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Thompson WR, Manuel R, Abbruscato A, Carr J, Campbell J, Hornby B, Vaz FM, Vernon HJ. Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. Genet Med 2024; 26:101138. [PMID: 38602181 DOI: 10.1016/j.gim.2024.101138] [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] [Received: 12/24/2023] [Revised: 04/04/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
PURPOSE Evaluate long-term efficacy and safety of elamipretide during the open-label extension (OLE) of the TAZPOWER trial in individuals with Barth syndrome (BTHS). METHODS TAZPOWER was a 28-week randomized, double-blind, and placebo-controlled trial followed by a 168-week OLE. Patients entering the OLE continued elamipretide 40 mg subcutaneous daily. OLE primary endpoints were safety and tolerability; secondary endpoints included change from baseline in the 6-minute walk test (6MWT) and BarTH Syndrome Symptom Assessment (BTHS-SA) Total Fatigue score. Muscle strength, physician- and patient-assessed outcomes, echocardiographic parameters, and biomarkers, including cardiolipin (CL) and monolysocardiolipin (MLCL), were assessed. RESULTS Ten patients entered the OLE; 8 reached the week 168 visit. Elamipretide was well tolerated, with injection-site reactions being the most common adverse events. Significant improvements from OLE baseline on 6MWT occurred at all OLE time points (cumulative 96.1 m of improvement [week 168, P = .003]). Mean BTHS-SA Total Fatigue scores were below baseline (improved) at all OLE time points. Three-dimensional (3D) left ventricular stroke, end-diastolic, and end-systolic volumes improved, showing significant trends for improvement from baseline to week 168. MLCL/CL values showed improvement, correlating to important clinical outcomes. CONCLUSION Elamipretide was associated with sustained long-term tolerability and efficacy, with improvements in functional assessments and cardiac function in BTHS.
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Affiliation(s)
- William R Thompson
- The Blalock-Taussig-Thomas Pediatric and Congenital Heart Center, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ryan Manuel
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | | | - Jim Carr
- Stealth BioTherapeutics, Inc., Newton, MA
| | | | - Brittany Hornby
- Department of Physical Therapy, Kennedy Krieger, Baltimore, MD
| | - Frédéric M Vaz
- Amsterdam UMC Location University of Amsterdam, Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Meibergdreef 9, Amsterdam, The Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Inborn Errors of Metabolism, Amsterdam, The Netherlands; Core Facility Metabolomics, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Hilary J Vernon
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD.
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Cunico C, Leite SN. Role of pharmacists in the context of rare diseases: a scoping review protocol. BMJ Open 2023; 13:e072001. [PMID: 37989368 PMCID: PMC10668274 DOI: 10.1136/bmjopen-2023-072001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 10/20/2023] [Indexed: 11/23/2023] Open
Abstract
INTRODUCTION Rare diseases are chronic conditions, generally incurable, progressive and disabling, which may result in early death. Access to therapeutic products, both medicines and appropriate medical devices, is essential to prevent the progression of the disease and maintain the patients' quality of life. Pharmacists can be part of health teams, in charge of guiding patients' journey, monitoring pharmacotherapy and identifying risks. This scoping review aims to identify and summarise evidence on the role of pharmacists and its impact in the field of rare diseases. METHODS AND ANALYSIS The searches will be conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline for protocols. Three electronic databases will be consulted. Studies reporting on qualitative and/or quantitative data from any world region will be considered. There will be no language or initial time limit for studies inclusion, until December 2022. To be eligible for inclusion, studies must focus on the role pharmacists in clinical services aimed at promote the access to medicines, prevention and resolution of problems related to pharmacotherapy. No assessments of items' quality will be made, as the purpose of this scoping review is to synthesise and describe the coverage of the evidence. Clinical, humanistic or economic outcomes from studies that meet the inclusion criteria will be included in the review. The analysis will synthesise the available evidence and may be able to push pharmaceutical practice forward, aiding professionals, educators and managers in the implementation of new approaches to better meet the needs of rare diseases and providing opportunities for future research. ETHICS AND DISSEMINATION Primary data will not be collected in this study and formal ethical approval is not required. The findings of this study will be disseminated through peer-reviewed publications and conference presentations.
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Affiliation(s)
- Cássia Cunico
- Graduate Program in Pharmaceutical Policy and Services PPGASFAR, Universidade Federal de Santa Catarina-Campus Universitário Reitor João David Ferreira Lima, Florianopolis, Brazil
| | - Silvana Nair Leite
- Graduate Program in Pharmaceutical Policy and Services PPGASFAR, Universidade Federal de Santa Catarina-Campus Universitário Reitor João David Ferreira Lima, Florianopolis, Brazil
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Vo L, Schmidtke MW, Da Rosa-Junior NT, Ren M, Schlame M, Greenberg ML. Cardiolipin metabolism regulates expression of muscle transcription factor MyoD1 and muscle development. J Biol Chem 2023; 299:102978. [PMID: 36739949 PMCID: PMC9999232 DOI: 10.1016/j.jbc.2023.102978] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The mitochondrial phospholipid cardiolipin (CL) is critical for numerous essential biological processes, including mitochondrial dynamics and energy metabolism. Mutations in the CL remodeling enzyme TAFAZZIN cause Barth syndrome, a life-threatening genetic disorder that results in severe physiological defects, including cardiomyopathy, skeletal myopathy, and neutropenia. To study the molecular mechanisms whereby CL deficiency leads to skeletal myopathy, we carried out transcriptomic analysis of the TAFAZZIN-knockout (TAZ-KO) mouse myoblast C2C12 cell line. Our data indicated that cardiac and muscle development pathways are highly decreased in TAZ-KO cells, consistent with a previous report of defective myogenesis in this cell line. Interestingly, the muscle transcription factor myoblast determination protein 1 (MyoD1) is significantly repressed in TAZ-KO cells and TAZ-KO mouse hearts. Exogenous expression of MyoD1 rescued the myogenesis defects previously observed in TAZ-KO cells. Our data suggest that MyoD1 repression is caused by upregulation of the MyoD1 negative regulator, homeobox protein Mohawk, and decreased Wnt signaling. Our findings reveal, for the first time, that CL metabolism regulates muscle differentiation through MyoD1 and identify the mechanism whereby MyoD1 is repressed in CL-deficient cells.
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Affiliation(s)
- Linh Vo
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | | | - Mindong Ren
- Department of Anesthesiology, Perioperative Care, and Pain Medicine at New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology at New York University Grossman School of Medicine, New York, New York, USA
| | - Michael Schlame
- Department of Anesthesiology, Perioperative Care, and Pain Medicine at New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology at New York University Grossman School of Medicine, New York, New York, USA
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA.
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Phenotypic Characterization of Male Tafazzin-Knockout Mice at 3, 6, and 12 Months of Age. Biomedicines 2023; 11:biomedicines11020638. [PMID: 36831174 PMCID: PMC9953241 DOI: 10.3390/biomedicines11020638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Barth syndrome (BTHS) is an X-linked mitochondrial disease caused by mutations in the gene encoding for tafazzin (TAZ), a key enzyme in the remodeling of cardiolipin. Mice with a germline deficiency in Taz have been generated (Taz-KO) but not yet fully characterized. We performed physiological assessments of 3-, 6-, and 12-month-old male Taz-KO mice, including measures of perinatal survival, growth, lifespan, gross anatomy, whole-body energy and substrate metabolism, glucose homeostasis, and exercise capacity. Taz-KO mice displayed reduced viability, with lower-than-expected numbers of mice recorded at 4 weeks of age, and a shortened lifespan due to disease progression. At all ages, Taz-KO mice had lower body weights compared with wild-type (Wt) littermates despite similar absolute food intakes. This finding was attributed to reduced adiposity and diminutive organs and tissues, including heart and skeletal muscles. Although there were no differences in basal levels of locomotion between age-matched genotypes, indirect calorimetry studies showed higher energy expenditure measures and respiratory exchange ratios in Taz-KO mice. At the youngest age, Taz-KO mice had comparable glucose tolerance and insulin action to Wt mice, but while these measures indicated metabolic impairments in Wt mice with advancing age that were likely associated with increasing adiposity, Taz-KO mice were protected. Comparisons across the three age-cohorts revealed a significant and more severe deterioration of exercise capacity in Taz-KO mice than in their Wt littermate controls. The Taz-KO mouse model faithfully recapitulates important aspects of BTHS, and thus provides an important new tool to investigate pathophysiological mechanisms and potential therapies.
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Chowdhury S, Jackson L, Byrne BJ, Bryant RM, Cade WT, Churchill TL, Buchanan J, Taylor C. Longitudinal Observational Study of Cardiac Outcome Risk Factor Prediction in Children, Adolescents, and Adults with Barth Syndrome. Pediatr Cardiol 2022; 43:1251-1263. [PMID: 35238957 PMCID: PMC9462389 DOI: 10.1007/s00246-022-02846-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 02/04/2022] [Indexed: 12/01/2022]
Abstract
Barth Syndrome (BTHS) is an X-linked mitochondrial cardioskeletal myopathy caused by defects in TAFAZZIN, a gene responsible for cardiolipin remodeling. Altered mitochondrial levels of cardiolipin lead to cardiomyopathy (CM), muscle weakness, exercise intolerance, and mortality. Cardiac risk factors predicting outcome are unknown. Therefore, we conducted a longitudinal observational study to determine risk factors for outcome in BTHS. Subjects with minimum two evaluations (or one followed by death or transplant) were included. Cardiac size, function, and QTc data were measured by echocardiography and electrocardiography at 7 time points from 2002 to 2018. Analysis included baseline, continuous, and categorical variables. Categorical risk factors included prolonged QTc, abnormal right ventricle fractional area change (RV FAC), left ventricle (LV) or RV non-compaction, and restrictive CM phenotype. The association between variables and cardiac death or transplant (CD/TX) was assessed. Median enrollment age was 7 years (range 0.5-22; n = 44). Transplant-free survival (TFS) was 74.4% at 15 years from first evaluation. The cohort demonstrated longitudinal declines in LV size and stroke volume z-scores (end-diastolic volume, p = 0.0002; stroke volume p < 0.0001), worsening RV FAC (p = 0.0405), and global longitudinal strain (GLS) (p = 0.0001) with stable ejection (EF) and shortening (FS) fraction. CD/TX subjects (n = 9) displayed worsening LV dilation (p = 0.0066), EF (p ≤ 0.0001), FS (p = 0.0028), and RV FAC (p = .0032) versus stability in TFS. Having ≥ 2 categorical risk factors predicted CD/TX (p = 0.0073). Over 15 years, 25% of BTHS subjects progressed to CD/TX. Those with progressive LV enlargement, dysfunction, and multiple cardiac risk factors warrant increased surveillance and intense therapy.
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Affiliation(s)
| | - Lanier Jackson
- Medical University of South Carolina, Charleston, SC, USA
| | - Barry J. Byrne
- School of Medicine, University of Florida, Gainesville, FL, USA
| | | | - W. Todd Cade
- Duke University School of Medicine, Durham, NC, USA
| | | | - Julia Buchanan
- Medical University of South Carolina, Charleston, SC, USA
| | - Carolyn Taylor
- MUSC Children's Heart Program, Pediatric Echocardiography Lab, Pediatric Cardiology, Shawn Jenkins Children's Hospital, MSC 915, 10 McClennan Banks Dr., Charleston, SC, 29425-8905, USA.
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Kim AY, Vernon H, Manuel R, Almuqbil M, Hornby B. Quality of life in Barth syndrome. THERAPEUTIC ADVANCES IN RARE DISEASE 2022; 3:26330040221093743. [PMID: 37180415 PMCID: PMC10032447 DOI: 10.1177/26330040221093743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 03/25/2022] [Indexed: 05/16/2023]
Abstract
Introduction Barth syndrome (BTHS) is a rare X-linked disorder characterized by cardiomyopathy, neutropenia, growth abnormalities, and skeletal myopathy. There have been few studies investigating health-related quality of life (HRQoL) in this population. This study investigated the impact of BTHS on HRQoL and select physiologic measures in affected boys and men. Methods In this study, we characterize HRQoL in boys and men with BTHS through cross-sectional analysis of a variety of outcome measures including the Pediatric Quality of Life Inventory (PedsQLTM) Version 4.0 Generic Core Scales, PedsQLTM Multidimensional Fatigue Scale, Barth Syndrome Symptom Assessment, the PROMISTM Fatigue Short Form, the EuroQol Group EQ-5DTM, the Patient Global Impression of Symptoms (PGIS), and the Caregiver Global Impression of Symptoms (CaGIS). For a specific subset of participants, physiologic data were available in addition to HRQoL data. Results For the PedsQLTM questionnaires, 18 unique child and parent reports were analyzed for children aged 5-18 years, and nine unique parent reports were analyzed for children aged 2-4 years. For the other HRQoL outcome measures and physiologic measurements, the data from 12 subjects (age range 12-35 years) were analyzed. Based on parent and child reports, HRQoL is significantly impaired in boys and men with BTHS, especially in school functioning and physical functioning. Parent and child reports of more severe fatigue are significantly correlated with more impaired HRQoL. When exploring the potential relationship between physiology and HRQoL, the CaGIS as a whole for pediatric subjects and individual questionnaire items from the PGIS and CaGIS for pediatric subjects assessing tiredness, muscle weakness, and muscle pain showed the strongest correlations. Conclusion This study provides a unique characterization of the HRQoL in boys and men with BTHS using a variety of outcome measures, and it highlights the negative impact of fatigue and muscle weakness on HRQoL in BTHS. Trial registry name A Trial to Evaluate Safety, Tolerability and Efficacy of Elamipretide in Subjects with Barth Syndrome (TAZPOWER). https://clinicaltrials.gov/ct2/show/NCT03098797.Registration Number: NCT03098797.
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Affiliation(s)
- Alexander Y. Kim
- Division of Genetics, Johns Hopkins All
Children’s Hospital, St. Petersburg, FL, USA
| | - Hilary Vernon
- Department of Genetic Medicine, Johns Hopkins
University School of Medicine, Baltimore, MD, USADepartment of
Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Ryan Manuel
- Department of Genetic Medicine, Johns Hopkins
University School of Medicine, Baltimore, MD, USA
| | - Mohammed Almuqbil
- College of Medicine, King Saud Bin Abdulaziz
University for Health Sciences (KSAU-HS), Riyadh, Saudi ArabiaDivision of
Pediatric Neurology, King Abdullah Specialist Children’s Hospital (KASCH),
National Guard Health Affairs (NGHA), Riyadh, Saudi ArabiaKing Abdullah
International Medical Research Center (KAIMRC), Ministry of National Guard,
Riyadh, Saudi Arabia
| | - Brittany Hornby
- Physical Therapy Department, Kennedy Krieger
Institute, 801 N Broadway, Baltimore, MD 21205, USA
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Taylor C, Rao ES, Pierre G, Chronopoulou E, Hornby B, Heyman A, Vernon HJ. Clinical presentation and natural history of Barth Syndrome: An overview. J Inherit Metab Dis 2022; 45:7-16. [PMID: 34355402 DOI: 10.1002/jimd.12422] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/23/2021] [Accepted: 08/04/2021] [Indexed: 01/25/2023]
Abstract
Barth Syndrome is a rare X-linked disorder caused by pathogenic variants in the gene TAFAZZIN, which encodes for an enzyme involved in the remodeling of cardiolipin, a phospholipid primarily localized to the inner mitochondrial membrane. Barth Syndrome is characterized by cardiomyopathy, skeletal myopathy, neutropenia, and growth abnormalities, among other features. In this review, we will discuss the clinical presentation and natural history of Barth Syndrome, review key features of this disease, and introduce less common clinical associations. Recognition and understanding of the natural history of Barth Syndrome are important for ongoing patient management and developing endpoints for the demonstration of efficacy of new and emerging therapies.
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Affiliation(s)
- Carolyn Taylor
- Department of Pediatrics, Division of Cardiology, Children's Hospital, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Emily S Rao
- Department of Pediatrics, Division of Hematology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Germaine Pierre
- Department of Inherited Metabolic Disease, Division of Women's and Children's Services, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Estathia Chronopoulou
- Department of Inherited Metabolic Disease, Division of Women's and Children's Services, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | - Brittany Hornby
- Department of Physical Therapy, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Andrea Heyman
- Department of Nutrition, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Hilary J Vernon
- Department of Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Ralph-Epps T, Onu CJ, Vo L, Schmidtke MW, Le A, Greenberg ML. Studying Lipid-Related Pathophysiology Using the Yeast Model. Front Physiol 2021; 12:768411. [PMID: 34777024 PMCID: PMC8581491 DOI: 10.3389/fphys.2021.768411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/04/2021] [Indexed: 01/01/2023] Open
Abstract
Saccharomyces cerevisiae, commonly known as baker's yeast, is one of the most comprehensively studied model organisms in science. Yeast has been used to study a wide variety of human diseases, and the yeast model system has proved to be an especially amenable tool for the study of lipids and lipid-related pathophysiologies, a topic that has gained considerable attention in recent years. This review focuses on how yeast has contributed to our understanding of the mitochondrial phospholipid cardiolipin (CL) and its role in Barth syndrome (BTHS), a genetic disorder characterized by partial or complete loss of function of the CL remodeling enzyme tafazzin. Defective tafazzin causes perturbation of CL metabolism, resulting in many downstream cellular consequences and clinical pathologies that are discussed herein. The influence of yeast research in the lipid-related pathophysiologies of Alzheimer's and Parkinson's diseases is also summarized.
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Affiliation(s)
- Tyler Ralph-Epps
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Chisom J Onu
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Linh Vo
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Anh Le
- Muskegon Catholic Central High School, Muskegon, MI, United States
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
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Searle A, Herbert G, Dabner L, Steward CG, Damin M, Pieles G. Self-regulation in Barth syndrome: a qualitative perspective of adolescents, adults and parents in the U.K. Orphanet J Rare Dis 2021; 16:404. [PMID: 34587980 PMCID: PMC8482682 DOI: 10.1186/s13023-021-02027-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/17/2021] [Indexed: 11/29/2022] Open
Abstract
Background Barth syndrome (BS) is a life-threatening genetic disease caused by abnormal lipids in the mitochondria of cells and mostly affects young males. Those living with BS have severe exercise intolerance, lethargy and fatigue due to muscle disease which affect their daily life. Previous research suggests a need for qualitative exploration of self-regulation in BS and the inter-personal processes at play in family life. Therefore this study aimed to explore self-regulation and coping strategies and inter-personal responses in individuals and families affected by Barth syndrome. A multi-perspective qualitative study based on face to face, semi-structured, in-depth interviews with 11 participants (9–27 years, mean 15 years) with BS and/or their parents participating in a randomised double-blind clinical drug trial (CARDIOMAN). Interviews were transcribed verbatim and managed in NVivo prior to conducting a thematic analysis (AS and GH). Results Four key themes were identified: diagnosis and treatment, social support, identity and social integration, symptoms and self-regulation. The present findings suggest that self-regulation and coping in boys with BS was interpersonal and contingent on parental awareness such that parents were aware that their child had a limited energy reserve and that had to be managed due to the implications of fatigue for daily living. Conclusion The findings support previous quantitative work demonstrating that children and parents tend to share a coherent view of BS. However, there is a need for greater awareness from others within the wider context of social and employment networks to minimise adverse implications for future life choices.
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Affiliation(s)
- Aidan Searle
- National Institute of Health Research (NIHR) Bristol Biomedical Research Centre (Nutrition Theme), Education and Research Centre, University of Bristol, Upper Maudlin Street, Bristol, BS2 8AE, UK.
| | - Georgia Herbert
- National Institute of Health Research (NIHR) Bristol Biomedical Research Centre (Nutrition Theme), Education and Research Centre, University of Bristol, Upper Maudlin Street, Bristol, BS2 8AE, UK
| | - Lucy Dabner
- Clinical Trials and Evaluation Unit, Bristol Trials Centre, Bristol Medical School, University of Bristol, Bristol, UK
| | - Colin G Steward
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Michaela Damin
- Barth Syndrome UK, 1 The Vikings, Romsey, SO51 5RG, Hampshire, UK
| | - Guido Pieles
- Bristol Congenital Heart Centre, University Hospitals Bristol NHS Foundation, Bristol, UK.,National Institute of Health Research (NIHR) Biomedical Research Centre (Cardiovascular Theme), University Hospitals Bristol NHS Foundation Trust and University of Bristol, Bristol, UK
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Elkes M, Andonovski M, Vidal D, Farago M, Modafferi R, Claypool SM, LeBlanc PJ. The Influence of Supplemental Dietary Linoleic Acid on Skeletal Muscle Contractile Function in a Rodent Model of Barth Syndrome. Front Physiol 2021; 12:731961. [PMID: 34489741 PMCID: PMC8416984 DOI: 10.3389/fphys.2021.731961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/02/2021] [Indexed: 11/13/2022] Open
Abstract
Barth syndrome is a rare and incurable X-linked (male-specific) genetic disease that affects the protein tafazzin (Taz). Taz is an important enzyme responsible for synthesizing biologically relevant cardiolipin (for heart and skeletal muscle, cardiolipin rich in linoleic acid), a critical phospholipid of mitochondrial form and function. Mutations to Taz cause dysfunctional mitochondria, resulting in exercise intolerance due to skeletal muscle weakness. To date, there has been limited research on improving skeletal muscle function, with interventions focused on endurance and resistance exercise. Previous cell culture research has shown therapeutic potential for the addition of exogenous linoleic acid in improving Taz-deficient mitochondrial function but has not been examined in vivo. The purpose of this study was to examine the influence of supplemental dietary linoleic acid on skeletal muscle function in a rodent model of Barth syndrome, the inducible Taz knockdown (TazKD) mouse. One of the main findings was that TazKD soleus demonstrated an impaired contractile phenotype (slower force development and rates of relaxation) in vitro compared to their WT littermates. Interestingly, this impaired contractile phenotype seen in vitro did not translate to altered muscle function in vivo at the whole-body level. Also, supplemental linoleic acid attenuated, to some degree, in vitro impaired contractile phenotype in TazKD soleus, and these findings appear to be partially mediated by improvements in cardiolipin content and resulting mitochondrial supercomplex formation. Future research will further examine alternative mechanisms of dietary supplemental LA on improving skeletal muscle contractile dysfunction in TazKD mice.
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Affiliation(s)
- Mario Elkes
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Martin Andonovski
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Daislyn Vidal
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Madison Farago
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Ryan Modafferi
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Paul J LeBlanc
- Faculty of Applied Health Sciences, Center for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
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11
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Olivar-Villanueva M, Ren M, Phoon CKL. Neurological & psychological aspects of Barth syndrome: Clinical manifestations and potential pathogenic mechanisms. Mitochondrion 2021; 61:188-195. [PMID: 34197965 DOI: 10.1016/j.mito.2021.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 06/10/2021] [Accepted: 06/23/2021] [Indexed: 02/06/2023]
Abstract
Barth syndrome is a rare X-linked multisystem mitochondrial disease that is caused by variants in the tafazzin gene leading to deficient and abnormal cardiolipin. Previous research has focused on the cardiomyopathy and neutropenia in individuals with Barth syndrome, yet just as common are the least explored neurological aspects of Barth syndrome. This review focuses on the major neuropsychological and neurophysiological phenotypes that affect the quality of life of individuals with Barth syndrome, including difficulties in sensory perception and feeding, fatigue, and cognitive and psychological challenges. We propose selected pathogenetic mechanisms underlying these phenotypes and draw parallels to other relevant disorders. Finally, avenues for future research are also suggested.
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Affiliation(s)
- Melissa Olivar-Villanueva
- Departments of Pediatrics, New York University Grossman School of Medicine, New York, NY, United States
| | - Mindong Ren
- Departments of Anesthesiology, New York University Grossman School of Medicine, New York, NY, United States; Departments of Cell Biology, New York University Grossman School of Medicine, New York, NY, United States
| | - Colin K L Phoon
- Departments of Pediatrics, New York University Grossman School of Medicine, New York, NY, United States.
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Zhu S, Chen Z, Zhu M, Shen Y, Leon LJ, Chi L, Spinozzi S, Tan C, Gu Y, Nguyen A, Zhou Y, Feng W, Vaz FM, Wang X, Gustafsson AB, Evans SM, Kunfu O, Fang X. Cardiolipin Remodeling Defects Impair Mitochondrial Architecture and Function in a Murine Model of Barth Syndrome Cardiomyopathy. Circ Heart Fail 2021; 14:e008289. [PMID: 34129362 PMCID: PMC8210459 DOI: 10.1161/circheartfailure.121.008289] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cardiomyopathy is a major clinical feature in Barth syndrome (BTHS), an X-linked mitochondrial lipid disorder caused by mutations in Tafazzin (TAZ), encoding a mitochondrial acyltransferase required for cardiolipin remodeling. Despite recent description of a mouse model of BTHS cardiomyopathy, an in-depth analysis of specific lipid abnormalities and mitochondrial form and function in an in vivo BTHS cardiomyopathy model is lacking. METHODS We performed in-depth assessment of cardiac function, cardiolipin species profiles, and mitochondrial structure and function in our newly generated Taz cardiomyocyte-specific knockout mice and Cre-negative control mice (n≥3 per group). RESULTS Taz cardiomyocyte-specific knockout mice recapitulate typical features of BTHS and mitochondrial cardiomyopathy. Fewer than 5% of cardiomyocyte-specific knockout mice exhibited lethality before 2 months of age, with significantly enlarged hearts. More than 80% of cardiomyocyte-specific knockout displayed ventricular dilation at 16 weeks of age and survived until 50 weeks of age. Full parameter analysis of cardiac cardiolipin profiles demonstrated lower total cardiolipin concentration, abnormal cardiolipin fatty acyl composition, and elevated monolysocardiolipin to cardiolipin ratios in Taz cardiomyocyte-specific knockout, relative to controls. Mitochondrial contact site and cristae organizing system and F1F0-ATP synthase complexes, required for cristae morphogenesis, were abnormal, resulting in onion-shaped mitochondria. Organization of high molecular weight respiratory chain supercomplexes was also impaired. In keeping with observed mitochondrial abnormalities, seahorse experiments demonstrated impaired mitochondrial respiration capacity. CONCLUSIONS Our mouse model mirrors multiple physiological and biochemical aspects of BTHS cardiomyopathy. Our results give important insights into the underlying cause of BTHS cardiomyopathy and provide a framework for testing therapeutic approaches to BTHS cardiomyopathy, or other mitochondrial-related cardiomyopathies.
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Affiliation(s)
- Siting Zhu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Ze’e Chen
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Mason Zhu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Ying Shen
- Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, University Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - Leonardo J Leon
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Liguo Chi
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
| | - Simone Spinozzi
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Changming Tan
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yusu Gu
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Anh Nguyen
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Yi Zhou
- Department of Molecular Biology, University of California, San Diego, La Jolla, California, USA
| | - Wei Feng
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and Pediatrics, Amsterdam Gastroenterology Endocrinology Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC
| | - Xiaohong Wang
- Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, China
| | - Asa B Gustafsson
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Sylvia M Evans
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
- Department of Pharmacology, University of California, San Diego, La Jolla, California, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Ouyang Kunfu
- Department of Cardiovascular Surgery, Peking University Shenzhen Hospital, School of Chemical Biology and Biotechnology, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xi Fang
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
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Schaaf J, Prokosch HU, Boeker M, Schaefer J, Vasseur J, Storf H, Sedlmayr M. Interviews with experts in rare diseases for the development of clinical decision support system software - a qualitative study. BMC Med Inform Decis Mak 2020; 20:230. [PMID: 32938448 PMCID: PMC7493382 DOI: 10.1186/s12911-020-01254-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 09/09/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Patients with rare diseases (RDs) are often diagnosed too late or not at all. Clinical decision support systems (CDSSs) could support the diagnosis in RDs. The MIRACUM (Medical Informatics in Research and Medicine) consortium, which is one of four funded consortia in the German Medical Informatics Initiative, will develop a CDSS for RDs based on distributed clinical data from ten university hospitals. This qualitative study aims to investigate (1) the relevant organizational conditions for the operation of a CDSS for RDs when diagnose patients (e.g. the diagnosis workflow), (2) which data is necessary for decision support, and (3) the appropriate user group for such a CDSS. METHODS Interviews were carried out with RDs experts. Participants were recruited from staff physicians at the Rare Disease Centers (RDCs) at the MIRACUM locations, which offer diagnosis and treatment of RDs. An interview guide was developed with a category-guided deductive approach. The interviews were recorded on an audio device and then transcribed into written form. We continued data collection until all interviews were completed. Afterwards, data analysis was performed using Mayring's qualitative content analysis approach. RESULTS A total of seven experts were included in the study. The results show that medical center guides and physicians from RDC B-centers (with a focus on different RDs) are involved in the diagnostic process. Furthermore, interdisciplinary case discussions between physicians are conducted. The experts explained that RDs exist which cannot be fully differentiated, but rather described only by their overall symptoms or findings: diagnosis is dependent on the disease or disease group. At the end of the diagnostic process, most centers prepare a summary of the patient case. Furthermore, the experts considered both physicians and experts from the B-centers to be potential users of a CDSS. The experts also have different experiences with CDSS for RDs. CONCLUSIONS This qualitative study is a first step towards establishing the requirements for the development of a CDSS for RDs. Further research is necessary to create solutions by also including the experts on RDs.
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Affiliation(s)
- Jannik Schaaf
- Medical Informatics Group (MIG), University Hospital Frankfurt, Frankfurt, Germany.
| | - Hans-Ulrich Prokosch
- Chair of Medical Informatics, Department of Medical Informatics, Biometrics and Epidemiology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Boeker
- Institute of Medical Biometry and Statistics, Medical Faculty and Medical Centre - University of Freiburg, Freiburg, Germany
| | - Johanna Schaefer
- Medical Informatics Group (MIG), University Hospital Frankfurt, Frankfurt, Germany
| | - Jessica Vasseur
- Medical Informatics Group (MIG), University Hospital Frankfurt, Frankfurt, Germany
| | - Holger Storf
- Medical Informatics Group (MIG), University Hospital Frankfurt, Frankfurt, Germany
| | - Martin Sedlmayr
- Institute for Medical Informatics and Biometry, Carl Gustav Carus Faculty of Medicine Technical University of Dresden, Dresden, Germany
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