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Mordel P, Schaeffer S, Dupas Q, Laville MA, Gérard M, Chapon F, Allouche S. A 2 bp deletion in the mitochondrial ATP 6 gene responsible for the NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome. Biochem Biophys Res Commun 2017; 494:133-137. [PMID: 29054413 DOI: 10.1016/j.bbrc.2017.10.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 10/13/2017] [Indexed: 01/12/2023]
Abstract
Mitochondrial (mt) DNA-associated NARP (neurogenic muscle weakness, ataxia, and retinitis pigmentosa) syndrome is due to mutation in the MT-ATP6 gene. We report the case of a 18-year-old man who presented with deafness, a myoclonic epilepsy, muscle weakness since the age of 10 and further developed a retinitis pigmentosa and ataxia. The whole mtDNA analysis by next-generation sequencing revealed the presence of the 2 bp microdeletion m.9127-9128 del AT in the ATP6 gene at 82% heteroplasmy in muscle and to a lower load in blood (10-20%) and fibroblasts (50%). Using the patient's fibroblasts, we demonstrated a 60% reduction of the oligomycin-sensitive ATPase hydrolytic activity, a 40% decrease in the ATP synthesis and determination of the mitochondrial membrane potential using the fluorescent probe tetramethylrhodamine, ethyl ester indicated a significant reduction in oligomycin sensitivity. In conclusion, we demonstrated that this novel AT deletion in the ATP6 gene is pathogenic and responsible for the NARP syndrome.
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Affiliation(s)
- Patrick Mordel
- Normandie Univ, UNICAEN, CHU Caen, Signalisation, électrophysiologie et imagerie des lésions d'ischémie-reperfusion myocardique, Caen, F-14032, France
| | | | - Quentin Dupas
- Normandie Univ, UNICAEN, CHU Caen, Signalisation, électrophysiologie et imagerie des lésions d'ischémie-reperfusion myocardique, Caen, F-14032, France
| | | | - Marion Gérard
- CHU de Caen, Department of medical genetics, Caen, F-14032, France
| | - Françoise Chapon
- CHU de Caen, Neuromuscular Competence Center, Caen, F-14032, France; CHU de Caen, Department of Pathology, Caen, F-14032, France
| | - S Allouche
- Normandie Univ, UNICAEN, CHU Caen, Signalisation, électrophysiologie et imagerie des lésions d'ischémie-reperfusion myocardique, Caen, F-14032, France; CHU de Caen, Department of biochemistry, Caen, F-14032, France.
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Demily C, Duwime C, Poisson A, Boddaert N, Munnich A. Low dose clozapine controls adult-onset psychosis associated with the neurogenic ataxia-retinitis pigmentosa (NARP) mutation. Mol Genet Metab Rep 2016; 10:20-22. [PMID: 28003964 PMCID: PMC5157794 DOI: 10.1016/j.ymgmr.2016.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 12/07/2016] [Indexed: 11/03/2022] Open
Affiliation(s)
- Caroline Demily
- GénoPsy, Centre Hospitalier le Vinatier et Centre de Neuroscience Cognitive, UMR 5229 (CNRS et Université Claude Bernard Lyon 1), Bron, France
| | | | - Alice Poisson
- GénoPsy, Centre Hospitalier le Vinatier et Centre de Neuroscience Cognitive, UMR 5229 (CNRS et Université Claude Bernard Lyon 1), Bron, France
| | - Nathalie Boddaert
- INSERM U1163, Université Paris-Descartes, Service de radiologie pédiatrique, Institut Imagine, hôpital Necker-Enfants malades, Paris, France
| | - Arnold Munnich
- INSERM UMR 1163, Université Paris Descartes-Sorbonne, Service de génétique clinique, Institut Imagine, Hôpital Necker-Enfants Malades, Paris, France
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Blanco-Grau A, Bonaventura-Ibars I, Coll-Cantí J, Melià MJ, Martinez R, Martínez-Gallo M, Andreu AL, Pinós T, García-Arumí E. Identification and biochemical characterization of the novel mutation m.8839G>C in the mitochondrial ATP6 gene associated with NARP syndrome. Genes Brain Behav 2013; 12:812-20. [PMID: 24118886 DOI: 10.1111/gbb.12089] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/25/2013] [Accepted: 09/30/2013] [Indexed: 12/21/2022]
Abstract
Mutations in the ATP6 gene are reported to be associated with Leber hereditary optic neuropathy, bilateral striatal necrosis, coronary atherosclerosis risk and neuropathy, ataxia and retinitis pigmentosa (NARP)/maternally inherited Leigh syndromes. Here, we present a patient with NARP syndrome, in whom a previously undescribed mutation was detected in the ATP6 gene: m.8839G>C. Several observations support the concept that m.8839G>C is pathogenically involved in the clinical phenotype of this patient: (1) the mutation was heteroplasmic in muscle; (2) mutation load was higher in the symptomatic patient than in the asymptomatic carriers; (3) cybrids carrying this mutation presented lower cell proliferation, increased mitochondrial DNA (mtDNA) copy number, increased steady-state OxPhos protein levels and decreased mitochondrial membrane potential with respect to isogenic wild-type cybrids; (4) this change was not observed in 2959 human mtDNAs from different mitochondrial haplogroups; (5) the affected amino acid was conserved in all the ATP6 sequences analyzed; and (6) using in silico prediction, the mutation was classified as 'probably damaging'. However, measurement of ATP synthesis showed no differences between wild-type and mutated cybrids. Thus, we suggest that m.8839G>C may lower the efficiency between proton translocation within F0 and F1 rotation, required for ATP synthesis. Further experiments are needed to fully characterize the molecular mechanisms involved in m.8839G>C pathogenicity.
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Affiliation(s)
- A Blanco-Grau
- Departament de Patología Mitocondrial i Neuromuscular, Universitari Vall d'Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona
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