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Liu O, Chinni BK, Manlhiot C, Vernon HJ. FGF21 and GDF15 are elevated in Barth Syndrome and are correlated to important clinical measures. Mol Genet Metab 2023; 140:107676. [PMID: 37549445 DOI: 10.1016/j.ymgme.2023.107676] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/09/2023]
Abstract
Barth Syndrome (BTHS) is a rare X-linked disorder that is caused by defects TAFAZZIN, which leads to an abnormal cardiolipin (CL) profile of the inner mitochondrial membrane and clinical features including cardiomyopathy, neutropenia and skeletal myopathy. The ratio of monolysocardiolipin (MLCL, the remodeling intermediate of cardiolipin) to remodeled CL is always abnormal in Barth Syndrome and 3-methylglutaconic acid is often elevated affected patients, however neither of these biomarkers has been shown to temporally correlate to clinical status. In this study, we measured plasma FGF21 and GDF15 levels in 16 individuals with Barth Syndrome and evaluated whether these biomarkers were correlated to the MLCL/CL ratio in patient bloodspots and clinical laboratory parameters indicative of organ involvement in Barth Syndrome including: neutrophil and monocyte counts, liver function, and cardiac function (NT-proBNP). We found that FGF21 and GDF15 were elevated in all 16 patients and that FGF21 was significantly correlated to AST, ALT GGT, percentage of neutrophils comprising total white blood cells, percent monocytes comprising total white blood cells, and NT-proBNP levels. GDF-15 was significantly positively associated with NT-proBNP. We conclude that clinical measurements of FGF21 and GDF-15 may be relevant in the monitoring multi-organ system involvement in Barth Syndrome.
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Affiliation(s)
- Olivia Liu
- The Blalock-Taussig-Thomas Pediatric and Congenital Heart Center, Department of Pediatrics, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Bhargava Kumar Chinni
- The Blalock-Taussig-Thomas Pediatric and Congenital Heart Center, Department of Pediatrics, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Cedric Manlhiot
- The Blalock-Taussig-Thomas Pediatric and Congenital Heart Center, Department of Pediatrics, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Hilary J Vernon
- Department of Genetic Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD, USA..
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Tomczewski MV, Chan JZ, Al-Majmaie DM, Liu MR, Cocco AD, Stark KD, Strathdee D, Duncan RE. Phenotypic Characterization of Female Carrier Mice Heterozygous for Tafazzin Deletion. Biology (Basel) 2023; 12:1238. [PMID: 37759637 PMCID: PMC10525480 DOI: 10.3390/biology12091238] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/02/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023]
Abstract
Barth syndrome (BTHS) is caused by mutations in tafazzin resulting in deficits in cardiolipin remodeling that alter major metabolic processes. The tafazzin gene is encoded on the X chromosome, and therefore BTHS primarily affects males. Female carriers are typically considered asymptomatic, but age-related changes have been reported in female carriers of other X-linked disorders. Therefore, we examined the phenotype of female mice heterozygous for deletion of the tafazzin gene (Taz-HET) at 3 and 12 months of age. Food intakes, body masses, lean tissue and adipose depot weights, daily activity levels, metabolic measures, and exercise capacity were assessed. Age-related changes in mice resulted in small but significant genotype-specific differences in Taz-HET mice compared with their female Wt littermates. By 12 months, Taz-HET mice weighed less than Wt controls and had smaller gonadal, retroperitoneal, and brown adipose depots and liver and brain masses, despite similar food consumption. Daily movement, respiratory exchange ratio, and total energy expenditure did not vary significantly between the age-matched genotypes. Taz-HET mice displayed improved glucose tolerance and insulin sensitivity at 12 months compared with their Wt littermates but had evidence of slightly reduced exercise capacity. Tafazzin mRNA levels were significantly reduced in the cardiac muscle of 12-month-old Taz-HET mice, which was associated with minor but significant alterations in the heart cardiolipin profile. This work is the first to report the characterization of a model of female carriers of heterozygous tafazzin deficiency and suggests that additional study, particularly with advancing age, is warranted.
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Affiliation(s)
- Michelle V. Tomczewski
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - John Z. Chan
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Duaa M. Al-Majmaie
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Ming Rong Liu
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Alex D. Cocco
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Ken D. Stark
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
| | - Douglas Strathdee
- Transgenic Technology Laboratory, Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, Scotland, UK;
| | - Robin E. Duncan
- Department of Kinesiology and Health Sciences, Faculty of Health, University of Waterloo, 200 University Ave W., BMH1044, Waterloo, ON N2L 3G1, Canada; (M.V.T.); (J.Z.C.); (D.M.A.-M.); (M.R.L.); (K.D.S.)
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Hornby B, Thompson WR, Almuqbil M, Manuel R, Abbruscato A, Carr J, Vernon HJ. Natural history comparison study to assess the efficacy of elamipretide in patients with Barth syndrome. Orphanet J Rare Dis 2022; 17:336. [PMID: 36056411 PMCID: PMC9438322 DOI: 10.1186/s13023-022-02469-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 11/26/2021] [Accepted: 08/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Natural history studies are increasingly recognized as having an important role in drug development for rare diseases. A phase 3, observational, retrospective, and non-interventional study was designed to establish a natural history control (NHC) cohort of patients with Barth syndrome (BTHS) to provide further analysis of the efficacy of elamipretide observed in an open-label extension (OLE) phase of the TAZPOWER trial, a clinical trial that tested the efficacy of 40 mg daily of elamipretide in patients with BTHS. Methods This was a retrospective, non-interventional study. A propensity score model was used to compare elamipretide-treated patients and NHCs. The analysis included 8 patients from the TAZPOWER OLE and 19 untreated NHCs (including 12 with serial echocardiographic assessments). Results For the 6-min walk test (6MWT, primary endpoint), the least squares (LS) mean difference between groups was 79.7 m (P = 0.0004) at week 64 and 91.0 m (P = 0.0005) at week 76 in favor of elamipretide. Significant improvements in muscle strength (secondary endpoint), as assessed by handheld dynamometry (HHD) were also observed with elamipretide, with LS mean differences of 40.8 Newtons at 64 weeks (P = 0.0002) and 56.7 Newtons at 76 weeks (P = 0.0005). Patients continuously treated with elamipretide also experienced statistically significant improvements in other secondary endpoints (i.e., 5 times sit-to-stand [5XSST], multi-domain responder index [MDRI]). The functional improvements were robust to sensitivity analyses. Left ventricular stroke volume increased from baseline in patients with elamipretide but decreased in NHCs.
Conclusions Overall, the study established a NHC for use in assessing the efficacy of therapeutic interventions in patients with BTHS and the results suggest that elamipretide may improve natural history of BTHS at least in part by attenuating the natural decline in heart function and provide meaningful improvements in heart function and functional capacity in patients with BTHS compared to NHCs. Highlights A matched Natural History Control (NHC) was used to evaluate elamipretide in BTHS Elamipretide may improve natural history of BTHS by attenuating natural decline in heart function Elamipretide was associated with meaningful clinical improvements in skeletal muscle and cardiovascular parameters that were not observed in NHCs The study established a NHC for use in assessing the efficacy of therapeutic interventions in BTHS
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Affiliation(s)
- Brittany Hornby
- Department of Physical Therapy, Kennedy Krieger, Baltimore, MD, USA
| | - William Reid Thompson
- Department of Pediatric Cardiology, Taussig Heart Center, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Mohammed Almuqbil
- College of Medicine, King Saud Bin Abdulaziz University for Health Sciences (KSAU-HS); King Abdullah Specialized Children's Hospital (KASCH), Riyadh, Saudi Arabia
| | - Ryan Manuel
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, MRB 512, Baltimore, Maryland, 21205, USA
| | | | - Jim Carr
- Stealth BioTherapeutics, Inc, Needham, MA, USA
| | - Hilary J Vernon
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, MRB 512, Baltimore, Maryland, 21205, USA.
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Pang J, Bao Y, Mitchell-Silbaugh K, Veevers J, Fang X. Barth Syndrome Cardiomyopathy: An Update. Genes (Basel) 2022; 13:genes13040656. [PMID: 35456462 PMCID: PMC9030331 DOI: 10.3390/genes13040656] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/23/2022] [Accepted: 04/02/2022] [Indexed: 12/28/2022] Open
Abstract
Barth syndrome (BTHS) is an X-linked mitochondrial lipid disorder caused by mutations in the TAFAZZIN (TAZ) gene, which encodes a mitochondrial acyltransferase/transacylase required for cardiolipin (CL) biosynthesis. Cardiomyopathy is a major clinical feature of BTHS. During the past four decades, we have witnessed many landmark discoveries that have led to a greater understanding of clinical features of BTHS cardiomyopathy and their molecular basis, as well as the therapeutic targets for this disease. Recently published Taz knockout mouse models provide useful experimental models for studying BTHS cardiomyopathy and testing potential therapeutic approaches. This review aims to summarize key findings of the clinical features, molecular mechanisms, and potential therapeutic approaches for BTHS cardiomyopathy, with particular emphasis on the most recent studies.
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Affiliation(s)
- Jing Pang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Yutong Bao
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Department of Biological Science, University of California San Diego, La Jolla, CA 92093, USA
| | - Kalia Mitchell-Silbaugh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Jennifer Veevers
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
| | - Xi Fang
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; (J.P.); (Y.B.); (K.M.-S.); (J.V.)
- Correspondence: ; Tel.: +1-858-246-4637
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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: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Vaz FM, van Lenthe H, Vervaart MAT, Stet FS, Klinkspoor JH, Vernon HJ, Goorden SMI, Houtkooper RH, Kulik W, Wanders RJA. An improved functional assay in blood spot to diagnose Barth syndrome using the monolysocardiolipin/cardiolipin ratio. J Inherit Metab Dis 2022; 45:29-37. [PMID: 34382226 PMCID: PMC9291596 DOI: 10.1002/jimd.12425] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/29/2022]
Abstract
Barth syndrome is an X-linked disorder characterized by cardiomyopathy, skeletal myopathy, and neutropenia, caused by deleterious variants in TAFAZZIN. This gene encodes a phospholipid-lysophospholipid transacylase that is required for the remodeling of the mitochondrial phospholipid cardiolipin (CL). Biochemically, individuals with Barth syndrome have a deficiency of mature CL and accumulation of the remodeling intermediate monolysocardiolipin (MLCL). Diagnosis typically relies on mass spectrometric measurement of CL and MLCL in cells or tissues, and we previously described a method in blood spot that uses a specific MLCL/CL ratio as diagnostic biomarker. Here, we describe the evolution of our blood spot assay that is based on the implementation of reversed phase-UHPLC separation followed by full scan high resolution mass spectrometry. In addition to the MLCL/CL ratio, our improved method also generates a complete CL spectrum allowing the interrogation of the CL fatty acid composition, which considerably enhances the diagnostic reliability. This addition negates the need for a confirmatory test in lymphocytes thereby providing a shorter turn-around-time while achieving a more certain test result. As one of the few laboratories that offer this assay, we also evaluated the diagnostic yield and performance from 2006 to 2021 encompassing the use of both the original and improved assay. In this period, we performed 796 diagnostic analyses of which 117 (15%) were characteristic of Barth syndrome. In total, we diagnosed 93 unique individuals with Barth syndrome, including three females, which together amounts to about 40% of all reported individuals with Barth syndrome in the world.
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Affiliation(s)
- Frédéric M. Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Department of PediatricsEmma Children's Hospital, Amsterdam UMC, University of AmsterdamAmsterdamThe Netherlands
- Core Facility Metabolomics, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Henk van Lenthe
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Core Facility Metabolomics, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Martin A. T. Vervaart
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Core Facility Metabolomics, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Femke S. Stet
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Core Facility Metabolomics, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Johanne H. Klinkspoor
- Central Diagnostic Laboratory, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Hilary J. Vernon
- Department of Medical GeneticsJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Susan M. I. Goorden
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
| | - Riekelt H. Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
| | - Willem Kulik
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Core Facility Metabolomics, Amsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
| | - Ronald J. A. Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry and PediatricsAmsterdam Gastroenterology Endocrinology MetabolismAmsterdamThe Netherlands
- Department of PediatricsEmma Children's Hospital, Amsterdam UMC, University of AmsterdamAmsterdamThe Netherlands
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Thompson R, Jefferies J, Wang S, Pu WT, Takemoto C, Hornby B, Heyman A, Chin MT, Vernon HJ. Current and future treatment approaches for Barth syndrome. J Inherit Metab Dis 2022; 45:17-28. [PMID: 34713454 DOI: 10.1002/jimd.12453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022]
Abstract
Barth Syndrome is an X-linked disorder of mitochondrial cardiolipin metabolism caused by pathogenic variants in TAFAZZIN with pleiotropic effects including cardiomyopathy, neutropenia, growth delay, and skeletal myopathy. Management requires a multidisciplinary approach to the organ-specific manifestations including specialists from cardiology, hematology, nutrition, physical therapy, genetics, and metabolism. Currently, treatment is centered on management of specific clinical features, and is not targeted toward remediating the underlying biochemical defect. However, two clinical trials have been recently undertaken which target the mitochondrial pathology of this disease: a study to examine the effects of elamipretide, a cardiolipin targeted agent, and a study to examine the effects of bezafibrate, a peroxisome proliferator-activated receptor (PPAR) agonist. Treatments to directly target the defective TAFAZZIN pathway are under development, including enzyme and gene therapies.
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Affiliation(s)
- Reid Thompson
- Department of Pediatric Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - John Jefferies
- The Cardiovascular Institute, The University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Suya Wang
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - William T Pu
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Clifford Takemoto
- Division of Clinical Hematology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Brittany Hornby
- Department of Physical Therapy, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Andrea Heyman
- Department of Nutrition, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Michael T Chin
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Hilary J Vernon
- Department of Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Maryland, USA
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Vanderniet JA, Benitez-Aguirre PZ, Broderick CR, Kelley RI, Balasubramaniam S. Barth syndrome with severe dilated cardiomyopathy and growth hormone resistance: a case report. J Pediatr Endocrinol Metab 2021; 34:951-955. [PMID: 33851526 DOI: 10.1515/jpem-2020-0666] [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] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/19/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES To describe the metabolic and endocrine features of a patient with Barth syndrome who showed evidence of growth hormone resistance. CASE PRESENTATION A male proband deteriorated rapidly with lactic acidosis after a circumcision at age three weeks and was found to have severe dilated cardiomyopathy. A cardiomyopathy gene panel led to the diagnosis of TAZ-deficiency Barth syndrome. He subsequently experienced hypotonia and gross motor delay, feeding difficulties for the first four years, constitutional growth delay and one episode of ketotic hypoglycaemia. Cardiomyopathy resolved on oral anti-failure therapy by age three years. He had a hormonal pattern of growth hormone resistance, and growth hormone treatment was considered, however height velocity improved spontaneously after age 3½ years. He also had biochemical primary hypothyroidism. CONCLUSIONS With careful metabolic management with l-arginine supplementation, overnight corn starch, and a prescribed exercise program, our patient's strength, endurance, level of physical activity and body composition improved significantly by age six years.
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Affiliation(s)
- Joel A Vanderniet
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Paul Z Benitez-Aguirre
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia
- Discipline of Paediatrics and Child Health, University of Sydney, Sydney, NSW, Australia
| | - Carolyn R Broderick
- Children's Hospital Institute of Sports Medicine, The Children's Hospital at Westmead, Sydney, NSW, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Richard I Kelley
- Department of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Shanti Balasubramaniam
- Genetic Metabolic Disorders Service, The Children's Hospital at Westmead, Sydney, NSW, Australia
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9
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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: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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10
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Chin MT, Conway SJ. Role of Tafazzin in Mitochondrial Function, Development and Disease. J Dev Biol 2020; 8:jdb8020010. [PMID: 32456129 PMCID: PMC7344621 DOI: 10.3390/jdb8020010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Tafazzin, an enzyme associated with the rare inherited x-linked disorder Barth Syndrome, is a nuclear encoded mitochondrial transacylase that is highly conserved across multiple species and plays an important role in mitochondrial function. Numerous studies have elucidated the mechanisms by which Tafazzin affects mitochondrial function, but its effects on development and susceptibility to adult disease are incompletely understood. The purpose of this review is to highlight previous functional studies across a variety of model organisms, introduce recent studies that show an important role in development, and also to provide an update on the role of Tafazzin in human disease. The profound effects of Tafazzin on cardiac development and adult cardiac homeostasis will be emphasized. These studies underscore the importance of mitochondrial function in cardiac development and disease, and also introduce the concept of Tafazzin as a potential therapeutic modality.
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Affiliation(s)
- Michael T. Chin
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA 02111, USA
- Correspondence: (M.T.C.); (S.J.C.); Tel.: +1-617-636-8776 (M.T.C.); +1-317-278-8780 (S.J.C.)
| | - Simon J. Conway
- Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Correspondence: (M.T.C.); (S.J.C.); Tel.: +1-617-636-8776 (M.T.C.); +1-317-278-8780 (S.J.C.)
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11
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Miller PC, Ren M, Schlame M, Toth MJ, Phoon CKL. A Bayesian Analysis to Determine the Prevalence of Barth Syndrome in the Pediatric Population. J Pediatr 2020; 217:139-144. [PMID: 31732128 DOI: 10.1016/j.jpeds.2019.09.074] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/30/2019] [Accepted: 09/26/2019] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To determine the prevalence of Barth syndrome in the pediatric population. STUDY DESIGN Data were collected from the Barth Syndrome Foundation Registry and relevant literature. With the advent of genetic testing and whole-exome sequencing, a multipronged Bayesian analysis was used to estimate the prevalence of Barth syndrome based on published data on the incidence and prevalence of cardiomyopathy and neutropenia, and the respective subpopulations of patients with Barth syndrome indicated in these publications. RESULTS Based on 7 published studies of cardiomyopathy and 2 published studies of neutropenia, the estimated prevalence of Barth syndrome is approximately 1 case per million male population. This contrasts with 99 cases in the Barth Syndrome Foundation Registry, 58 of which indicate a US location, and only 230-250 cases known worldwide. CONCLUSIONS It appears that Barth syndrome is greatly underdiagnosed. There is a need for better education and awareness of this rare disease to move toward early diagnosis and treatment.
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Affiliation(s)
- Paighton C Miller
- Division of Pediatric Cardiology, Department of Pediatrics, New York University School of Medicine, New York, NY
| | - Mindong Ren
- Department of Anesthesiology, New York University School of Medicine, New York, NY; Department of Cell Biology, New York University School of Medicine, New York, NY
| | - Michael Schlame
- Department of Anesthesiology, New York University School of Medicine, New York, NY; Department of Cell Biology, New York University School of Medicine, New York, NY
| | | | - Colin K L Phoon
- Division of Pediatric Cardiology, Department of Pediatrics, New York University School of Medicine, New York, NY.
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12
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Garlid AO, Schaffer CT, Kim J, Bhatt H, Guevara-Gonzalez V, Ping P. TAZ encodes tafazzin, a transacylase essential for cardiolipin formation and central to the etiology of Barth syndrome. Gene 2019; 726:144148. [PMID: 31647997 DOI: 10.1016/j.gene.2019.144148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 05/02/2019] [Revised: 09/12/2019] [Accepted: 09/27/2019] [Indexed: 12/31/2022]
Abstract
Tafazzin, which is encoded by the TAZ gene, catalyzes transacylation to form mature cardiolipin and shows preference for the transfer of a linoleic acid (LA) group from phosphatidylcholine (PC) to monolysocardiolipin (MLCL) with influence from mitochondrial membrane curvature. The protein contains domains and motifs involved in targeting, anchoring, and an active site for transacylase activity. Tafazzin activity affects many aspects of mitochondrial structure and function, including that of the electron transport chain, fission-fusion, as well as apoptotic signaling. TAZ mutations are implicated in Barth syndrome, an underdiagnosed and devastating disease that primarily affects male pediatric patients with a broad spectrum of disease pathologies that impact the cardiovascular, neuromuscular, metabolic, and hematologic systems.
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Affiliation(s)
- Anders O Garlid
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Physiology, University of California at Los Angeles, CA 90095, USA.
| | - Calvin T Schaffer
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Physiology, University of California at Los Angeles, CA 90095, USA
| | - Jaewoo Kim
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Physiology, University of California at Los Angeles, CA 90095, USA
| | - Hirsh Bhatt
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Physiology, University of California at Los Angeles, CA 90095, USA
| | - Vladimir Guevara-Gonzalez
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Mathematics, University of California at Los Angeles, CA 90095, USA
| | - Peipei Ping
- Cardiovascular Data Science Training Program at UCLA, University of California at Los Angeles, CA 90095, USA; Department of Physiology, University of California at Los Angeles, CA 90095, USA; Department of Medicine/Cardiology, University of California at Los Angeles, CA 90095, USA; Department of Bioinformatics, University of California at Los Angeles, CA 90095, USA; Scalable Analytics Institute (ScAi), University of California at Los Angeles, CA 90095, USA.
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13
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Abstract
Objectives: Barth syndrome is an ultra-rare, infantile-onset, X-linked recessive mitochondrial disorder, primarily affecting males, due to variants in TAZ encoding for the cardiolipin transacylase tafazzin. This review aimed to summarize and discuss recent and earlier findings concerning the etiology, pathogenesis, clinical presentation, diagnosis, treatment, and outcome of Barth syndrome. Method: A literature review was undertaken through a MEDLINE search. Results: The phenotype of Barth syndrome is highly variable but most frequently patients present with hypertrophic/dilated/non-compaction cardiomyopathy, fibroelastosis, arrhythmias, neutropenia, mitochondrial myopathy, growth retardation, dysmorphism, cognitive impairment, and other, rarer features. Lactic acid and creatine kinase, and blood and urine organic acids, particularly 3-methylglutaconic acid and monolysocardiolipin, are often elevated. Cardiolipin is decreased. Biochemical investigations may show decreased activity of various respiratory chain complexes. The diagnosis is confirmed by documentation of a causative TAZ variant. Treatment is symptomatic and directed toward treating heart failure, arrhythmias, neutropenia, and mitochondrial myopathy. Conclusions: Although Barth syndrome is still an orphan disease, with fewer than 200 cases described so far, there is extensive ongoing research with regard to its pathomechanism and new therapeutic approaches. Although most of these approaches are still experimental, it can be expected that causative strategies will be developed in the near future.
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Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, Austria
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Li CJ, Chen CS, Yiang GT, Tsai APY, Liao WT, Wu MY. Advanced Evolution of Pathogenesis Concepts in Cardiomyopathies. J Clin Med 2019; 8:jcm8040520. [PMID: 30995779 PMCID: PMC6518034 DOI: 10.3390/jcm8040520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 03/07/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022] Open
Abstract
Cardiomyopathy is a group of heterogeneous cardiac diseases that impair systolic and diastolic function, and can induce chronic heart failure and sudden cardiac death. Cardiomyopathy is prevalent in the general population, with high morbidity and mortality rates, and contributes to nearly 20% of sudden cardiac deaths in younger individuals. Genetic mutations associated with cardiomyopathy play a key role in disease formation, especially the mutation of sarcomere encoding genes and ATP kinase genes, such as titin, lamin A/C, myosin heavy chain 7, and troponin T1. Pathogenesis of cardiomyopathy occurs by multiple complex steps involving several pathways, including the Ras-Raf-mitogen-activated protein kinase-extracellular signal-activated kinase pathway, G-protein signaling, mechanotransduction pathway, and protein kinase B/phosphoinositide 3-kinase signaling. Excess biomechanical stress induces apoptosis signaling in cardiomyocytes, leading to cell loss, which can induce myocardial fibrosis and remodeling. The clinical features and pathophysiology of cardiomyopathy are discussed. Although several basic and clinical studies have investigated the mechanism of cardiomyopathy, the detailed pathophysiology remains unclear. This review summarizes current concepts and focuses on the molecular mechanisms of cardiomyopathy, especially in the signaling from mutation to clinical phenotype, with the aim of informing the development of therapeutic interventions.
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Affiliation(s)
- Chia-Jung Li
- Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
| | - Chien-Sheng Chen
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Giou-Teng Yiang
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Andy Po-Yi Tsai
- Department of Medical Research, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan.
| | - Wan-Ting Liao
- Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan.
- Chinese Medicine Department, Show Chwan Memorial Hospital, Changhua 500, Taiwan.
| | - Meng-Yu Wu
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
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15
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Stöllberger C, Finsterer J. Understanding left ventricular hypertrabeculation/noncompaction: pathomorphologic findings and prognostic impact of neuromuscular comorbidities. Expert Rev Cardiovasc Ther 2018; 17:95-109. [PMID: 30570401 DOI: 10.1080/14779072.2019.1561280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION When >3 trabeculations associated with interventricular recesses are found, this is termed 'left ventricular hypertrabeculation/noncompaction' (LVHT). Cardiac-imaging methods detect LVHT in all ages, isolated or associated with extracardiac, especially neuromuscular disorders (NMDs). Many issues about LVHT are unclear. The review gives an update about pathomorphologic findings in patients >14 years and the role of NMDs in LVHT. Areas covered: A PubMed-search for the terms "noncompaction" or "non-compaction" or "hypertrabeculation" AND "autopsy" or 'biopsy' or 'ultrastructure' or 'electron microscopy' AND 'neuromuscular' or 'myopathy' or 'neuropathy' was carried out from 1985 to July 2018. Expert commentary: Macroanatomic (n = 65), histopathologic (n = 59) and ultrastructural (n = 7) reports were found. A comparison with echocardiography was described in 45 cases. Measurements of non-compacted and compacted layer were only given from hearts investigated in short-axis cuts after formaldehyde-fixation. Endocardial, subendocardial and interstitial fibrosis were frequent findings. When LVHT-patients were systematically investigated, a NMD was found in 80%, most frequently mitochondrial disorders, Barth syndrome, zaspopathy, and myotonic dystrophy type 1. LVHT does not seem to be a special type of cardiac involvement of NMDs. NMDs affect prognosis in LVHT as well as LVHT affects prognosis in patients with Duchenne muscular dystrophy.
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Affiliation(s)
- Claudia Stöllberger
- a 2nd Medical Department with Cardiology and Intensive Care Medicine , Rudolfstifung Hospital , Vienna , Austria
| | - Josef Finsterer
- b Rudolfstiftung Hospital , Danube University Krems , Vienna , Austria
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16
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Finsterer J, Stollberger C. Female and Male Carriers of TAZ Mutations Need to be Thoroughly Investigated. Balkan J Med Genet 2018; 20:91-94. [PMID: 29876239 PMCID: PMC5972509 DOI: 10.1515/bjmg-2017-0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- J Finsterer
- Josef Finsterer, M.D., Ph.D., Krankenanstalt Rudolfstiftung, Postfach 20, 1180 Vienna, Austria. Tel: +43-1-71165. Fax. +43-1-4781711
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17
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Finsterer J, Stöllberger C. Reasons for missing noncompaction in myopathies and vice versa. Cardiovasc Pathol 2018; 35:20-22. [PMID: 29730526 DOI: 10.1016/j.carpath.2018.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/20/2018] [Accepted: 04/03/2018] [Indexed: 11/18/2022] Open
Affiliation(s)
| | - Claudia Stöllberger
- 2nd Medical Department with Cardiology and Intensive Care Medicine, Krankenanstalt Rudolfstiftung, Vienna, Austria
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18
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Finsterer J, Stollberger C. Acquired noncompaction in Barth syndrome due to the TAZ mutation c.481_482ins20. J Pediatr 2017; 186:214. [PMID: 28318529 DOI: 10.1016/j.jpeds.2017.02.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 02/24/2017] [Indexed: 10/19/2022]
Affiliation(s)
| | - Claudia Stollberger
- 2nd Medical Department with Cardiology and Intensive Care Medicine Krankenanstalt Rudolfstiftung Vienna, Austria
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19
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Abstract
Barth syndrome (BTHS) is a rare X-linked genetic disorder characterized by cardiomyopathy, skeletal myopathy, neutropenia, and organic aciduria. The presence and severity of clinical manifestations are highly variable in BTHS, even among patients with identical gene mutations. Currently, less than 200 patients are diagnosed worldwide, but it is estimated that the disorder may be substantially under-diagnosed due to the variable spectrum of clinical manifestations. BTHS is caused by mutations in the gene tafazzin (TAZ), resulting in defective remodeling of cardiolipin (CL), the signature phospholipid of the mitochondrial membranes. Many of the clinical sequela associated with BTHS can be directly attributed to mitochondria defects. In 2008, a definitive biochemical test was described based on detection of the abnormal CL profile characteristic of BTHS. This mini-review provides an overview of the etiology of BTHS, as well as a description of common clinical phenotypes associated with the disorder.
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Affiliation(s)
- Vaishnavi Raja
- Department of Biological Sciences, Wayne State University, USA
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20
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Borna NN, Kishita Y, Ishikawa K, Nakada K, Hayashi JI, Tokuzawa Y, Kohda M, Nyuzuki H, Yamashita-Sugahara Y, Nasu T, Takeda A, Murayama K, Ohtake A, Okazaki Y. A novel mutation in TAZ causes mitochondrial respiratory chain disorder without cardiomyopathy. J Hum Genet 2017; 62:539-547. [PMID: 28123175 DOI: 10.1038/jhg.2016.165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 11/17/2016] [Accepted: 12/08/2016] [Indexed: 12/15/2022]
Abstract
Tafazzin, encoded by the TAZ gene, is a mitochondrial membrane-associated protein that remodels cardiolipin (CL), an important mitochondrial phospholipid. TAZ mutations are associated with Barth syndrome (BTHS). BTHS is an X-linked multisystemic disorder affecting usually male patients. Through sequence analysis of TAZ, we found one novel mutation c.39_60del p.(Pro14Alafs*19) by whole-exome sequencing and a reported missense mutation c.280C>T p.(Arg94Cys) by Sanger sequencing in two male patients (Pt1 and Pt2). Patient with c.280C>T mutation had dilated cardiomyopathy, while another patient with c.39_60del mutation had no feature of cardiomyopathy. A reported m.1555A>G homoplasmic variant was also identified in the patient having mutation c.39_60del by whole mitochondrial DNA sequencing method. This variant was not considered to be the main cause of mitochondrial dysfunction based on a cytoplasmic hybrid (cybrid) assay. Tafazzin expression was absent in both patient-derived fibroblast cells. Complementation of TAZ expression in fibroblasts from the patient with the novel mutation c.39_60del restored mitochondrial respiratory complex assembly. High-performance liquid chromatography-tandem mass spectrometry-based metabolic analysis revealed the decline of CL and the accumulation of monolysocardiolipin, indicating the loss of tafazzin activity. Owing to phenotypic variability, it is difficult to diagnose BTHS based on clinical features only. We conclude that genetic analysis should be performed to avoid underdiagnosis of this potentially life-threatening inborn error of metabolism.
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Affiliation(s)
- Nurun N Borna
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Yoshihito Kishita
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Kaori Ishikawa
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Kazuto Nakada
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Jun-Ichi Hayashi
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yoshimi Tokuzawa
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Masakazu Kohda
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Hiromi Nyuzuki
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Yzumi Yamashita-Sugahara
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Takashi Nasu
- Department of Pediatrics, Obihiro Kosei General Hospital, Obihiro, Japan
| | - Atsuhito Takeda
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Hokkaido, Japan
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, Chiba, Japan
| | - Akira Ohtake
- Department of Pediatrics, Saitama Medical University, Saitama, Japan
| | - Yasushi Okazaki
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan.,Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
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22
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Bakšienė M, Benušienė E, Morkūnienė A, Ambrozaitytė L, Utkus A, Kučinskas V. A novel intronic splice site tafazzin gene mutation detected prenatally in a family with Barth syndrome. Balkan J Med Genet 2016; 19:95-100. [PMID: 28289596 PMCID: PMC5343338 DOI: 10.1515/bjmg-2016-0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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] [Indexed: 11/15/2022] Open
Abstract
Barth syndrome (BTHS) is a rare X-linked disease characterized by dilated cardiomyopathy, proximal skeletal myopathy and cyclic neutropenia. It is caused by various mutations in the tafazzin (TAZ) gene located on Xq28 that results in remodeling of cardiolipin and abnormalities in mitochondria stability and energy production. Here we report on a novel c.285-1G>C splice site mutation in intron 3 of the TAZ gene that was detected prenatally.
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Affiliation(s)
- M Bakšienė
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - E Benušienė
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - A Morkūnienė
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - L Ambrozaitytė
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - A Utkus
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
| | - V Kučinskas
- Center for Medical Genetics, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania; Department of Human and Medical Genetics, Vilnius University, Vilnius, Lithuania
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23
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Bradley RM, Stark KD, Duncan RE. Influence of tissue, diet, and enzymatic remodeling on cardiolipin fatty acyl profile. Mol Nutr Food Res 2016; 60:1804-18. [PMID: 27061349 DOI: 10.1002/mnfr.201500966] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [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: 12/15/2015] [Revised: 03/21/2016] [Accepted: 03/28/2016] [Indexed: 11/10/2022]
Abstract
Cardiolipin is a specialized phospholipid found primarily in the inner mitochondrial membrane. Because of its unique dimeric structure, cardiolipin plays an important role in mitochondrial function, stability, and membrane fluidity. As such, cardiolipin is subject to a high degree of remodeling by phospholipases, acyltransferases, and transacylases that create a fatty acyl profile that tends to be highly tissue-specific. Despite this overarching regulation, the molecular species of cardiolipin produced are also influenced by dietary lipid composition. A number of studies have characterized the tissue-specific profile of cardiolipin species and have investigated the specific nature of cardiolipin remodeling, including the role of both enzymes and diet. The aim of this review is to highlight tissue specific differences in cardiolipin composition and, collectively, the enzymatic and dietary factors that contribute to these differences. Consequences of aberrant cardiolipin fatty acyl remodeling are also discussed.
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Affiliation(s)
- Ryan M Bradley
- Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Ken D Stark
- Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Robin E Duncan
- Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
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24
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Saric A, Andreau K, Armand AS, Møller IM, Petit PX. Barth Syndrome: From Mitochondrial Dysfunctions Associated with Aberrant Production of Reactive Oxygen Species to Pluripotent Stem Cell Studies. Front Genet 2016; 6:359. [PMID: 26834781 PMCID: PMC4719219 DOI: 10.3389/fgene.2015.00359] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [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: 02/16/2015] [Accepted: 12/15/2015] [Indexed: 12/22/2022] Open
Abstract
Mutations in the gene encoding the enzyme tafazzin, TAZ, cause Barth syndrome (BTHS). Individuals with this X-linked multisystem disorder present cardiomyopathy (CM) (often dilated), skeletal muscle weakness, neutropenia, growth retardation, and 3-methylglutaconic aciduria. Biopsies of the heart, liver and skeletal muscle of patients have revealed mitochondrial malformations and dysfunctions. It is the purpose of this review to summarize recent results of studies on various animal or cell models of Barth syndrome, which have characterized biochemically the strong cellular defects associated with TAZ mutations. Tafazzin is a mitochondrial phospholipidlysophospholipid transacylase that shuttles acyl groups between phospholipids and regulates the remodeling of cardiolipin (CL), a unique inner mitochondrial membrane phospholipid dimer consisting of two phosphatidyl residues linked by a glycerol bridge. After their biosynthesis, the acyl chains of CLs may be modified in remodeling processes involving up to three different enzymes. Their characteristic acyl chain composition depends on the function of tafazzin, although the enzyme itself surprisingly lacks acyl specificity. CLs are crucial for correct mitochondrial structure and function. In addition to their function in the basic mitochondrial function of ATP production, CLs play essential roles in cardiac function, apoptosis, autophagy, cell cycle regulation and Fe-S cluster biosynthesis. Recent developments in tafazzin research have provided strong insights into the link between mitochondrial dysfunction and the production of reactive oxygen species (ROS). An important tool has been the generation of BTHS-specific induced pluripotent stem cells (iPSCs) from BTHS patients. In a complementary approach, disease-specific mutations have been introduced into wild-type iPSC lines enabling direct comparison with isogenic controls. iPSC-derived cardiomyocytes were then characterized using biochemical and classical bioenergetic approaches. The cells are tested in a "heart-on-chip" assay to model the pathophysiology in vitro, to characterize the underlying mechanism of BTHS deriving from TAZ mutations, mitochondrial deficiencies and ROS production and leading to tissue defects, and to evaluate potential therapies with the use of mitochondrially targeted antioxidants.
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Affiliation(s)
- Ana Saric
- INSERM U 1124 "Toxicologie, Pharmacologie et Signalisation Cellulaire" and "FR 3567" CNRS Chimie, Toxicologie, Signalisation Cellulaire et Cibles Thérapeutiques, Université Paris Descartes - Centre Universitaire des Saints-PèresParis, France; Division of Molecular Medicine, Ruđer Bošković InstituteZagreb, Croatia
| | - Karine Andreau
- INSERM U 1124 "Toxicologie, Pharmacologie et Signalisation Cellulaire" and "FR 3567" CNRS Chimie, Toxicologie, Signalisation Cellulaire et Cibles Thérapeutiques, Université Paris Descartes - Centre Universitaire des Saints-Pères Paris, France
| | - Anne-Sophie Armand
- INSERM U 1124 "Toxicologie, Pharmacologie et Signalisation Cellulaire" and "FR 3567" CNRS Chimie, Toxicologie, Signalisation Cellulaire et Cibles Thérapeutiques, Université Paris Descartes - Centre Universitaire des Saints-Pères Paris, France
| | - Ian M Møller
- Department of Molecular Biology and Genetics, Aarhus University Slagelse, Denmark
| | - Patrice X Petit
- INSERM U 1124 "Toxicologie, Pharmacologie et Signalisation Cellulaire" and "FR 3567" CNRS Chimie, Toxicologie, Signalisation Cellulaire et Cibles Thérapeutiques, Université Paris Descartes - Centre Universitaire des Saints-Pères Paris, France
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Abstract
Left ventricular non-compaction, the most recently classified form of cardiomyopathy, is characterised by abnormal trabeculations in the left ventricle, most frequently at the apex. It can be associated with left ventricular dilation or hypertrophy, systolic or diastolic dysfunction, or both, or various forms of congenital heart disease. Affected individuals are at risk of left or right ventricular failure, or both. Heart failure symptoms can be induced by exercise or be persistent at rest, but many patients are asymptomatic. Patients on chronic treatment for compensated heart failure sometimes present acutely with decompensated heart failure. Other life-threatening risks of left ventricular non-compaction are ventricular arrhythmias or complete atrioventricular block, presenting clinically as syncope, and sudden death. Genetic inheritance arises in at least 30-50% of patients, and several genes that cause left ventricular non-compaction have been identified. These genes seem generally to encode sarcomeric (contractile apparatus) or cytoskeletal proteins, although, in the case of left ventricular non-compaction with congenital heart disease, disturbance of the NOTCH signalling pathway seems part of a final common pathway for this form of the disease. Disrupted mitochondrial function and metabolic abnormalities have a causal role too. Treatments focus on improvement of cardiac efficiency and reduction of mechanical stress in patients with systolic dysfunction. Further, treatment of arrhythmia and implantation of an automatic implantable cardioverter-defibrillator for prevention of sudden death are mainstays of therapy when deemed necessary and appropriate. Patients with left ventricular non-compaction and congenital heart disease often need surgical or catheter-based interventions. Despite progress in diagnosis and treatment in the past 10 years, understanding of the disorder and outcomes need to be improved.
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Affiliation(s)
- Jeffrey A Towbin
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Angela Lorts
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - John Lynn Jefferies
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Lu YW, Claypool SM. Disorders of phospholipid metabolism: an emerging class of mitochondrial disease due to defects in nuclear genes. Front Genet 2015; 6:3. [PMID: 25691889 PMCID: PMC4315098 DOI: 10.3389/fgene.2015.00003] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [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: 11/26/2014] [Accepted: 01/06/2015] [Indexed: 01/14/2023] Open
Abstract
The human nuclear and mitochondrial genomes co-exist within each cell. While the mitochondrial genome encodes for a limited number of proteins, transfer RNAs, and ribosomal RNAs, the vast majority of mitochondrial proteins are encoded in the nuclear genome. Of the multitude of mitochondrial disorders known to date, only a fifth are maternally inherited. The recent characterization of the mitochondrial proteome therefore serves as an important step toward delineating the nosology of a large spectrum of phenotypically heterogeneous diseases. Following the identification of the first nuclear gene defect to underlie a mitochondrial disorder, a plenitude of genetic variants that provoke mitochondrial pathophysiology have been molecularly elucidated and classified into six categories that impact: (1) oxidative phosphorylation (subunits and assembly factors); (2) mitochondrial DNA maintenance and expression; (3) mitochondrial protein import and assembly; (4) mitochondrial quality control (chaperones and proteases); (5) iron–sulfur cluster homeostasis; and (6) mitochondrial dynamics (fission and fusion). Here, we propose that an additional class of genetic variant be included in the classification schema to acknowledge the role of genetic defects in phospholipid biosynthesis, remodeling, and metabolism in mitochondrial pathophysiology. This seventh class includes a small but notable group of nuclear-encoded proteins whose dysfunction impacts normal mitochondrial phospholipid metabolism. The resulting human disorders present with a diverse array of pathologic consequences that reflect the variety of functions that phospholipids have in mitochondria and highlight the important role of proper membrane homeostasis in mitochondrial biology.
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Affiliation(s)
- Ya-Wen Lu
- Department of Physiology, School of Medicine, Johns Hopkins University Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, School of Medicine, Johns Hopkins University Baltimore, MD, USA
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27
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Abstract
Barth Syndrome is a rare X-linked disorder characterized principally by dilated cardiomyopathy, skeletal myopathy and neutropenia and caused by defects in tafazzin, an enzyme responsible for modifying the acyl chain moieties of cardiolipin. While several comprehensive clinical studies of Barth Syndrome have been published detailing cardiac and hematologic features, descriptions of its biochemical characteristics are limited. To gain a better understanding of the clinical biochemistry of this rare disease, we measured hematologic and biochemical values in a cohort of Barth Syndrome patients. We characterized multiple biochemical parameters, including plasma amino acids, plasma 3-methylglutaconic acid, cholesterol, cholesterol synthetic intermediates, and red blood cell membrane fatty acid profiles in 28 individuals with Barth Syndrome from ages 10 months to 30 years. We describe a unique biochemical profile for these patients, including decreased plasma arginine levels. We further studied the plasma amino acid profiles, cholesterol, cholesterol synthetic intermediates, and plasma 3-methylglutaconic acid levels in 8 female carriers and showed that they do not share any of the distinct, Barth Syndrome-specific biochemical laboratory abnormalities. Our studies augment and expand the biochemical profiles of individuals with Barth Syndrome, describe a unique biochemical profile for these patients, and provide insight into the possible underlying biochemical pathology in this disorder.
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Affiliation(s)
- Hilary J Vernon
- Division of Metabolism, Kennedy Krieger Institute, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Yana Sandlers
- Division of Metabolism, Kennedy Krieger Institute, USA
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28
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Finsterer J, Stöllberger C, Brandau O, Laccone F, Bichler K, Laing NG. Novel MYH7 mutation associated with mild myopathy but life-threatening ventricular arrhythmias and noncompaction. Int J Cardiol 2014; 173:532-5. [DOI: 10.1016/j.ijcard.2014.03.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 03/09/2014] [Indexed: 11/27/2022]
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29
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Mazurová S, Tesařová M, Magner M, Houšťková H, Hansíková H, Augustínová J, Tomek V, Vondráčková A, Zeman J, Honzík T. Novel mutations in the TAZ gene in patients with Barth syndrome. Prague Med Rep 2014; 114:139-53. [PMID: 24093814 DOI: 10.14712/23362936.2014.16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Barth syndrome is an X-linked recessive disorder that is caused by mutations in Taffazin gene (TAZ), leading to severe cardiolipin deficiency which results in respiratory chain dysfunction. Barth syndrome is characterized by cardiomyopathy, neutropenia, skeletal myopathy, growth deficiency and 3-methylglutaconic aciduria. In this paper, we present clinical, biochemical and molecular data of the first four Czech patients from four unrelated families diagnosed with this rare disease. The mean age of onset was 5.5 ± 3.8 months. One child suffered from sudden cardiac death at the age of 2 years, the age of living patients is between 3 and 13 years. Muscle hypotonia was present in all four patients; cardiomyopathy and growth retardation in three and neutropenia in two of them. Two patients manifested a dilated and one patient a hypertrophic cardiomyopathy. A characteristic laboratory abnormality was the intermittently increased excretion of 3-methylglutaconic acid. Three novel hemizygous mutations in the TAZ gene were found (c.584G>T; c.109+6T>C; c.86G>A). We conclude that Barth syndrome should be included in differential diagnosis of cardiomyopathy in childhood, especially in the cooccurrence of dilated cardiomyopathy and 3-methylglutaconic aciduria.
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Affiliation(s)
- S Mazurová
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Prague, Czech Republic
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30
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Finsterer J, Stöllberger C. Unclassified cardiomyopathies in neuromuscular disorders. Wien Med Wochenschr 2013; 163:505-13. [DOI: 10.1007/s10354-013-0243-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/27/2013] [Indexed: 02/01/2023]
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31
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Abstract
Barth syndrome (BTHS) is an X-linked recessive disorder that is typically characterized by cardiomyopathy (CMP), skeletal myopathy, growth retardation, neutropenia, and increased urinary levels of 3-methylglutaconic acid (3-MGCA). There may be a wide variability of phenotypes amongst BTHS patients with some exhibiting some or all of these findings. BTHS was first described as a disease of the mitochondria resulting in neutropenia as well as skeletal and cardiac myopathies. Over the past few years, a greater understanding of BTHS has developed related to the underlying genetic mechanisms responsible for the disease. Mutations in the TAZ gene on chromosome Xq28, also known as G4.5, are responsible for the BTHS phenotype resulting in a loss-of-function in the protein product tafazzin. Clinical management of BTHS has also seen improvement. Patients with neutropenia are susceptible to life-threatening bacterial infections with sepsis being a significant concern for possible morbidity and mortality. Increasingly, BTHS patients are suffering from heart failure secondary to their CMP. Left ventricular noncompaction (LVNC) and dilated CMP are the most common cardiac phenotypes reported and can lead to symptoms of heart failure as well as ventricular arrhythmias. Expanded treatment options for end-stage myocardial dysfunction now offer an opportunity to change the natural history for these patients. Herein, we will provide a current review of the genetic and molecular basis of BTHS, the clinical features and management of BTHS, and potential future directions for therapeutic strategies.
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Affiliation(s)
- John L Jefferies
- Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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32
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Rigaud C, Lebre AS, Touraine R, Beaupain B, Ottolenghi C, Chabli A, Ansquer H, Ozsahin H, Di Filippo S, De Lonlay P, Borm B, Rivier F, Vaillant MC, Mathieu-Dramard M, Goldenberg A, Viot G, Charron P, Rio M, Bonnet D, Donadieu J. Natural history of Barth syndrome: a national cohort study of 22 patients. Orphanet J Rare Dis 2013; 8:70. [PMID: 23656970 PMCID: PMC3656783 DOI: 10.1186/1750-1172-8-70] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 04/28/2013] [Indexed: 12/16/2022] Open
Abstract
Background This study describes the natural history of Barth syndrome (BTHS). Methods The medical records of all patients with BTHS living in France were identified in multiple sources and reviewed. Results We identified 16 BTHS pedigrees that included 22 patients. TAZ mutations were observed in 15 pedigrees. The estimated incidence of BTHS was 1.5 cases per million births (95%CI: 0.2–2.3). The median age at presentation was 3.1 weeks (range, 0–1.4 years), and the median age at last follow-up was 4.75 years (range, 3–15 years). Eleven patients died at a median age of 5.1 months; 9 deaths were related to cardiomyopathy and 2 to sepsis. The 5-year survival rate was 51%, and no deaths were observed in patients ≥3 years. Fourteen patients presented with cardiomyopathy, and cardiomyopathy was documented in 20 during follow-up. Left ventricular systolic function was very poor during the first year of life and tended to normalize over time. Nineteen patients had neutropenia. Metabolic investigations revealed inconstant moderate 3-methylglutaconic aciduria and plasma arginine levels that were reduced or in the low-normal range. Survival correlated with two prognostic factors: severe neutropenia at diagnosis (<0.5 × 109/L) and birth year. Specifically, the survival rate was 70% for patients born after 2000 and 20% for those born before 2000. Conclusions This survey found that BTHS outcome was affected by cardiac events and by a risk of infection that was related to neutropenia. Modern management of heart failure and prevention of infection in infancy may improve the survival of patients with BTHS without the need for heart transplantation.
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Affiliation(s)
- Charlotte Rigaud
- AP-HP, Registre français des neutropénies chroniques sévères, Centre de référence des déficits Immunitaires Héréditaires, Service d'Hémato-oncologie Pédiatrique Hôpital Trousseau, Paris, France.
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33
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Abstract
PURPOSE OF REVIEW This review highlights recent advances concerning pathogenesis, clinical presentation, diagnosis and treatment of Barth syndrome with particular regard to haematological abnormalities (e.g., neutropenia). RECENT FINDINGS Directed motility and killing activity of neutrophils is normal in patients with Barth syndrome, but neutrophils and eospinophils show phosphatidylserine exposure without exhibiting other markers of apoptosis. Apparently, neutropenia does not result from apoptosis of myeloid precursors or end-stage neutrophils but from reactive oxygen species triggered exposure of phosphatidylserine, leading to increased clearance of neutrophils by tissue macrophages. Lymphoblasts of patients with Barth syndrome show increased variability of mitochondrial size and increased mitochondrial mass due to increased clustering of fragmented mitochondria inside nuclear invaginations. Lymphoblast mitochondria show reduced cristae density, reduced cristae alignment and heterogenous cristae distribution. Areas of adhesion of opposing inner membranes result in obliteration of the inter-cristae space. Short or extended adhesion zones result in sheets of collapsed cristae, which are packaged as multiple concentric layers. In single patients, neutropenia may favourably respond to biweekly injections of granulocyte colony stimulating factor. SUMMARY Neutropenia in Barth syndrome is most likely due to reactive oxygen species induced exposure of phosphatidylserine, leading to increased clearance of neutrophils by tissue macrophages. In single patients, application of granulocyte colony stimulating factor may resolve neutropenia in Barth syndrome.
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Affiliation(s)
| | - Zaza Khuchua
- Division of Molecular and Cardiovascular Biology; Cincinnati Children's Research Foundation; Cincinnati; OH; USA
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35
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Ferri L, Donati MA, Funghini S, Malvagia S, Catarzi S, Lugli L, Ragni L, Bertini E, Vaz FM, Cooper DN, Guerrini R, Morrone A. New clinical and molecular insights on Barth syndrome. Orphanet J Rare Dis 2013; 8:27. [PMID: 23409742 PMCID: PMC3599367 DOI: 10.1186/1750-1172-8-27] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/30/2013] [Indexed: 11/26/2022] Open
Abstract
Background Barth syndrome (BS) is an X-linked infantile-onset cardioskeletal disease characterized by cardiomyopathy, hypotonia, growth delay, neutropenia and 3-methylglutaconic aciduria. It is caused by mutations in the TAZ gene encoding tafazzin, a protein involved in the metabolism of cardiolipin, a mitochondrial-specific phospholipid involved in mitochondrial energy production. Methods Clinical, biochemical and molecular characterization of a group of six male patients suspected of having BS. Three patients presented early with severe metabolic decompensation including respiratory distress, oxygen desaturation and cardiomyopathy and died within the first year of life. The remaining three patients had cardiomyopathy, hypotonia and growth delay and are still alive. Cardiomyopathy was detected during pregnancy through a routine check-up in one patient. All patients exhibited 3-methylglutaconic aciduria and neutropenia, when tested and five of them also had lactic acidosis. Results We confirmed the diagnosis of BS with sequence analysis of the TAZ gene, and found five new mutations, c.641A>G p.His214Arg, c.284dupG (p.Thr96Aspfs*37), c.678_691del14 (p.Tyr227Trpfs*79), g.8009_16445del8437 and g.[9777_9814del38; 9911-?_14402del] and the known nonsense mutation c.367C>T (p.Arg123Term). The two gross rearrangements ablated TAZ exons 6 to 11 and probably originated by non-allelic homologous recombination and by Serial Replication Slippage (SRS), respectively. The identification of the breakpoints boundaries of the gross deletions allowed the direct detection of heterozygosity in carrier females. Conclusions Lactic acidosis associated with 3-methylglutaconic aciduria is highly suggestive of BS, whilst the severity of the metabolic decompensation at disease onset should be considered for prognostic purposes. Mutation analysis of the TAZ gene is necessary for confirming the clinical and biochemical diagnosis in probands in order to identify heterozygous carriers and supporting prenatal diagnosis and genetic counseling.
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Affiliation(s)
- Lorenzo Ferri
- Department of Neurosciences, Psychology, Pharmacology and Child Health, University of Florence and Paediatric Neurology Unit and Laboratories, Meyer Children's Hospital, Viale Pieraccini n, 24, 50139 Florence, Italy
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Clarke SLN, Bowron A, Gonzalez IL, Groves SJ, Newbury-Ecob R, Clayton N, Martin RP, Tsai-Goodman B, Garratt V, Ashworth M, Bowen VM, McCurdy KR, Damin MK, Spencer CT, Toth MJ, Kelley RI, Steward CG. Barth syndrome. Orphanet J Rare Dis 2013; 8:23. [PMID: 23398819 PMCID: PMC3583704 DOI: 10.1186/1750-1172-8-23] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/05/2013] [Indexed: 02/07/2023] Open
Abstract
First described in 1983, Barth syndrome (BTHS) is widely regarded as a rare X-linked genetic disease characterised by cardiomyopathy (CM), skeletal myopathy, growth delay, neutropenia and increased urinary excretion of 3-methylglutaconic acid (3-MGCA). Fewer than 200 living males are known worldwide, but evidence is accumulating that the disorder is substantially under-diagnosed. Clinical features include variable combinations of the following wide spectrum: dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), endocardial fibroelastosis (EFE), left ventricular non-compaction (LVNC), ventricular arrhythmia, sudden cardiac death, prolonged QTc interval, delayed motor milestones, proximal myopathy, lethargy and fatigue, neutropenia (absent to severe; persistent, intermittent or perfectly cyclical), compensatory monocytosis, recurrent bacterial infection, hypoglycaemia, lactic acidosis, growth and pubertal delay, feeding problems, failure to thrive, episodic diarrhoea, characteristic facies, and X-linked family history. Historically regarded as a cardiac disease, BTHS is now considered a multi-system disorder which may be first seen by many different specialists or generalists. Phenotypic breadth and variability present a major challenge to the diagnostician: some children with BTHS have never been neutropenic, whereas others lack increased 3-MGCA and a minority has occult or absent CM. Furthermore, BTHS was first described in 2010 as an unrecognised cause of fetal death. Disabling mutations or deletions of the tafazzin (TAZ) gene, located at Xq28, cause the disorder by reducing remodeling of cardiolipin, a principal phospholipid of the inner mitochondrial membrane. A definitive biochemical test, based on detecting abnormal ratios of different cardiolipin species, was first described in 2008. Key areas of differential diagnosis include metabolic and viral cardiomyopathies, mitochondrial diseases, and many causes of neutropenia and recurrent male miscarriage and stillbirth. Cardiolipin testing and TAZ sequencing now provide relatively rapid diagnostic testing, both prospectively and retrospectively, from a range of fresh or stored tissues, blood or neonatal bloodspots. TAZ sequencing also allows female carrier detection and antenatal screening. Management of BTHS includes medical therapy of CM, cardiac transplantation (in 14% of patients), antibiotic prophylaxis and granulocyte colony-stimulating factor (G-CSF) therapy. Multidisciplinary teams/clinics are essential for minimising hospital attendances and allowing many more individuals with BTHS to live into adulthood.
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Affiliation(s)
- Sarah L N Clarke
- NHS Specialised Services Barth Syndrome Service, Royal Hospital for Children, Upper Maudlin St, Bristol, BS2 8BJ, UK.
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