1
|
Dell'Era E, Polidori M, Bernardini M, Capomaccio S, Cappelli K, Balducci F, Mandara MT. Selective symmetrical necrotizing encephalopathy secondary to primary mitochondrial disorder in a cat. J Vet Intern Med 2021; 35:2401-2408. [PMID: 34291836 PMCID: PMC8478069 DOI: 10.1111/jvim.16222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 06/25/2021] [Accepted: 07/12/2021] [Indexed: 11/28/2022] Open
Abstract
A 2‐year‐old female cat was referred for progressive neurological signs indicative of involvement of the prosencephalon, cerebellum, and brainstem. Magnetic resonance imaging identified multifocal, bilateral, symmetrical lesions with strong contrast enhancement, affecting multiple areas of the brain. Neuropathology at necropsy showed demyelination, necrotic lesions, spongiosis, and neuropil edema with reactive astrogliosis and neovascularization. Ultrastructural study indicated mitochondrial polymorphism. Genetic investigations outlined 2 polymorphisms within the tRNA‐Leu(UUR) gene of mitochondrial DNA. Imaging and neuropathological findings were consistent with selective symmetrical necrotizing encephalopathy, for which genetic investigations support mitochondrial pathogenesis.
Collapse
Affiliation(s)
- Elena Dell'Era
- Neurology Unit, AniCura Portoni Rossi Veterinary Hospital, Bologna, Italy
| | - Margherita Polidori
- Department of Veterinary Medicine, Neuropathology Laboratory, University of Perugia, Perugia, Italy
| | - Marco Bernardini
- Neurology Unit, AniCura Portoni Rossi Veterinary Hospital, Bologna, Italy.,Department of Animal Medicine, Production and Health, Clinical Section, University of Padua, Legnaro, Italy
| | - Stefano Capomaccio
- Department of Veterinary Medicine, Laboratory of Molecular Biology, University of Perugia, Perugia, Italy
| | - Katia Cappelli
- Department of Veterinary Medicine, Laboratory of Molecular Biology, University of Perugia, Perugia, Italy
| | - Federica Balducci
- Neurology Unit, AniCura Portoni Rossi Veterinary Hospital, Bologna, Italy
| | - Maria T Mandara
- Department of Veterinary Medicine, Neuropathology Laboratory, University of Perugia, Perugia, Italy
| |
Collapse
|
2
|
Life-threatening lactic acidosis occurring in adults with mitochondrial disorders. Rev Neurol (Paris) 2019; 175:564-567. [PMID: 31053354 DOI: 10.1016/j.neurol.2018.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/02/2018] [Accepted: 12/07/2018] [Indexed: 11/20/2022]
Abstract
Although relatively common in children, severe acute lactic acidosis is rare in adults with mitochondrial myopathies. We report here three cases, aged 27, 32 and 32 years, who developed life-threatening metabolic crisis with severe lactic acidosis, requiring hospitalisation in intensive care unit. Plasma lactates were elevated 10 to 15 fold normal values, necessitating extra-renal dialysis. By contrast CK levels were moderately increased (3 to 5N). No triggering factor was identified, but retrospectively all patients reported long-lasting mild muscle fatigability and weakness before their acute metabolic crisis. All of them recovered after prolonged intensive care but resting lactate levels remained elevated. Muscle biopsy showed ragged-red and COX-negative fibers in two patients and mild lipidosis in the third one. Heteroplasmic pathogenic point mutations were detected in MT-TL1 (m.3280G>A;m.3258C>T) and MT-TK (m.8363A>G). Life-threatening lactic acidosis may thus be a major inaugural clinical manifestation in adults with mitochondrial myopathies. Prolonged intensive care may lead to a dramatic and sustained improvement and is mandatory in such cases.
Collapse
|
3
|
MELAS syndrome, cardiomyopathy, rhabdomyolysis, and autism associated with the A3260G mitochondrial DNA mutation. Biochem Biophys Res Commun 2010; 402:443-7. [PMID: 20965148 DOI: 10.1016/j.bbrc.2010.10.060] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 10/14/2010] [Indexed: 12/15/2022]
Abstract
The A to G transition mutation at position 3260 of the mitochondrial genome is usually associated with cardiomyopathy and myopathy. One Japanese kindred reported the phenotype of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS syndrome) in association with the A3260G mtDNA mutation. We describe the first Caucasian cases of MELAS syndrome associated with the A3260G mutation. Furthermore, this mutation was associated with exercise-induced rhabdomyolysis, hearing loss, seizures, cardiomyopathy, and autism in the large kindred. We conclude that the A3260G mtDNA mutation is associated with wide phenotypic heterogeneity with MELAS and other "classical" mitochondrial phenotypes being manifestations.
Collapse
|
4
|
Du W, Li W, Chen G, Cao H, Tang H, Tang X, Jin Q, Sun Z, Zhao H, Zhou W, He S, Lv Y, Zhao J, Zhang X. Detection of known base substitution mutations in human mitochondrial DNA of MERRF and MELAS by biochip technology. Biosens Bioelectron 2008; 24:2371-6. [PMID: 19155171 DOI: 10.1016/j.bios.2008.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/07/2008] [Accepted: 12/03/2008] [Indexed: 11/25/2022]
Abstract
We developed a DNA biochip specialized for detection of known base substitution mutations in mitochondrial DNA causing mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) and myoclonic epilepsy associated with ragged-red fibers (MERRF). A set of probes sharing a given allele-specific sequence with a single base substitution near the middle of the sequence was covalently immobilized. Cy5-labeled DNA targets were amplified from sample DNAs containing 31 potential MELAS and/or MERRF mutations by a multiplex PCR method. Detection parameters for the DNA biochip-based assay were accordingly optimized. Seven clinically confirmed patients with MELAS, 5 patients with MERRF, 1 suspected MERRF case and 25 healthy controls were tested using the DNA biochip. For discriminating of homoplasmic and heteroplasmic point mutations in mtDNA, a diagnostic factor based on the ratio between the hybridization signals from the reference and test targets with each probe was used. The results showed that all the cases with MELAS had a causal heteroplasmic A3243G tRNA(Leu(UUR)) mutation. In the MERRF patients, four cases were found to be a homoplasmic A8344G tRNA(Lys) mutation and one case was a heteroplasmic T8356C tRNA(Lys) mutation. None of the healthy controls carried the potential mutations. The results of the DNA biochip were completely consistent with those by DNA sequencing. Thus, the DNA biochip would potentially become a valuable tool in clinical specific screening of the mtDNA point mutations associated with MELAS and/or MERRF syndrome.
Collapse
Affiliation(s)
- Weidong Du
- Key Lab of Gene Resource Utilization for Severe Hereditary Diseases of Ministry of Education of China, Anhui Medical University, Hefei 230032, China.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Scaglia F, Wong LJC. Human mitochondrial transfer RNAs: role of pathogenic mutation in disease. Muscle Nerve 2008; 37:150-71. [PMID: 17999409 DOI: 10.1002/mus.20917] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The human mitochondrial genome encodes 13 proteins. All are subunits of the respiratory chain complexes involved in energy metabolism. These proteins are translated by a set of 22 mitochondrial transfer RNAs (tRNAs) that are required for codon reading. Human mitochondrial tRNA genes are hotspots for pathogenic mutations and have attracted interest over the last two decades with the rapid discovery of point mutations associated with a vast array of neuromuscular disorders and diverse clinical phenotypes. In this review, we use a scoring system to determine the pathogenicity of the mutations and summarize the current knowledge of structure-function relationships of these mutant tRNAs. We also provide readers with an overview of a large variety of mechanisms by which mutations may affect the mitochondrial translation machinery and cause disease.
Collapse
Affiliation(s)
- Fernando Scaglia
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | | |
Collapse
|
6
|
Maeso E, Rueda A, Jiménez S, Del Hoyo P, Martín R, Cabello A, Mendoza LM, Arenas J, Campos Y. A novel mutation in the mitochondrial DNA tRNA Leu (UUR) gene associated with late-onset ocular myopathy. Neuromuscul Disord 2007; 17:415-8. [PMID: 17363246 DOI: 10.1016/j.nmd.2007.01.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 11/29/2006] [Accepted: 01/30/2007] [Indexed: 11/26/2022]
Abstract
We identified a novel G3283A transition in the mitochondrial DNA tRNA(Leu (UUR)) gene in a patient with ptosis, ophthalmoparesis and hyporeflexia. Muscle biopsy showed cytochrome oxidase positive ragged-red fibers, and defects of complexes I, III and IV of the mitochondrial respiratory chain. The mutation was heteroplasmic in muscle of the proband, being absent in her blood. Ragged-red fibers harbored greater levels of mutant genomes than normal fibers. The G3283A mutation affects a strictly conserved base pair in the TPsiC stem of the gene and was not found in controls, thus satisfying the accepted criteria for pathogenicity.
Collapse
Affiliation(s)
- E Maeso
- Centro de Investigación, Hospital 12 de Octubre, Avda. de Córdoba km 5.4, 28041 Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Mancuso M, Petrozzi L, Filosto M, Nesti C, Rocchi A, Choub A, Pistolesi S, Massetani R, Fontanini G, Siciliano G. MERRF syndrome without ragged-red fibers: the need for molecular diagnosis. Biochem Biophys Res Commun 2007; 354:1058-60. [PMID: 17275787 DOI: 10.1016/j.bbrc.2007.01.099] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 01/19/2007] [Indexed: 11/29/2022]
Abstract
We report a patient with myoclonic epilepsy who underwent muscle biopsy for suspected mitochondrial disease (myoclonic epilepsy with ragged-red fibers, MERRF). In spite of normal histochemical studies and of the absence of a severe COX deficiency, the molecular analysis showed the common MERRF mutation (A8344G) in the tRNA(Lys) gene on mitochondrial DNA. The case serves to illustrate the importance of pursuing the proposed mitochondrial genetic abnormality, even in patients with normal biopsy findings.
Collapse
Affiliation(s)
- Michelangelo Mancuso
- Department of Neuroscience, Neurological Clinic, University of Pisa, Via Roma 67, 56126 Pisa, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Seligmann H, Krishnan NM, Rao BJ. Mitochondrial tRNA sequences as unusual replication origins: Pathogenic implications for Homo sapiens. J Theor Biol 2006; 243:375-85. [DOI: 10.1016/j.jtbi.2006.06.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 05/10/2006] [Accepted: 06/27/2006] [Indexed: 12/19/2022]
|
9
|
Kirino Y, Goto YI, Campos Y, Arenas J, Suzuki T. Specific correlation between the wobble modification deficiency in mutant tRNAs and the clinical features of a human mitochondrial disease. Proc Natl Acad Sci U S A 2005; 102:7127-32. [PMID: 15870203 PMCID: PMC1129107 DOI: 10.1073/pnas.0500563102] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in mtDNA are responsible for a variety of mitochondrial diseases, where the mitochondrial tRNA(Leu(UUR)) gene has especially hot spots for pathogenic mutations. Clinical features often depend on the tRNA species and/or positions of the mutations; however, molecular pathogenesis elucidating the relation between the location of the mutations and their leading phenotype are not fully understood. We report here that mitochondrial tRNAs(Leu(UUR)) harboring one of five mutations found in tissues from patients with symptoms of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) (A3243G, G3244A, T3258C, T3271C, and T3291C) lacked the normal taurine-containing modification (5-taurinomethyluridine) at the anticodon wobble position. In contrast, mitochondrial tRNAs(Leu(UUR)) with different mutations found in patients that have mitochondrial diseases but do not show the MELAS symptoms (G3242A, T3250C, C3254T, and A3280G) had the normal 5-taurinomethyluridine modifications. These observations were made by using a modified primer extension technique that can detect the modification deficiency in the extremely limited quantities of mutant tRNAs obtainable from patient tissues. These results strongly suggest deficient wobble modification could be a key molecular factor responsible for the phenotypic features of MELAS, which can explain why the different MELAS-associated mutations result in indistinguishable clinical features.
Collapse
Affiliation(s)
- Yohei Kirino
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | | | | | | | | |
Collapse
|
10
|
Berbel-Garcia A, Barbera-Farre JR, Etessam JP, Salio AM, Cabello A, Gutierrez-Rivas E, Campos Y. Coenzyme Q 10 Improves Lactic Acidosis, Strokelike Episodes, and Epilepsy in a Patient With MELAS (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Strokelike episodes). Clin Neuropharmacol 2004; 27:187-91. [PMID: 15319706 DOI: 10.1097/01.wnf.0000137862.67131.bf] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mitochondrial encephalomyopathies encompass a group of disorders that have impaired oxidative metabolism in skeletal muscles and central nervous system. Many compounds have been used in clinical trials on mitochondrial diseases, but the outcomes have been variable. It remains controversial whether treatment of mitochondrial diseases with coenzyme Q 10 is effective. This paper describes a case of mitochondrial myopathy, encephalopathy, lactic acidosis, strokelike episodes, and exercise intolerance successfully treated with coenzyme Q 10. Efficacy of this therapy in this patient is correlated to control of lactic acidosis and serum creatine kinase levels. Disappointingly, larger studies with coenzyme Q 10 failed to demonstrate a clear beneficial effect on the entire study population with regard to clinical improvement or several parameters of the oxidative metabolism. They suggest that the use of coenzyme Q in treatment of mitochondrial diseases should be confined to protocols. There is a confounding variation in phenotype and genotype, and the natural history of the disorders in individual patients is not accurately predictable. The unpredictable a priori efficacy of therapy suggests that a long-term trial of oral coenzyme Q may be warranted.
Collapse
Affiliation(s)
- Angel Berbel-Garcia
- Department of Neurology, Hospital Mancha Centro, Alcazar de San Juan, Ciudad Real, Spain.
| | | | | | | | | | | | | |
Collapse
|