cox
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Stanford University, CA, USA
| | - Deirdre J Lyell
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | - Melissa Hurwitz
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Stanford University, CA, USA
| | | | | | | | - Marshall L Summar
- Department of Genetics and Metabolism, Children's National Medical Center, Washington, DC, USA
| | | |
Collapse
|
39
|
Jurcă AD, Jurcă MC, Bembea M, Kozma K, Budişteanu M, Gug C. Clinical and genetic diversity of congenital hyperammonemia. Rom J Morphol Embryol 2018; 59:945-948. [PMID: 30534838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Congenital hyperammonemia (HA) due to inborn errors of metabolism is a rare condition with a high rate of mortality. The main effects occur at the central nervous system (CNS) level, being neurotoxic by alteration of the neurotransmitter function. HA can be triggered by an inappropriate diet, infection or stress, but can also occur without a precise cause. In cases of metabolic crises, patients require immediately intensive care. In the last seven years (2011-2017), we cared in the Department of Genetics, "Dr. Gavril Curteanu" Municipal Clinical Hospital, Oradea, Romania, six patients with different causes of congenital HA: one case with argininosuccinate lyase deficiency, two cases (brothers) with argininosuccinate synthase deficiency, one case with non-ketotic hyperglycinemia, one case hyperglycinemia and one case with HA with unknown etiology. The medical surveillance and care of these children over a long period of time raise serious problems for the family and society. These patients are dependent on medical services: qualified medical staff (pediatrician, geneticist, radiologist, biochemist, nutritionist, and psychologist), expensive and repeated medical investigations, prolonged and costly medication. Most of these costs could be avoided by early diagnosis and treatment, rigorous monitoring of HA, ensuring proper diet and medication. Our experience regarding the clinical and genetic particularities of patients with congenital HA could be an opportunity for the better knowledge of special needs of these patients, especially regarding the psychological and social aspects.
Collapse
Affiliation(s)
- Alexandru Daniel Jurcă
- Department of Preclinical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, Romania;
| | | | | | | | | | | |
Collapse
|
40
|
Tan JQ, Chen DY, Li ZT, Yan TZ, Huang JW, Cai R. [Genetic diagnosis of 10 neonates with primary carnitine deficiency]. Zhongguo Dang Dai Er Ke Za Zhi 2017; 19:1150-1154. [PMID: 29132460 PMCID: PMC7389330 DOI: 10.7499/j.issn.1008-8830.2017.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To study the gene mutation profile of primary carnitine deficiency (PCD) in neonates, and to provide a theoretical basis for early diagnosis and treatment, genetic counseling, and prenatal diagnosis of PCD. METHODS Acylcarnitine profile analysis was performed by tandem mass spectrometry using 34 167 dry blood spots on filter paper. The SLC22A5 gene was sequenced and analyzed in neonates with free carnitine (C0) levels lower than 10 μmol/L as well as their parents. RESULTS In the acylcarnitine profile analysis, a C0 level lower than 10 μmol/L was found in 10 neonates, but C0 level was not reduced in their mothers. The 10 neonates had 10 types of mutations at 20 different sites in the SLC22A5 gene, which included 4 previously unreported mutations: c.976C>T, c.919delG, c.517delC, and c.338G>A. Bioinformatics analysis showed that the four new mutations were associated with a risk of high pathogenicity. CONCLUSIONS Tandem mass spectrometry combined with SLC22A5 gene sequencing may be useful for the early diagnosis of PCD. Identification of new mutations enriches the SLC22A5 gene mutation profile.
Collapse
Affiliation(s)
- Jian-Qiang Tan
- Department of Medical Genetics, Liuzhou Maternal and Child Health Care Hospital, Liuzhou, Guangxi 545001, China.
| | | | | | | | | | | |
Collapse
|
41
|
Tan JQ, Chen DY, Li ZT, Yan TZ, Huang JW, Cai R. [Genetic diagnosis of 10 neonates with primary carnitine deficiency]. Zhongguo Dang Dai Er Ke Za Zhi 2017; 19:1150-1154. [PMID: 29132460 PMCID: PMC7389330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/07/2017] [Indexed: 11/12/2023]
Abstract
OBJECTIVE To study the gene mutation profile of primary carnitine deficiency (PCD) in neonates, and to provide a theoretical basis for early diagnosis and treatment, genetic counseling, and prenatal diagnosis of PCD. METHODS Acylcarnitine profile analysis was performed by tandem mass spectrometry using 34 167 dry blood spots on filter paper. The SLC22A5 gene was sequenced and analyzed in neonates with free carnitine (C0) levels lower than 10 μmol/L as well as their parents. RESULTS In the acylcarnitine profile analysis, a C0 level lower than 10 μmol/L was found in 10 neonates, but C0 level was not reduced in their mothers. The 10 neonates had 10 types of mutations at 20 different sites in the SLC22A5 gene, which included 4 previously unreported mutations: c.976C>T, c.919delG, c.517delC, and c.338G>A. Bioinformatics analysis showed that the four new mutations were associated with a risk of high pathogenicity. CONCLUSIONS Tandem mass spectrometry combined with SLC22A5 gene sequencing may be useful for the early diagnosis of PCD. Identification of new mutations enriches the SLC22A5 gene mutation profile.
Collapse
Affiliation(s)
- Jian-Qiang Tan
- Department of Medical Genetics, Liuzhou Maternal and Child Health Care Hospital, Liuzhou, Guangxi 545001, China.
| | | | | | | | | | | |
Collapse
|
42
|
Adeva-Andany MM, Calvo-Castro I, Fernández-Fernández C, Donapetry-García C, Pedre-Piñeiro AM. Significance of l-carnitine for human health. IUBMB Life 2017; 69:578-594. [PMID: 28653367 DOI: 10.1002/iub.1646] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/24/2017] [Indexed: 12/29/2022]
Abstract
Carnitine acyltransferases catalyze the reversible transfer of acyl groups from acyl-coenzyme A esters to l-carnitine, forming acyl-carnitine esters that may be transported across cell membranes. l-Carnitine is a wáter-soluble compound that humans may obtain both by food ingestion and endogenous synthesis from trimethyl-lysine. Most l-carnitine is intracellular, being present predominantly in liver, skeletal muscle, heart and kidney. The organic cation transporter-2 facilitates l-carnitine uptake inside cells. Congenital dysfunction of this transporter causes primary l-carnitine deficiency. Carnitine acetyltransferase is involved in the export of excess acetyl groups from the mitochondria and in acetylation reactions that regulate gene transcription and enzyme activity. Carnitine octanoyltransferase is a peroxysomal enzyme required for the complete oxidation of very long-chain fatty acids and phytanic acid, a branched-chain fatty acid. Carnitine palmitoyltransferase-1 is a transmembrane protein located on the outer mitochondrial membrane where it catalyzes the conversion of acyl-coenzyme A esters to acyl-carnitine esters. Carnitine acyl-carnitine translocase transports acyl-carnitine esters across the inner mitochondrial membrane in exchange for free l-carnitine that exits the mitochondrial matrix. Carnitine palmitoyltransferase-2 is anchored on the matrix side of the inner mitochondrial membrane, where it converts acyl-carnitine esters back to acyl-coenzyme A esters, which may be used in metabolic pathways, such as mitochondrial β-oxidation. l-Carnitine enhances nonoxidative glucose disposal under euglycemic hyperinsulinemic conditions in both healthy individuals and patients with type 2 diabetes, suggesting that l-carnitine strengthens insulin effect on glycogen storage. The plasma level of acyl-carnitine esters, primarily acetyl-carnitine, increases during diabetic ketoacidosis, fasting, and physical activity, particularly high-intensity exercise. Plasma concentration of free l-carnitine decreases simultaneously under these conditions. © 2017 IUBMB Life, 69(8):578-594, 2017.
Collapse
|
43
|
Dercksen M, Duran M, IJlst L, Kulik W, Ruiter JPN, van Cruchten A, Tuchman M, Wanders RJA. A novel UPLC-MS/MS based method to determine the activity of N-acetylglutamate synthase in liver tissue. Mol Genet Metab 2016; 119:307-310. [PMID: 27771289 DOI: 10.1016/j.ymgme.2016.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 10/11/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND N-acetylglutamate synthase (NAGS) plays a key role in the removal of ammonia via the urea cycle by catalyzing the synthesis of N-acetylglutamate (NAG), the obligatory cofactor in the carbamyl phosphate synthetase 1 reaction. Enzymatic analysis of NAGS in liver homogenates has remained insensitive and inaccurate, which prompted the development of a novel method. METHODS UPLC-MS/MS was used in conjunction with stable isotope (N-acetylglutamic-2,3,3,4,4-d5 acid) dilution for the quantitative detection of NAG produced by the NAGS enzyme. The assay conditions were optimized using purified human NAGS and the optimized enzyme conditions were used to measure the activity in mouse liver homogenates. RESULTS A low signal-to-noise ratio in liver tissue samples was observed due to non-enzymatic formation of N-acetylglutamate and low specific activity, which interfered with quantitative analysis. Quenching of acetyl-CoA immediately after the incubation circumvented this analytical difficulty and allowed accurate and sensitive determination of mammalian NAGS activity. The specificity of the assay was validated by demonstrating a complete deficiency of NAGS in liver homogenates from Nags -/- mice. CONCLUSION The novel NAGS enzyme assay reported herein can be used for the diagnosis of inherited NAGS deficiency and may also be of value in the study of secondary hyperammonemia present in various inborn errors of metabolism as well as drug treatment.
Collapse
Affiliation(s)
- Marli Dercksen
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Human Metabonomics, North-West University, Potchefstroom Campus, South Africa.
| | - Marinus Duran
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Lodewijk IJlst
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Wim Kulik
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jos P N Ruiter
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Arno van Cruchten
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Mendel Tuchman
- Children's National Medical Center, The George Washington University, Washington, DC, USA
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Departments of Pediatrics and Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
44
|
Qadri SK, Ting TW, Lim JS, Jamuar SS. Milder Form of Urea Cycle Defect Revisited: Report and Review of Hyperornithinaemia-Hyperammonaemia-Homocitrullinuria (HHH) Syndrome Diagnosed in a Teenage Girl Presenting with Recurrent Encephalopathy. Ann Acad Med Singap 2016; 45:563-566. [PMID: 28062886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Syeda Kashfi Qadri
- Department of Paediatrics, KK Women's and Children's Hospital, Singapore
| | | | | | | |
Collapse
|
45
|
Abstract
We report a 3-year-old Saudi boy with recurrent episodes of vomiting, poor feeding, and altered mental status accompanied by an intermittent mild hyperammonemia, and a large elevation of urinary orotic acid. Sanger sequencing of the ornithine transcarbamylase (OTC) gene revealed a novel hemizygous deletion at the fourth nucleotide of intron 4 (c.386+4delT) in the proband and his asymptomatic mother. This novel mutation in the OTC gene is responsible for the late-onset phenotype of OTC deficiency.
Collapse
Affiliation(s)
- Sarar Mohamed
- Department of Pediatrics (39), College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia. E-mail.
| | | | | | | |
Collapse
|
46
|
Nałęcz KA, Nałęcz MJ. [Carnitine - mitochondria and beyond]. Postepy Biochem 2016; 62:85-93. [PMID: 28132459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 05/19/2016] [Indexed: 06/06/2023]
Abstract
Carnitine [(3R)-3-hydroxy-4-(trimethylazaniumyl)butanoate] in mammals is mainly delivered with diet. It enters the cell due to the activity of organic cation/carnitine transporter OCTN2 (SLC22A5), it can be as well transported by CT2 (SLC22A16) and a transporter of neutral and basic amino acids ATB0, + (SLC6A14). The hydroxyl group of carnitine is able to form esters with organic acids (xenobiotics, fatty acids) due to the activity of acylcarnitine transferases. Carnitine is necessary for transfer of fatty acids to mitochondria: in functioning of the so-called carnitine shuttle an essential role is fulfilled by palmitoylcarnitine transferase 1, carnitine carrier (SLC25A20) in the inner mitochondrial membrane and palmitoylcarnitine transferase 2. Oxidation of fatty acids takes also place in peroxisomes. The produced medium-chain acyl derivatives are exported as acylcarnitines, most probably by OCTN3 (Slc22a21). It has been postulated that acylcarnitines can cross the outer mitochondrial membrane through the voltage-dependent anion channel (VDAC) and/or through the palmitoycarnitine transferase 1 oligomer. Mutations of genes coding carnitine plasma membrane transporters result in the primary carnitine deficiency, with symptoms affecting normal functioning of muscles (including heart) and brain. Mechanisms regulating functioning of these transporters have been presented with emphasis on their role as potential therapeutic targets.
Collapse
Affiliation(s)
- Katarzyna A Nałęcz
- Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| | - Maciej J Nałęcz
- Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland
| |
Collapse
|
47
|
Bijvoet GP, van der Sijs-Bos CJM, Wielders JPM, Groot OA. Fatal hyperammonaemia due to late-onset ornithine transcarbamylase deficiency. Neth J Med 2016; 74:36-39. [PMID: 26819360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this case report we describe a 67-year-old male, admitted to the ICU with pneumonia who unexpectedly developed a fatal coma due to hyperammonaemia. At postmortem the diagnosis late-onset ornithine transcarbamylase deficiency was made. The non-specific clinical presentation, the rapid deterioration and incidentally the fatal outcome all underline the importance of recognition and knowledge of this genetic disorder. Several measures to treat and prevent potentially fatal episodes of hyperammonaemia are available, if only the disorder is recognised in time. In retrospect, several clues to the diagnosis were available in this fatal case, such as voluntary protein avoidance, as well as several male family members who died at a young age of an unknown cause. After his death, two daughters were discovered to be carriers of an OTC gene mutation, as well as his infant grandson. We emphasise the importance of obtaining ammonia levels in all patients with unexplained coma, seizures or cerebral oedema, irrespective of their age, especially in patients in the ICU or in an otherwise catabolic state.
Collapse
Affiliation(s)
- G P Bijvoet
- Department of Cardiology, Meander Medical Center, Amersfoort, the Netherlands
| | | | | | | |
Collapse
|
48
|
Hu L, Ibrahim K, Stucki M, Frapolli M, Shahbeck N, Chaudhry FA, Görg B, Häussinger D, Penberthy WT, Ben-Omran T, Häberle J. Secondary NAD+ deficiency in the inherited defect of glutamine synthetase. J Inherit Metab Dis 2015; 38:1075-83. [PMID: 25896882 DOI: 10.1007/s10545-015-9846-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/03/2015] [Accepted: 03/20/2015] [Indexed: 01/05/2023]
Abstract
Glutamine synthetase (GS) deficiency is an ultra-rare inborn error of amino acid metabolism that has been described in only three patients so far. The disease is characterized by neonatal onset of severe encephalopathy, low levels of glutamine in blood and cerebrospinal fluid, chronic moderate hyperammonemia, and an overall poor prognosis in the absence of an effective treatment. Recently, enteral glutamine supplementation was shown to be a safe and effective therapy for this disease but there are no data available on the long-term effects of this intervention. The amino acid glutamine, severely lacking in this disorder, is central to many metabolic pathways in the human organism and is involved in the synthesis of nicotinamide adenine dinucleotide (NAD(+)) starting from tryptophan or niacin as nicotinate, but not nicotinamide. Using fibroblasts, leukocytes, and immortalized peripheral blood stem cells (PBSC) from a patient carrying a GLUL gene point mutation associated with impaired GS activity, we tested whether glutamine deficiency in this patient results in NAD(+) depletion and whether it can be rescued by supplementation with glutamine, nicotinamide or nicotinate. The present study shows that congenital GS deficiency is associated with NAD(+) depletion in fibroblasts, leukocytes and PBSC, which may contribute to the severe clinical phenotype of the disease. Furthermore, it shows that NAD(+) depletion can be rescued by nicotinamide supplementation in fibroblasts and leukocytes, which may open up potential therapeutic options for the treatment of this disorder.
Collapse
Affiliation(s)
- Liyan Hu
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
- Center for Neuroscience Zurich, Zurich, Switzerland
| | - Khalid Ibrahim
- Section of Pediatric Neurology, Hamad Medical Corporation, Doha, Qatar
| | - Martin Stucki
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
| | - Michele Frapolli
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland
| | - Noora Shahbeck
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
| | - Farrukh A Chaudhry
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Boris Görg
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Dieter Häussinger
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Düsseldorf, Düsseldorf, Germany
| | | | - Tawfeg Ben-Omran
- Section of Clinical and Metabolic Genetics, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar
- Department of Pediatrics, Weil-Cornell Medical College, New York, USA
- Department of Genetic Medicine, Weil-Cornell Medical College, Doha, Qatar
| | - Johannes Häberle
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, Zurich, 8032, Switzerland.
- Center for Neuroscience Zurich, Zurich, Switzerland.
| |
Collapse
|
49
|
Yilmaz BS, Kor D, Mungan NO, Erdem S, Ceylaner S. Primary systemic carnitine deficiency: a Turkish case with a novel homozygous SLC22A5 mutation and 14 years follow-up. J Pediatr Endocrinol Metab 2015; 28:1179-81. [PMID: 26030785 DOI: 10.1515/jpem-2014-0528] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/30/2015] [Indexed: 11/15/2022]
Abstract
Systemic primary carnitine deficiency is an autosomal recessive disorder caused by the deficiency of carnitine transporter. Main features are cardiomyopathy, myopathy and hypoglycemic encephalopathy. We report a Turkish case with a novel SLC22A5 gene mutation presented with a pure cardiac phenotype. During the 14-year follow-up study, cardiac functions were remained within a normal range with oral L-carnitine supplementation.
Collapse
|
50
|
Tran C, Konstantopoulou V, Mecjia M, Perlman K, Mercimek-Mahmutoglu S, Kronick JB. Hyperinsulinemic hypoglycemia: think of hyperinsulinism/hyperammonemia (HI/HA) syndrome caused by mutations in the GLUD1 gene. J Pediatr Endocrinol Metab 2015; 28:873-6. [PMID: 25781533 DOI: 10.1515/jpem-2014-0441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/21/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND Hyperinsulinism-hyperammonemia syndrome (HI/HA) is a rare autosomal dominant disorder presenting with hypoglycemia and hyperammonemia. It is caused by activating mutations in the GLUD1 gene. CASE REPORTS Three patients from two different centers, a 14-month-old female, a 28-year-old female (mother of the first patient) from Toronto and an unrelated 2.5-year-old male from Vienna, presented with multiple episodes of seizures associated with hypoglycemia. RESULTS All patients had mild to moderate hypoglycemia, inappropriate insulin levels and mild hyperammonemia, thus suggesting a disorder of glutamate dehydrogenase (GDH). Molecular genetic testing of the GLUD1 gene identified heterozygous mutations in all patients (patient 1 and her mother a novel c.1526G>C mutation; patient 3 a known c.809C>G mutation). CONCLUSION We present three new patients with GDH caused by heterozygous mutation in the GLUD1 gene. Mild hyperammonemia and inappropriately elevated insulin levels should suggest a GLUD1 mutation. Early onset hypoglycemia associated with seizures, and especially a good response to diazoxide treatment, should include this disorder in the differential diagnosis of hyperinsulinemic hypoglycemia.
Collapse
|