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Tsai NC, Liou CW, Cheng YH, Lien HT, Lin TL, Lin TK, Lan MY, Hung PL, Wang TJ, Lee CH, Liang YC, Lan KC. The establishment of a molecular diagnostic platform for mitochondrial diseases: from conventional to next-generation sequencing. Biomed J 2024:100770. [PMID: 39048080 DOI: 10.1016/j.bj.2024.100770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 06/14/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND The aim of this study was to create a molecular diagnostic platform and establish a diagnostic pipeline for patients highly suspected of mitochondrial disorders. The effectiveness of three methods, namely, traditional restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR), Sanger sequencing for hotspot detection and whole mitochondrial DNA (mtDNA), and third-generation (Nanopore) whole mtDNA sequencing, will be compared in diagnosing patients with suspected primary mitochondrial diseases (PMDs). The strengths and limitations of different methods are also discussed. MATERIAL AND METHODS A single-center prospective cohort study was conducted to validate the diagnostic pipeline for suspected mitochondrial diseases. In the first stage, a PCR-based method with five sets of primers was used to screen for eight hotspots (m.3243A>G, m.3460G>A, m.8344A>G, m.8993T>G, m.9185T>C, m.11778G>A, m.13513G>A, and m.4977deletion) using either RFLP or direct Sanger sequencing. Sanger sequencing was also used to confirm the RFLP-positive samples. In the second stage, for samples with negative screening results for the eight hotspots, mitochondrial whole-genome sequencing was performed using Sanger sequencing or third-generation nanopore sequencing. RESULTS Between June 2020 and May 2023, 30 patients from ages 0 to 63 with clinically suspected mitochondrial disease were enrolled. The positive yield for the diagnosis of PMDs was 8/30=26.7%, and the sensitivity of the heteroplasmy level for the RFLP-based method was approximately 5%. The remaining 22 patients who tested negative at the first stage were tested using Sanger sequencing or the third-generation sequencing Nanopore, and all tested negative for pathological mtDNA mutations. Compared to the Sanger sequencing method, the results of RFLP-PCR were compromised by the limitations of incomplete RFLP enzyme digestion. For whole-genome sequencing of mtDNA, Sanger sequencing, instead of nanopore sequencing, is preferred at our institution because of its cost-effectiveness. CONCLUSIONS In our highly selective cohort, most tested positive in the first stage of the 8 hot spots screen. Sanger sequencing is a conventional and accurate method for mitochondrial disease screening, at least for the most common hot spots in the region. The results revealed that Sanger sequencing is an accurate method with the benefit of being more cost-effective. This integral platform of molecular diagnosis bears the advantages of being relatively low cost and having a shorter reporting time, facilitating crucial identification of patients with clinical evidence of such disorders. This diagnostic flowchart has also been translated into routine clinical use in the tertiary hospital.
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Affiliation(s)
- Ni-Chin Tsai
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan; Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Chai-Wai Liou
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yin-Hua Cheng
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Hao-Ting Lien
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tzu-Ling Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital
| | - Tsu-Kung Lin
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Min-Yu Lan
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Pi-Lien Hung
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Tzu-Jou Wang
- Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chen-Hao Lee
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Yi-Chih Liang
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Kuo-Chung Lan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung, 80708, Taiwan; Center for Mitochondrial Research and Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan; Department of Obstetrics and Gynecology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Menopause and Reproductive Medicine Research, Kaohsiung Chang Gung Memorial Hospital; Department of Obstetrics and Gynecology, Jen-Ai Hospital, Taichung 412, Taiwan.
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Auditory and Vestibular Dysfunction in M.3243A>G Carriers. Otol Neurotol 2019; 40:1260. [PMID: 31469803 DOI: 10.1097/mao.0000000000002411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mitochondrial Transfer of Wharton's Jelly Mesenchymal Stem Cells Eliminates Mutation Burden and Rescues Mitochondrial Bioenergetics in Rotenone-Stressed MELAS Fibroblasts. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:9537504. [PMID: 31249652 PMCID: PMC6556302 DOI: 10.1155/2019/9537504] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/03/2019] [Indexed: 12/28/2022]
Abstract
Wharton's jelly mesenchymal stem cells (WJMSCs) transfer healthy mitochondria to cells harboring a mitochondrial DNA (mtDNA) defect. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the major subgroups of mitochondrial diseases, caused by the mt.3243A>G point mutation in the mitochondrial tRNALeu(UUR) gene. The specific aim of the study is to investigate whether WJMSCs exert therapeutic effect for mitochondrial dysfunction in cells of MELAS patient through donating healthy mitochondria. We herein demonstrate that WJMSCs transfer healthy mitochondria into rotenone-stressed fibroblasts of a MELAS patient, thereby eliminating mutation burden and rescuing mitochondrial functions. In the coculture system in vitro study, WJMSCs transferred healthy mitochondria to rotenone-stressed MELAS fibroblasts. By inhibiting actin polymerization to block tunneling nanotubes (TNTs), the WJMSC-conducted mitochondrial transfer was abrogated. After mitochondrial transfer, the mt.3243A>G mutation burden of MELAS fibroblasts was reduced to an undetectable level, with long-term retention. Sequencing results confirmed that the transferred mitochondria were donated from WJMSCs. Furthermore, mitochondrial transfer of WJMSCs to MELAS fibroblasts improves mitochondrial functions and cellular performance, including protein translation of respiratory complexes, ROS overexpression, mitochondrial membrane potential, mitochondrial morphology and bioenergetics, cell proliferation, mitochondrion-dependent viability, and apoptotic resistance. This study demonstrates that WJMSCs exert bioenergetic therapeutic effects through mitochondrial transfer. This finding paves the way for the development of innovative treatments for MELAS and other mitochondrial diseases.
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Heteroplasmy Detection of Mitochondrial DNA A3243G Mutation Using Quantitative Real-Time PCR Assay Based on TaqMan-MGB Probes. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1286480. [PMID: 30539000 PMCID: PMC6260548 DOI: 10.1155/2018/1286480] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/16/2018] [Accepted: 09/18/2018] [Indexed: 12/22/2022]
Abstract
A point mutation of mitochondrial DNA (mtDNA) at nucleotide position 3243 A to G (mt.3243A>G) is involved in many common diseases, including maternally inherited diabetes and deafness (MIDD) and mitochondrial encephalomyopathy, lactic acidosis with stroke-like episodes (MELAS). However, the mutant level of mt.3243A>G varies both among individuals and in different organs, tissues, and even cells of single individuals. For detection of this mutation, current methods have limited universality and sensitivity and may be not adequate for a routine clinical test. Here, we develop and evaluate a rapid TaqMan-MGB quantitative real-time PCR (qPCR) method for detecting and quantifying the heteroplasmy level of mt.3243A>G in single-tube analysis. With our method, the sensitivity of detection was as low as 0.1%, but the accuracy of quantification was reliable, down to 4%. All positives could be correctly identified, and the heteroplasmy levels determined by qPCR correlated well with the results from restriction fragment length polymorphism (RFLP) and pyrosequencing assays (r = 0.921~0.973 and 0.972~0.984). In addition, we demonstrated that the urinary sediments, leukocytes, or hair follicles might be ideal templates to detect and quantify the heteroplasmy of mt.3243A>G mutation; however, they should be optimized or retreated for further accurate quantification. Our study should allow rapid and high throughput diagnostic testing and can potentially be used to clarify the association between clinical phenotype and pathogenic mitochondrial mutations derived from various tissues.
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Wilson IJ, Carling PJ, Alston CL, Floros VI, Pyle A, Hudson G, Sallevelt SCEH, Lamperti C, Carelli V, Bindoff LA, Samuels DC, Wonnapinij P, Zeviani M, Taylor RW, Smeets HJM, Horvath R, Chinnery PF. Mitochondrial DNA sequence characteristics modulate the size of the genetic bottleneck. Hum Mol Genet 2016; 25:1031-41. [PMID: 26740552 PMCID: PMC4754047 DOI: 10.1093/hmg/ddv626] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/22/2015] [Indexed: 01/03/2023] Open
Abstract
With a combined carrier frequency of 1:200, heteroplasmic mitochondrial DNA (mtDNA) mutations cause human disease in ∼1:5000 of the population. Rapid shifts in the level of heteroplasmy seen within a single generation contribute to the wide range in the severity of clinical phenotypes seen in families transmitting mtDNA disease, consistent with a genetic bottleneck during transmission. Although preliminary evidence from human pedigrees points towards a random drift process underlying the shifting heteroplasmy, some reports describe differences in segregation pattern between different mtDNA mutations. However, based on limited observations and with no direct comparisons, it is not clear whether these observations simply reflect pedigree ascertainment and publication bias. To address this issue, we studied 577 mother–child pairs transmitting the m.11778G>A, m.3460G>A, m.8344A>G, m.8993T>G/C and m.3243A>G mtDNA mutations. Our analysis controlled for inter-assay differences, inter-laboratory variation and ascertainment bias. We found no evidence of selection during transmission but show that different mtDNA mutations segregate at different rates in human pedigrees. m.8993T>G/C segregated significantly faster than m.11778G>A, m.8344A>G and m.3243A>G, consistent with a tighter mtDNA genetic bottleneck in m.8993T>G/C pedigrees. Our observations support the existence of different genetic bottlenecks primarily determined by the underlying mtDNA mutation, explaining the different inheritance patterns observed in human pedigrees transmitting pathogenic mtDNA mutations.
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Affiliation(s)
| | - Phillipa J Carling
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Vasileios I Floros
- Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Angela Pyle
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Gavin Hudson
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Suzanne C E H Sallevelt
- Department of Clinical Genetics, Research Schools GROW/CARIM, Maastricht University Medical Center, Maastricht, Netherlands
| | - Costanza Lamperti
- Division of Molecular Neurogenetics, National Neurological Institute 'C. Besta', Milano, Italy
| | - Valerio Carelli
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy, Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Laurence A Bindoff
- Department of Neurology, Haukeland University Hospital, Bergen, Norway, Department of Clinical Medicine (K1), University of Bergen, Bergen, Norway
| | - David C Samuels
- Vanderbilt Genetics Institute, Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Nashville, TN, USA and
| | - Passorn Wonnapinij
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
| | - Massimo Zeviani
- Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Division of Molecular Neurogenetics, National Neurological Institute 'C. Besta', Milano, Italy
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research and Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| | - Hubert J M Smeets
- Department of Clinical Genetics, Research Schools GROW/CARIM, Maastricht University Medical Center, Maastricht, Netherlands
| | - Rita Horvath
- Institute of Genetic Medicine, Wellcome Trust Centre for Mitochondrial Research and
| | - Patrick F Chinnery
- Wellcome Trust Centre for Mitochondrial Research and Medical Research Council Mitochondrial Biology Unit, Cambridge, UK, Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK,
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Pallotti F, Binelli G, Fabbri R, Valentino ML, Vicenti R, Macciocca M, Cevoli S, Baruzzi A, DiMauro S, Carelli V. A wide range of 3243A>G/tRNALeu(UUR) (MELAS) mutation loads may segregate in offspring through the female germline bottleneck. PLoS One 2014; 9:e96663. [PMID: 24805791 PMCID: PMC4013013 DOI: 10.1371/journal.pone.0096663] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/10/2014] [Indexed: 12/19/2022] Open
Abstract
Segregation of mutant mtDNA in human tissues and through the germline is debated, with no consensus about the nature and size of the bottleneck hypothesized to explain rapid generational shifts in mutant loads. We investigated two maternal lineages with an apparently different inheritance pattern of the same pathogenic mtDNA 3243A>G/tRNALeu(UUR) (MELAS) mutation. We collected blood cells, muscle biopsies, urinary epithelium and hair follicles from 20 individuals, as well as oocytes and an ovarian biopsy from one female mutation carrier, all belonging to the two maternal lineages to assess mutant mtDNA load, and calculated the theoretical germline bottleneck size (number of segregating units). We also evaluated “mother-to-offspring” segregations from the literature, for which heteroplasmy assessment was available in at least three siblings besides the proband. Our results showed that mutation load was prevalent in skeletal muscle and urinary epithelium, whereas in blood cells there was an inverse correlation with age, as previously reported. The histoenzymatic staining of the ovarian biopsy failed to show any cytochrome-c-oxidase defective oocyte. Analysis of four oocytes and one offspring from the same unaffected mother of the first family showed intermediate heteroplasmic mutant loads (10% to 75%), whereas very skewed loads of mutant mtDNA (0% or 81%) were detected in five offspring of another unaffected mother from the second family. Bottleneck size was 89 segregating units for the first mother and 84 for the second. This was remarkably close to 88, the number of “segregating units” in the “mother-to-offspring” segregations retrieved from literature. In conclusion, a wide range of mutant loads may be found in offspring tissues and oocytes, resulting from a similar theoretical bottleneck size.
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Affiliation(s)
- Francesco Pallotti
- Department of Neurology, Columbia University, New York City, New York, United States of America
- Dipartimento di Scienze Chirurgiche e Morfologiche, University of Insubria, Varese, Italy
| | - Giorgio Binelli
- Dipartimento di Scienze Teoriche e Applicate, University of Insubria, Varese, Italy
| | - Raffaella Fabbri
- Unità Operativa di Ginecologia e Fisiopatologia della Riproduzione Umana, Ospedale S.Orsola-Malpighi, University of Bologna, Bologna, Italy
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), University of Bologna, Bologna, Italy
| | - Maria L. Valentino
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Rossella Vicenti
- Unità Operativa di Ginecologia e Fisiopatologia della Riproduzione Umana, Ospedale S.Orsola-Malpighi, University of Bologna, Bologna, Italy
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), University of Bologna, Bologna, Italy
| | - Maria Macciocca
- Unità Operativa di Ginecologia e Fisiopatologia della Riproduzione Umana, Ospedale S.Orsola-Malpighi, University of Bologna, Bologna, Italy
- Dipartimento di Scienze Mediche e Chirurgiche (DIMEC), University of Bologna, Bologna, Italy
| | - Sabina Cevoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Agostino Baruzzi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
| | - Salvatore DiMauro
- Department of Neurology, Columbia University, New York City, New York, United States of America
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Ospedale Bellaria, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), University of Bologna, Bologna, Italy
- * E-mail:
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Harihara S, Nakamura K, Takubo K, Takeuchi F. Spontaneous event of mitochondrial DNA mutation, A3243G, found in a family of identical twins. ACTA ACUST UNITED AC 2012; 24:158-62. [PMID: 23072508 DOI: 10.3109/19401736.2012.731402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A mutation in mitochondrial DNA (mtDNA) A3243G is an important cause of some serious mitochondrial diseases, and maternal inheritance of the mutation has been reported. In order to investigate the heredity of the mutation, we measured the ratio of the mutated mtDNA molecule among 32 families of identical twins. Both twins from one family showed 20.16% and 18.49% mutated molecules, and the level is significantly high in comparison with members of other families and control subjects (0.23-0.86%). Their parents, however, showed normal level of mutated molecules (0.70% and 0.66%). The high-level mutation of the twins may be due to a spontaneous event, which occurred during development of germ line of their mother, or oogenesis of their mother, or during early stage of their development.
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Affiliation(s)
- Shinji Harihara
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
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Mehrazin M, Shanske S, Kaufmann P, Wei Y, Coku J, Engelstad K, Naini A, De Vivo DC, DiMauro S. Longitudinal changes of mtDNA A3243G mutation load and level of functioning in MELAS. Am J Med Genet A 2009; 149A:584-7. [PMID: 19253345 DOI: 10.1002/ajmg.a.32703] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), one of the most common mitochondrial multisystemic diseases, is most commonly associated with an A-to-G transition at nucleotide position 3243 (A3243G) in mitochondrial DNA. We studied 34 individuals harboring the A3243G mutation for up to 7 years; 17 had the full MELAS phenotype and 17 who were classified as "carrier relatives" because they were either asymptomatic or had some symptoms suggestive of mitochondrial disease but no seizures or strokes. Using the sensitive real-time polymerase chain reaction to quantify the A3243G mutation, we confirmed that the percent mutation decreases progressively in DNA isolated from blood: the average percent decrease was 0.5% per year for fully symptomatic patients and 0.2% per year for oligosymptomatic carrier relatives. We also correlated mutant loads with functional status estimated by the Karnofksky score: even though the mutation load decreases, the level of functioning worsens in fully symptomatic patients, whereas the level of functioning of carrier relatives remains largely unchanged. This study suggests that A3243G mutant load in DNA isolated from blood is neither useful for prognosis nor for functional assessment.
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Affiliation(s)
- Mahsa Mehrazin
- Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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Lin CM, Thajeb P. Valproic acid aggravates epilepsy due to MELAS in a patient with an A3243G mutation of mitochondrial DNA. Metab Brain Dis 2007; 22:105-9. [PMID: 17226098 DOI: 10.1007/s11011-006-9039-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Accepted: 11/10/2006] [Indexed: 10/23/2022]
Abstract
Epilepsy is one of the most common presentations of patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). MELAS is typically caused by an A-to-G substitution at nucleotide position 3243 of mitochondrial DNA. Valproic acid, a common anticonvulsant, can actually increase the frequency of seizures in individuals with MELAS. Here, we report a single case-study of a 38-year-old man who presented with focal seizures and had MELAS Syndrome due to the A3243G mitochondrial DNA mutation. Manifestation of epilepsia partialis continua was aggravated by use of valproic acid. Convulsions abated after discontinuation of valproic acid. Our experience suggests that valproic acid should be avoided for the treatment of epilepsy in individuals with mitochondrial disease.
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Affiliation(s)
- Chih-Ming Lin
- Department of Neurology, Mackay Memorial Hospital, No. 92, Chungshan North Road, Section 2, Taipei, Taiwan.
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Paradoxical effect of sodium valproate that aggravates epilepsy of MELAS in a patient with A3243G mutation of the mitochondrial DNA. Open Med (Wars) 2007. [DOI: 10.2478/s11536-007-0007-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractEpilepsy is an associated feature of patients with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). A substitution at nucleotide position 3243 A>G of the mitochondrial DNA is the most common mutation encountered both in Caucasians and in Chinese/Taiwanese. We herein report a 38-year-old man with A3243G mutation of the mitochondrial DNA whom developed MELAS. The manifestation of his focal motor epilepsy was aggravated by use of sodium valproate (VPA). The mechanism of this paradoxical effect is proposed.
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Thajeb P, Dai DF. Current Opinion on the Clinical Approach to the Diagnosis of Mitochondrial Disease. INT J GERONTOL 2007. [DOI: 10.1016/s1873-9598(08)70020-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Thajeb P, Dai D, Chiang MF, Shyu WC. Genotype-phenotype correlation of maternally inherited disorders due to mutations in mitochondrial DNA. Taiwan J Obstet Gynecol 2007; 45:201-7. [PMID: 17175464 DOI: 10.1016/s1028-4559(09)60225-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Mitochondrial disorders are heterogeneous systemic ailments that are most often caused by maternal inheritance of a variety of mutations of the mitochondrial (mt) DNA. Paternal inheritance and somatic mutation are rare. The disorders are well recognized not only for the genotypic heterogeneity, but also the phenotypic variation among the affected members of a single family. The genotype-phenotype correlation of the diversity of the syndromic and non-syndromic features of mitochondrial disorders are discussed. Some aspects of the molecular mechanisms of this heterogeneity, and the histopathologic findings are highlighted.
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Affiliation(s)
- Peterus Thajeb
- Department of Neurology, Mackay Memorial Hospital, Taiwan.
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Thajeb P, Wu MC, Shih BF, Tzen CY, Chiang MF, Yuan RY. Brain single photon emission computed tomography in patients with A3243G mutation in mitochondrial DNA tRNA. Ann N Y Acad Sci 2006; 1042:48-54. [PMID: 15965044 DOI: 10.1196/annals.1338.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Brain single photon emission computed tomography (SPECT) studies were conducted in three patients with A3243G mutation of the mitochondrial (mt) DNA tRNA. All were born to mothers suffering from chronic progressive external ophthalmoplegia (CPEO) with the same A3243G point mutation of the mtDNA tRNA. The first case manifested clinically with MELAS, the second case manifested with CPEO, and third case was characterized by recurrent migraine-like headache, tremor, and epilepsy. Brain SPECT of all patients, regardless of whether they had or had not suffered from stroke-like episodes, showed multiple areas of asymmetrical decreased perfusion, particularly in the posterior and lateral head regions, especially the temporal lobes. Crossed-cerebellar diaschisis may occur. Conventional brain magnetic resonance images failed to show some of the lesions. Decreased regional cerebral blood flow, rather than previously proposed hyperemia, is likely to be the cause. We conclude that mitochondrial vasculopathy with regional cerebral hypoperfusion may be seen on brain SPECT in patients with mitochondrial disorders and A3243G mutations, regardless of whether they have or have not suffered from stroke-like episodes.
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Affiliation(s)
- Peterus Thajeb
- Department of Neurology, Mackay Memorial Hospital, P.O. Box Nei-hu 6-30, Taipei 11499, Taiwan, ROC.
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Thajeb P, Ma YS, Tzen CY, Chuang CK, Wu TY, Chen SC, Wei YH. Oculopharyngeal somatic myopathy in a patient with a novel large-scale 3,399 bp deletion and a homoplasmic T5814C transition of the mitochondrial DNA. Clin Neurol Neurosurg 2006; 108:407-10. [PMID: 16644408 DOI: 10.1016/j.clineuro.2005.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Revised: 12/29/2004] [Accepted: 01/04/2005] [Indexed: 11/25/2022]
Abstract
We report a 65-year-old woman with a sporadic form of progressive oculopharyngeal somatic myopathy due to a novel large-scale 3,399 base pair (bp) deletion of the mitochondrial DNA (mtDNA) and co-occurrence of a homoplasmic T5814C transition. The onset of myopathy began from chronic progressive external ophthalmoplegia (CPEO) at age of 20 years. Bulbar weakness, neck and proximal limb paralysis, slowly progressed to eventual respiratory failure. The plasma levels of pyruvate (1.5 mg/dL) and lactate (20.2 mg/dL) were elevated. Muscle biopsy showed decreased enzymatic activity of cytochrome c oxidase, but no ragged-red fibers. Electron microscopy showed "parking-lot" paracrystalline inclusions in the enlarged mitochondria suggestive for mitochondrial myopathy. Sequencing of the whole mitochondrial genome of the patient's muscle and leukocytes showed 3,399 bp deletion of the mtDNA from nucleotide position 8,024 to 11,423 and a homoplasmic thymidine to cytosine transition at nucleotide position 5,814 of the tRNA(Cys) gene of mtDNA (T5814C). T5814C was absent in the white blood cells of the patient's daughter and in 205 normal controls. We conclude that a large-scale deletion may coexist with T5814C transition in patients with sporadic form of mitochondrial cytopathy manifested by slowly progressive oculopharyngeal somatic myopathy.
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Affiliation(s)
- Peterus Thajeb
- Department of Neurology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China.
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15
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Liolitsa D, Hanna MG. Models of mitochondrial disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 53:429-66. [PMID: 12512349 DOI: 10.1016/s0074-7742(02)53016-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Danae Liolitsa
- Centre for Neuromuscular Disease, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom
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16
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Clinical phenotype, prognosis and mitochondrial DNA mutation load in mitochondrial encephalomyopathies. J Biomed Sci 2002. [DOI: 10.1007/bf02254979] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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17
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Ko CH, Lam CW, Tse PW, Kong CK, Chan AK, Wong LJ. De novo mutation in the mitochondrial tRNALeu(UUR) gene (A3243G) with rapid segregation resulting in MELAS in the offspring. J Paediatr Child Health 2001; 37:87-90. [PMID: 11168879 DOI: 10.1046/j.1440-1754.2001.00611.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A 14-year-old Chinese boy with a normal perinatal and early developmental history presented at 5 years of age with migraine, intractable epilepsy, ataxia, supraventricular tachycardia, paralytic ileus and progressive mental deterioration. Computerized tomography revealed multiple cerebral infarcts in the parieto-occipital region without basal ganglial calcification. Magnetic resonance imaging showed increased signal intensity in T2 weighted images in the same regions. A cerebral digital subtraction angiogram was normal. Venous lactate, pyruvate, lactate to pyruvate ratio and cerebrospinal fluid lactate were elevated. Muscle biopsy did not reveal any ragged red fibres; dinucleotide-tetrazolium reductase activity was normal. Mitochondrial DNA analysis detected an adenine to guanine mutation at nucleotide position 3243 of tRNALeu(UUR). All four tissues analysed demonstrated heteroplasmy: leucocyte 56%, hair follicle 70%; buccal cell 64%; muscle 54%. The mother and brother of the proband, both asymptomatic, were also found to have a heteroplasmic A3243G mutation in the leucocytes, hair follicle and buccal cells. Other members of the maternal lineage, including the maternal grandmother, did not have the mutation. This report describes a patient with mitochondrial encephalopathy, lactic acidosis, stroke-like episodes, who presented with multisystem involvement. The absence of ragged red fibres in muscle biopsy did not preclude the diagnosis. Mutational analysis of mitochondrial DNA conveniently confirmed the diagnosis of the disorder. A de novo mutation is demonstrated in this family.
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Affiliation(s)
- C H Ko
- Department of Paediatrics, Caritas Medical Centre, Hong Kong, China.
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18
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Singh SK, Sarin D, Puliyel JM, Srivastav R, Gupta R, Kumar N, Mathews A. Melas syndrome. Indian J Pediatr 1999; 66:621-5. [PMID: 10798118 DOI: 10.1007/bf02727181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
An 11 year old male presented with headache, vomiting and weakness of right side of body. One day after admission he developed right focal seizures. He had 5 previous episodes of stroke, the first at 11 months age. His milestones were normal upto the first episode but subsequent mile stones were delayed. His serum and CSF lactic acids were raised. Muscle biopsy showed ragged red fibres on modified Gomori-trichrome staining. His EEG, CT scan and MRI were normal this time. The child improved spontaneously after 7 days. His recovery time progressively became shorter with each episode of stroke. Maximum time for recovery was noted during first episode and least in current episode. This is the first report of Melas syndrome in Indian literature.
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Affiliation(s)
- S K Singh
- Department of Pediatrics, St. Stephen's Hospital, Tis Hazari, Delhi
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19
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Syndrome MELAS chez un enfant de 5 ans: caractéristiques cliniques, biologiques et génétiques. Arch Pediatr 1998. [DOI: 10.1016/s0929-693x(98)80011-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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20
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Thompson VA, Wahr JA. Anesthetic Considerations in Patients Presenting with Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes (MELAS) Syndrome. Anesth Analg 1997. [DOI: 10.1213/00000539-199712000-00041] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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21
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Thompson VA, Wahr JA. Anesthetic considerations in patients presenting with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Anesth Analg 1997; 85:1404-6. [PMID: 9390617 DOI: 10.1097/00000539-199712000-00041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- V A Thompson
- Department of Anesthesiology, University of Michigan, Ann Arbor 48109-0048, USA
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22
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Huang CC, Chen RS, Chu NS, Pang CY, Wei YH. Random mitotic segregation of mitochondrial DNA in MELAS syndrome. Acta Neurol Scand 1996; 93:198-202. [PMID: 8741143 DOI: 10.1111/j.1600-0404.1996.tb00199.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We describe the heterogeneity of clinical features and molecular genetic characteristics of the probands and other members in two families with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. A point mutation at the 3243rd nucleotide position of mtDNA was found only in some of the maternal lineage members of the two families. Furthermore, the proportions of mutant mtDNA were varied and found only in some tissues of the individuals. Intriguingly, in some subjects, the mutant mtDNA was found in blood cells or hair follicles but was absent in muscles. The data do not support the notion of a selective advantage of wild-type mtDNA to rapidly replicating cells. We suggest that a rapid replicative segregation may occur in early embryogenesis.
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Affiliation(s)
- C C Huang
- Department of Neurology, Chang Gung Memorial Hospital, Taipei, Taiwan, Republic of China
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23
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Love S, Hilton DA. Assessment of the distribution of mitochondrial ribosomal RNA in melas and in thrombotic cerebral infarcts by in situ hybridization. J Pathol 1996; 178:182-9. [PMID: 8683387 DOI: 10.1002/(sici)1096-9896(199602)178:2<182::aid-path434>3.0.co;2-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In situ hybridization to mitochondrial ribosomal RNA (rRNA) has been used to study the distribution of mitochondria in paraffin-embedded autopsy brain tissue from two patients with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) and other organs from one of the patients. Comparison of in situ hybridization and electron microscopic findings in an antemortem biopsy specimen of pylorus from the latter patient showed a close correspondence between the distribution of hybridization signal on light microscopy and of mitochondria in ultrathin sections. Strong hybridization signal was present over smooth muscle fibres of the muscularis externa, which contained abnormal accumulations of mitochondria on electron microscopy. Hybridization to sections of skeletal muscle confirmed previous reports of 'ragged-red' fibres in this disorder and of mitochondrial accumulations in the walls of intramuscular blood vessels. To try to elucidate the role of vessel wall accumulation of mitochondria in the genesis of the stroke-like lesions, the distribution of mitochondrial rRNA was assessed in sections of brain from both of the cases of MFLAS and several cases of atherothrombotic cerebrovascular disease. Blood vessels in and adjacent to the cerebral lesions of MELAS showed strong hybridization signal with the mitochondrial probes, as was also seen in infarcts of various ages in the control brains. Only weak signal was present in the walls of blood vessels distant from the lesions, in both MELAS and control brains. These findings suggest that mitochondria accumulate in vascular endothelium and tunica media as a normal response to cerebral infarction or ischaemia. The accumulation of mitochondria in the cerebral lesions of MELAS may, at least in part, be a reaction to the destructive effects of the underlying metabolic dysfunction.
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Affiliation(s)
- S Love
- Department of Neuropathology, Frenchay Hospital, Bristol, UK
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