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Bachmann-Gagescu R, Merritt JL, Hahn SH. A cognitively normal PDH-deficient 18-year-old man carrying the R263G mutation in the PDHA1 gene. J Inherit Metab Dis 2009; 32 Suppl 1. [PMID: 19639391 DOI: 10.1007/s10545-009-1101-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 06/04/2009] [Accepted: 06/12/2009] [Indexed: 10/20/2022]
Abstract
Pyruvate dehydrogenase (PDH) is a crucial multienzyme system linking glycolysis to the tricarboxylic acid cycle by catalysing the decarboxylation of pyruvate to acetyl-CoA. Deficiency in pyruvate dehydrogenase is most commonly secondary to mutations in the X-linked PDHA1 gene encoding the E1 alpha subunit. There is a wide range of clinical presentations from severe neonatal lactic acidosis to chronic encephalopathy (Leigh syndrome). In recent years, a small subset of patients was recognized with less severe involvement, presenting initially only with intermittent symptoms, mainly of ataxia. Most of these patients remain stable for a number of years before developing progressive neurological deterioration around puberty at the latest. There does not appear to be a reliable correlation between genotype, phenotype, or enzyme activity. This makes counselling in a clinical setting challenging. We report a case with a previously known common mutation in PDHA1 (R263G) with an excellent outcome at 18 years of age. Previous patients with this mutation have presented with mental retardation and/or Leigh syndrome, while our patient's clinical outcome is exceptional. He is cognitively normal and has normal brain MRI. His management includes a stringent carbohydrate-free diet, as well as supplementation with thiamine, carnitine and vitamin E. This case further broadens the clinical spectrum, including now an example of a cognitively normal adult with PDH deficiency.
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Affiliation(s)
- R Bachmann-Gagescu
- Division of Medical Genetics, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Han Z, Berendzen K, Zhong L, Surolia I, Chouthai N, Zhao W, Maina N, Srivastava A, Stacpoole PW. A combined therapeutic approach for pyruvate dehydrogenase deficiency using self-complementary adeno-associated virus serotype-specific vectors and dichloroacetate. Mol Genet Metab 2008; 93:381-7. [PMID: 18206410 PMCID: PMC2583368 DOI: 10.1016/j.ymgme.2007.10.131] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [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] [Received: 09/07/2007] [Revised: 10/18/2007] [Accepted: 10/18/2007] [Indexed: 11/20/2022]
Abstract
We determined the ability of self-complementary adeno-associated virus (scAAV) vectors to deliver and express the pyruvate dehydrogenase E1alpha subunit gene (PDHA1) in primary cultures of skin fibroblasts from 3 patients with defined mutations in PHDA1 and 3 healthy subjects. Cells were transduced with scAAV vectors containing the cytomegalovirus promoter-driven enhanced green fluorescent protein (EGFP) reporter gene at a vector:cell ratio of 200. Transgene expression was measured 72h later. The transduction efficiency of scAAV2 and scAAV6 vectors was 3- to 5-fold higher than that of the other serotypes, which were subsequently used to transduce fibroblasts with wild-type PDHA1 cDNA under the control of the chicken beta-action (CBA) promoter at a vector:cell ratio of 1000. Total PDH-specific activity and E1alpha protein expression were determined 10 days post-transduction. Both vectors increased E1alpha expression 40-60% in both control and patient cells, and increased PDH activity in two patient cell lines. We also used dichloroacetate (DCA) to maximally activate PDH through dephosphorylation of E1alpha. Exposure for 24h to 5mM DCA increased PDH activity in non-transduced control (mean 37% increase) and PDH deficient (mean 44% increase) cells. Exposure of transduced patient fibroblasts to DCA increased PDH activity up to 90% of the activity measured in untreated control cells. DCA also increased expression of E1alpha protein and, to variable extents, that of other components of the PDH complex in both non-transduced and transduced cells. These data suggest that a combined gene delivery and pharmacological approach may hold promise for the treatment of PDH deficiency.
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Affiliation(s)
- Zongchao Han
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
| | - Kristen Berendzen
- Department of Medicine, Division of Endocrinology and Metabolism, PO Box 100226, University of Florida College of Medicine, Gainesville, FL 32610-0226, USA
| | - Li Zhong
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
| | - Ira Surolia
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
| | - Nitin Chouthai
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
| | - Weihong Zhao
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Nephrology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China
| | - Njeri Maina
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Arun Srivastava
- Department of Pediatrics, Division of Cellular and Molecular Therapy, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Molecular Genetics & Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
- Powell Gene Therapy Center, University of Florida College of Medicine, Gainesville, FL, USA
- General Clinical Research Center, University of Florida College of Medicine, Gainesville, FL, USA
| | - Peter W Stacpoole
- Department of Medicine, Division of Endocrinology and Metabolism, PO Box 100226, University of Florida College of Medicine, Gainesville, FL 32610-0226, USA
- Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, USA
- General Clinical Research Center, University of Florida College of Medicine, Gainesville, FL, USA
- Corresponding author. Address: Department of Medicine, Division of Endocrinology and Metabolism, PO Box 100226, University of Florida College of Medicine, Gainesville, FL32610-0226, USA. Fax:+1 352 392 4529. E-mail address: (P.W. Stacpoole)
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Head RA, Brown RM, Zolkipli Z, Shahdadpuri R, King MD, Clayton PT, Brown GK. Clinical and genetic spectrum of pyruvate dehydrogenase deficiency: Dihydrolipoamide acetyltransferase (E2) deficiency. Ann Neurol 2005; 58:234-41. [PMID: 16049940 DOI: 10.1002/ana.20550] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Pyruvate dehydrogenase deficiency is a major cause of primary lactic acidosis and neurological dysfunction in infancy and early childhood. Most cases are caused by mutations in the X-linked gene for the E1alpha subunit of the complex. Mutations in DLAT, the gene encoding dihydrolipoamide acetyltransferase, the E2 core component of the complex, have not been described previously. We report two unrelated patients with pyruvate dehydrogenase deficiency caused by defects in the E2 subunit. Both patients are less severely affected than typical patients with E1alpha mutations and both have survived well into childhood. Episodic dystonia was the major neurological manifestation, with other more common features of pyruvate dehydrogenase deficiency, such as hypotonia and ataxia, being less prominent. The patients had neuroradiological evidence of discrete lesions restricted to the globus pallidus, and both are homozygous for different mutations in the DLAT gene. The clinical presentation and neuroradiological findings are not typical of pyruvate dehydrogenase deficiency and extend the clinical and mutational spectrum of this condition.
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Affiliation(s)
- Rosemary A Head
- Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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Abstract
Here we review the rationale for considering the pyruvate dehydrogenase multienzyme complex (PDC) as a target for gene therapy for defects in mitochondrial energetics. PDC is entirely nuclear encoded and is situated in the mitochondrial inner membrane. The complex catalyzes the rate-determining step in aerobic carbohydrate metabolism and plays a critical role in the efficient conversion of substrate fuel into energy by cells. PDC activity is regulated in large part by reversible phosphorylation (inactivation) of its E1alpha subunit. Congenital defects in PDC are usually due to mutations in E1alpha and are typified by lactic acidosis, neurodegeneration and early death. Acquired deficiency in PDC has been implicated in the etiopathology of several other metabolic or neurodegenerative disorders. Recently, a vector using recombinant adeno-associated virus (rAAV) that contained a fusion protein of full-length E1alpha and the reporter gene green fluorescent protein was used to deliver wild type E1alpha into mitochondria after injection of the construct in vivo into the central nervous system of rats and in vitro into human cells. Transduction of cultured fibroblasts from a male patient with E1alpha deficiency led to partial restoration of PDC activity, as determined by decarboxylation of 14C-pyruvate. These data indicate that at least partial correction of PDC defects may be feasible by gene transfer. Furthermore, the combination of AAV-mediated delivery of E1alpha with pharmacologic activation (dephosphorylation) of the wild type enzyme subunit may provide an optimal therapeutic strategy for patients with acquired or congenital deficiencies in mitochondrial energy metabolism.
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Affiliation(s)
- Peter W Stacpoole
- Department of Medicine, Division of Endocrinology and Metabolism, University of Florida, College of Medicine, Gainesville, FL 32610, USA.
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Easley RB, Johnson TR, Tobias JD. Continuous pH monitoring using the Paratrend 7 inserted into a peripheral vein in a patient with shock and congenital lactic acidosis. Clin Pediatr (Phila) 2002; 41:351-5. [PMID: 12086201 DOI: 10.1177/000992280204100508] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The authors present a 25-year-old woman who was admitted to the ICU for treatment of shock, respiratory failure, and acidosis related to congenital lactic acidosis from pyruvate dehydrogenase deficiency. To aid in ongoing management of the metabolic acidosis, the Paratrend blood gas monitoring sensor was inserted through a peripheral venous site to provide a continuous measurement of pH and partial pressure of carbon dioxide (Pco2). With the venous insertion of the Paratrend, a clinically useful correlation with arterial blood gas values was noted. Linear regression analysis of the pH values from the venous blood gas analyses and the Paratrend monitor revealed r2 = 0.71 with p = 0.001 and r2 = 0.78 with a p = 0.0003 for the Pco2 values. Our preliminary experience suggests that venous placement of the Paratrend monitor can be used to provide clinically useful, continuous measurement of pH and Pco2.
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Affiliation(s)
- R Blaine Easley
- Department of Child Health and Anesthesiology, The University of Missouri, Columbia 65212, USA
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Abstract
Congenital lactic acidoses form a heterogeneous group of disorders: this paper considers primarily defects of the pyruvate dehydrogenase complex and the respiratory chain. Attempts to treat these disorders are hampered by uncertainty concerning the pathophysiology and by the central role of the enzymes in cellular metabolism. Few strategies are of proven efficacy, though many have been tried, including dietary manipulation, enhancement of residual enzyme activity, artificial electron acceptors and free-radical scavengers. Evaluation of treatment is complicated by the rarity, heterogeneity and unpredictable course of the diseases. Double-blind placebo-controlled trials are needed.
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Affiliation(s)
- A A Morris
- Metabolic Unit, London Centre for Paediatric Endocrinology and Metabolism, UK
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Harada M, Tanouchi M, Arai K, Nishitani H, Miyoshi H, Hashimoto T. Therapeutic efficacy of a case of pyruvate dehydrogenase complex deficiency monitored by localized proton magnetic resonance spectroscopy. Magn Reson Imaging 1996; 14:129-33. [PMID: 8656986 DOI: 10.1016/0730-725x(95)02047-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We experienced a case of pyruvate dehydrogenase deficiency observed by proton magnetic resonance spectroscopy (1H MRS). This case was diagnosed as West syndrome by characteristic convulsion and the periodic hypsarrhythmia pattern of EEG. At the age of 11 months, the first examination of 1H MRS revealed a high peak of lactate, and the high concentration of lactate and pyruvate was confirmed in sampled cerebrospinal fluid (CSF). Deficiency of pyruvate dehydrogenase complex was finally diagnosed by genetic examination. Dichloroacetate was administered to the patient as therapy. Decrease of lactate in the brain was found by 1H MRS. Lactate and pyruvate in the CSF was also decreased. In accordance with the suspension of dichloroacetate, increase of lactate in the brain was detected and the convulsions reappeared. After readministration of dichloroacetate, the patient was almost symptom free and lactate in the brain and CSF had decreased to the normal extent. We considered that 1H MRS provides useful information for screening metabolic disorders of infants and assessing the efficacy of therapy.
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Affiliation(s)
- M Harada
- Department of Radiology, School of Medicine, University of Tokushima Kuramoto-cho, Japan
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