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Cordts I, Semmler L, Prasuhn J, Seibt A, Herebian D, Navaratnarajah T, Park J, Deininger N, Laugwitz L, Göricke SL, Lingor P, Brüggemann N, Münchau A, Synofzik M, Timmann D, Mayr JA, Haack TB, Distelmaier F, Deschauer M. Bi-Allelic COQ4 Variants Cause Adult-Onset Ataxia-Spasticity Spectrum Disease. Mov Disord 2022; 37:2147-2153. [PMID: 36047608 DOI: 10.1002/mds.29167] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/11/2022] [Accepted: 06/21/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND COQ4 codes for a mitochondrial protein required for coenzyme Q10 (CoQ10 ) biosynthesis. Autosomal recessive COQ4-associated CoQ10 deficiency leads to an early-onset mitochondrial multi-organ disorder. METHODS In-house exome and genome datasets (n = 14,303) were screened for patients with bi-allelic variants in COQ4. Work-up included clinical characterization and functional studies in patient-derived cell lines. RESULTS Six different COQ4 variants, three of them novel, were identified in six adult patients from four different families. Three patients had a phenotype of hereditary spastic paraparesis, two sisters showed a predominant cerebellar ataxia, and one patient had mild signs of both. Studies in patient-derived fibroblast lines revealed significantly reduced amounts of COQ4 protein, decreased CoQ10 concentrations, and elevated levels of the metabolic intermediate 6-demethoxyubiquinone. CONCLUSION We report bi-allelic variants in COQ4 causing an adult-onset ataxia-spasticity spectrum phenotype and a disease course much milder than previously reported. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Isabell Cordts
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Luisa Semmler
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Jannik Prasuhn
- Department of Neurology, Center for Brain, Behavior, and Metabolism, University Medical Center Schleswig-Holstein, Lübeck, Germany.,Institute of Neurogenetics, University Medical Center Schleswig-Holstein, Lübeck, Germany
| | - Annette Seibt
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Diran Herebian
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Tharsini Navaratnarajah
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Joohyun Park
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Natalie Deininger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Lucia Laugwitz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Department of Neuropediatrics, Developmental Neurology, and Social Pediatrics, University of Tübingen, Tübingen, Germany
| | - Sophia L Göricke
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Paul Lingor
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Norbert Brüggemann
- Department of Neurology, Center for Brain, Behavior, and Metabolism, University Medical Center Schleswig-Holstein, Lübeck, Germany.,Institute of Neurogenetics, University Medical Center Schleswig-Holstein, Lübeck, Germany
| | - Alexander Münchau
- Institute of Systems Motor Science, University of Lübeck, Lübeck, Germany
| | - Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Dagmar Timmann
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), Essen University Hospital, Essen, Germany
| | - Johannes A Mayr
- University Children's Hospital, Salzburger Landeskliniken and Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Centre for Rare Diseases, University of Tübingen, Tübingen, Germany
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Marcus Deschauer
- Department of Neurology, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
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Uccella S, Pisciotta L, Severino M, Bertini E, Giacomini T, Zanni G, Prato G, De Grandis E, Nobili L, Mancardi MM. Photoparoxysmal response in ADCK3 autosomal recessive ataxia: a case report and literature review. Epileptic Disord 2021; 23:153-60. [PMID: 33622667 DOI: 10.1684/epd.2021.1243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mutations in AarF domain-containing kinase 3 (ADCK3) are responsible for the most frequent form of hereditary coenzyme Q10 (CoQ10) deficiency (Q10 deficiency-4), which is mainly associated with autosomal recessive cerebellar ataxia type 2 (ARCA2). Clinical presentation is characterized by a variable degree of cerebellar atrophy and a broad spectrum of associated symptoms, including muscular involvement, movement disorders, neurosensory loss, cognitive impairment, psychiatric symptoms and epilepsy. In this report, we describe, for the first time, a case of photoparoxysmal response in a female patient with a mutation in ADCK3. Disease onset occurred in early childhood with gait ataxia, and mild-to-moderate degeneration. Seizures appeared at eight years and six months, occurring only during sleep. Photoparoxysmal response was observed at 14 years, almost concomitant with the genetic diagnosis (c.901C>T;c.589-3C>G) and the start of CoQ10 oral supplementation. A year later, disease progression slowed down, and photosensitivity was attenuated. A review of the literature is provided focusing on epileptic features of ADCK3-related disease as well as the physiopathology of photoparoxysmal response and supposed cerebellar involvement in photosensitivity. Moreover, the potential role of CoQ10 oral supplementation is discussed. Prospective studies on larger populations are needed to further understand these data.
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Wainwright L, Hargreaves IP, Georgian AR, Turner C, Dalton RN, Abbott NJ, Heales SJR, Preston JE. CoQ 10 Deficient Endothelial Cell Culture Model for the Investigation of CoQ 10 Blood-Brain Barrier Transport. J Clin Med 2020; 9:jcm9103236. [PMID: 33050406 PMCID: PMC7601674 DOI: 10.3390/jcm9103236] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/02/2020] [Accepted: 10/06/2020] [Indexed: 12/31/2022] Open
Abstract
Primary coenzyme Q10 (CoQ10) deficiency is unique among mitochondrial respiratory chain disorders in that it is potentially treatable if high-dose CoQ10 supplements are given in the early stages of the disease. While supplements improve peripheral abnormalities, neurological symptoms are only partially or temporarily ameliorated. The reasons for this refractory response to CoQ10 supplementation are unclear, however, a contributory factor may be the poor transfer of CoQ10 across the blood-brain barrier (BBB). The aim of this study was to investigate mechanisms of CoQ10 transport across the BBB, using normal and pathophysiological (CoQ10 deficient) cell culture models. The study identifies lipoprotein-associated CoQ10 transcytosis in both directions across the in vitro BBB. Uptake via SR-B1 (Scavenger Receptor) and RAGE (Receptor for Advanced Glycation Endproducts), is matched by efflux via LDLR (Low Density Lipoprotein Receptor) transporters, resulting in no "net" transport across the BBB. In the CoQ10 deficient model, BBB tight junctions were disrupted and CoQ10 "net" transport to the brain side increased. The addition of anti-oxidants did not improve CoQ10 uptake to the brain side. This study is the first to generate in vitro BBB endothelial cell models of CoQ10 deficiency, and the first to identify lipoprotein-associated uptake and efflux mechanisms regulating CoQ10 distribution across the BBB. The results imply that the uptake of exogenous CoQ10 into the brain might be improved by the administration of LDLR inhibitors, or by interventions to stimulate luminal activity of SR-B1 transporters.
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Affiliation(s)
- Luke Wainwright
- UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
| | - Iain P. Hargreaves
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- Department of Pharmacy and Biomolecular Science, Liverpool John Moores University, Liverpool L3 5UA, UK
| | - Ana R. Georgian
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Charles Turner
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - R. Neil Dalton
- Evelina London Children’s Hospital, Guy’s and St. Thomas’ NHS Foundation Trust, London SE1 7EH, UK; (C.T.); (R.N.D.)
| | - N. Joan Abbott
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
| | - Simon J. R. Heales
- Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London WC1N 3BG, UK;
- UCL Great Ormond Street Institute of Child Health, University College London, London WC1E 6BT, UK;
| | - Jane E. Preston
- School of Cancer and Pharmaceutical Sciences, King’s College London, London SE1 9NH, UK; (A.R.G.); (N.J.A.)
- Correspondence: ; Tel.: +44-207-848-4881
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Di Lorenzo A, Iannuzzo G, Parlato A, Cuomo G, Testa C, Coppola M, D’Ambrosio G, Oliviero DA, Sarullo S, Vitale G, Nugara C, Sarullo FM, Giallauria F. Clinical Evidence for Q10 Coenzyme Supplementation in Heart Failure: From Energetics to Functional Improvement. J Clin Med 2020; 9:jcm9051266. [PMID: 32349341 PMCID: PMC7287951 DOI: 10.3390/jcm9051266] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 04/19/2020] [Accepted: 04/24/2020] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress and mitochondrial dysfunction are hallmarks of heart failure (HF). Coenzyme Q10 (CoQ10) is a vitamin-like organic compound widely expressed in humans as ubiquinol (reduced form) and ubiquinone (oxidized form). CoQ10 plays a key role in electron transport in oxidative phosphorylation of mitochondria. CoQ10 acts as a potent antioxidant, membrane stabilizer and cofactor in the production of adenosine triphosphate by oxidative phosphorylation, inhibiting the oxidation of proteins and DNA. Patients with HF showed CoQ10 deficiency; therefore, a number of clinical trials investigating the effects of CoQ10 supplementation in HF have been conducted. CoQ10 supplementation may confer potential prognostic advantages in HF patients with no adverse hemodynamic profile or safety issues. The latest evidence on the clinical effects of CoQ10 supplementation in HF was reviewed.
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Affiliation(s)
- Anna Di Lorenzo
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Gabriella Iannuzzo
- Department of Clinical Medicine and Surgery, “Federico II” University of Naples, 80131 Naples, Italy;
| | - Alessandro Parlato
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Gianluigi Cuomo
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Crescenzo Testa
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Marta Coppola
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Giuseppe D’Ambrosio
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Domenico Alessandro Oliviero
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
| | - Silvia Sarullo
- Cardiovascular Rehabilitation Unit, Buccheri La Ferla Fatebenefratelli Hospital, 90123 Palermo, Italy; (S.S.); (G.V.); (C.N.); (F.M.S.)
| | - Giuseppe Vitale
- Cardiovascular Rehabilitation Unit, Buccheri La Ferla Fatebenefratelli Hospital, 90123 Palermo, Italy; (S.S.); (G.V.); (C.N.); (F.M.S.)
| | - Cinzia Nugara
- Cardiovascular Rehabilitation Unit, Buccheri La Ferla Fatebenefratelli Hospital, 90123 Palermo, Italy; (S.S.); (G.V.); (C.N.); (F.M.S.)
| | - Filippo M. Sarullo
- Cardiovascular Rehabilitation Unit, Buccheri La Ferla Fatebenefratelli Hospital, 90123 Palermo, Italy; (S.S.); (G.V.); (C.N.); (F.M.S.)
| | - Francesco Giallauria
- Department of Translational Medical Sciences, “Federico II” University of Naples, 80131 Naples, Italy; (A.D.L.); (A.P.); (G.C.); (C.T.); (M.C.); (G.D.); (D.A.O.)
- Correspondence: ; Tel.: +39-(0)8-1746-3519
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Berardo A, Quinzii CM. Redefining infantile-onset multisystem phenotypes of coenzyme Q 10-deficiency in the next-generation sequencing era. J Transl Genet Genom 2020; 4:22-35. [PMID: 33426503 PMCID: PMC7791541 DOI: 10.20517/jtgg.2020.02] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Primary coenzyme Q10 (CoQ10) deficiency encompasses a subset of mitochondrial diseases caused by mutations affecting proteins involved in the CoQ10 biosynthetic pathway. One of the most frequent clinical syndromes associated with primary CoQ10 deficiency is the severe infantile multisystemic form, which, until recently, was underdiagnosed. In the last few years, the availability of genetic screening through whole exome sequencing and whole genome sequencing has enabled molecular diagnosis in a growing number of patients with this syndrome and has revealed new disease phenotypes and molecular defects in CoQ10 biosynthetic pathway genes. Early genetic screening can rapidly and non-invasively diagnose primary CoQ10 deficiencies. Early diagnosis is particularly important in cases of CoQ10 deficient steroid-resistant nephrotic syndrome, which frequently improves with treatment. In contrast, the infantile multisystemic forms of CoQ10 deficiency, particularly when manifesting with encephalopathy, present therapeutic challenges, due to poor responses to CoQ10 supplementation. Administration of CoQ10 biosynthetic intermediate compounds is a promising alternative to CoQ10; however, further pre-clinical studies are needed to establish their safety and efficacy, as well as to elucidate the mechanism of actions of the intermediates. Here, we review the molecular defects causes of the multisystemic infantile phenotype of primary CoQ10 deficiency, genotype-phenotype correlations, and recent therapeutic advances.
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Affiliation(s)
- Andres Berardo
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
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Chang A, Ruiz-Lopez M, Slow E, Tarnopolsky M, Lang AE, Munhoz RP. ADCK3-related Coenzyme Q10 Deficiency: A Potentially Treatable Genetic Disease. Mov Disord Clin Pract 2018; 5:635-639. [PMID: 30637285 DOI: 10.1002/mdc3.12667] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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: 06/01/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 12/31/2022] Open
Abstract
Background Disorders related to dysfunction of coenzyme (CoQ10) metabolism, including AarF domain containing kinase 3 gene (ADCK3) mutations, have received attention due to the potential for response to CoQ10 supplementation. Methods We describe two new cases of neurological syndromes due to ADCK3 mutations that obtained striking benefit from CoQ10, and a third who did not. We also review 20 cases from the literature in which responses to CoQ10 were documented out of all 38 previously reported cases. Results Despite the remarkable responses in some cases with ataxia and movement disorders (myoclonus, dystonia, tremor), overall, we were not able to identify variables that predicted response to CoQ10 supplementation. Conclusions Based on our experience and data from the literature, we recommend a minimum of 10 mg/kg/day of ubiquinone with titration up to 15 mg/kg/day, maintained at least for 6 months in order to obtain or exclude potential benefit from therapy.
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Affiliation(s)
- Anna Chang
- Morton and Gloria Shulman Movement Disorders Clinic, Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, UHN, Division of Neurology University of Toronto Toronto Ontario Canada.,Department of Neurology Shin Kong Wu Ho-Su Memorial Hospital Taipei Taiwan
| | - Marta Ruiz-Lopez
- Morton and Gloria Shulman Movement Disorders Clinic, Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, UHN, Division of Neurology University of Toronto Toronto Ontario Canada
| | - Elizabeth Slow
- Morton and Gloria Shulman Movement Disorders Clinic, Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, UHN, Division of Neurology University of Toronto Toronto Ontario Canada
| | - Mark Tarnopolsky
- Department of Pediatrics and Neuromuscular and Neurometabolic Clinic McMaster University Medical Center Hamilton Ontario Canada
| | - Anthony E Lang
- Morton and Gloria Shulman Movement Disorders Clinic, Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, UHN, Division of Neurology University of Toronto Toronto Ontario Canada
| | - Renato P Munhoz
- Morton and Gloria Shulman Movement Disorders Clinic, Edmond J. Safra Program in Parkinson's Disease, Toronto Western Hospital, UHN, Division of Neurology University of Toronto Toronto Ontario Canada
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Yubero D, Allen G, Artuch R, Montero R. The Value of Coenzyme Q 10 Determination in Mitochondrial Patients. J Clin Med 2017; 6:jcm6040037. [PMID: 28338638 PMCID: PMC5406769 DOI: 10.3390/jcm6040037] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/17/2017] [Accepted: 03/17/2017] [Indexed: 12/26/2022] Open
Abstract
Coenzyme Q10 (CoQ) is a lipid that is ubiquitously synthesized in tissues and has a key role in mitochondrial oxidative phosphorylation. Its biochemical determination provides insight into the CoQ status of tissues and may detect CoQ deficiency that can result from either an inherited primary deficiency of CoQ metabolism or may be secondary to different genetic and environmental conditions. Rapid identification of CoQ deficiency can also allow potentially beneficial treatment to be initiated as early as possible. CoQ may be measured in different specimens, including plasma, blood mononuclear cells, platelets, urine, muscle, and cultured skin fibroblasts. Blood and urinary CoQ also have good utility for CoQ treatment monitoring.
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Affiliation(s)
- Delia Yubero
- Clinical Biochemistry and Molecular Medicine Department, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Passeig Sant Joan de Déu, 2, 08950 Esplugues, Barcelona, Spain.
| | - George Allen
- Department of Blood Sciences, Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK.
| | - Rafael Artuch
- Clinical Biochemistry and Molecular Medicine Department, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Passeig Sant Joan de Déu, 2, 08950 Esplugues, Barcelona, Spain.
| | - Raquel Montero
- Clinical Biochemistry and Molecular Medicine Department, Institut de Recerca Sant Joan de Déu and CIBERER-ISCIII, Passeig Sant Joan de Déu, 2, 08950 Esplugues, Barcelona, Spain.
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Sommerville RB, Zaidman CM, Pestronk A. Coenzyme Q10 deficiency in children: frequent type 2C muscle fibers with normal morphology. Muscle Nerve 2013; 48:722-6. [PMID: 23494902 DOI: 10.1002/mus.23837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2013] [Indexed: 11/10/2022]
Abstract
INTRODUCTION Neurological disorders with low tissue coenzyme Q10 (CoQ10) levels are important to identify, as they may be treatable. METHODS We evaluated retrospectively clinical, laboratory, and muscle histochemistry and oxidative enzyme characteristics in 49 children with suspected mitochondrial disorders. We compared 18 with CoQ10 deficiency in muscle to 31 with normal CoQ10 values. RESULTS Muscle from CoQ10-deficient patients averaged 5.5-fold more frequent type 2C muscle fibers than controls (P < 0.0001). A type 2C fiber frequency of ≥ 5% had 89% sensitivity and 84% specificity for CoQ10 deficiency in this cohort. No biopsy showed active myopathy. There were no differences between groups in frequencies of mitochondrial myopathologic, clinical, or laboratory features. Multiple abnormalities in muscle oxidative enzyme activities were more frequent in CoQ10-deficient patients than in controls. CONCLUSIONS When a childhood mitochondrial disorder is suspected, an increased frequency of type 2C fibers in morphologically normal muscle suggests CoQ10 deficiency.
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Affiliation(s)
- R Brian Sommerville
- Washington University School of Medicine, Department of Neurology, 660 S. Euclid Avenue, Box 8111, St. Louis, Missouri, USA
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