Read by QxMD icon Read


Carlo Viscomi, Massimo Zeviani
A large group of mitochondrial disorders, ranging from early-onset pediatric encephalopathic syndromes to late-onset myopathy with chronic progressive external ophthalmoplegia (CPEOs), are inherited as Mendelian disorders characterized by disturbed mitochondrial DNA (mtDNA) maintenance. These errors of nuclear-mitochondrial intergenomic signaling may lead to mtDNA depletion, accumulation of mtDNA multiple deletions, or both, in critical tissues. The genes involved encode proteins belonging to at least three pathways: mtDNA replication and maintenance, nucleotide supply and balance, and mitochondrial dynamics and quality control...
March 21, 2017: Journal of Inherited Metabolic Disease
Simão Cruz, Ricardo Taipa, Célia Nogueira, Cristina Pereira, Lígia S Almeida, Raquel Neiva, Tiago Geraldes, António Guimarães, Manuel Melo-Pires, Laura Vilarinho
INTRODUCTION: Mitochondrial disorders display remarkable genetic and phenotypic heterogeneity. METHODS: We performed a retrospective analysis of the clinical, histological, biochemical, and genetic features of 65 patients with molecular diagnoses of mitochondrial disorders. RESULTS: The most common genetic diagnosis was a single large-scale mitochondrial DNA (mtDNA) deletion (41.5%), and the most frequent clinical phenotype was chronic progressive external ophthalmoplegia (CPEO)...
January 27, 2017: Muscle & Nerve
Jennifer Murdock, Preeti J Thyparampil, Michael T Yen
Chronic progressive external ophthalmoplegia (CPEO) is a mitochondrial myopathy with slowly progressive, often symmetric blepharoptosis and limitation of ocular motility in all directions of gaze. The authors present an unusual case of CPEO that initially presented with the unique features of markedly asymmetric facial weakness and the lack of blepharoptosis. However, over the subsequent three decades, the patient developed progressive facial and eyelid dysfunction more consistent with a classical description of CPEO...
February 2016: Neuro-ophthalmology
Gitte Hedermann, Nicoline Løkken, Julia R Dahlqvist, John Vissing
BACKGROUND: The aim of this study was to assess the frequency of subjective and objective dysphagia in patients with chronic progressive external ophthalmoplegia (CPEO) due to single, large-scale deletions (LSDs) of mitochondrial DNA (mtDNA). METHODS: Sixteen patients with CPEO and single LSDs of mtDNA were included in the study and compared to a control group of 12 patients with the m.3243A>G mtDNA mutation. Patients had to drink 80ml of water at 4°C as fast as they could (cold-water test) and fill out a standardized questionnaire about dysphagia...
November 14, 2016: Mitochondrion
Diana Lehmann, Malte E Kornhuber, Carolina Clajus, Charlotte L Alston, Andreas Wienke, Marcus Deschauer, Robert W Taylor, Stephan Zierz
OBJECTIVE: To characterize peripheral nerve involvement in patients with chronic progressive external ophthalmoplegia (CPEO) with single and multiple mitochondrial DNA (mtDNA) deletions, based on clinical scores and detailed nerve conduction studies. METHODS: Peripheral nerve involvement was prospectively investigated in 33 participants with CPEO (single deletions n = 18 and multiple deletions n = 15). Clinically, a modified Total Neuropathy Score (mTNS) and a modified International Cooperative Ataxia Rating Scale (mICARS) were used...
December 2016: Neurology. Genetics
Ravikumar Komandur Elayavilli, Hongfang Liu
BACKGROUND: Computational modeling of biological cascades is of great interest to quantitative biologists. Biomedical text has been a rich source for quantitative information. Gathering quantitative parameters and values from biomedical text is one significant challenge in the early steps of computational modeling as it involves huge manual effort. While automatically extracting such quantitative information from bio-medical text may offer some relief, lack of ontological representation for a subdomain serves as impedance in normalizing textual extractions to a standard representation...
2016: AMIA Summits on Translational Science Proceedings
V Dvorakova, H Kolarova, M Magner, M Tesarova, H Hansikova, J Zeman, T Honzik
BACKGROUND: Mitochondrial myopathy, Encephalopathy, Lactic Acidosis and Stroke-like episodes syndrome (MELAS) is a common mitochondrial disorder with varying multisystemic clinical manifestation. We present a comprehensive clinical picture of 50 Czech m.3243A>G carriers with emphasis on the sequence of symptoms in symptomatic patients. RESULTS: Symptoms developed in 33 patients (66%) and 17 carriers remained unaffected (34%). The age of onset varied from 1month to 47years of age, with juvenile presentation occurring in 53% of patients...
August 2016: Molecular Genetics and Metabolism
Robert C Bucelli, Michael S Lee, Collin M McClelland
Classically defined as bilateral, symmetric, and progressive ophthalmoparesis with myopathic ptosis, chronic progressive external ophthalmoplegia (CPEO) rarely has been reported in the absence of ptosis. We describe 2 patients with CPEO and without ptosis who presented with binocular diplopia related to small-angle esodeviations, poor fusional amplitudes, and slow saccades. In both cases, hematological studies and neuroimaging ruled out alternative etiologies, whereas muscle biopsy showed findings of mitochondrial myopathy...
September 2016: Journal of Neuro-ophthalmology: the Official Journal of the North American Neuro-Ophthalmology Society
Cheng-Cheng Zhu, Elias I Traboulsi, Sumit Parikh
BACKGROUND: Mitochondrial disease often manifests with ophthalmologic signs and symptoms. Due to the important role of mitochondria in aerobic metabolism, the eyes are among the more preferentially involved organs. The clinical diagnosis of mitochondrial disease can be facilitated by an improved knowledge of the types and magnitude of their various manifestations. The aim of this study was to describe the ophthalmological manifestations of patients with mitochondrial diseases that are currently not well elucidated...
January 2017: Ophthalmic Genetics
Massimiliano Filosto, Gaetana Lanzi, Claudia Nesti, Valentina Vielmi, Eleonora Marchina, Anna Galvagni, Silvia Giliani, Filippo M Santorelli, Alessandro Padovani
Chronic progressive external ophthalmoplegia is a mitochondrial disorder usually caused by single or multiple mitochondrial DNA (mtDNA) deletions and, more rarely, by maternally inherited mtDNA point mutations, most frequently in tRNA genes (MTT). We report on a patient presenting with a progressive eyelid ptosis with bilateral ophthalmoparesis, dysphagia, dysphonia and mild proximal limb weakness associate with a mild movement disorder characterized by abnormal involuntary movements involving head and limbs, imbalance and gait instability...
March 2016: Molecular Genetics and Metabolism Reports
E Keilland, C A Rupar, Asuri N Prasad, K Y Tay, A Downie, C Prasad
m.3291T > C mutation in the MT-TL1 gene has been infrequently encountered in association with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), however remains poorly characterized from a clinical perspective. In the following report we describe in detail the phenotypic features, long term follow up (> 7 years) and management in a Caucasian family with MELAS due to the m.3291T > C mutation and review the literature on m.3291T > C mutation. The clinical phenotype in the proposita included overlapping features of MELAS, MERRF (Myoclonic epilepsy and ragged-red fiber syndrome), MNGIE (Mitochondrial neurogastrointestinal encephalopathy), KSS (Kearns-Sayre Syndrome) and CPEO (Chronic progressive external ophthalmoplegia)...
March 2016: Molecular Genetics and Metabolism Reports
Arumugam Paramasivam, Angamuthu Kannan Meena, Lalitha Pedaparthi, Vuskamalla Jyothi, Megha S Uppin, Shaikh Afshan Jabeen, Challa Sundaram, Kumarasamy Thangaraj
Chronic progressive external ophthalmoplegia (CPEO) is caused by defects in both mitochondrial and nuclear genes, however, the causal genetic factors in large number of patients remains undetermined. Therefore, our aim was to screen 12 unrelated patients with CPEO for mutation/multiple deletions in mtDNA and mutations in the coding regions of C10orf2, which is essential for mtDNA replication. Histopathological study of muscle biopsy revealed cytochrome c oxidase-deficient fibers and ragged blue fibers in all the patients...
January 2016: Mitochondrion
J Sládková, J Spáčilová, M Čapek, M Tesařová, H Hansíková, T Honzík, J Martínek, J Zámečník, O Kostková, J Zeman
Mitochondrial morphology was studied in cultivated myoblasts obtained from patients with mitochondrial disorders, including CPEO, MELAS and TMEM70 deficiency. Mitochondrial networks and ultrastructure were visualized by fluorescence microscopy and transmission electron microscopy, respectively. A heterogeneous picture of abnormally sized and shaped mitochondria with fragmentation, shortening, and aberrant cristae, lower density of mitochondria and an increased number of "megamitochondria" were found in patient myoblasts...
2015: Ultrastructural Pathology
Aurelio Reyes, Laura Melchionda, Alessia Nasca, Franco Carrara, Eleonora Lamantea, Alice Zanolini, Costanza Lamperti, Mingyan Fang, Jianguo Zhang, Dario Ronchi, Sara Bonato, Gigliola Fagiolari, Maurizio Moggio, Daniele Ghezzi, Massimo Zeviani
Chronic progressive external ophthalmoplegia (CPEO) is common in mitochondrial disorders and is frequently associated with multiple mtDNA deletions. The onset is typically in adulthood, and affected subjects can also present with general muscle weakness. The underlying genetic defects comprise autosomal-dominant or recessive mutations in several nuclear genes, most of which play a role in mtDNA replication. Next-generation sequencing led to the identification of compound-heterozygous RNASEH1 mutations in two singleton subjects and a homozygous mutation in four siblings...
July 2, 2015: American Journal of Human Genetics
Anca Florian, Anna Ludwig, Bianca Stubbe-Dräger, Matthias Boentert, Peter Young, Johannes Waltenberger, Sabine Rösch, Udo Sechtem, Ali Yilmaz
BACKGROUND: Mitochondrial myopathies (MM) are a heterogeneous group of inherited conditions resulting from a primary defect in the mitochondrial respiratory chain with consecutively impaired cellular energy metabolism. Small sized studies using mainly electrocardiography (ECG) and echocardiography have revealed cardiac abnormalities ranging from conduction abnormalities and arrhythmias to hypertrophic or dilated cardiomyopathy in these patients. Recently, characteristic patterns of cardiac involvement were documented by cardiovascular magnetic resonance (CMR) in patients with chronic progressive external ophthalmoplegia (CPEO)/Kearns-Sayre syndrome (KSS) and with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS)...
2015: Journal of Cardiovascular Magnetic Resonance
Robert D S Pitceathly, Jasper M Morrow, Christopher D J Sinclair, Cathy Woodward, Mary G Sweeney, Shamima Rahman, Gordon T Plant, Nadeem Ali, Fion Bremner, Indran Davagnanam, Tarek A Yousry, Michael G Hanna, John S Thornton
OBJECTIVES: Conventional and quantitative MRI was performed in patients with chronic progressive external ophthalmoplegia (CPEO), a common manifestation of mitochondrial disease, to characterise MRI findings in the extra-ocular muscles (EOMs) and investigate whether quantitative MRI provides clinically relevant measures of disease. METHODS: Patients with CPEO due to single mitochondrial DNA deletions were compared with controls. Range of eye movement (ROEM) measurements, peri-orbital 3 T MRI T1-weighted (T1w) and short-tau-inversion-recovery (STIR) images, and T2 relaxation time maps were obtained...
January 2016: European Radiology
Valerio Carelli, Olimpia Musumeci, Leonardo Caporali, Claudia Zanna, Chiara La Morgia, Valentina Del Dotto, Anna Maria Porcelli, Michela Rugolo, Maria Lucia Valentino, Luisa Iommarini, Alessandra Maresca, Piero Barboni, Michele Carbonelli, Costantino Trombetta, Enza Maria Valente, Simone Patergnani, Carlotta Giorgi, Paolo Pinton, Giovanni Rizzo, Caterina Tonon, Raffaele Lodi, Patrizia Avoni, Rocco Liguori, Agostino Baruzzi, Antonio Toscano, Massimo Zeviani
OBJECTIVE: Mounting evidence links neurodegenerative disorders such as Parkinson disease and Alzheimer disease with mitochondrial dysfunction, and recent emphasis has focused on mitochondrial dynamics and quality control. Mitochondrial dynamics and mtDNA maintenance is another link recently emerged, implicating mutations in the mitochondrial fusion genes OPA1 and MFN2 in the pathogenesis of multisystem syndromes characterized by neurodegeneration and accumulation of mtDNA multiple deletions in postmitotic tissues...
July 2015: Annals of Neurology
A C Gimenes, D M Bravo, L M Nápolis, M T Mello, A S B Oliveira, J A Neder, L E Nery
Exercise intolerance due to impaired oxidative metabolism is a prominent symptom in patients with mitochondrial myopathy (MM), but it is still uncertain whether L-carnitine supplementation is beneficial for patients with MM. The aim of our study was to investigate the effects of L-carnitine on exercise performance in MM. Twelve MM subjects (mean age±SD=35.4±10.8 years) with chronic progressive external ophthalmoplegia (CPEO) were first compared to 10 healthy controls (mean age±SD=29±7.8 years) before they were randomly assigned to receive L-carnitine supplementation (3 g/daily) or placebo in a double-blind crossover design...
April 2015: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
Sedat Işikay, Şamil Hizli, Kutluhan Yilmaz
OBJECTIVE: This study has examined the prevalence of celiac disease in Turkish children with idiopathic epilepsy. METHODS: Children with idiopathic epilepsy were screened for celiac disease using the IgA anti-tissue transglutaminase antibody and compared with the healthy control group in order to find the association of celiac disease (CD) with idiopathic epilepsy. Upper gastrointestinal endoscopy and small intestinal biopsies were offered to all antibody-positive patients...
June 2014: Iranian Journal of Pediatrics
Satoshi Fuke, Mizue Kametani, Kazuyuki Yamada, Takaoki Kasahara, Mie Kubota-Sakashita, Gregory C Kujoth, Tomas A Prolla, Seiji Hitoshi, Tadafumi Kato
OBJECTIVE: Mutations in nuclear-encoded mitochondrial DNA (mtDNA) polymerase (POLG) are known to cause autosomal dominant chronic progressive external ophthalmoplegia (adCPEO) with accumulation of multiple mtDNA deletions in muscles. However, no animal model with a heterozygous Polg mutation representing mtDNA impairment and symptoms of CPEO has been established. To understand the pathogenic mechanism of CPEO, it is important to determine the age dependency and tissue specificity of mtDNA impairment resulting from a heterozygous mutation in the Polg gene in an animal model...
November 2014: Annals of Clinical and Translational Neurology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"