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Horga A, Woodward CE, Mills A, Pareés I, Hargreaves IP, Brown RM, Bugiardini E, Brooks T, Manole A, Remzova E, Rahman S, Reilly MM, Houlden H, Sweeney MG, Brown GK, Polke JM, Gago F, Parton MJ, Pitceathly RDS, Hanna MG. Differential phenotypic expression of a novel PDHA1 mutation in a female monozygotic twin pair. Hum Genet 2019; 138:1313-22. [PMID: 31673819 DOI: 10.1007/s00439-019-02075-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/18/2019] [Indexed: 01/27/2023]
Abstract
Pyruvate dehydrogenase complex (PDC) deficiency caused by mutations in the X-linked PDHA1 gene has a broad clinical presentation, and the pattern of X-chromosome inactivation has been proposed as a major factor contributing to its variable expressivity in heterozygous females. Here, we report the first set of monozygotic twin females with PDC deficiency, caused by a novel, de novo heterozygous missense mutation in exon 11 of PDHA1 (NM_000284.3: c.1100A>T). Both twins presented in infancy with a similar clinical phenotype including developmental delay, episodes of hypotonia or encephalopathy, epilepsy, and slowly progressive motor impairment due to pyramidal, extrapyramidal, and cerebellar involvement. However, they exhibited clear differences in disease severity that correlated well with residual PDC activities (approximately 60% and 20% of mean control values, respectively) and levels of immunoreactive E1α subunit in cultured skin fibroblasts. To address whether the observed clinical and biochemical differences could be explained by the pattern of X-chromosome inactivation, we undertook an androgen receptor assay in peripheral blood. In the less severely affected twin, a significant bias in the relative activity of the two X chromosomes with a ratio of approximately 75:25 was detected, while the ratio was close to 50:50 in the other twin. Although it may be difficult to extrapolate these results to other tissues, our observation provides further support to the hypothesis that the pattern of X-chromosome inactivation may influence the phenotypic expression of the same mutation in heterozygous females and broadens the clinical and genetic spectrum of PDC deficiency.
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Golias T, Kery M, Radenkovic S, Papandreou I. Microenvironmental control of glucose metabolism in tumors by regulation of pyruvate dehydrogenase. Int J Cancer 2018; 144:674-686. [PMID: 30121950 DOI: 10.1002/ijc.31812] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [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: 02/27/2018] [Revised: 07/13/2018] [Accepted: 08/06/2018] [Indexed: 12/13/2022]
Abstract
During malignant progression cancer cells undergo a series of changes, which promote their survival, invasiveness and metastatic process. One of them is a change in glucose metabolism. Unlike normal cells, which mostly rely on the tricarboxylic acid cycle (TCA), many cancer types rely on glycolysis. Pyruvate dehydrogenase complex (PDC) is the gatekeeper enzyme between these two pathways and is responsible for converting pyruvate to acetyl-CoA, which can then be processed further in the TCA cycle. Its activity is regulated by PDP (pyruvate dehydrogenase phosphatases) and PDHK (pyruvate dehydrogenase kinases). Pyruvate dehydrogenase kinase exists in 4 tissue specific isoforms (PDHK1-4), the activities of which are regulated by different factors, including hormones, hypoxia and nutrients. PDHK1 and PDHK3 are active in the hypoxic tumor microenvironment and inhibit PDC, resulting in a decrease of mitochondrial function and activation of the glycolytic pathway. High PDHK1/3 expression is associated with worse prognosis in patients, which makes them a promising target for cancer therapy. However, a better understanding of PDC's enzymatic regulation in vivo and of the mechanisms of PDHK-mediated malignant progression is necessary for the design of better PDHK inhibitors and the selection of patients most likely to benefit from such inhibitors.
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Affiliation(s)
- Tereza Golias
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Martin Kery
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Silvia Radenkovic
- Institute of Virology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Ioanna Papandreou
- Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and Wexner Medical Center, Columbus, OH
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Qin L, Wang J, Tian X, Yu H, Truong C, Mitchell JJ, Wierenga KJ, Craigen WJ, Zhang VW, Wong LJC. Detection and Quantification of Mosaic Mutations in Disease Genes by Next-Generation Sequencing. J Mol Diagn 2016; 18:446-453. [PMID: 26944031 DOI: 10.1016/j.jmoldx.2016.01.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 01/08/2016] [Accepted: 01/14/2016] [Indexed: 12/19/2022] Open
Abstract
The identification of mosaicism is important in establishing a disease diagnosis, assessing recurrence risk, and genetic counseling. Next-generation sequencing (NGS) with deep sequence coverage enhances sensitivity and allows for accurate quantification of the level of mosaicism. NGS identifies low-level mosaicism that would be undetectable by conventional Sanger sequencing. A customized DNA probe library was used for capturing targeted genes, followed by deep NGS analysis. The mean coverage depth per base was approximately 800×. The NGS sequence data were analyzed for single-nucleotide variants and copy number variations. Mosaic mutations in 10 cases/families were detected and confirmed by NGS analysis. Mosaicism was identified for autosomal dominant (JAG1, COL3A1), autosomal recessive (PYGM), and X-linked (PHKA2, PDHA1, OTC, and SLC6A8) disorders. The mosaicism was identified either in one or more tissues from the probands or in a parent of an affected child. When analyzing data from patients with unusual testing results or inheritance patterns, it is important to further evaluate the possibility of mosaicism. Deep NGS analysis not only provides insights into the spectrum of mosaic mutations but also underlines the importance of the detection of mosaicism as an integral part of clinical molecular diagnosis and genetic counseling.
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Affiliation(s)
- Lan Qin
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | - Jing Wang
- Baylor Miraca Genetics Laboratories, Houston, Texas; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Xia Tian
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | - Hui Yu
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | | | - John J Mitchell
- Division of Pediatric Endocrinology, Montreal Children's Hospital, Montreal, Quebec, Canada
| | - Klaas J Wierenga
- Department of Pediatrics, Section of Genetics, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Victor Wei Zhang
- Baylor Miraca Genetics Laboratories, Houston, Texas; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Lee-Jun C Wong
- Baylor Miraca Genetics Laboratories, Houston, Texas; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.
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Deeb KK, Bedoyan JK, Wang R, Sremba L, Schroeder MC, Grahame GJ, Boyer M, McCandless SE, Kerr DS, Zhang S. Somatic mosaicism for a novel PDHA1 mutation in a male with severe pyruvate dehydrogenase complex deficiency. Mol Genet Metab Rep 2014; 1:362-367. [PMID: 27896109 PMCID: PMC5121365 DOI: 10.1016/j.ymgmr.2014.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [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: 06/18/2014] [Revised: 08/01/2014] [Accepted: 08/02/2014] [Indexed: 11/19/2022] Open
Abstract
Pyruvate dehydrogenase complex (PDC) deficiencies are mostly due to mutations in the X-linked PDHA1 gene. Males with hemizygous PDHA1 mutations are clinically more severely affected, while those with mosaic PDHA1 mutations may manifest milder phenotypes. We report a patient harboring a novel, mosaic missense PDHA1 mutation, c.523G > A (p.A175T), with a severe clinical presentation of congenital microcephaly, significant brain abnormalities, persistent seizures, profound developmental delay, and failure to thrive. We review published cases of PDHA1 mosaicism.
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Affiliation(s)
- Kristin K. Deeb
- Center for Human Genetics Laboratory University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Jirair K. Bedoyan
- Center for Inherited Disorders of Energy Metabolism (CIDEM), University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Raymond Wang
- Division of Metabolic Disorders, CHOC Children's Hospital, Orange, CA, USA
| | - Leighann Sremba
- Division of Metabolic Disorders, CHOC Children's Hospital, Orange, CA, USA
| | - Molly C. Schroeder
- Center for Human Genetics Laboratory University Hospitals Case Medical Center, Cleveland, OH, USA
| | - George J. Grahame
- Center for Inherited Disorders of Energy Metabolism (CIDEM), University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Monica Boyer
- Division of Metabolic Disorders, CHOC Children's Hospital, Orange, CA, USA
| | - Shawn E. McCandless
- Center for Inherited Disorders of Energy Metabolism (CIDEM), University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Douglas S. Kerr
- Center for Inherited Disorders of Energy Metabolism (CIDEM), University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Shulin Zhang
- Center for Human Genetics Laboratory University Hospitals Case Medical Center, Cleveland, OH, USA
- Corresponding author at: Molecular Genetics Laboratory, Center for Human Genetics Laboratory, University Hospitals Case Medical Center, Department of Pathology, Case Western Reserve University, W.O. Walker Building, 6th floor, 10524 Euclid Avenue, Cleveland, OH 44106. Fax: + 1 216 9831144.
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Patel KP, O’Brien TW, Subramony SH, Shuster J, Stacpoole PW. The spectrum of pyruvate dehydrogenase complex deficiency: clinical, biochemical and genetic features in 371 patients. Mol Genet Metab 2012; 106:385-94. [PMID: 22896851 PMCID: PMC4003492 DOI: 10.1016/j.ymgme.2012.03.017] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [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] [Indexed: 01/01/2023]
Abstract
CONTEXT Pyruvate dehydrogenase complex (PDC) deficiency is a genetic mitochondrial disorder commonly associated with lactic acidosis, progressive neurological and neuromuscular degeneration and, usually, death during childhood. There has been no recent comprehensive analysis of the natural history and clinical course of this disease. OBJECTIVE We reviewed 371 cases of PDC deficiency, published between 1970 and 2010, that involved defects in subunits E1α and E1β and components E1, E2, E3 and the E3 binding protein of the complex. DATA SOURCES AND EXTRACTION English language peer-reviewed publications were identified, primarily by using PubMed and Google Scholar search engines. RESULTS Neurodevelopmental delay and hypotonia were the commonest clinical signs of PDC deficiency. Structural brain abnormalities frequently included ventriculomegaly, dysgenesis of the corpus callosum and neuroimaging findings typical of Leigh syndrome. Neither gender nor any clinical or neuroimaging feature differentiated the various biochemical etiologies of the disease. Patients who died were younger, presented clinically earlier and had higher blood lactate levels and lower residual enzyme activities than subjects who were still alive at the time of reporting. Survival bore no relationship to the underlying biochemical or genetic abnormality or to gender. CONCLUSIONS Although the clinical spectrum of PDC deficiency is broad, the dominant clinical phenotype includes presentation during the first year of life; neurological and neuromuscular degeneration; structural lesions revealed by neuroimaging; lactic acidosis and a blood lactate:pyruvate ratio ≤ 20.
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Affiliation(s)
- Kavi P. Patel
- Department of Medicine (Division of Endocrinology, Metabolism and
Diabetes), College of Medicine, University of Florida, Gainesville, FL 32611,
USA
| | - Thomas W. O’Brien
- Department of Biochemistry and Molecular Biology, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
| | | | - Jonathan Shuster
- Department of Epidemiology and Health Policy Research, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Peter W. Stacpoole
- Department of Medicine (Division of Endocrinology, Metabolism and
Diabetes), College of Medicine, University of Florida, Gainesville, FL 32611,
USA
- Department of Biochemistry and Molecular Biology, College of
Medicine, University of Florida, Gainesville, FL 32611, USA
- Corresponding author at: UF College of Medicine, 1600 SW
Archer Road M2-238, P.O. Box 100226, Gainesville, FL 32610, USA. Fax: +1
352 273 9013. (P.W. Stacpoole)
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Patel KP, O'Brien TW, Subramony SH, Shuster J, Stacpoole PW. The spectrum of pyruvate dehydrogenase complex deficiency: clinical, biochemical and genetic features in 371 patients. Mol Genet Metab 2012; 105:34-43. [PMID: 22079328 PMCID: PMC3754811 DOI: 10.1016/j.ymgme.2011.09.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [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: 09/02/2011] [Revised: 09/27/2011] [Accepted: 09/27/2011] [Indexed: 01/01/2023]
Abstract
CONTEXT Pyruvate dehydrogenase complex (PDC) deficiency is a genetic mitochondrial disorder commonly associated with lactic acidosis, progressive neurological and neuromuscular degeneration and, usually, death during childhood. There has been no recent comprehensive analysis of the natural history and clinical course of this disease. OBJECTIVE We reviewed 371 cases of PDC deficiency, published between 1970 and 2010, that involved defects in subunits E1α and E1β and components E1, E2, E3 and the E3 binding protein of the complex. DATA SOURCES AND EXTRACTION English language peer-reviewed publications were identified, primarily by using PubMed and Google Scholar search engines. RESULTS Neurodevelopmental delay and hypotonia were the commonest clinical signs of PDC deficiency. Structural brain abnormalities frequently included ventriculomegaly, dysgenesis of the corpus callosum and neuroimaging findings typical of Leigh syndrome. Neither gender nor any clinical or neuroimaging feature differentiated the various biochemical etiologies of the disease. Patients who died were younger, presented clinically earlier and had higher blood lactate levels and lower residual enzyme activities than subjects who were still alive at the time of reporting. Survival bore no relationship to the underlying biochemical or genetic abnormality or to gender. CONCLUSIONS Although the clinical spectrum of PDC deficiency is broad, the dominant clinical phenotype includes presentation during the first year of life; neurological and neuromuscular degeneration; structural lesions revealed by neuroimaging; lactic acidosis and a blood lactate:pyruvate ratio ≤20.
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Affiliation(s)
- Kavi P. Patel
- Department of Medicine (Division of Endocrinology and Metabolism), College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Thomas W. O'Brien
- Department of Biochemistry and Molecular Biology College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | | | - Jonathan Shuster
- Epidemiology and Health Policy Research College of Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Peter W. Stacpoole
- Department of Medicine (Division of Endocrinology and Metabolism), College of Medicine, University of Florida, Gainesville, FL, 32611, USA
- Department of Biochemistry and Molecular Biology College of Medicine, University of Florida, Gainesville, FL, 32611, USA
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Imbard A, Boutron A, Vequaud C, Zater M, de Lonlay P, de Baulny HO, Barnerias C, Miné M, Marsac C, Saudubray JM, Brivet M. Molecular characterization of 82 patients with pyruvate dehydrogenase complex deficiency. Structural implications of novel amino acid substitutions in E1 protein. Mol Genet Metab 2011; 104:507-16. [PMID: 21914562 DOI: 10.1016/j.ymgme.2011.08.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [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: 07/09/2011] [Revised: 08/10/2011] [Accepted: 08/10/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Pyruvate dehydrogenase complex (PDHc) deficiencies are an important cause of primary lactic acidosis. Most cases result from mutations in the X-linked gene for the pyruvate dehydrogenase E1α subunit (PDHA1) while a few cases result from mutations in genes for E1β (PDHB), E2 (DLAT), E3 (DLD) and E3BP (PDHX) subunits or PDH-phosphatase (PDP1). AIM To report molecular characterization of 82 PDHc-deficient patients and analyze structural effects of novel missense mutations in PDHA1. METHODS PDHA1 variations were investigated first, by exon sequencing using a long range PCR product, gene dosage assay and cDNA analysis. Mutation scanning in PDHX, PDHB, DLAT and DLD cDNAs was further performed in unsolved cases. Novel missense mutations in PDHA1 were located on the tridimensional model of human E1 protein to predict their possible functional consequences. RESULTS PDHA1 mutations were found in 30 girls and 35 boys. Three large rearrangements, including two contiguous gene deletion syndrome were identified. Novel missense, frameshift and splicing mutations were also delineated and a nonsense mutation in a mosaic male. Mutations p.Glu75Ala, p.Arg88Ser, p.Arg119Trp, p.Gly144Asp, p.Pro217Arg, p.Arg235Gly, p.Tyr243Cys, p.Tyr243Ser, p.Arg245Gly, p.Pro250Leu, p.Gly278Arg, p.Met282Val, p.Gly298Glu in PDHA1 were predicted to impair active site channel conformation or subunit interactions. Six out of the seven patients with PDHB mutations displayed the recurrent p.Met101Val mutation; 9 patients harbored PDHX mutations and one patient DLD mutations. CONCLUSION We provide an efficient stepwise strategy for mutation screening in PDHc genes and expand the growing list of PDHA1 mutations analyzed at the structural level.
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Affiliation(s)
- A Imbard
- Biochimie-Hôpital de Bicêtre, Hôpitaux Universitaires Paris-Sud, AP-HP, Paris, France
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