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Duan M, Chen L, Ge Q, Lu N, Li J, Pan X, Qiao Y, Tu J, Lu Z. Evaluating heteroplasmic variations of the mitochondrial genome from whole genome sequencing data. Gene 2019; 699:145-154. [PMID: 30876822 DOI: 10.1016/j.gene.2019.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 12/23/2022]
Abstract
BACKGROUND Detecting heteroplasmic variations in the mitochondrial genome can help identify potential pathogenic possibilities, which is significant for disease prevention. The development of next-generation sequencing changed the quantification of mitochondrial DNA (mtDNA) heteroplasmy from scanning limited recorded points to the entire mitochondrial genome. However, due to the presence of nuclear mtDNA homologous sequences (nuMTs), maximally retaining real variations while excluding falsest heteroplasmic variations from nuMTs and sequencing errors presents a dilemma. RESULTS Herein, we used an improved method for detecting low-frequency mtDNA heteroplasmic variations from whole genome sequencing data, including point variations and short-fragment length alterations, and evaluated the effect of this method. A two-step alignment was designed and performed to accelerate data processing, to obtain and retain the true mtDNA reads and to eliminate most nuMTs reads. After analyzing whole genome sequencing data of K562 and GM12878 cells, ~90% of heteroplasmic point variations were identified in MitoMap. The results were consistent with the results of an amplification refractory mutation system qPCR. Many linkages of the detected heteroplasmy variations were also discovered. CONCLUSIONS Our improved method is a simple, efficient and accurate way to mine mitochondrial low-frequency heteroplasmic variations from whole genome sequencing data. By evaluating the highest misalignment possibility caused by the remaining nuMTs-like reads and sequencing errors, our procedure can detect mtDNA heteroplasmic variations whose heteroplasmy frequencies are as low as 0.2%.
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Affiliation(s)
- Mengqin Duan
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Liang Chen
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Qinyu Ge
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Na Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Junji Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xuan Pan
- Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, Nanjing Medical University Affiliated Cancer Hospital, Nanjing 210009, China
| | - Yi Qiao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Jing Tu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
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Matthews L, Enzinger C, Fazekas F, Rovira A, Ciccarelli O, Dotti MT, Filippi M, Frederiksen JL, Giorgio A, Küker W, Lukas C, Rocca MA, De Stefano N, Toosy A, Yousry T, Palace J. MRI in Leber's hereditary optic neuropathy: the relationship to multiple sclerosis. J Neurol Neurosurg Psychiatry 2015; 86:537-42. [PMID: 25053773 PMCID: PMC4413690 DOI: 10.1136/jnnp-2014-308186] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/18/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) and a multiple sclerosis (MS)-like illness appear to coexist 50 times more frequently than would be expected by chance. This association of LHON and MS (LMS) raises an important question about whether there could be a common pathophysiological mechanism involving mitochondrial dysfunction. OBJECTIVE The primary aim was to define MRI features of LMS and LHON, and to assess the proportions of individuals displaying features typical of MS. Secondarily, we investigated the effect of gender on the risk of developing white matter lesions in the context of LHON. METHODS A blinded standardised review of conventional brain MRIs of 30 patients with MS, 31 patients with LHON and 11 patients with LMS was conducted by three independent experts in the field. MS-like MRI features were assessed. RESULTS All patients with LMS and 26% of patients with LHON had white matter lesions. Of these, all patients with LMS and 25% with LHON were found to have an MRI appearance typical of MS. Female patients with LHON had a significantly greater risk of having white matter lesions consistent with MS compared with male patients (relative risk 8.3). CONCLUSIONS A blinded review of conventional brain MRIs shows that patients with LMS have a scan appearance indistinguishable from MS. Mitochondrial dysfunction could be a common pathophysiological pathway in the formation of white matter lesions. There appears to be a strong female influence on the radiological appearance as well as clinical development of MS in patients with LHON.
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Affiliation(s)
- Lucy Matthews
- Oxford University Hospitals NHS Trust, Oxford, UK Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, UK
| | - Christian Enzinger
- Department of Neurology, Medical University of Graz, Graz, Austria Department of Radiology, Division of Neuroradiology, Medical University of Graz, Graz, Austria
| | - Franz Fazekas
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Alex Rovira
- Department of Radiology, Hospital Vall d'Hebron, Barcelona, Spain
| | | | - Maria Teresa Dotti
- Department of Neurological and Behavioural Sciences, University of Siena, Siena, Italy
| | - Massimo Filippi
- Neuroimaging Research Unit and Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Jette L Frederiksen
- Department of Neurology, Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Antonio Giorgio
- Department of Neurological and Behavioural Sciences, University of Siena, Siena, Italy
| | - Wilhelm Küker
- Oxford University Hospitals NHS Trust, Oxford, UK Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, UK
| | - Carsten Lukas
- Department of Radiology, St. Josef Hospital Ruhr-University, Bochum, Germany
| | - Maria A Rocca
- Neuroimaging Research Unit and Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy
| | - Nicola De Stefano
- Department of Neurological and Behavioural Sciences, University of Siena, Siena, Italy
| | | | | | - Jacqueline Palace
- Oxford University Hospitals NHS Trust, Oxford, UK Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, UK
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Llobet L, Gómez-Durán A, Iceta R, Iglesias E, Montoya J, Martín-Martínez J, Ara JR, Ruiz-Pesini E. Stressed cybrids model demyelinated axons in multiple sclerosis. Metab Brain Dis 2013; 28:639-45. [PMID: 23612782 DOI: 10.1007/s11011-013-9410-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 04/15/2013] [Indexed: 11/28/2022]
Abstract
Multiple sclerosis is likely caused by a complex interaction of multiple genes and environmental factors. The contribution of mitochondrial DNA genetic backgrounds has been frequently reported. To evaluate the effect of mitochondrial DNA haplogroups in the same genetic and environmental circumstances, we have built human transmitochondrial cell lines and simulated the effect of axon demyelination, one of the hallmarks of multiple sclerosis pathology, by altering the ionic gradients through the plasmalemma and increasing ATP consumption. In this model, mitochondrial biogenesis is observed. This process is larger in Uk cybrids, which mirrors their lower oxidative phosphorylation capacity in basal conditions. This model replicates a process occurring in both patients suffering from multiple sclerosis and several animal models of axon demyelination. Therefore, it can be used to analyze the contribution of various mitochondrial DNA genotypes to multiple sclerosis. In this sense, a longer or stronger energy stress, such as that associated with demyelinated axons in multiple sclerosis, could make Uk individuals more susceptible to this pathology. Finally, pharmacologic compounds targeted to mitochondrial biogenesis could be a potential therapy for multiple sclerosis.
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Affiliation(s)
- Laura Llobet
- Departamento de Bioquímica, Biología Molecular y Celular, Centro de Investigaciones Biomédicas En Red de Enfermedades Raras (CIBERER) Universidad de Zaragoza, Zaragoza, Spain
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5
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Pfeffer G, Burke A, Yu-Wai-Man P, Compston DAS, Chinnery PF. Clinical features of MS associated with Leber hereditary optic neuropathy mtDNA mutations. Neurology 2013; 81:2073-81. [PMID: 24198293 PMCID: PMC3863351 DOI: 10.1212/01.wnl.0000437308.22603.43] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Objective: To determine whether the association between multiple sclerosis (MS) and Leber hereditary optic neuropathy (LHON) (known as “Harding disease”) is a chance finding, or the 2 disorders are mechanistically linked. Methods: We performed a United Kingdom–wide prospective cohort study of prevalent cases of MS with LHON mitochondrial DNA (mtDNA) mutations. The new cases were compared with published cases, enabling a comprehensive clinical description. We also performed a meta-analysis of studies screening patients with MS for LHON mtDNA mutations to find evidence of a genetic association. Results: Twelve new patients were identified from 11 pedigrees, and 44 cases were identified in the literature. The combined cohort had the following characteristics: multiple episodes of visual loss, predominance for women, and lengthy time interval before the fellow eye is affected (average 1.66 years), which is very atypical of LHON; conversely, most patients presented without eye pain and had a poor visual prognosis, which is unusual for optic neuritis associated with MS. The number of UK cases of LHON-MS fell well within the range predicted by the chance occurrence of MS and the mtDNA mutations known to cause LHON. There was no association between LHON mtDNA mutations and MS in a meta-analysis of the published data. Conclusions: Although the co-occurrence of MS and LHON mtDNA mutations is likely to be due to chance, the resulting disorder has a distinct phenotype, implicating a mechanistic interaction. Patients with LHON-MS have a more aggressive course, and prognostication and treatment should be guarded.
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Affiliation(s)
- Gerald Pfeffer
- From the Institute of Genetic Medicine (G.P., P.Y.-W.-M., P.F.C.), Newcastle; Institute of Neurology (A.B.), University College London; and Department of Clinical Neurosciences (D.A.S.C.), University of Cambridge, UK
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Andalib S, Talebi M, Sakhinia E, Farhoudi M, Sadeghi-Bazargani H, Motavallian A, Pilehvar-Soltanahmadi Y. Multiple sclerosis and mitochondrial gene variations: a review. J Neurol Sci 2013; 330:10-5. [PMID: 23669867 DOI: 10.1016/j.jns.2013.04.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 04/16/2013] [Accepted: 04/18/2013] [Indexed: 01/07/2023]
Abstract
Multiple sclerosis (MS) is a debilitating disease of the central nervous system. Its etiology is still an unanswered enigma; its symptoms are varied and unpredictable; and there is no cure for it. Genetics has been introduced as a contributing factor to MS. Not only may MS stem from nuclear gene variations/mutations, but also it may arise from mitochondrial gene variations/mutations. The association of mitochondrial DNA variations/mutations with the pathogenesis of MS has, so far, been analyzed by several studies. This paper reviews the literature with regard to MS and corresponding mitochondrial DNA variations.
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Affiliation(s)
- Sasan Andalib
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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7
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Multiple sclerosis associated with Leber's Hereditary Optic Neuropathy. J Neurol Sci 2009; 286:24-7. [PMID: 19800080 DOI: 10.1016/j.jns.2009.09.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 09/07/2009] [Accepted: 09/15/2009] [Indexed: 11/21/2022]
Abstract
The cause of multiple sclerosis is unknown although it is recognised to involve an inflammatory process associated with demyelinating plaques and more widespread neurodegeneration. It appears to have become progressively more common in females which is further discussed in this issue, and genetic factors, as identified to date, appear to play only a moderate role. One curious observation is that Leber's Hereditary Optic Neuropathy (LHON), a rare genetic syndrome, presents clinically overwhelmingly in males, but can be associated with an MS-like illness and when it does it occurs mainly in females. It is interesting to examine this further to assess if this could give us any clues as to the pathogenesis of MS.
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Borazanci AP, Harris MK, Schwendimann RN, Gonzalez-Toledo E, Maghzi AH, Etemadifar M, Alekseeva N, Pinkston J, Kelley RE, Minagar A. Multiple sclerosis: clinical features, pathophysiology, neuroimaging and future therapies. FUTURE NEUROLOGY 2009. [DOI: 10.2217/14796708.4.2.229] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiple sclerosis (MS) is a common immune-mediated progressive neurodegenerative disease of the CNS that typically manifests with periods of disease activity followed by intervals of remission. The etiology of MS remains unknown; however, existing evidence indicates that MS is a ‘whole-brain disease’ that is driven by a potent immune response against CNS antigen(s), particularly myelin peptide antigens. The immunopathogenesis of MS includes both the cell- and humorally-mediated arms of the immune system. Genetic and environmental factors play important roles in the development of MS. Application of various neuroimaging techniques to the world of MS have expanded our knowledge concerning its pathogenesis and assist us in the more accurate diagnosis of MS versus its imitators. Current treatments target acute attacks and aim to reduce future clinical relapses. A summary of the potential future therapies for MS is presented.
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Affiliation(s)
- Aimee Pasqua Borazanci
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Meghan K Harris
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Robert N Schwendimann
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Eduardo Gonzalez-Toledo
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Amir H Maghzi
- School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Masoud Etemadifar
- School of Medicine, Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nadejda Alekseeva
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - James Pinkston
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Roger E Kelley
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Alireza Minagar
- Department of Neurology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
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Ban M, Elson J, Walton A, Turnbull D, Compston A, Chinnery P, Sawcer S. Investigation of the role of mitochondrial DNA in multiple sclerosis susceptibility. PLoS One 2008; 3:e2891. [PMID: 18682780 PMCID: PMC2494944 DOI: 10.1371/journal.pone.0002891] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 07/15/2008] [Indexed: 11/18/2022] Open
Abstract
Several lines of evidence suggest that mitochondrial genetic factors may influence susceptibility to multiple sclerosis. To explore this hypothesis further, we re-sequenced the mitochondrial genome (mtDNA) from 159 patients with multiple sclerosis and completed a haplogroup analysis including a further 835 patients and 1,506 controls. A trend towards over-representation of super-haplogroup U was the only evidence for association with mtDNA that we identified in these samples. In a parallel analysis of nuclear encoded mitochondrial genes, we also found a trend towards association with the complex I gene, NDUFS2. These results add to the evidence suggesting that variation in mtDNA and nuclear encoded mitochondrial genes may contribute to disease susceptibility in multiple sclerosis.
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Affiliation(s)
- Maria Ban
- Department of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
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Affiliation(s)
- Mara Giordano
- Department of Medical Sciences and Interdisciplinary Research Centre on Autoimmune Diseases (IRCAD), Eastern Piedmont University, 28100 Novara, Italy.
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Carelli V. Chapter 4 Leber's Hereditary Optic Neuropathy. MITOCHONDRIAL DISORDERS IN NEUROLOGY 2 2002. [DOI: 10.1016/s1877-3419(09)70063-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Abstract
Multiple sclerosis (MS) is characterized by chronic inflammation and demyelination in the central nervous system (CNS). Although the etiology of MS is unknown, both genetic and environmental contributions to the pathogenesis are inferred from epidemiologic studies. Geographic distributions and epidemics of MS and data from migration studies provide evidence for some, thus far unidentified, environmental effects. The co-occurrence of MS with high and low frequencies in ethnic groups often sharing an environment, the increased recurrence rate in families, and the high concordance rate among identical twins point to inheritable determinants of susceptibility. Based on the autoimmune hypothesis of demyelination, genetic studies sought associations between MS and polymorphic alleles of candidate genes which regulate either the immune response or myelin production. The most consistent finding in case-control studies was the association with the major histocompatibility complex (MHC) (also called human leukocyte antigen--HLA) class II, DR15, DQ6, Dw2 haplotype. Studies on other gene products encoded within or close to the MHC complex on chromosome 6p21.3 (e.g., HLA DP, complement components, transporter proteins, tumor necrosis factor, and myelin-oligodendrocyte glycoprotein) resulted in conflicting observations in different patient populations. The potential contribution of polymorphic alleles within the genes of the T-cell receptor alpha beta chains, immunoglobulins, cytokines, and oligodendrocyte growth factors or their receptors to MS susceptibility either remains equivocal or is rejected. Studies on families with multiple affected members have revealed that MS is a complex trait, that the contribution of individual genes to susceptibility is probably small, and that differences are possible between familial and sporadic forms. The development of molecular and computer technologies have facilitated the performance of comprehensive genomic scans in multiplex families, which have confirmed the possible linkage of multiple loci to susceptibility, each with a minor contribution. Several provisional sites were reported, but only 6p21 (MHC complex), 5p14, and 17q22 were positive in more than one study. The British update demonstrated segregation among regions of interest depending on DR15 sharing, and excluded a gene of major effect from 95%, and one with a moderate effect from 65% of the genome. The extended study by the US collaboration group revealed that the MHC linkage was limited to families segregating HLA DR2 alleles, which suggested that linkage to the MHC is related to the HLA DR2 association, and that sporadic and familial MS share at least one common susceptibility marker. Further identification of MS susceptibility loci may involve additional family sets, more polymorphic markers, and the exploration of telomeric chromosomal regions. Data from these studies may further elucidate pathogenic mechanisms of MS.
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Affiliation(s)
- B Kalman
- Department of Neurology, MCP-Hahnemann University, Philadelphia, PA 19102, USA
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Kalman B, Li S, Chatterjee D, O'Connor J, Voehl MR, Brown MD, Alder H. Large scale screening of the mitochondrial DNA reveals no pathogenic mutations but a haplotype associated with multiple sclerosis in Caucasians. Acta Neurol Scand 1999; 99:16-25. [PMID: 9925234 DOI: 10.1111/j.1600-0404.1999.tb00653.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report the first large-scale screening of mitochondrial (mt) DNA in 77 Caucasian patients with relapsing-remitting or secondary progressive form of multiple sclerosis (MS) and in 84 Caucasian controls by using the method of restriction site polymorphism and haplotype analysis. No pathogenic mtDNA mutation was found in association with MS. However, mtDNA haplotypes K* and J* defined by the simultaneous presence of Ddel restriction sites at nucleotides 10,394 and 14,798 of the mtDNA in haplogroups K and J showed association with MS at a P-value of 0.001. A relative increase of MS patients compared to controls either with the J* or with the K* haplotype (+10,394Ddel/+14,798Ddel in haplogroup J or K) also was detected (each with a P<0.05). No distinct phenotypic characteristics of MS were observed when clinical data of patients with haplotypes K* or J* were analyzed. In addition to previous complete sequencing in several MS patients, the population screening of mtDNA presented here suggests that mtDNA point mutations are not likely to be involved in the pathogenesis of typical forms of MS. However, the mitochondrial genetic background (haplotype K* and J*) may moderately contribute to MS susceptibility. The reported association between MS and Leber's hereditary optic nerve atrophy, a disease caused by mtDNA point mutations preferentially occurring in haplogroup J, may be at least in part related to the overlapping mitochondrial genetic background of the two diseases.
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Affiliation(s)
- B Kalman
- Center for Neurovirology, Allegheny University of the Health Sciences, Philadelphia, PA 19102, USA
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Kalman B, Alder H. Is the mitochondrial DNA involved in determining susceptibility to multiple sclerosis? Acta Neurol Scand 1998; 98:232-7. [PMID: 9808271 DOI: 10.1111/j.1600-0404.1998.tb07301.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An increasing number of case reports on Leber's hereditary optic neuropathy (LHON) associated mitochondrial (mt)DNA point mutations in patients with multiple sclerosis (MS) raised the possibility that mitochondrial determinants may contribute to genetic susceptibility to MS. These observations prompted many laboratories including ours to perform comprehensive sequencing or large scale screening of the mtDNA in MS patients. Here we review the available data arguing for or against a mitochondrial hypothesis for MS. We conclude that pathogenic mtDNA point mutations are not associated with typical forms of this disease. A very small subgroup of MS patients, usually with prominent optic neuritis (PON), may carry pathogenic LHON mutations. This partial overlap between the two diseases may be related to the association of MS with a mtDNA haplotype (a set of mtDNA polymorphisms) within which pathogenic LHON mutations preferentially occur.
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Affiliation(s)
- B Kalman
- Department of Neurology, Center for Neurovirology, Allegheny University of the Health Sciences, Philadelphia, PA 19102, USA
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16
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Taylor RW, Chinnery PF, Bates MJ, Jackson MJ, Johnson MA, Andrews RM, Turnbull DM. A novel mitochondrial DNA point mutation in the tRNA(Ile) gene: studies in a patient presenting with chronic progressive external ophthalmoplegia and multiple sclerosis. Biochem Biophys Res Commun 1998; 243:47-51. [PMID: 9473477 DOI: 10.1006/bbrc.1997.8055] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We report a new mutation, a G to A transition at nucleotide position 4298 within the mitochondrial tRNA(Ile) gene in a patient with chronic progressive external ophthalmoplegia and multiple sclerosis. The mutation, which alters an evolutionary conserved nucleotide within the anticodon stem, was heteroplasmic in skeletal muscle but was not present in the patient's blood. Single fibre PCR analysis revealed significantly higher levels of the G4298A mutation in cytochrome c oxidase (COX) negative fibres than in COX-positive fibres. This mutation represents the seventh pathogenic nucleotide substitution to be found in this gene and as such confirms the tRNA(Ile) gene as a susceptible "hot spot" for mitochondrial DNA point mutations. Of particular interest is that this patient has the clinical features of both multiple sclerosis and a mitochondrial DNA disorder.
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MESH Headings
- Animals
- Base Sequence
- DNA, Mitochondrial/chemistry
- DNA, Mitochondrial/genetics
- Electron Transport Complex IV/metabolism
- Female
- Humans
- Middle Aged
- Mitochondrial Myopathies/complications
- Mitochondrial Myopathies/genetics
- Mitochondrial Myopathies/metabolism
- Molecular Sequence Data
- Multiple Sclerosis/complications
- Multiple Sclerosis/genetics
- Multiple Sclerosis/metabolism
- Muscle Fibers, Skeletal/metabolism
- Muscle, Skeletal/metabolism
- Nucleic Acid Conformation
- Ophthalmoplegia, Chronic Progressive External/complications
- Ophthalmoplegia, Chronic Progressive External/genetics
- Ophthalmoplegia, Chronic Progressive External/metabolism
- Point Mutation
- RNA, Transfer, Ile/genetics
- Sequence Homology, Nucleic Acid
- Species Specificity
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Affiliation(s)
- R W Taylor
- Department of Neurology, Medical School, University of Newcastle upon Tyne, United Kingdom
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Leuzzi V, Carducci C, Lenza M, Salvetti M, Ristori G, Di Giovanni S, Torroni A. LHON mutations in Italian patients affected by multiple sclerosis. Acta Neurol Scand 1997; 96:145-8. [PMID: 9300066 DOI: 10.1111/j.1600-0404.1997.tb00257.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The occurrence of a multiple sclerosis (MS)-like phenotype in subjects carrying mitochondrial DNA (mtDNA) mutations associated with Leber hereditary optic neuropathy (LHON) has suggested that mitochondrial genes may contribute to susceptibility to MS. With the present study 74 unrelated Italian patients (53 females and 21 males; mean age 37.9, SD 9.9, range 20-59) affected by MS with early and prominent optic nerve involvement and 99 normal control subjects were analysed for the presence of primary (nps 11778, 3460, 14484) and an alleged secondary one (np 15257) LHON mutations. A single MS patient carrying a virtually homoplasmic LHON mutation at np 11778 was found. Family history revealed a maternal uncle affected by MS, decreased at age of 64 in consequence of a stroke. The patient's mother harboured the same mutation in a homoplasmic way. Primary LHON mutations were not detected in any other MS patient or control. Of the MS patients 5.4% (4 out of 74), and 5.1% (5 out of 99) of the controls carried the 15257 mutation in a homoplasmic state. Present data do not support any contribution of primary LHON mutations to genetically determined susceptibility in MS. There is no evidence that the 15257 mutation has any pathogenetic significance in the Italian population.
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Affiliation(s)
- V Leuzzi
- Dipartimento di Scienze Neurologiche e Psichiatriche dell'Età Evolutiva, University La Sapienza, Roma, Italy
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