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Smith KK, Moreira JD, Wilson CR, Padera JO, Lamason AN, Xue L, Gopal DM, Flynn DB, Fetterman JL. A systematic review on the biochemical threshold of mitochondrial genetic variants. Genome Res 2024; 34:341-365. [PMID: 38627095 PMCID: PMC11067886 DOI: 10.1101/gr.278200.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 03/15/2024] [Indexed: 05/05/2024]
Abstract
Mitochondrial DNA (mtDNA) variants cause a range of diseases from severe pediatric syndromes to aging-related conditions. The percentage of mtDNA copies carrying a pathogenic variant, variant allele frequency (VAF), must reach a threshold before a biochemical defect occurs, termed the biochemical threshold. Whether the often-cited biochemical threshold of >60% VAF is similar across mtDNA variants and cell types is unclear. In our systematic review, we sought to identify the biochemical threshold of mtDNA variants in relation to VAF by human tissue/cell type. We used controlled vocabulary terms to identify articles measuring oxidative phosphorylation (OXPHOS) complex activities in relation to VAF. We identified 76 eligible publications, describing 69, 12, 16, and 49 cases for complexes I, III, IV, and V, respectively. Few studies evaluated OXPHOS activities in diverse tissue types, likely reflective of clinical access. A number of cases with similar VAFs for the same pathogenic variant had varying degrees of residual activity of the affected complex, alluding to the presence of modifying variants. Tissues and cells with VAFs <60% associated with low complex activities were described, suggesting the possibility of a biochemical threshold of <60%. Using Kendall rank correlation tests, the VAF of the m.8993T > G variant correlated with complex V activity in skeletal muscle (τ = -0.58, P = 0.01, n = 13); however, no correlation was observed in fibroblasts (P = 0.7, n = 9). Our systematic review highlights the need to investigate the biochemical threshold over a wider range of VAFs in disease-relevant cell types to better define the biochemical threshold for specific mtDNA variants.
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Affiliation(s)
- Karan K Smith
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - Jesse D Moreira
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
- Programs in Human Physiology, Department of Health Sciences, Boston University Sargent College, Boston, Massachusetts 02215, USA
| | - Callum R Wilson
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - June O Padera
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - Ashlee N Lamason
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - Liying Xue
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - Deepa M Gopal
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - David B Flynn
- Medical Sciences and Education, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA
| | - Jessica L Fetterman
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts 02118, USA;
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Al Asoom L, Khan J, Al Sunni A, Rafique N, Latif R, Alabdali M, AbdulAzeez S, Borgio JF. A Pilot Mitochondrial Genome-Wide Association on Migraine Among Saudi Arabians. Int J Gen Med 2022; 15:6249-6258. [PMID: 35903646 PMCID: PMC9316482 DOI: 10.2147/ijgm.s371707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/06/2022] [Indexed: 12/12/2022] Open
Abstract
Background Mitochondrial DNA (mtDNA) mutations have been reported in multiple neurological diseases and helped to explain the pathophysiology of these diseases. Similarly, variations in mtDNA might exist in migraine and can explain the effect of low ATP production in the neurons on the initiation of migraine attack. Therefore, in the current study we aim to explore the association of mtDNA mutations on migraine in the Saudi population. Subjects and Methods Over 1950 young Saudi female students were screened for migraine, among that a total of 103 satisfied the ICHD-3 criteria. However, 20 migraine cases confirmed in the neurology clinic and gave consent to participate in the study. Another 20 age-matched healthy controls were also recruited. Mitochondrial sequence variations were filtered from exome sequencing using NCBI GenBank Reference Sequence: NC_012920.1 and analysed using MITOMAP. Genes with significant single nucleotide polymorphisms (SNPs) were investigated by the gene functional classification tool DAVID and functional enrichment analysis of protein-protein interaction networks through STRING 11.5 for the most significant associated genes. Results Genome wide analysis of the mitochondrial sequence variations between the patients with migraine and control revealed the association of 30 SNPs (p < 0.05) in the mitochondrial genome. The highest significance (p = 0.001033) was observed in a coding SNP (rs1603225278) in the CYTB gene and rs386829281 in the region of origin of replication. Twenty-four significant SNPs were in the coding region of nine (ND5, ND4, COX2, COX1, ND3, CYTB, COX3, ND2 and ND1) genes. Conclusion This is the first study to demonstrate the association of mtDNA variations with migraine in the Saudi population. The current findings will help to highlight the significance of mtDNA mutations to migraine pathophysiology and will serve as a reference data for larger national and international studies.
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Affiliation(s)
- Lubna Al Asoom
- Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 31541, Saudi Arabia
| | - Johra Khan
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Majmaah, 11952, Saudi Arabia.,Health and Basic Sciences Research Center, Majmaah University, Majmaah, 11952, Saudi Arabia
| | - Ahmad Al Sunni
- Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 31541, Saudi Arabia
| | - Nazish Rafique
- Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 31541, Saudi Arabia
| | - Rabia Latif
- Department of Physiology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 31541, Saudi Arabia
| | - Majed Alabdali
- Department of Neurology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, 31952, Saudi Arabia
| | - Sayed AbdulAzeez
- Department of Genetic Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, 31441, Saudi Arabia
| | - J Francis Borgio
- Department of Genetic Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, 31441, Saudi Arabia
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Amor H, Hammadeh ME. A Systematic Review of the Impact of Mitochondrial Variations on Male Infertility. Genes (Basel) 2022; 13:genes13071182. [PMID: 35885965 PMCID: PMC9325252 DOI: 10.3390/genes13071182] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
According to current estimates, infertility affects one in four couples trying to conceive. Primary or secondary infertility can be due either to both partners or only to the man or the woman. Up to 15% of infertility cases in men can be attributed to genetic factors that can lead to irreversible partial or complete spermatogenic arrest. The increased use of assisted reproductive technology (ART) has provided not only insights into the causes of male infertility but also afforded a diagnostic tool to detect and manage this condition among couples. Genes control a variety of physiological attributes, such as the hypothalamic–pituitary–gonadal axis, development, and germ cell differentiation. In the era of ART, it is important to understand the genetic basis of infertility so as to provide the most tailored therapy and counseling to couples. Genetic factors involved in male infertility can be chromosome abnormalities or single-gene disorders, mitochondrial DNA (mtDNA) mutations, Y-chromosome deletions, multifactorial disorders, imprinting disorders, or endocrine disorders of genetic origin. In this review, we discuss the role of mitochondria and the mitochondrial genome as an indicator of sperm quality and fertility.
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Lo Faro V, Nolte IM, Ten Brink JB, Snieder H, Jansonius NM, Bergen AA. Mitochondrial Genome Study Identifies Association Between Primary Open-Angle Glaucoma and Variants in MT-CYB, MT-ND4 Genes and Haplogroups. Front Genet 2021; 12:781189. [PMID: 34976016 PMCID: PMC8719162 DOI: 10.3389/fgene.2021.781189] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 11/29/2021] [Indexed: 11/21/2022] Open
Abstract
Background and purpose: Primary open-angle glaucoma (POAG) is an optic neuropathy characterized by death of retinal ganglion cells and atrophy of the optic nerve head. The susceptibility of the optic nerve to damage has been shown to be mediated by mitochondrial dysfunction. In this study, we aimed to determine a possible association between mitochondrial SNPs or haplogroups and POAG. Methods: Mitochondrial DNA single nucleotide polymorphisms (mtSNPs) were genotyped using the Illumina Infinium Global Screening Array-24 (GSA) 700K array set. Genetic analyses were performed in a POAG case-control study involving the cohorts, Groningen Longitudinal Glaucoma Study-Lifelines Cohort Study and Amsterdam Glaucoma Study, including 721 patients and 1951 controls in total. We excluded samples not passing quality control for nuclear genotypes and samples with low call rate for mitochondrial variation. The mitochondrial variants were analyzed both as SNPs and haplogroups. These were determined with the bioinformatics software HaploGrep, and logistic regression analysis was used for the association, as well as for SNPs. Results: Meta-analysis of the results from both cohorts revealed a significant association between POAG and the allele A of rs2853496 [odds ratio (OR) = 0.64; p = 0.006] within the MT-ND4 gene, and for the T allele of rs35788393 (OR = 0.75; p = 0.041) located in the MT-CYB gene. In the mitochondrial haplogroup analysis, the most significant p-value was reached by haplogroup K (p = 1.2 × 10−05), which increases the risk of POAG with an OR of 5.8 (95% CI 2.7–13.1). Conclusion: We identified an association between POAG and polymorphisms in the mitochondrial genes MT-ND4 (rs2853496) and MT-CYB (rs35788393), and with haplogroup K. The present study provides further evidence that mitochondrial genome variations are implicated in POAG. Further genetic and functional studies are required to substantiate the association between mitochondrial gene polymorphisms and POAG and to define the pathophysiological mechanisms of mitochondrial dysfunction in glaucoma.
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Affiliation(s)
- Valeria Lo Faro
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
| | - Ilja M. Nolte
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Jacoline B. Ten Brink
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
| | - Harold Snieder
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Nomdo M. Jansonius
- Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Arthur A. Bergen
- Department of Clinical Genetics, Amsterdam University Medical Center (AMC), Amsterdam, Netherlands
- Department of Ophthalmology, Amsterdam UMC, Amsterdam, Netherlands
- *Correspondence: Arthur A. Bergen,
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Bakare AB, Lesnefsky EJ, Iyer S. Leigh Syndrome: A Tale of Two Genomes. Front Physiol 2021; 12:693734. [PMID: 34456746 PMCID: PMC8385445 DOI: 10.3389/fphys.2021.693734] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 07/22/2021] [Indexed: 12/21/2022] Open
Abstract
Leigh syndrome is a rare, complex, and incurable early onset (typically infant or early childhood) mitochondrial disorder with both phenotypic and genetic heterogeneity. The heterogeneous nature of this disorder, based in part on the complexity of mitochondrial genetics, and the significant interactions between the nuclear and mitochondrial genomes has made it particularly challenging to research and develop therapies. This review article discusses some of the advances that have been made in the field to date. While the prognosis is poor with no current substantial treatment options, multiple studies are underway to understand the etiology, pathogenesis, and pathophysiology of Leigh syndrome. With advances in available research tools leading to a better understanding of the mitochondria in health and disease, there is hope for novel treatment options in the future.
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Affiliation(s)
- Ajibola B. Bakare
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
| | - Edward J. Lesnefsky
- Division of Cardiology, Pauley Heart Center, Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Physiology/Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
- Department of Biochemistry and Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Shilpa Iyer
- Department of Biological Sciences, J. William Fulbright College of Arts and Sciences, University of Arkansas, Fayetteville, AR, United States
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Yu X, Ji K, Lin Y, Xu X, Wang W, Li Y, Lu JQ, Zhao Y, Yan C. Leber hereditary optic neuropathy and dystonia overlapping mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes due to m.14459G>A mutation. Neurol Sci 2021; 42:5123-5130. [PMID: 33779865 DOI: 10.1007/s10072-021-05155-9] [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: 08/17/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To report a Chinese family with combined m.14459G>A mutation and m.6064A>T mutation of which the female proband presenting unique Leber hereditary optic neuropathy and dystonia (LDYT) overlapping mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) phenotype. METHODS Clinical information of the pedigree was collected. We performed muscle biopsy and whole-length mitochondrial DNA (mtDNA) sequencing on the proband. The activity of respiratory chain complexes in immortalized lymphoblasts was determined. RESULTS The current 23-year-old proband suffered from vision decline at age 15 and developed seizures and dystonia with bilateral lesions in precentral gyri at age 18. When she was 21, the lesions in bilateral putamen were found with elevated cerebrospinal fluid lactate. Her mother had optic atrophy; one of her brother died at age 4 with respiratory distress; and the other 8-year-old brother was asymptomatic. Muscle biopsy of the proband was unremarkable. The mtDNA sequencing revealed a heteroplasmic m.14459G>A mutation and a previously unreported m.6064A>T mutation. The respiratory chain complex I activity in the proband's immortalized lymphoblasts was 50% less than the normal control; while there was no statistical difference between the proband and the normal control in the activity of complex IV. CONCLUSIONS We presented the first case exhibiting LDYT and MELAS phenotype with m.14459G>A mutation, and the decreased complex I activity contributed to the pathogenicity. Our study expanded the clinical spectrum of m.14459G>A mutation.
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Affiliation(s)
- Xiaolin Yu
- Department of Geriatrics Medicine, Qilu Hospital, Shandong University, Jinan, Shandong, China.,Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Kunqian Ji
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Yan Lin
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Xuebi Xu
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Wei Wang
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Ying Li
- Department of Geriatrics Medicine, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Jian-Qiang Lu
- Department of Pathology and Molecular Medicine/Neuropathology, McMaster University, Hamilton, Ontario, Canada
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China.
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, Shandong, China. .,Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao, Shandong, China. .,Brain Science Research Institute, Shandong University, Jinan, Shandong, China.
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7
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Loos MA, Gomez G, Mayorga L, Caraballo RH, Eiroa HD, Obregon MG, Rugilo C, Lubieniecki F, Taratuto AL, Saccoliti M, Alonso CN, Aráoz HV. Clinical and molecular characterization of mitochondrial DNA disorders in a group of Argentinian pediatric patients. Mol Genet Metab Rep 2021; 27:100733. [PMID: 33717984 PMCID: PMC7933530 DOI: 10.1016/j.ymgmr.2021.100733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 11/02/2022] Open
Abstract
Objective To describe the clinical and molecular features of a group of Argentinian pediatric patients with mitochondrial DNA (mtDNA) disorders, and to evaluate the results of the implementation of a classical approach for the molecular diagnosis of mitochondrial diseases. Methods Clinical data from 27 patients with confirmed mtDNA pathogenic variants were obtained from a database of 89 patients with suspected mitochondrial disease, registered from 2014 to 2020. Clinical data, biochemical analysis, neuroimaging findings, muscle biopsy and molecular studies were analyzed. Results Patients were 18 females and 9 males, with ages at onset ranging from 1 week to 14 years (median = 4 years). The clinical phenotypes were: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome (n = 11), Leigh syndrome (n = 5), Kearns-Sayre syndrome (n = 3), Chronic Progressive External Ophthalmoplegia (n = 2), Leber hereditary optic neuropathy (n = 2), myoclonic epilepsy associated with ragged-red fibers (n = 1) and reversible infantile myopathy with cytochrome-C oxidase deficiency (n = 3). Most of the patients harbored pathogenic single nucleotide variants, mainly involving mt-tRNA genes, such as MT-TL1, MT-TE and MT-TK. Other point variants were found in complex I subunits, like MT-ND6, MT-ND4, MT-ND5; or in MT-ATP6. The m.13513G > A variant in MT-ND5 and the m.9185 T > C variant in MT-ATP6 were apparently de novo. The rest of the patients presented large scale-rearrangements, either the "common" deletion or a larger deletion. Conclusions This study highlights the clinical and genetic heterogeneity of pediatric mtDNA disorders. All the cases presented with classical phenotypes, being MELAS the most frequent. Applying classical molecular methods, it was possible to achieve a genetic diagnosis in 30% of the cases, suggesting that this is an effective first approach, especially for those centers from low-middle income countries, leaving NGS studies for those patients with inconclusive results.
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Affiliation(s)
- Mariana Amina Loos
- Department of Neurology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Gimena Gomez
- Genomics Laboratory, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Lía Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM, Universidad Nacional de Cuyo, CONICET), Centro Universitario UNCuyo, 5500 Mendoza, Argentina
| | - Roberto Horacio Caraballo
- Department of Neurology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Hernán Diego Eiroa
- Department of Inborn Errors of Metabolism, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires, 1245, Argentina
| | - María Gabriela Obregon
- Department of Medical Genetics, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Carlos Rugilo
- Department of DiagnosticImaging, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Fabiana Lubieniecki
- Department of Pathology, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Ana Lía Taratuto
- Neuropathology and Neuromuscular Diseases Laboratory, Buenos Aires, Argentina
| | - María Saccoliti
- Neuropathology and Neuromuscular Diseases Laboratory, Buenos Aires, Argentina
| | - Cristina Noemi Alonso
- Genomics Laboratory, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
| | - Hilda Verónica Aráoz
- Department of Medical Genetics, Hospital de Pediatría "Juan P. Garrahan", Combate de los Pozos 1881, Buenos Aires 1245, Argentina
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Abstract
Mitochondria play various important roles in energy production, metabolism, and apoptosis. Mitochondrial dysfunction caused by alterations in mitochondrial DNA (mtDNA) can lead to the initiation and progression of cancers and other diseases. These alterations include mutations and copy number variations. Especially, the mutations in D-loop, MT-ND1, and MT-ND5 affect mitochondrial functions and are widely detected in various cancers. Meanwhile, several other mutations have been correlated with muscular and neuronal diseases, especially MT-TL1 is deeply related. These pieces of evidence indicated mtDNA alterations in diseases show potential as a novel therapeutic target. mtDNA repair enzymes are the target for delaying or stalling the mtDNA damage-induced cancer progression and metastasis. Moreover, some mutations reveal a prognosis ability of the drug resistance. Current efforts aim to develop mitochondrial transplantation technique as a direct cure for deregulated mitochondria-associated diseases. This review summarizes the implications of mitochondrial dysfunction in cancers and other pathologies; and discusses the relevance of mitochondria-targeted therapies, along with their contribution as potential biomarkers.
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Affiliation(s)
- Ngoc Ngo Yen Nguyen
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea.,Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea
| | - Sung Soo Kim
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Yong Hwa Jo
- Biomedical Science Institute, Kyung Hee University, Seoul, Republic of Korea.,Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
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Zhong S, Wen S, Qiu Y, Yu Y, Xin L, He Y, Gao X, Fang H, Hong D, Zhang J. Bilateral striatal necrosis due to homoplasmic mitochondrial 3697G>A mutation presents with incomplete penetrance and sex bias. Mol Genet Genomic Med 2019; 7:e541. [PMID: 30623604 PMCID: PMC6418351 DOI: 10.1002/mgg3.541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/09/2018] [Accepted: 12/02/2018] [Indexed: 12/28/2022] Open
Abstract
Background Heteroplasmic mitochondrial 3697G>A mutation has been associated with leber hereditary optic neuropathy (LHON), mitochondrial encephalopathy, lactic acidosis and stroke‐like episodes (MELAS), and LHON/MELAS overlap syndrome. However, homoplasmic m.3697G>A mutation was only found in a family with Leigh syndrome, and the phenotype and pathogenicity of this homoplasmic mutation still need to be investigated in new patients. Methods The clinical interviews were conducted in 12 individuals from a multiple‐generation inherited family. Mutations were screened through exome next‐generation sequencing and subsequently confirmed by PCR‐restriction fragment length polymorphism. Mitochondrial complex activities and ATP production rate were measured by biochemical analysis. Results The male offspring with bilateral striatal necrosis (BSN) were characterized by severe spastic dystonia and complete penetrance, while the female offspring presented with mild symptom and low penetrance. All offspring carried homoplasmic mutation of NC_012920.1: m.3697G>A, p.(Gly131Ser). Biochemical analysis revealed an isolated defect of complex I, but the magnitude of the defect was higher in the male patients than that in the female ones. The ATP production rate also exhibited a similar pattern. However, no possible modifier genes on the X chromosome were identified. Conclusion Homoplasmic m.3697G>A mutation could be associated with BSN, which expanded the clinical spectrum of m.3697G>A. Our preliminary investigations had not found the underlying modifiers to support the double hit hypothesis, while the high level of estrogens in the female patients might exert a potential compensatory effect on mutant cell metabolism.
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Affiliation(s)
- Shanshan Zhong
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Shumeng Wen
- Key Laboratory of Laboratory Medicine, College of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Yusen Qiu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yanyan Yu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ling Xin
- Department of Health, Exercise Science, and Recreation Management, University of Mississippi, University, Mississippi
| | - Yang He
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Xuguang Gao
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Hezhi Fang
- Key Laboratory of Laboratory Medicine, College of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
| | - Daojun Hong
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Jun Zhang
- Department of Neurology, Peking University People's Hospital, Beijing, China
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10
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Mauri E, Dilena R, Boccazzi A, Ronchi D, Piga D, Triulzi F, Gagliardi D, Brusa R, Faravelli I, Bresolin N, Magri F, Corti S, Comi GP. Subclinical Leber's hereditary optic neuropathy with pediatric acute spinal cord onset: more than meets the eye. BMC Neurol 2018; 18:220. [PMID: 30591017 PMCID: PMC6307307 DOI: 10.1186/s12883-018-1227-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 12/13/2018] [Indexed: 01/10/2023] Open
Abstract
Background Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by visual loss consequent to optic nerve atrophy. In some cases, LHON is associated with heterogeneous neurological extraocular manifestations and is referred to as “Leber plus disease”; rarely it is associated with a multiple sclerosis (MS)-like syndrome known as Harding disease, but no pediatric extraocular acute spinal onset is reported. Case presentation We describe the case of a 5-year-old girl carrying the G3460A mtDNA mutation who was referred to clinical examination for bilateral upper and lower limb weakness with no sign of optic neuropathy. Spinal cord MRI showed hyperintense signal alterations in T2-weighted and restricted diffusion in DWI sequences in the anterior portion of the cervical and dorsal spinal cord resembling a spinal cord vascular injury. No association between this mutation and pediatric spinal cord lesions has previously been reported. Alternative diagnostic hypotheses, including infective, ischemic and inflammatory disorders, were not substantiated by clinical and instrumental investigations. Conclusions Our case reports a novel pediatric clinical manifestation associated with the m.3460G > A mtDNA mutation, broadening the clinical spectrum of this disease. Early identification of new cases and monitoring of carriers beginning in childhood is important to prevent neurological deterioration and preserve long-term function.
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Affiliation(s)
- Eleonora Mauri
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Robertino Dilena
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Unit of Neurophysiopathology, Milan, Italy
| | - Antonio Boccazzi
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Pediatric Unit "Media Intensità di Cura", Milan, Italy
| | - Dario Ronchi
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Daniela Piga
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Fabio Triulzi
- Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neuroradiology Unit, Milan, Italy
| | - Delia Gagliardi
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Roberta Brusa
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Irene Faravelli
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy
| | - Nereo Bresolin
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Francesca Magri
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Stefania Corti
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy.,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy
| | - Giacomo P Comi
- Department of Pathophysiology and Transplantation, Dino Ferrari Centre, University of Milan, Milan, Italy. .,Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Neurology Unit, Milan, Italy.
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11
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Aretini P, Mazzanti CM, La Ferla M, Franceschi S, Lessi F, De Gregorio V, Nesti C, Valetto A, Bertini V, Toschi B, Battini R, Caligo MA. Next generation sequencing technologies for a successful diagnosis in a cold case of Leigh syndrome. BMC Neurol 2018; 18:99. [PMID: 30029642 PMCID: PMC6054728 DOI: 10.1186/s12883-018-1103-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 07/12/2018] [Indexed: 01/30/2023] Open
Abstract
Background Leigh Syndrome (LS, OMIM 256000) is an early-onset, progressive neurodegenerative disorder characterized by broad clinical and genetic heterogeneity; it is the most frequent disorder of mitochondrial energy production in children. LS inheritance is complex because patients may present mutations in mitochondrial DNA (mtDNA) or in nuclear genes, which predominantly encode proteins involved in respiratory chain structure and assembly or in coenzyme Q10 biogenesis. However, during the last 15 years, the discovery of several genetic mutations and improved knowledge of the natural history of LS has significantly increased our understanding of this mitochondrial disorder. Case presentation Here we describe a 19-year-old male with clinical and neuroimaging LS diagnosed at 3 years of age. Genetic analyses of the whole mtDNA for maternally inherited LS (MILS) and neuropathy ataxia retinitis pigmentosa (NARP) syndrome failed to reveal any pathogenic mutations. Conclusions Recently, a missense mutation in ECHS1 and a ~ 35 kb deletion in 10q26.3 involving the region including the gene were identified by WES (whole exome sequencing), uncovering the genetic diagnosis clinically hypothesized for 15 years. We also report the long-term follow-up of this patient, showing a comparison with classical LS or other Leigh-like pictures. Electronic supplementary material The online version of this article (10.1186/s12883-018-1103-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paolo Aretini
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Chiara Maria Mazzanti
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Marco La Ferla
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Sara Franceschi
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Francesca Lessi
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Veronica De Gregorio
- Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini, 13, 56017, San Giuliano Terme, Pisa, Italy
| | - Claudia Nesti
- Molecular Medicine, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy
| | - Angelo Valetto
- Cytogenetics Laboratory, Santa Chiara University Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Veronica Bertini
- Cytogenetics Laboratory, Santa Chiara University Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Benedetta Toschi
- Department of Clinical and Experimental Medicine, Santa Chiara University Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Roberta Battini
- Department of Clinical and Experimental Medicine, University of Pisa , Via Savi P, 56126, Pisa, Italy. .,Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy.
| | - Maria Adelaide Caligo
- Molecular Genetics Laboratory, Santa Chiara University Hospital, Via Roma 67, 56126, Pisa, Italy
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12
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Complete elimination of a pathogenic homoplasmic mtDNA mutation in one generation. Mitochondrion 2018; 45:18-21. [PMID: 29408632 DOI: 10.1016/j.mito.2018.01.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/17/2018] [Accepted: 01/26/2018] [Indexed: 01/23/2023]
Abstract
Mitochondrial DNA (mtDNA) mutations have been implicated in a wide variety of neurological conditions and are maternally inherited through a complex process which is not fully understood. Genetic counselling for mitochondrial conditions secondary to a mtDNA mutation can be challenging as it is not currently possible to accurately predict the mutational load/heteroplasmy of the mutation which could be passed to the offspring. In general, one expects that the higher the level of heteroplasmy the more likely that the same mtDNA mutation will be seen in the offspring. We report here a family which places a caveat on genetic counselling for mtDNA disorders. The proband is a 63 year old woman with m.14459G>A associated dystonia/spasticity/ataxia. The m.14459G>A mutation was detected at homoplasmic/near homoplasmic levels in her muscle tissue and fibroblasts, but did not appear to have been passed on to any of her offspring. To our knowledge, this is the first report of complete selection against a homoplasmic variant within maternally transmitted mtDNA. It is not clear if this novel phenomenon occurred by random chance or by another method of mitochondrial selection.
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13
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Hirayanagi K, Okamoto Y, Takai E, Ishizawa K, Makioka K, Fujita Y, Kaneko Y, Tanaka M, Takashima H, Ikeda Y. Bilateral striatal necrosis caused by a founder mitochondrial 14459G > A mutation in two independent Japanese families. J Neurol Sci 2017; 378:177-181. [DOI: 10.1016/j.jns.2017.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/01/2017] [Accepted: 05/09/2017] [Indexed: 02/08/2023]
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14
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Miryounesi M, Fardaei M, Tabei SM, Ghafouri-Fard S. Leigh syndrome associated with a novel mutation in the COX15 gene. J Pediatr Endocrinol Metab 2016; 29:741-4. [PMID: 26959537 DOI: 10.1515/jpem-2015-0396] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/04/2016] [Indexed: 11/15/2022]
Abstract
Leigh syndrome (LS) is a subacute necrotizing encephalomyelopathy with a diverse range of symptoms, such as psychomotor delay or regression, weakness, hypotonia, truncal ataxia, intention tremor as well as lactic acidosis in the blood, cerebrospinal fluid or urine. Both nuclear gene defects and mutations of the mitochondrial genome have been detected in these patients. Here we report a 7-year-old girl with hypotonia, tremor, developmental delay and psychomotor regression. However, serum lactate level as well as brain magnetic resonance imaging were normal. Mutational analysis has revealed a novel mutation in exon 4 of COX15 gene (c.415C>G) which results in p.Leu139Val. Previous studies have demonstrated that COX15 mutations are associated with typical LS as well as fatal infantile hypertrophic cardiomyopathy. Consequently, clinical manifestations of COX15 mutations may be significantly different in patients. Such information is of practical importance in genetic counseling.
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15
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Paquay S, Benoit V, Wetzburger C, Cordonnier M, Meire F, Charon A, Roland D, Van Coster R, Nassogne MC, Maystadt I. Uncommon Leber "plus" disease associated with mitochondrial mutation m.11778G>A in a premature child. J Child Neurol 2014; 29:NP18-23. [PMID: 23864591 DOI: 10.1177/0883073813492895] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Indexed: 11/16/2022]
Abstract
Leber hereditary optic neuropathy is a well-known mitochondrial disorder that leads to bilateral subacute visual failure. Although visual impairment is often the sole clinical feature, additional and severe neurologic abnormalities also have been documented for this disease. We report on a 13-year-old boy who has presented with severe visual failure since early childhood in a context of prematurity. In the first years of his life, clinical features included delayed psychomotor development and ataxia. The clinical presentation, which was initially attributed to prematurity, worsened thereafter, and the child developed acute neurologic degradation with the typical radiological findings of Leigh syndrome. The mitochondrial DNA point mutation 11778G>A was identified in the ND4 gene. The probable influence of environmental background on clinical expression of Leber optic neuropathy, particularly those of prematurity and oxygen therapy, is discussed in our manuscript.
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Affiliation(s)
- Stéphanie Paquay
- Service de Neurologie Pédiatrique, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Valérie Benoit
- Département de Biologie Moléculaire, Institut de Pathologie et de Génétique, Gosselies, Belgium
| | - Catherine Wetzburger
- Service de Neurologie Pédiatrique, Centre Hospitalier Universitaire de Charleroi, Charleroi, Belgium
| | - Monique Cordonnier
- Service d'Ophtalmologie, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Françoise Meire
- Service d'Ophtalmologie, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
| | - Anne Charon
- Service de Néonatologie, Grand Hôpital de Charleroi, Charleroi, Belgium
| | - Dominique Roland
- Centre des Maladies Métaboliques, Institut de Pathologie et de Génétique, Gosselies, Belgium
| | - Rudy Van Coster
- Department of Pediatrics and Medical Genetics, University of Ghent, Ghent, Belgium
| | - Marie-Cécile Nassogne
- Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Isabelle Maystadt
- Centre de Génétique Humaine, Institut de Pathologie et de Génétique, Gosselies, Belgium
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16
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Novel mitochondrial C15620A variant may modulate the phenotype of mitochondrial G11778A mutation in a Chinese family with Leigh syndrome. Neuromolecular Med 2013; 16:119-26. [PMID: 24062162 DOI: 10.1007/s12017-013-8264-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/03/2013] [Indexed: 01/25/2023]
Abstract
We report a case of 3-year-old boy who presented with Leigh syndrome but carried a mitochondrial G11778A mutation in the fourth subunit of the NADH dehydrogenase gene (MTND4). Additional to G11778A mutation, a novel C15620A variant was detected, which resulted in the conversion from leucine to isoleucine in the mitochondrial cytochrome b gene. As G11778A mutation is the most common mutation associated with Leber's hereditary optic neuropathy (LHON), given the unusual phenotype, the C15620A mutation was postulated to influence the pathogenicity of the G11778A mutation. This case further expands the clinical spectrum associated with the primary G11778A LHON mutation.
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17
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Meunier B, Fisher N, Ransac S, Mazat JP, Brasseur G. Respiratory complex III dysfunction in humans and the use of yeast as a model organism to study mitochondrial myopathy and associated diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:1346-61. [PMID: 23220121 DOI: 10.1016/j.bbabio.2012.11.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 11/21/2012] [Accepted: 11/28/2012] [Indexed: 11/25/2022]
Abstract
The bc1 complex or complex III is a central component of the aerobic respiratory chain in prokaryotic and eukaryotic organisms. It catalyzes the oxidation of quinols and the reduction of cytochrome c, establishing a proton motive force used to synthesize adenosine triphosphate (ATP) by the F1Fo ATP synthase. In eukaryotes, the complex III is located in the inner mitochondrial membrane. The genes coding for the complex III have a dual origin. While cytochrome b is encoded by the mitochondrial genome, all the other subunits are encoded by the nuclear genome. In this review, we compile an exhaustive list of the known human mutations and associated pathologies found in the mitochondrially-encoded cytochrome b gene as well as the fewer mutations in the nuclear genes coding for the complex III structural subunits and accessory proteins such as BCS1L involved in the assembly of the complex III. Due to the inherent difficulties of studying human biopsy material associated with complex III dysfunction, we also review the work that has been conducted to study the pathologies with the easy to handle eukaryotic microorganism, the yeast Saccharomyces cerevisiae. Phenotypes, biochemical data and possible effects due to the mutations are also discussed in the context of the known three-dimensional structure of the eukaryotic complex III. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- B Meunier
- CNRS, Centre de Génétique Moléculaire, UPR 3404, Gif-sur-Yvette, F-91198, France
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18
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Saracchi E, Difrancesco JC, Brighina L, Marzorati L, Curtò NA, Lamperti C, Carrara F, Zeviani M, Ferrarese C. A case of Leber hereditary optic neuropathy plus dystonia caused by G14459A mitochondrial mutation. Neurol Sci 2012; 34:407-8. [PMID: 22426787 DOI: 10.1007/s10072-012-1013-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Accepted: 03/07/2012] [Indexed: 11/29/2022]
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19
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Roshan M, Kabekkodu SP, Vijaya PH, Manjunath K, Graw J, Gopinath PM, Satyamoorthy K. Analysis of mitochondrial DNA variations in Indian patients with congenital cataract. Mol Vis 2012; 18:181-93. [PMID: 22312186 PMCID: PMC3272057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 01/17/2012] [Indexed: 10/29/2022] Open
Abstract
PURPOSE Identification of mitochondrial DNA (mtDNA) variations in the inherited cataract patients from south India. METHODS Three families with inherited cataract of maternal origin were evaluated. Clinical and ophthalmologic examinations were performed on available affected as well as unaffected family members. Samples of mtDNA were amplified using 24 pairs of overlapping primers to analyze the entire mitochondrial genome to screen for variations and analyzed for both coding and non-coding regions. Bioinformatic analysis was performed to evaluate the effect of nucleotide variations. RESULTS DNA sequence analysis of inherited cataract families showed 72 nucleotide variations, of which 15 were observed in the major non-coding D-loop region, 3 in the tRNA genes, 5 in the rRNA genes, and 49 in the protein coding region. Among these variations 56 were reported previously and 16 were novel of which, 12 synonymous substitutions, 2 non-synonymous substitutions along with a frameshift mutation, and one was in the non-coding region. Nicotinamide adenine dinucleotide dehydrogenase (NADH) subunit (ND) gene of mtDNA was highly altered, in general, and found to contain 4 variations specific for cataract patients of the first family, six for the second, and one for the third family. CONCLUSIONS Seventy-two variations were observed in three inherited cataract families. Four variations were specific for cataract patients of the first family, six for the second, and one for the third family. This is perhaps the first report on the presence of mitochondrial mutations in inherited cataracts.
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Affiliation(s)
- Mascarenhas Roshan
- Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Manipal, India
| | | | - Pai H. Vijaya
- Department of Ophthalmology, Kasturba Hospital, Manipal University, Manipal, India
| | - Kamath Manjunath
- Department of Ophthalmology, Government Wenlock Hospital, Mangalore, India
| | - Jochen Graw
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
| | - PM. Gopinath
- Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Manipal, India
| | - Kapeattu Satyamoorthy
- Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Manipal, India
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