1
|
Hikmat O, Naess K, Engvall M, Klingenberg C, Rasmussen M, Brodtkorb E, Ostergaard E, de Coo I, Pias-Peleteiro L, Isohanni P, Uusimaa J, Majamaa K, Kärppä M, Ortigoza-Escobar JD, Tangeraas T, Berland S, Harrison E, Biggs H, Horvath R, Darin N, Rahman S, Bindoff LA. Status epilepticus in POLG disease: a large multinational study. J Neurol 2024; 271:5156-5164. [PMID: 38822839 PMCID: PMC11319559 DOI: 10.1007/s00415-024-12463-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/16/2024] [Accepted: 05/20/2024] [Indexed: 06/03/2024]
Abstract
We aimed to provide a detailed phenotypic description of status epilepticus (SE) in a large cohort of patients with POLG disease and identify prognostic biomarkers to improve the management of this life-threatening condition. In a multinational, retrospective study with data on patients with POLG disease from seven European countries, we identified those who had SE. The age of SE onset, accompanying clinical, laboratory, imaging and genetic findings were analysed. One hundred and ninety-five patients with genetically confirmed POLG disease were recruited, of whom 67% (130/194) had epilepsy. SE was identified in 77% (97/126), with a median age of SE onset of 7 years. SE was the presenting symptom of the disease in 43% (40/93) of those with SE, while 57% (53/93) developed SE during the disease course. Convulsive SE was reported in 97% (91/94) followed by epilepsia partialis continua in 67% (56/84). Liver impairment 78% (74/95), ataxia 69% (60/87), stroke-like episodes 57% (50/88), were the major comorbidities. In the majority (66%; 57/86) with SE this became refractory or super-refractory. The presence of seizures was associated with significantly higher mortality compared to those without (P ≤ 0.001). The median time from SE debut to death was 5 months. SE is a major clinical feature of POLG disease in early and juvenile to adult-onset disease and can be the presenting feature or arise as part of a multisystem disease. It is associated with high morbidity and mortality, with the majority of patients with SE going on to develop refractory or super-refractory SE.
Collapse
Affiliation(s)
- Omar Hikmat
- Department of Paediatrics and Adolescent Medicine, Haukeland University Hospital, Bergen, Norway.
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway.
- European Reference Network for Hereditary Metabolic Disorders, Oslo, Norway.
| | - Karin Naess
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Department of Neuropediatrics, Astrid Lindgren Childrens Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Martin Engvall
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Claus Klingenberg
- Department of Paediatric and Adolescent Medicine, University Hospital of North Norway, Tromso, Norway
- Paediatric Research Group, Department of Clinical Medicine, UiT, The Arctic University of Norway, Tromso, Norway
| | - Magnhild Rasmussen
- Division of Paediatric and Adolescent Medicine, Department of Clinical Neurosciences for Children, Oslo University Hospital, Oslo, Norway
- Department of Neurology, Unit for Congenital and Hereditary Neuromuscular Disorders, Oslo University Hospital, Oslo, Norway
| | - Eylert Brodtkorb
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Neurology and Clinical Neurophysiology, St. Olav University Hospital, Trondheim, Norway
| | - Elsebet Ostergaard
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Irenaeus de Coo
- Faculty of Health, Medicine and Life Sciences, Department of Toxicology, University of Maastricht, Maastricht, The Netherlands
| | - Leticia Pias-Peleteiro
- Neurometabolic Disorders Unit, Department of Child Neurology/ Department of Genetics and Molecular Medicine, Sant Joan de Déu Children´S Hospital, Barcelona, Spain
| | - Pirjo Isohanni
- Department of Pediatric Neurology, Children's Hospital and Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- European Reference Network for Hereditary Metabolic Disorders, Helsinki, Finland
| | - Johanna Uusimaa
- Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
- Department of Pediatric Neurology, Clinic for Children and Adolescents and Medical Research Center, Oulu University Hospital, Oulu, Finland
| | - Kari Majamaa
- Research Unit of Clinical Medicine, Neurology, and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- Neurocenter, Oulu University Hospital, Oulu, Finland
| | - Mikko Kärppä
- Research Unit of Clinical Medicine, Neurology, and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
- Neurocenter, Oulu University Hospital, Oulu, Finland
| | - Juan Dario Ortigoza-Escobar
- Movement Disorders Unit, Institut de Recerca Sant Joan de Déu, CIBERER-ISCIII, Barcelona, Spain
- European Reference Network for Rare Neurological Diseases (ERN-RND), Barcelona, Spain
| | - Trine Tangeraas
- European Reference Network for Hereditary Metabolic Disorders, Oslo, Norway
- Norwegian National Unit for Newborn Screening, Division of Pediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
| | - Siren Berland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Emma Harrison
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Heather Biggs
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Niklas Darin
- Department of Pediatrics, Institute of Clinical Sciences, University of Gothenburg, Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Shamima Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Unit, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
- European Reference Network for Hereditary Metabolic Disorders, London, UK
| | - Laurence A Bindoff
- Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
- European Reference Network for Hereditary Metabolic Disorders, Oslo, Norway
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway
| |
Collapse
|
2
|
Kristensen E, Mathisen L, Berland S, Klingenberg C, Brodtkorb E, Rasmussen M, Tangeraas T, Bliksrud YT, Rahman S, Bindoff LA, Hikmat O. Epidemiology and natural history of POLG disease in Norway: a nationwide cohort study. Ann Clin Transl Neurol 2024; 11:1819-1830. [PMID: 38845467 PMCID: PMC11251482 DOI: 10.1002/acn3.52088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/27/2024] [Accepted: 04/29/2024] [Indexed: 07/17/2024] Open
Abstract
OBJECTIVE To investigate the prevalence and natural history of POLG disease in the Norwegian population. METHODS A national, population-based, retrospective study using demographic, clinical, and genetic data of patients with genetically confirmed POLG disease. The patients were diagnosed between 2002 and 2022, and were included into the Norwegian POLG Patient Registry. Patients were stratified according to age at disease onset (early <12 years, juvenile to adult 12-40 years, late ≥40 years) and resident region. RESULTS Ninety-one patients were included. The point prevalence of POLG disease was 1:149,253. Birth prevalence was 1:48,780. Median age at clinical onset was 16 years (range: 2 months to 70 years). Onset occurred early in 35% (32 out of 91), juvenile-adult in 55% (50 out of 91) and late in 10% (9 out of 91). A distinct seasonal pattern in disease onset was observed, with 57% (52 out of 91) presenting between May and August. Forty-five patients (49%) had acute exacerbations that required intensive care, and this affected 72% of those in the early-onset group. The mortality rate was 54% (49 out of 91), with a median time from disease onset to death of 3 years (range: 1 month to 36 years). INTERPRETATION We provide the point prevalence and birth prevalence of POLG disease in the first nationwide study in which epidemiological and clinical data were integrated. Seasonal variations in clinical onset may offer valuable insights into disease mechanisms and modifying factors. The findings from this study are crucial for quantifying the disease burden, and contribute to evidence-based healthcare planning.
Collapse
Affiliation(s)
- Erle Kristensen
- Department of Medical BiochemistryOslo University HospitalOslo0424Norway
- Department of Clinical Medicine (K1)University of BergenBergen5020Norway
| | - Linda Mathisen
- Department of Medical GeneticsOslo University HospitalOslo0424Norway
| | - Siren Berland
- Department of Medical GeneticsHaukeland University HospitalBergen5021Norway
| | - Claus Klingenberg
- Paediatric Research Group, Department of Clinical MedicineUiT The Arctic University of NorwayTromsø9019Norway
- Department of PaediatricsUniversity Hospital of North NorwayTromsø9019Norway
| | - Eylert Brodtkorb
- Department of NeurologySt. Olavs University HospitalTrondheim7006Norway
- Department of Neuromedicine and Movement Science, Faculty of MedicineNorwegian University of Science and TechnologyTrondheim7491Norway
| | - Magnhild Rasmussen
- Unit for Congenital and Hereditary Neuromuscular Conditions (EMAN), Department of NeurologyOslo University HospitalOslo0424Norway
- Department of Clinical Neurosciences for ChildrenOslo University HospitalOslo0424Norway
| | - Trine Tangeraas
- Department of Paediatric and Adolescent MedicineOslo University HospitalOslo0424Norway
- European Reference Network for Hereditary Metabolic Disorders
| | - Yngve T. Bliksrud
- Department of Medical BiochemistryOslo University HospitalOslo0424Norway
| | - Shamima Rahman
- European Reference Network for Hereditary Metabolic Disorders
- Metabolic UnitGreat Ormond Street HospitalLondonUK
- Mitochondrial Research Group, Genetics and Genomic Medicine DepartmentUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Laurence Albert Bindoff
- Department of Paediatric and Adolescent MedicineOslo University HospitalOslo0424Norway
- European Reference Network for Hereditary Metabolic Disorders
- Department of NeurologyHaukeland University HospitalBergen5021Norway
| | - Omar Hikmat
- Department of Clinical Medicine (K1)University of BergenBergen5020Norway
- Department of Paediatric and Adolescent MedicineOslo University HospitalOslo0424Norway
- European Reference Network for Hereditary Metabolic Disorders
- Department of Paediatrics and Adolescent MedicineHaukeland University HospitalBergen5021Norway
| |
Collapse
|
3
|
Ng YS, Gorman GS. Stroke-like episodes in adult mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:65-78. [PMID: 36813321 DOI: 10.1016/b978-0-12-821751-1.00005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Stroke-like episode is a paroxysmal neurological manifestation which affects a specific group of patients with mitochondrial disease. Focal-onset seizures, encephalopathy, and visual disturbances are prominent findings associated with stroke-like episodes, with a predilection for the posterior cerebral cortex. The most common cause of stroke-like episodes is the m.3243A>G variant in MT-TL1 gene followed by recessive POLG variants. This chapter aims to review the definition of stroke-like episode and delineate the clinical phenomenology, neuroimaging and EEG findings typically seen in patients. In addition, several lines of evidence supporting neuronal hyper-excitability as the key mechanism of stroke-like episodes are discussed. The management of stroke-like episodes should focus on aggressive seizure management and treatment for concomitant complications such as intestinal pseudo-obstruction. There is no robust evidence to prove the efficacy of l-arginine for both acute and prophylactic settings. Progressive brain atrophy and dementia are the sequalae of recurrent stroke-like episode, and the underlying genotype in part predicts prognosis.
Collapse
Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
| |
Collapse
|
4
|
Meyrick J, Stefanetti RJ, Errington L, McFarland R, Gorman GS, Lax NZ. Model systems informing mechanisms and drug discovery: a systematic review of POLG-related disease models. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.18637.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Introduction Pathogenic variants in the gene encoding the catalytic subunit of DNA polymerase gamma (POLG), comprise an important single-gene cause of inherited mitochondrial disorders. Clinical manifestations are now recognised as an array of overlapping clinical features rather than discrete syndromes as originally conceptualised. Animal and cellular models have been used to address numerous scientific questions, from basic science to the development and assessment of novel therapies. Here, we sought to perform a systematic review of the existing models used in mitochondrial research and their effectiveness in recapitulating POLG-related disease. Methods Four databases were searched from inception to May 31, 2022: MEDLINE, Scopus, Web of Science, and Cochrane Review. Original articles available in English, reporting the use of a model system designed to recapitulate POLG-related disease, or related pathogenicity, were eligible for inclusion. Risk of bias and the methodological quality of articles were assessed by an adapted version of the Cochrane Risk of Bias Tool, with the quality of evidence synthesized across each model. Results A total of 55 articles, including seven model organisms (Human, yeast [Saccharomyces cerevisiae and Schizosaccharomyces pombe], Drosophila, Mouse, Nematoda, and Zebrafish) with 258 distinct variants were included. Of these, 66% (N=38) of articles recapitulated mitochondrial DNA (mtDNA) depletion and 42% (N=23) recapitulated POLG-related disease. Thirty-three percent of articles (N=18/55) utilised tissue-specific models of POLG-related dysfunction, while 13% (N=7) investigated the effect of potential therapeutics in POLG-related mitochondrial disorders. Discussion The available evidence supporting the ability of models for POLG-related disease to recapitulate molecular mechanisms and phenotype is limited, inconsistent and of poor methodologic quality. Further success in examining and translating novel therapies into effective treatments will be enhanced by the availability of more robust models that better recapitulate the entire spectrum of POLG-related disease. PROSPERO registration: CRD42021234883
Collapse
|
5
|
Malyshev SM, Popov KD, Simakov KV, Marichev AO, Topuzova MP, Smirnova AY, Ryzhkov AV, Basek IV, Yanishevskij SN, Alekseeva TM, Schlyakhto EV. [Status epilepticus in a pregnant patient with a previously unrecognized POLG-associated disease]. Zh Nevrol Psikhiatr Im S S Korsakova 2023; 123:129-135. [PMID: 37966452 DOI: 10.17116/jnevro2023123101129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
POLG-associated diseases are rare causes of pharmacoresistant epilepsy and status epilepticus, especially in adult patients. Phenotypic and genotypic variability in these conditions causes the complexity of their diagnosis. In the study, we report a case of a 33-year-old female patient who developed recurrent convulsive status epilepticus with focal clonic onset at the week 22/23 of pregnancy. Intensive anti-seizure therapy was administered, including the use of valproic acid, as well as the treatment of somatic complications. Given the acute onset, the semiology of seizures, the presence of psychopathological symptoms, autoimmune etiology of the disease was initially suspected. A month after the withdrawal of valproic acid, the patient began to show signs of toxic hepatitis, which eventually led to death. According to the results of whole-exome sequencing obtained later, the patient was a carrier of a pathogenic homozygous variant c.2243G>C (p.W748S) in the POLG gene. The presented case highlights the importance of molecular genetic testing and the risk associated with valproic acid hepatotoxicity in patients with cryptogenic epileptic status.
Collapse
Affiliation(s)
- S M Malyshev
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - K D Popov
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - K V Simakov
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - A O Marichev
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - M P Topuzova
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - A Yu Smirnova
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - A V Ryzhkov
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - I V Basek
- Almazov National Medical Research Centre, St Petersburg, Russia
| | | | - T M Alekseeva
- Almazov National Medical Research Centre, St Petersburg, Russia
| | - E V Schlyakhto
- Almazov National Medical Research Centre, St Petersburg, Russia
| |
Collapse
|
6
|
Pedersen ZO, Holm-Yildiz S, Dysgaard T. Nutritional Interventions for Patients with Mitochondrial POLG-Related Diseases: A Systematic Review on Efficacy and Safety. Int J Mol Sci 2022; 23:ijms231810658. [PMID: 36142570 PMCID: PMC9502393 DOI: 10.3390/ijms231810658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 12/03/2022] Open
Abstract
Ketogenic diet is recommended as a treatment to reduce seizure frequency in patients with intractable epilepsy. The evidence and safety results are sparse for diet interventions in patients with pathogenic polymerase gamma (POLG) variants and intractable epilepsy. The aim of this systematic review is to summarize the efficacy of diet treatment on seizure frequency, clinical symptoms, and potential deleterious effect of liver involvement in patients with mitochondrial diseases caused by pathogenic POLG variants. Literature was searched in PubMed, Embase; and Cochrane in April 2022; no filter restrictions were imposed. The reference lists of retrieved studies were checked for additional literature. Eligibility criteria included verified pathogenic POLG variant and diet treatment. Overall, 880 studies were identified, providing eight case-reports representing nine patients eligible for inclusion. In eight of nine cases, clinical symptoms were improved; six out of nine cases reported improvements in seizure frequency. However, increasing levels of liver enzymes after initiating ketogenic diet were found in four of the nine cases, with one case revealing decreased levels of liver enzymes after initiating long-chain triglyceride restriction. Viewed together, the studies imply that ketogenic diet can have a positive impact on seizure frequency, but may induce progression of liver impairment in patients with pathogenic POLG variants.
Collapse
|
7
|
Thomas RH, Hunter A, Butterworth L, Feeney C, Graves TD, Holmes S, Hossain P, Lowndes J, Sharpe J, Upadhyaya S, Varhaug KN, Votruba M, Wheeler R, Staley K, Rahman S. Research priorities for mitochondrial disorders: Current landscape and patient and professional views. J Inherit Metab Dis 2022; 45:796-803. [PMID: 35543492 PMCID: PMC9429991 DOI: 10.1002/jimd.12521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/16/2022] [Accepted: 04/27/2022] [Indexed: 11/15/2022]
Abstract
Primary mitochondrial disorders encompass a wide range of clinical presentations and a spectrum of severity. They currently lack effective disease-modifying therapies and have a high mortality and morbidity rate. It is therefore essential to know that competitively funded research designed by academics meets the core needs of people with mitochondrial disorders and their clinicians. Priority setting partnerships are an established collaborative methodology that brings patients, carers and families, charity representatives and clinicians together to try to establish the most pressing and unanswered research priorities for a particular disease. We developed a web-based questionnaire, requesting all patients affected by primary mitochondrial disease, their carers and clinicians to pose their research questions. This yielded 709 questions from 147 participants. These were grouped into overarching themes including basic biology, causation, health services, clinical management, social impacts, prognosis, prevention, symptoms, treatment and psychological impact. Following the removal of "answered questions", the process resulted in a list of 42 discrete, answerable questions. This was further refined by web-based ranking by the community to 24 questions. These were debated at a face-to-face workshop attended by a diverse range of patients, carers, charity representatives and clinicians to create a definitive "Top 10 of unanswered research questions for primary mitochondrial disorders". These Top 10 questions related to understanding biological processes, including triggers of disease onset, mechanisms underlying progression and reasons for differential symptoms between individuals with identical genetic mutations; new treatments; biomarker discovery; psychological support and optimal management of stroke-like episodes and fatigue.
Collapse
Affiliation(s)
- Rhys H. Thomas
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | | | | | - Catherine Feeney
- NHS Highly Specialised Service for Rare Mitochondrial Diseases, Newcastle Hospitals NHS Foundation TrustNewcastleUK
| | - Tracey D. Graves
- Hinchingbrooke HospitalHuntingdonUK
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | - Sarah Holmes
- The National Hospital for Neurology and NeurosurgeryLondonUK
| | | | - Jo Lowndes
- Oxford University Hospitals NHS Foundation TrustOxfordUK
| | - Jenny Sharpe
- Centre for Innovation in Regulatory ScienceLondonUK
| | | | - Kristin N. Varhaug
- Translational and Clinical Research InstituteNewcastle UniversityNewcastleUK
| | - Marcela Votruba
- University Hospital Wales and School of Vision SciencesCardiff UniversityCardiffUK
| | | | | | - Shamima Rahman
- Mitochondrial Research Group, UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation TrustLondonUK
| |
Collapse
|
8
|
Ng YS, Lim AZ, Panagiotou G, Turnbull DM, Walker M. Endocrine Manifestations and New Developments in Mitochondrial Disease. Endocr Rev 2022; 43:583-609. [PMID: 35552684 PMCID: PMC9113134 DOI: 10.1210/endrev/bnab036] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Indexed: 11/19/2022]
Abstract
Mitochondrial diseases are a group of common inherited diseases causing disruption of oxidative phosphorylation. Some patients with mitochondrial disease have endocrine manifestations, with diabetes mellitus being predominant but also include hypogonadism, hypoadrenalism, and hypoparathyroidism. There have been major developments in mitochondrial disease over the past decade that have major implications for all patients. The collection of large cohorts of patients has better defined the phenotype of mitochondrial diseases and the majority of patients with endocrine abnormalities have involvement of several other systems. This means that patients with mitochondrial disease and endocrine manifestations need specialist follow-up because some of the other manifestations, such as stroke-like episodes and cardiomyopathy, are potentially life threatening. Also, the development and follow-up of large cohorts of patients means that there are clinical guidelines for the management of patients with mitochondrial disease. There is also considerable research activity to identify novel therapies for the treatment of mitochondrial disease. The revolution in genetics, with the introduction of next-generation sequencing, has made genetic testing more available and establishing a precise genetic diagnosis is important because it will affect the risk for involvement for different organ systems. Establishing a genetic diagnosis is also crucial because important reproductive options have been developed that will prevent the transmission of mitochondrial disease because of mitochondrial DNA variants to the next generation.
Collapse
Affiliation(s)
- Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Albert Zishen Lim
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Grigorios Panagiotou
- Department of Diabetes and Endocrinology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Mark Walker
- Department of Diabetes and Endocrinology, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
9
|
Bender F, Timmann D, van de Warrenburg BP, Adarmes-Gómez AD, Bender B, Thieme A, Synofzik M, Schöls L. Natural History of Polymerase Gamma-Related Ataxia. Mov Disord 2021; 36:2642-2652. [PMID: 34288125 DOI: 10.1002/mds.28713] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/31/2021] [Accepted: 06/16/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Mutations in the mitochondrial DNA polymerase gamma are causing a wide phenotypic spectrum including ataxia as one of the most common presentations. OBJECTIVE The objective of this study was to determine the course of disease of polymerase gamma-related ataxia. METHODS In a prospective natural history study, we assessed 24 adult ataxia patients with biallelic polymerase gamma mutations for (1) severity of cerebellar dysfunction using the Scale for the Assessment and Rating of Ataxia score, (2) presence of nonataxia signs using the Inventory of Non-Ataxia Symptoms, (3) gray- and white-matter changes in brain MRI, and (4) findings in nerve conduction studies. RESULTS Assessment included follow-up visits up to 11.6 years. The Scale for the Assessment and Rating of Ataxia showed a mean annual increase of 1.02 ± 0.78 points/year. Disease progression was faster in patients with age at onset ≤ 30 years (1.5 Scale for the Assessment and Rating of Ataxia points/year) than with later onset (0.5 points/year); P = 0.008. The Inventory of Non-Ataxia Symptoms count increased by 0.30 ± 0.4 points/year. External ophthalmoplegia, brain stem oculomotor signs, areflexia, and sensory deficits were the most common nonataxic features. On MRI cerebellar atrophy was mild. T2 signal alterations affected mostly cerebellar white matter, middle cerebellar peduncles, thalamus, brain stem, and occipital and frontal white matter. Within 4 years, progression was primarily observed in the context of repeated epileptic seizures. Nerve conduction studies revealed axonal sensory peripheral neuropathy with mild motor nerve involvement. Exploratory sample size calculation implied 38 patients per arm as sufficient to detect a reduction of progression by 50% in hypothetical interventions within a 1-year trial. CONCLUSION The results recommend the Scale for the Assessment and Rating of Ataxia as a primary outcome measure for future interventional trials in polymerase gamma-related ataxia. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Friedemann Bender
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research & Center of Neurology, University of Tuebingen, Tuebingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany
| | - Dagmar Timmann
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Bart P van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Astrid D Adarmes-Gómez
- Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Benjamin Bender
- Department of Diagnostics and Interventional Neuroradiology, University of Tuebingen, Tuebingen, Germany
| | - Andreas Thieme
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research & Center of Neurology, University of Tuebingen, Tuebingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany
| | - Ludger Schöls
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research & Center of Neurology, University of Tuebingen, Tuebingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tuebingen, Germany
| |
Collapse
|