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Braunisch MC, Gallwitz H, Abicht A, Diebold I, Holinski-Feder E, Van Maldergem L, Lammens M, Kovács-Nagy R, Alhaddad B, Strom TM, Meitinger T, Senderek J, Rudnik-Schöneborn S, Haack TB. Extension of the phenotype of biallelic loss-of-function mutations in SLC25A46 to the severe form of pontocerebellar hypoplasia type I. Clin Genet 2017; 93:255-265. [PMID: 28653766 DOI: 10.1111/cge.13084] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 06/18/2017] [Accepted: 06/20/2017] [Indexed: 01/04/2023]
Abstract
Biallelic mutations in SLC25A46, encoding a modified solute transporter involved in mitochondrial dynamics, have been identified in a wide range of conditions such as hereditary motor and sensory neuropathy with optic atrophy type VIB (OMIM: *610826) and congenital lethal pontocerebellar hypoplasia (PCH). To date, 18 patients from 13 families have been reported, presenting with the key clinical features of optic atrophy, peripheral neuropathy, and cerebellar atrophy. The course of the disease was highly variable ranging from severe muscular hypotonia at birth and early death to first manifestations in late childhood and survival into the fifties. Here we report on 4 patients from 2 families diagnosed with PCH who died within the first month of life from respiratory insufficiency. Patients from 1 family had pathoanatomically proven spinal motor neuron degeneration (PCH1). Using exome sequencing, we identified biallelic disease-segregating loss-of-function mutations in SLC25A46 in both families. Our study adds to the definition of the SLC25A46-associated phenotypic spectrum that includes neonatal fatalities due to PCH as the severe extreme.
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Affiliation(s)
- M C Braunisch
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Department of Nephrology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - H Gallwitz
- Department of Pediatrics, Socio-Pediatric Center, Klinikum Memmingen, Memmingen, Germany
| | - A Abicht
- Medical Genetics Center, Munich, Germany.,Friedrich-Baur-Institut, Neurologische Klinik und Poliklinik, Klinikum der Universität München, Munich, Germany
| | - I Diebold
- Medical Genetics Center, Munich, Germany
| | - E Holinski-Feder
- Medical Genetics Center, Munich, Germany.,Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, Munich, Germany
| | - L Van Maldergem
- Center for Human Genetics, University of Franche-Comté, Besançon, France
| | - M Lammens
- Department of Pathology, Antwerp University Hospital, Edegem, Belgium.,Department of Neuropathology, Born Bunge Institute, Antwerp University, Wilrijk, Belgium
| | - R Kovács-Nagy
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - B Alhaddad
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - T M Strom
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - T Meitinger
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - J Senderek
- Friedrich-Baur-Institut, Neurologische Klinik und Poliklinik, Klinikum der Universität München, Munich, Germany
| | - S Rudnik-Schöneborn
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria.,Institut für Humangenetik, Uniklinik RWTH Aachen, Aachen, Germany
| | - T B Haack
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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Gallwitz H, Bonse S, Martinez-Cruz A, Schlichting I, Schumacher K, Krauth-Siegel RL. Ajoene is an inhibitor and subversive substrate of human glutathione reductase and Trypanosoma cruzi trypanothione reductase: crystallographic, kinetic, and spectroscopic studies. J Med Chem 1999; 42:364-72. [PMID: 9986706 DOI: 10.1021/jm980471k] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ajoene ((E,Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide), a garlic-derived natural compound, is a covalent inhibitor as well as a substrate of human glutathione reductase (GR) and Trypanosoma cruzi trypanothione reductase (TR). The 2.1-A resolution crystal structure of GR inhibited by (E)-ajoene revealed a mixed disulfide between the active site Cys58 and the CH2=CH-CH2-SO-CH2-CH=CH-S moiety of ajoene. The modified enzyme has a markedly increased oxidase activity when compared to free GR. GR reduces (Z)-ajoene with a kcat/Km of 6.8 x 10(3) M-1 s-1 yielding 4,5,9-trithiadodeca-1, 6,11-triene (deoxyajoene) and 4,8,9,13-tetrathiahexadeca-1,6,10, 15-tetraene as stable reaction products. The reaction leads also to the formation of single-electron reduced products and concomitantly superoxide anion radicals as shown by coupling the reaction to the reduction of cytochrome c. The interactions between the flavoenzymes and ajoene are expected to increase the oxidative stress of the respective cell. The antiparasitic and cytostatic actions of ajoene may at least in part be due to the multiple effects on key enzymes of the antioxidant thiol metabolism.
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Affiliation(s)
- H Gallwitz
- Biochemie-Zentrum, Heidelberg University, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany
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