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Yang HK, Seong MW, Kim JY, Park SS, Hwang JM. Poor visual prognosis of Asian patients with 3460 mitochondrial DNA mutation in Leber's hereditary optic neuropathy. CANADIAN JOURNAL OF OPHTHALMOLOGY 2024:S0008-4182(24)00095-4. [PMID: 38593981 DOI: 10.1016/j.jcjo.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/07/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024]
Abstract
BACKGROUND Among the 3 primary mutations of Leber's hereditary optic neuropathy (LHON), the incidence of LHON with a mutation at nucleotide position 3460 is the lowest in Asians. Therefore, information about the clinical manifestations of LHON mutations in Asians with the 3460 mutation is limited. OBJECTIVE To determine the clinical manifestations including visual prognosis of Asians with the LHON 3460 mutation. METHODS We performed a retrospective study of 5 Korean LHON patients with the 3460 mutation. RESULTS All patients were male, and the age of onset for visual impairment varied from 17 to 35 years, with an average of 25.4 ± 7.16 years. Among the 10 affected eyes, only 1 eye of 1 patient showed visual improvement to 20/50 at 2 years after onset. The remaining patients had a visual acuity of worse than 20/200. CONCLUSION The visual prognosis of Korean patients with the LHON 3460 mutation was generally poor. Further studies regarding Asian patients with the LHON 3460 mutation are necessary.
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Affiliation(s)
- Hee Kyung Yang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Ji Yeon Kim
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea; Clavis Therapeutics, Inc, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jeong-Min Hwang
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
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Wan X, Chen J, Wu Y, Chen Z, Liu Y, Li T, Sun J, Zhang T, Zhou F, Huang X, Li Y, Wang X, Sun X. Rapid and Sensitive Diagnosis of Leber Hereditary Optic Neuropathy Variants Using CRISPR/Cas12a Detection. J Mol Diagn 2023; 25:540-554. [PMID: 37517824 DOI: 10.1016/j.jmoldx.2023.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/08/2022] [Accepted: 04/05/2023] [Indexed: 08/01/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common maternally inherited mitochondrial disease, with >90% of cases harboring one of three point variants (m.3460G>A, m.11778G>A, and m.14484T>C). Rapid and sensitive diagnosis of LHON variants is urgently needed for early diagnosis and timely treatment after onset, which is currently limited. Herein, we adapted the Cas12a-based DNA detection platform for LHON mitochondrial variant diagnosis. Single-strand guide CRISPR RNAs and enzymatic recombinase amplification primers were first screened, the CRISPR/Cas12a system was then optimized with restriction enzymes, and finally compared with Sanger sequencing and next-generation sequencing (NGS) in multicenter clinical samples. This approach can be completed within 30 minutes using only one drop of blood and could reach a sensitivity of 1% of heteroplasmy. Among the 182 multicenter clinical samples, the CRISPR/Cas12a detection system showed high consistency with Sanger sequencing and NGS in both specificity and sensitivity. Notably, a sample harboring a de novo 3.78% m.11778G>A variant detected by NGS, but not by Sanger sequencing, was successfully confirmed using the CRISPR/Cas12a assay, which proved the effectiveness of our method. Overall, our CRISPR/Cas12a detection system provides an alternative for rapid, convenient, and sensitive detection of LHON variants, exhibiting great potential for clinical practice.
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Affiliation(s)
- Xiaoling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Jieqiong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yidong Wu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Zhixuan Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Yin Liu
- Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Tong Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Junran Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Ting Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China
| | - Fuling Zhou
- Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xingxu Huang
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Xinjie Wang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rula Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai, China; Shanghai Key Laboratory of Fundus Diseases, Shanghai, China; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China.
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Zheng Y, Jia X, Li S, Xiao X, Zhang Q, Wang P. Non-Pharmaceutical Interventions against COVID-19 Causing a Lower Trend in Age of LHON Onset. Genes (Basel) 2023; 14:1253. [PMID: 37372433 DOI: 10.3390/genes14061253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/06/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) is a monogenic but multifactorial disease vulnerable to environmental triggers. Little is known about how LHON onset changed during the COVID-19 pandemic and how non-pharmaceutical interventions (NPHIs) against COVID-19 impact LHON onset. One hundred and forty-seven LHON patients with the m.11778G>A mutation complaining of vision loss were involved between January 2017 and July 2022. The onset time points, age of onset, and possible risk factors were evaluated. Analyses were conducted among 96 LHON patients in the Pre-COVID-19 group and 51 in the COVID-19 group. The median (IQR) age of onset decreased significantly from 16.65 (13.739, 23.02) in pre-COVID-19 to 14.17 (8.87, 20.29) during COVID-19. Compared with the Pre-COVID-19 group, the COVID-19 group exhibited bimodal distribution with an additional peak at six; the first quarter of 2020 also witnessed a relatively denser onset, with no subsequent second spike. NPHIs against COVID-19 significantly changed patients' lifestyles, including higher secondhand smoke exposure (p < 0.001), adherence to masks (p < 0.001), reduction in time spent outdoors for leisure (p = 0.001), and prolonged screen time (p = 0.007). Multivariate logistic regression revealed that secondhand smoke exposure and mask-wearing were independent risk factors of younger LHON onset. Lower age of onset of LHON appeared after the breakout of the COVID-19 pandemic, and novel risk factors were detected, including secondhand exposure and long mask-wearing. Carriers of LHON mtDNA mutations, especially teenagers or children, should be advised to avoid secondhand smoke exposure and there are possible adverse outcomes of longer mask-wearing.
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Affiliation(s)
- Yuxi Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, 54 Xianlie Road, Guangzhou 510060, China
- Gene Diagnostic Laboratory, Genetic Eye Clinic, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 Xianlie Road, Guangzhou 510060, China
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Buonfiglio PI, Menazzi S, Francipane L, Lotersztein V, Ferreiro V, Elgoyhen AB, Dalamón V. Mitochondrial DNA variants in a cohort from Argentina with suspected Leber's hereditary optic neuropathy (LHON). PLoS One 2023; 18:e0275703. [PMID: 36827238 PMCID: PMC9956067 DOI: 10.1371/journal.pone.0275703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/31/2023] [Indexed: 02/25/2023] Open
Abstract
The present study investigates the spectrum and analysis of mitochondrial DNA (mtDNA) variants associated with Leber hereditary optic neuropathy (LHON) in an Argentinean cohort, analyzing 3 LHON-associated mitochondrial genes. In 32% of the cases, molecular confirmation of the diagnosis could be established, due to the identification of disease-causing variants. A total of 54 variants were observed in a cohort of 100 patients tested with direct sequencing analysis. The frequent causative mutations m.11778G>A in MT-ND4, m.3460G>A in MT-ND1, and m.14484T>C in MT-ND6 were identified in 28% of the cases of our cohort. Secondary mutations in this Argentinean LHON cohort were m.11253T>C p.Ile165Thr in MT-ND4, identified in three patients (3/100, 3%) and m.3395A>G p.Tyr30Cys in MT-ND1, in one of the patients studied (1%). This study shows, for the first time, the analysis of mtDNA variants in patients with a probable diagnosis of LHON in Argentina. Standard molecular methods are an effective first approach in order to achieve genetic diagnosis of the disease, leaving NGS tests for those patients with negative results.
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Affiliation(s)
- Paula I. Buonfiglio
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas - INGEBI / CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Sebastián Menazzi
- División Genética, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Liliana Francipane
- División Genética, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Vanesa Lotersztein
- Servicio de Genética, Hospital Militar Central “Dr. Cosme Argerich”, Ciudad Autónoma de Buenos Aires, Argentina
| | | | - Ana Belén Elgoyhen
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas - INGEBI / CONICET, Ciudad Autónoma de Buenos Aires, Argentina
- División Genética, Hospital de Clínicas “José de San Martín”, Ciudad Autónoma de Buenos Aires, Argentina
- Servicio de Genética, Hospital Militar Central “Dr. Cosme Argerich”, Ciudad Autónoma de Buenos Aires, Argentina
- Laboratorio Genos, Ciudad Autónoma de Buenos Aires, Argentina
- Departamento de Farmacología, Facultad de Medicina, Universidad de Buenos Aires, C1121ABG, Ciudad Autónoma de Buenos Aires, Argentina
| | - Viviana Dalamón
- Laboratorio de Fisiología y Genética de la Audición, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres”, Consejo Nacional de Investigaciones Científicas y Técnicas - INGEBI / CONICET, Ciudad Autónoma de Buenos Aires, Argentina
- * E-mail:
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Leber's Hereditary Optic Neuropathy with Mitochondrial DNA Mutation G11778A: A Systematic Literature Review and Meta-Analysis. BIOMED RESEARCH INTERNATIONAL 2023; 2023:1107866. [PMID: 36743514 PMCID: PMC9893526 DOI: 10.1155/2023/1107866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/26/2023]
Abstract
Background LHON is a progressive disease with early disease onset and male predominance, usually causing devastating visual loss to patients. These systematic review and meta-analysis are aimed at summarizing epidemiology, disease onset and progression, visual recovery, risk factors, and treatment options of Leber's hereditary optic neuropathy (LHON) with mitochondrial DNA mutation G11778A from current evidence. Methods The PubMed database was examined from its inception date to November 2021. Data from included studies were pooled with either a fixed-effects model or a random-effects model, depending on the results of heterogeneity tests. Sensitivity analysis was conducted to test the robustness of results. Results A total of 41 articles were included in the systematic review for qualitative analysis, and 34 articles were included for quantitative meta-analysis. The pooled estimate of proportion of G11778A mutation among the three primary mutations of mitochondrial DNA (G11778A, G3460A, and T14484C) for LHON was 73% (95% CI: 67% and 79%), and the LHON patients with G11778A mutation included the pooled male ratio estimate of 77% (76% and 79%), the pooled age estimate of 35.3 years (33.2 years and 37.3 years), the pooled onset age estimate of 22.1 years (19.7 years and 24.6 years), the pooled visual acuity estimate of 1.4 LogMAR (1.2 LogMAR and 1.6 LogMAR), and the pooled estimate of spontaneous visual recovery rate (in either 1 eye) of 20% (15% and 27%). Conclusions The G11778A mutation is a prevalent mitochondrial DNA mutation accounting for over half of LHON cases with three primary mutations. Spontaneous visual recovery is rare, and no effective treatment is currently available.
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Barboni P, La Morgia C, Cascavilla ML, Hong EH, Battista M, Majander A, Caporali L, Starace V, Amore G, Renzo AD, Carbonelli M, Nucci P, Jurkute N, Chen BS, Panebianco R, De Negri AM, Sadun F, Parisi V, Bandello F, Sadun AA, Carelli V, Yu-Wai-Man P. Childhood-Onset Leber Hereditary Optic Neuropathy-Clinical and Prognostic Insights. Am J Ophthalmol 2022; 249:99-107. [PMID: 36543315 DOI: 10.1016/j.ajo.2022.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE To investigate the clinical and molecular genetic features of childhood-onset Leber hereditary optic neuropathy (LHON) to gain a better understanding of the factors influencing the visual outcome in this atypical form of the disease. DESIGN Retrospective cohort study. METHODS We retrospectively included 2 cohorts of patients with LHON with onset of visual loss before the age of 12 years from Italy and the United Kingdom. Ophthalmologic evaluation, including best-corrected visual acuity, orthoptic evaluation, slit-lamp biomicroscopy, visual field testing, and optical coherence tomography, was considered. Patients were classified based on both the age of onset and the pattern of visual loss. RESULTS A total of 68 patients were stratified based on the age of onset of visual loss: group 1 (<3 years): 14 patients (20.6%); group 2 (≥3 to <9 years): 27 patients (39.7%); and group 3 (≥9 to ≤12 years): 27 patients (39.7%). Patients in group 2 achieved a better visual outcome than those in group 3. Patients in groups 1 and 2 had better mean deviation on visual field testing than those in group 3. The mean ganglion cell layer thickness on optical coherence tomography in group 2 was higher than those in groups 1 and 3. Patients were also categorized based on the pattern of visual loss as follows: Subacute Bilateral: 54 patients (66.7%); Insidious Bilateral: 14 patients (17.3%); Unilateral: 9 patients (11.1%); and Subclinical Bilateral: 4 patients (4.9%). CONCLUSIONS Children who lose vision from LHON before the age of 9 years have a better visual prognosis than those who become affected in later years, likely representing a "form frustre" of the disease.
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Affiliation(s)
- Piero Barboni
- From the Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan (P.B., M.L.C., M.B., V.S., F.B.); Department of ophthalmology, Studio Oculistico d'Azeglio (P.B., M.C.).
| | - Chiara La Morgia
- Department of ophthalmology, IRCCS Istituto delle Scienze Neurologiche di Bologna, (C.L.M., L.C., V.C.) Bologna, Italy
| | - Maria Lucia Cascavilla
- From the Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan (P.B., M.L.C., M.B., V.S., F.B.)
| | - Eun Hee Hong
- Moorfields Eye Hospital, London, United Kingdom (E.H.H., A.M., N.J., P.Y-W-M.); Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Korea (E.H.H.)
| | - Marco Battista
- From the Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan (P.B., M.L.C., M.B., V.S., F.B.)
| | - Anna Majander
- Moorfields Eye Hospital, London, United Kingdom (E.H.H., A.M., N.J., P.Y-W-M.); UCL Institute of Ophthalmology, University College London, London, United Kingdom (A.M., N.J., P.Y-W-M.); Department of Ophthalmology, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland (A.M.)
| | - Leonardo Caporali
- Department of ophthalmology, IRCCS Istituto delle Scienze Neurologiche di Bologna, (C.L.M., L.C., V.C.) Bologna, Italy
| | - Vincenzo Starace
- From the Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan (P.B., M.L.C., M.B., V.S., F.B.)
| | - Giulia Amore
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna (G.A., M.C., V.C.)
| | | | - Michele Carbonelli
- Department of ophthalmology, Studio Oculistico d'Azeglio (P.B., M.C.); Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna (G.A., M.C., V.C.)
| | - Paolo Nucci
- Department of Clinical Science and Community Health, University of Milan, Milan, (P.N.), Italy
| | - Neringa Jurkute
- Moorfields Eye Hospital, London, United Kingdom (E.H.H., A.M., N.J., P.Y-W-M.); UCL Institute of Ophthalmology, University College London, London, United Kingdom (A.M., N.J., P.Y-W-M.)
| | - Benson S Chen
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge (B.S.C., P.Y-W-M.); Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, (B.S.C., P.Y-W-M.), Cambridge, United Kingdom
| | | | | | | | - Vincenzo Parisi
- IRCCS G.B. Bietti Foundation I.R.C.C.S., Rome (A.D.R., V.P.)
| | - Francesco Bandello
- From the Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan (P.B., M.L.C., M.B., V.S., F.B.)
| | - Alfredo A Sadun
- and Doheny Eye Institute/UCLA School of Medicine, Los Angeles, California, USA (A.A.S)
| | - Valerio Carelli
- Department of ophthalmology, IRCCS Istituto delle Scienze Neurologiche di Bologna, (C.L.M., L.C., V.C.) Bologna, Italy; Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna (G.A., M.C., V.C.)
| | - Patrick Yu-Wai-Man
- Moorfields Eye Hospital, London, United Kingdom (E.H.H., A.M., N.J., P.Y-W-M.); UCL Institute of Ophthalmology, University College London, London, United Kingdom (A.M., N.J., P.Y-W-M.); Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge (B.S.C., P.Y-W-M.); Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, (B.S.C., P.Y-W-M.), Cambridge, United Kingdom
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Sathianvichitr K, Sigkaman B, Chirapapaisan N, Laowanapiban P, Padungkiatsagul T, Apinyawasisuk S, Witthayaweerasak J, Chuenkongkaew W. The epidemiology and mutation types of Leber's hereditary optic neuropathy in Thailand. Ann Med 2022; 54:1601-1607. [PMID: 35723074 PMCID: PMC9191831 DOI: 10.1080/07853890.2022.2082517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE Leber's hereditary optic neuropathy (LHON), the most common mitochondrial optic neuropathy, causes visual loss, especially in young adults. Due to the absence of epidemiological data in Southeast Asia, we aimed to determine Thai LHON patients' characteristics (demographic data, mutation types, and prognoses) as the first study in this region. METHODS This retrospective chart review enrolled all Thai LHON patients confirmed by three mitochondrial DNA mutations (G11778A, T14484C, and G3460A) between January 1997 and December 2016. Patients with more than one year of follow-up were included in a visual progression analysis. The Mann-Whitney U-test was applied to compare groups, and prognosis-associated factors were analysed with the generalized estimating equation. RESULTS In all, 229 patients were enrolled, with only nineteen females. Most mutations were of the G11778A type (91%), with T14484C accounting for the remainder. The age at onset of G11778A (21.9 years; interquartile range [IQR] 14.9, 33.5) was younger than that of T14484C (33.0 years; IQR 19.4, 37.5). Of 45 patients, the T14484C group demonstrated good vision recovery, whereas the G11778A group did not improve (difference in logMAR -0.7 and IQR -1.5, -0.2 versus logMAR 0.0 and IQR -0.3, 0.2, respectively; P value .001). The G11778A mutation, male, and older age were related to poor prognoses. CONCLUSIONS The leading mutation in Thai LHON patients is the G11778A missense, followed by T14484C, while G3460A was not detected. The vast majority of patients were young adult males. The G11778A mutation, older age, and male gender are associated with poor vision outcomes. Key messageThe G11778A missense mutation is the most common among Thai LHON patients, followed by T14484C, while G3460A was not found. The G11778A mutation, older age, and male gender are associated with poor vision outcomes.
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Affiliation(s)
- Kanchalika Sathianvichitr
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Benjaporn Sigkaman
- Department of Ophthalmology, Bhumibol Adulyadej Hospital, Bangkok, Thailand
| | - Niphon Chirapapaisan
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Poramaet Laowanapiban
- Ophthalmology Service, Mettapracharak (Wat Rai Khing) Hospital, Nakhon Pathom, Thailand
| | - Tanyatuth Padungkiatsagul
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Supanut Apinyawasisuk
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Ophthalmology Department, King Chulalongkorn Memorial Hospital, Bangkok, Thailand
| | | | - Wanicha Chuenkongkaew
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Wilson V, Kaur P, Singh S, Ramachandran RP, Jyothi V, Mahesh KV, Takkar A, Chandak G, Singh R. Clinical Profile of Patients with Leber Hereditary Optic Neuropathy (LHON): An Ambispective Study of North Indian Cohorts. Ann Indian Acad Neurol 2022; 25:S65-S69. [PMID: 36589039 PMCID: PMC9795704 DOI: 10.4103/aian.aian_532_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 01/04/2023] Open
Abstract
Background Leber hereditary optic neuropathy (LHON) is a maternally inherited disease resulting in irreversible visual loss usually in patients belonging to the age group of 15-35 years. Clinically, the patients present with sequential or bilateral, painless, progressive visual loss with central (or ceco-central) scotomas. Although the three mutations, namely, G11778A, T14484C, and G3460A contribute to >95% of LHON cases globally, the relative frequency of each mutation varies. Aims and Objectives We aimed to assess the clinical and genetic profile of patients with mutation-positive LHON at a north Indian tertiary care center. Materials and Methodology One hundred sixty-one patients (61 prospective and 100 retrospective) presenting with the clinical diagnosis of LHON were screened for the three known mitochondrial mutations (G1178A, G3460A, T14448C). Patients were assessed for detailed clinical, ophthalmological, and neurological examinations. Five milliliter of blood sample was taken to assess the three known mutations using DNA isolation and Sanger sequencing. Results and Discussion Clinical profile of 83 patients with both positive and negative mutations was analyzed. Twenty-three out of 161 patients (14.3%) tested positive for either of the three mutations. The majority of the patients harbored G11778A mutation (56.52%) followed by T14484C (34.78%) and G3460A (8.69%). No statistical difference could be noted between the clinical profiles of mutation-negative and -positive patients.
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Affiliation(s)
- Vinny Wilson
- Department of Neurology, Armed Forces Medical College, Pune, Maharashtra, India
| | - Prabhjit Kaur
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Sofia Singh
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Radhika P. Ramachandran
- Genomic Research on Complex Diseases Laboratory (GRC Lab), CSIR-Center for Cellular and Molecular Biology (CCMB), Hyderabad, India
| | - Vislavath Jyothi
- Genomic Research on Complex Diseases Laboratory (GRC Lab), CSIR-Center for Cellular and Molecular Biology (CCMB), Hyderabad, India
| | - Karthik V. Mahesh
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Aastha Takkar
- Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh, India,Address for correspondence: Dr. Aastha Takkar, Department of Neurology, Post Graduate Institute of Medical Education and Research, Chandigarh - 160 012, India. E-mail:
| | - Giriraj Chandak
- Genomic Research on Complex Diseases Laboratory (GRC Lab), CSIR-Center for Cellular and Molecular Biology (CCMB), Hyderabad, India
| | - Ramandeep Singh
- Department of Ophthalmology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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9
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Kuan SW, Chua KH, Tan EW, Tan LK, Loch A, Kee BP. Whole mitochondrial genome sequencing of Malaysian patients with cardiomyopathy. PeerJ 2022; 10:e13265. [PMID: 35441061 PMCID: PMC9013480 DOI: 10.7717/peerj.13265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/23/2022] [Indexed: 01/13/2023] Open
Abstract
Cardiomyopathy (CMP) constitutes a diverse group of myocardium diseases affecting the pumping ability of the heart. Genetic predisposition is among the major factors affecting the development of CMP. Globally, there are over 100 genes in autosomal and mitochondrial DNA (mtDNA) that have been reported to be associated with the pathogenesis of CMP. However, most of the genetic studies have been conducted in Western countries, with limited data being available for the Asian population. Therefore, this study aims to investigate the mutation spectrum in the mitochondrial genome of 145 CMP patients in Malaysia. Long-range PCR was employed to amplify the entire mtDNA, and whole mitochondrial genome sequencing was conducted on the MiSeq platform. Raw data was quality checked, mapped, and aligned to the revised Cambridge Reference Sequence (rCRS). Variants were named, annotated, and filtered. The sequencing revealed 1,077 variants, including 18 novel and 17 CMP and/or mitochondrial disease-associated variants after filtering. In-silico predictions suggested that three of the novel variants (m.8573G>C, m.11916T>A and m.11918T>G) in this study are potentially pathogenic. Two confirmed pathogenic variants (m.1555A>G and m.11778G>A) were also found in the CMP patients. The findings of this study shed light on the distribution of mitochondrial mutations in Malaysian CMP patients. Further functional studies are required to elucidate the role of these variants in the development of CMP.
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Affiliation(s)
- Sheh Wen Kuan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - E-Wei Tan
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lay Koon Tan
- National Heart Institute, Kuala Lumpur, Malaysia
| | - Alexander Loch
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon Pin Kee
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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10
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Tian Z, Li X, Zheng W, Li B, Zhang Y. Variation in retinal nerve fiber layer thickness at different stages of Leber's hereditary optic neuropathy in patients with the ND4 G11778A mutation. Semin Ophthalmol 2021; 37:496-501. [PMID: 34702118 DOI: 10.1080/08820538.2021.1986078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To investigate retinal nerve fiber layer (RNFL) thickness changes at different stages of Leber's hereditary optic neuropathy (LHON) in patients bearing the ND4 G11778A mutation. METHODS Ninety-eight clinically diagnosed, G11778A-positive LHON patients underwent 538 optical coherence tomography (OCT) examinations from September 2015 to September 2017. Patients were grouped based on disease duration at examination. Fifty healthy volunteers underwent 100 examinations as controls. Differences in RNFL thickness were compared across groups. RESULTS During the onset of LHON patients with G11778A mutation, the thickness of nerve fiber layer in temporal quadrant decreased slowly within 1-3 months (p > .05), then entered in the rapid thinning period, which generally lasted until about 12 months of the course of disease (p < .05), and no obvious change occurred in the stable stage (p > .05); The optic nerve fiber layer in other quadrants was usually stayed in a significant thickening period within 1-3 months (p < .05), then entered in the rapid thinning period, which generally lasted until about 24 months of the course of disease (p < .05), and no obvious change occurred in the stable stage (p > .05) . CONCLUSION In LHON patients with G11778A mutation, the thickness of optic nerve fiber layer in the temporal side will experience slow thinning stage, rapid thinning stage and stable stage; The thickness of optic nerve fiber layer in other directions varies with the course of disease. Generally, it will experience five periods: significant thickening period, swelling period, recovery period, rapid thinning period and stable period.
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Affiliation(s)
- Zhen Tian
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Xin Li
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Wu Zheng
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Bin Li
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province, China
| | - Yong Zhang
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei Province, China
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Sundaramurthy S, SelvaKumar A, Ching J, Dharani V, Sarangapani S, Yu-Wai-Man P. Leber hereditary optic neuropathy-new insights and old challenges. Graefes Arch Clin Exp Ophthalmol 2021; 259:2461-2472. [PMID: 33185731 DOI: 10.1007/s00417-020-04993-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/16/2020] [Accepted: 10/23/2020] [Indexed: 12/20/2022] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial DNA (mtDNA) disorder with the majority of patients harboring one of three primary mtDNA point mutations, namely, m.3460G>A (MTND1), m.11778G>A (MTND4), and m.14484T>C (MTND6). LHON is characterized by bilateral subacute loss of vision due to the preferential loss of retinal ganglion cells (RGCs) within the inner retina, resulting in optic nerve degeneration. This review describes the clinical features associated with mtDNA LHON mutations and recent insights gained into the disease mechanisms contributing to RGC loss in this mitochondrial disorder. Although treatment options remain limited, LHON research has now entered an active translational phase with ongoing clinical trials, including gene therapy to correct the underlying pathogenic mtDNA mutation.
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Affiliation(s)
- Srilekha Sundaramurthy
- 1SN Oil and Natural Gas Corporation (ONGC) Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai, India.
| | - Ambika SelvaKumar
- Department of Neuro-Ophthalmology, Medical Research Foundation, Chennai, India
| | - Jared Ching
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- John Van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Vidhya Dharani
- Department of Neuro-Ophthalmology, Medical Research Foundation, Chennai, India
| | - Sripriya Sarangapani
- 1SN Oil and Natural Gas Corporation (ONGC) Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai, India
| | - Patrick Yu-Wai-Man
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- John Van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- NIHR Biomedical Research Centre, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
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12
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Mitochondrial Genetic Heterogeneity in Leber's Hereditary Optic Neuropathy: Original Study with Meta-Analysis. Genes (Basel) 2021; 12:genes12091300. [PMID: 34573281 PMCID: PMC8472268 DOI: 10.3390/genes12091300] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/06/2021] [Accepted: 08/08/2021] [Indexed: 11/17/2022] Open
Abstract
Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disorder that causes loss of central vision. Three primary variants (m.3460G>A, m.11778G>A, and m.14484T>C) and about 16 secondary variants are responsible for LHON in the majority of the cases. We investigated the complete mitochondrial DNA (mtDNA) sequences of 189 LHON patients and found a total of 54 disease-linked pathogenic variants. The primary variants m.11778G>A and m.14484T>C were accountable for only 14.81% and 2.64% cases, respectively. Patients with these two variants also possessed additional disease-associated variants. Among 156 patients who lacked the three primary variants, 16.02% harboured other LHON-associated variants either alone or in combination with other disease-associated variants. Furthermore, we observed that none of the haplogroups were explicitly associated with LHON. We performed a meta-analysis of m.4216T>C and m.13708G>A and found a significant association of these two variants with the LHON phenotype. Based on this study, we recommend the use of complete mtDNA sequencing to diagnose LHON, as we found disease-associated variants throughout the mitochondrial genome.
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13
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Shuai J, Shi J, Liang Y, Ji F, Gu L, Yuan Z. Mutational analysis of mitochondrial tRNA genes in 138 patients with Leber's hereditary optic neuropathy. Ir J Med Sci 2021; 191:865-876. [PMID: 34053002 DOI: 10.1007/s11845-021-02656-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Mutations in mitochondrial DNA (mtDNA) are the most important causes for Leber's hereditary optic neuropathy (LHON). Of these, three primary mtDNA mutations account for more than 90% cases of this disease. However, to date, little is known regarding the relationship between mitochondrial tRNA (mt-tRNA) variants and LHON. AIM In this study, we aimed to investigate the association between mt-tRNA variants and LHON. METHODOLOGY One hundred thirty-eight LHON patients lacking three primary mutations (ND1 3460G > A, ND4 11778Gxs > A, and ND6 14484 T > C), as well as 266 controls were enrolled in this study. PCR-Sanger sequencing was performed to screen the mt-tRNA variants. Moreover, the phylogenetic analysis, pathogenicity scoring system, as well as mitochondrial functions were performed. RESULTS We identified 8 possible pathogenic variants: tRNAPhe 593 T > C, tRNALeu(UUR) 3275C > T, tRNAGln 4363 T > C, tRNAMet 4435A > G, tRNAAla 5587 T > C, tRNAGlu 14693A > G, tRNAThr 15927G > A, and 15951A > G, which may change the structural and functional impact on the corresponding tRNAs, and subsequently lead to a failure in tRNA metabolism. Furthermore, significant reductions in mitochondrial ATP and MMP levels and an overproduction of ROS were observed in cybrid cells containing these mt-tRNA variants, suggesting that these variants may lead to mitochondrial dysfunction which was responsible for LHON. CONCLUSION Our study indicated that mt-tRNA variants were associated with LHON, and screening for mt-tRNA variants were recommended for early detection, diagnosis, and prevention of maternally inherited LHON.
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Affiliation(s)
- Jie Shuai
- Department of Ophthalmology, the Affiliated Hospital of Nantong University, Nantong, China
| | - Jian Shi
- Department of Ophthalmology, the Affiliated Hospital of Nantong University, Nantong, China
| | - Ya Liang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu Province, China
| | - Fangfang Ji
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu Province, China
| | - Luo Gu
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Zhilan Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu Province, China.
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14
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Vandeputte J, Van Heetvelde M, Van Cauwenbergh C, Seneca S, De Baere E, Leroy BP, De Zaeytijd J. Mild Leber hereditary optic neuropathy (LHON) in a Western European family due to the rare Asian m.14502T>C variant in the MT-ND6 gene. Ophthalmic Genet 2021; 42:440-445. [PMID: 33858285 DOI: 10.1080/13816810.2021.1913611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) is a mitochondrial neurodegenerative disease. The majority (>90%) is related to three primary mitochondrial DNA (mtDNA) variants: ND1 m.3460G>A, ND4 m.11778G>A and ND6 m.14484T>C. The remaining 10% is associated with >40 secondary variants with variable penetrance and incidence between different ethnic backgrounds. MATERIALS AND METHODS Five sisters underwent an extensive ophthalmic workup including psychophysical, electrophysiological, multimodal brain imaging, biochemical testing and molecular screening. MT-ND6 protein modelling was performed. RESULTS A 23-year-old woman presented with acute central visual loss to counting fingers in the right eye. She developed a central visual field scotoma, severe color vision deficiencies and impaired pattern visual evoked responses. Progressive optic atrophy ensued. The left eye was unremarkable, except for borderline thinning of the temporal retinal nerve fiber layer. Alcohol use and passive smoking were noted. MtDNA analysis revealed a rare variant, m.14502T>C in MT-ND6, exclusively known to cause optic neuropathy in an Asian population. Three sisters of the proband, two of whom reported tobacco and alcohol abuse, had bilateral temporal optic disc pallor without functional impact. A fourth non-smoker sister had a completely normal eye exam. CONCLUSIONS The rare Asian m.14502T>C variant in the MT-ND6 gene was linked to a mild LHON phenotype in a Western European family. Penetrance in this family was likely triggered by alcohol and tobacco abuse. A full mtDNA sequencing is warranted in the case of high clinical suspicion of LHON when mutation analysis for the three common pathogenic variants is negative.
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Affiliation(s)
| | - Mattias Van Heetvelde
- Center for Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.,Department of Head & Skin, Ghent University, Ghent, Belgium
| | - Sara Seneca
- Center for Medical Genetics, UZ Brussel, Research Group Reproduction & Genetics, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Bart P Leroy
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.,Department of Head & Skin, Ghent University, Ghent, Belgium.,Division of Ophthalmology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Center for Cellular & Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Julie De Zaeytijd
- Department of Ophthalmology, Ghent University Hospital, Ghent, Belgium
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15
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Blackout in the powerhouse: clinical phenotypes associated with defects in the assembly of OXPHOS complexes and the mitoribosome. Biochem J 2021; 477:4085-4132. [PMID: 33151299 PMCID: PMC7657662 DOI: 10.1042/bcj20190767] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria produce the bulk of the energy used by almost all eukaryotic cells through oxidative phosphorylation (OXPHOS) which occurs on the four complexes of the respiratory chain and the F1–F0 ATPase. Mitochondrial diseases are a heterogenous group of conditions affecting OXPHOS, either directly through mutation of genes encoding subunits of OXPHOS complexes, or indirectly through mutations in genes encoding proteins supporting this process. These include proteins that promote assembly of the OXPHOS complexes, the post-translational modification of subunits, insertion of cofactors or indeed subunit synthesis. The latter is important for all 13 of the proteins encoded by human mitochondrial DNA, which are synthesised on mitochondrial ribosomes. Together the five OXPHOS complexes and the mitochondrial ribosome are comprised of more than 160 subunits and many more proteins support their biogenesis. Mutations in both nuclear and mitochondrial genes encoding these proteins have been reported to cause mitochondrial disease, many leading to defective complex assembly with the severity of the assembly defect reflecting the severity of the disease. This review aims to act as an interface between the clinical and basic research underpinning our knowledge of OXPHOS complex and ribosome assembly, and the dysfunction of this process in mitochondrial disease.
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16
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A Typical Case Presentation with Spontaneous Visual Recovery in Patient Diagnosed with Leber Hereditary Optic Neuropathy due to Rare Point Mutation in MT-ND4 Gene ( m.11253T>C) and Literature Review. ACTA ACUST UNITED AC 2021; 57:medicina57030202. [PMID: 33652663 PMCID: PMC7996816 DOI: 10.3390/medicina57030202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 12/03/2022]
Abstract
Leber hereditary optic neuropathy (LHON) is one of the most common inherited mitochondrial optic neuropathies, caused by mitochondrial DNA (mtDNA) mutations. Three most common mutations, namely m.11778G>A, m.14484T>G and m.3460G>A, account for the majority of LHON cases. These mutations lead to mitochondrial respiratory chain complex I damage. Typically, LHON presents at the 15–35 years of age with male predominance. LHON is associated with severe, subacute, painless bilateral vision loss and account for one of the most common causes of legal blindness in young individuals. Spontaneous visual acuity recovery is rare and has been reported in patients harbouring m.14484T>C mutation. Up to date LHON treatment is limited. Idebenone has been approved by European Medicines Agency (EMA) to treat LHON. However better understanding of disease mechanisms and ongoing treatment trials are promising and brings hope for patients. In this article we report on a patient diagnosed with LHON harbouring rare m.11253T>C mutation in MT-ND4 gene, who experienced spontaneous visual recovery. In addition, we summarise clinical presentation, diagnostic features, and treatment.
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17
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Ding Y, Zhuo G, Guo Q, Li M. Leber's Hereditary Optic Neuropathy: the roles of mitochondrial transfer RNA variants. PeerJ 2021; 9:e10651. [PMID: 33552719 PMCID: PMC7819119 DOI: 10.7717/peerj.10651] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/04/2020] [Indexed: 02/01/2023] Open
Abstract
Leber’s Hereditary Optic Neuropathy (LHON) was a common maternally inherited disease causing severe and permanent visual loss which mostly affects males. Three primary mitochondrial DNA (mtDNA) mutations, ND1 3460G>A, ND4 11778G>A and ND6 14484T>C, which affect genes encoding respiratory chain complex I subunit, are responsible for >90% of LHON cases worldwide. Families with maternally transmitted LHON show incomplete penetrance with a male preponderance for visual loss, suggesting the involvement of secondary mtDNA variants and other modifying factors. In particular, variants in mitochondrial tRNA (mt-tRNA) are important risk factors for LHON. These variants decreased the tRNA stability, prevent tRNA aminoacylation, influence the post-transcriptionalmodification and affect tRNA maturation. Failure of mt-tRNA metabolism subsequently impairs protein synthesis and expression, folding, and function of oxidative phosphorylation (OXPHOS) enzymes, which aggravates mitochondrial dysfunction that is involved in the progression and pathogenesis of LHON. This review summarizes the recent advances in our understanding of mt-tRNA biology and function, as well as the reported LHON-related mt-tRNA second variants; it also discusses the molecular mechanism behind the involvement of these variants in LHON.
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Affiliation(s)
- Yu Ding
- Central laboratory, Hangzhou First People's Hospital, Hangzhou, Zhejiang, China
| | - Guangchao Zhuo
- Central laboratory, Hangzhou First People's Hospital, Hangzhou, Zhejiang, China
| | - Qinxian Guo
- Central laboratory, Hangzhou First People's Hospital, Hangzhou, Zhejiang, China
| | - Meiya Li
- Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
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18
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Newman NJ, Carelli V, Taiel M, Yu-Wai-Man P. Visual Outcomes in Leber Hereditary Optic Neuropathy Patients With the m.11778G>A (MTND4) Mitochondrial DNA Mutation. J Neuroophthalmol 2020; 40:547-557. [PMID: 32969847 DOI: 10.1097/wno.0000000000001045] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) is a maternally inherited bilaterally blinding optic neuropathy, predominantly affecting otherwise healthy young individuals, mostly men. The visual prognosis is generally poor, with most patients worsening to at least 20/200 visual acuity. The m.11778G>A (MTND4) mitochondrial DNA mutation is the most common cause of LHON and is associated with poor outcomes and limited potential for meaningful visual recovery. Treatments for LHON are limited, and clinical trials are hampered by inadequate data regarding the natural history of visual loss and recovery. In this article, we review the current literature specifically related to visual function of LHON patients with the m.11778G>A mutation. EVIDENCE ACQUISITION Literature review was performed using MEDLINE through PubMed, Cochrane Reviews Library, and Orpha.net with search terms of "Leber hereditary optic neuropathy," "LHON," "ND4," "G11778A," "visual acuity," "nadir," "natural history," and "registry." All English-language, peer-reviewed publications with study cohorts of at least 5 LHON patients with the molecularly confirmed m.11778G>A mutation were included. RESULTS Meta-analysis of 12 retrospective and 3 prospective studies provided visual function information on 695 LHON patients with the m.11778G>A mutation, 100 (14.4%) of whom were reported to have "recovered" some vision, although definitions of "recovery" varied among studies and idebenone use could not always be excluded. When incorporating age at onset of visual loss into the analyses, and specifically addressing those patients aged 15 years or older, meaningful visual recovery occurred in 23 of 204 (11.3%) patients. A younger age at onset, especially less than 12 years, portends a better visual prognosis and a different natural history of visual loss progression and recovery than in adults. CONCLUSIONS The classic presentation of LHON patients with the m.11778G>A mutation of severe visual loss with rare or poor recovery from nadir still holds true for most affected individuals. Among patients 15 years and older, recovery of meaningful vision likely occurs in less than 20% of patients, irrespective of how recovery is defined, and ultimate visual acuities of better than 20/200 are rare. Adequate prospective studies with sufficient sample sizes of genotypically homogeneous untreated LHON patients stratified by age, immediately enrolled when symptomatic, followed regularly for adequate periods of time with consistent measures of visual function, and analyzed with a standard definition of visual improvement are unfortunately lacking. Future clinical trials for LHON will require more standardized reporting of the natural history of this disorder.
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Affiliation(s)
- Nancy J Newman
- Departments of Ophthalmology (NJN), Neurology and Neurological Surgery, Emory University School of Medicine, Atlanta, Georgia, IRCCS Istituto Delle Scienze Neurologiche di Bologna (VC), UOC Clinica Neurologica, Bologna, Italy, Department of Biomedical and Neuromotor Sciences (DIBINEM) (VC), Unit of Neurology, University of Bologna, Bologna, Italy, GenSight Biologics (MT), Paris, France, Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit (PY-W-M), Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, Cambridge Eye Unit (PY-W-M), Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom, Moorfields Eye Hospital (PY-W-M), London, United Kingdom, and UCL Institute of Ophthalmology (PY-W-M), University College London, London, United Kingdom
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19
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Li JK, Li W, Gao FJ, Qu SF, Hu FY, Zhang SH, Li LL, Wang ZW, Qiu Y, Wang LS, Huang J, Wu JH, Chen F. Mutation Screening of mtDNA Combined Targeted Exon Sequencing in a Cohort With Suspected Hereditary Optic Neuropathy. Transl Vis Sci Technol 2020; 9:11. [PMID: 32855858 PMCID: PMC7422818 DOI: 10.1167/tvst.9.8.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/23/2020] [Indexed: 12/02/2022] Open
Abstract
Purpose Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) are the two commonest forms of hereditary optic neuropathy. The aim of this study was to comprehensively investigate the incidence and spectrum of mutations in patients with suspected hereditary optic neuropathy by combining mitochondrial DNA (mtDNA) genome-wide and targeted exon sequencing. Methods A cohort of 1101 subjects were recruited to participate in the study, comprising 177 families (177 probands and their family members, a total of 537 subjects, including 254 patients) and 164 sporadic cases with suspected hereditary optic neuropathy, and 400 unrelated control subjects for genetic analysis: all subjects (including control subjects) underwent a comprehensive ophthalmologic examination and were subjected to sequencing analysis of mtDNA genome-wide and targeted exon. Overall, targeted exon sequencing was used to screen 792 genes associated with common hereditary eye diseases, and the mtDNA genome-wide were screened by next-generation sequencing. Results We found variants detected in 168 (40.2%, 168/418) of the 418 patients screened. Among these, 132 cases (78.6%, 132/168) were detected with known LHON disease-causing mtDNA variants; 40 cases (23.8%, 40/168) were detected with nuclear DNA (ntDNA) variants, which included 36 cases (21.4%, 36/168) with detected OPA1 mutations, 4 patients (2.4%, 4/168) with detected OPA3 mutations, and 2 patients (1.2%, 2/168) with detected TMEM126A homozygous mutation. Coexistence variation (mtDNA/mtDNA [n = 16], ntDNA/ntDNA [n = 4], mtDNA/ntDNA [n = 7]) was found in 27 patients (16.4%, 27/165), including mtDNA/ntDNA coexistence variation that was detected in seven patients. Among these ntDNA mutations, 38 distinct disease-causing variants, including autosomal recessive heterozygous mutations, were detected, which included 22 novel variants and two de novo variants. Total haplogroup distribution showed that 34.5% (29/84) and 28.6% (24/84) of the affected subjects with m.11778G>A belonged to haplogroup D and M, with a high frequency of subhaplogroups D4, D5, and M7. Conclusions The LHON-mtDNA mutations are the commonest genetic defects in this Chinese cohort, followed by the OPA1 mutations. To our knowledge, this is the first comprehensive study of LHON, ADOA, and autosomal recessive optic atrophy combined with mtDNA genome-wide and targeted exon sequencing, as well as haplogroup analysis, in a large cohort of Chinese patients with suspected hereditary optic neuropathy. Our findings provide a powerful basis for genetic counseling in patients with suspected hereditary optic neuropathy. Translational Relevance We applied mtDNA genome-wide sequencing combined with panel-based targeted exon sequencing to explore the pathogenic variation spectrum and genetic characteristics of patients with suspected hereditary optic neuropathy, providing a comprehensive research strategy for clinical assistant diagnosis, treatment, and genetic counseling.
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Affiliation(s)
- Jian-Kang Li
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Wei Li
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,BGI-Shenzhen, Shenzhen, China
| | - Feng-Juan Gao
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Shou-Fang Qu
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Fang-Yuan Hu
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Li-Li Li
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Zi-Wei Wang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China.,BGI-Shenzhen, Shenzhen, China
| | - Yong Qiu
- BGI-Shenzhen, Shenzhen, China.,MGI, BGI-Shenzhen, Shenzhen, China
| | - Lu-Sheng Wang
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong.,BGI-Shenzhen, Shenzhen, China
| | - Jie Huang
- National Institutes for Food and Drug Control, Tiantan Xili Dongcheng District, Beijing, China
| | - Ji-Hong Wu
- Eye Institute, Eye, Ear, Nose and Throat Hospital, College of Medicine, Fudan University, Shanghai, China.,Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Fang Chen
- BGI-Shenzhen, Shenzhen, China.,MGI, BGI-Shenzhen, Shenzhen, China
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Ahn YJ, Park Y, Shin SY, Chae H, Kim M, Park SH. Genotypic and phenotypic characteristics of Korean children with childhood-onset Leber's hereditary optic neuropathy. Graefes Arch Clin Exp Ophthalmol 2020; 258:2283-2290. [PMID: 32506279 DOI: 10.1007/s00417-020-04757-x] [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: 10/14/2019] [Revised: 05/11/2020] [Accepted: 05/19/2020] [Indexed: 10/24/2022] Open
Abstract
PURPOSE We sought to identify the phenotypic and genotypic characteristics of Korean children with genetically confirmed Leber's hereditary optic neuropathy (LHON). METHODS The medical records of 64 genetically confirmed LHON patients were reviewed. Seventeen patients aged 13 years or younger with optic atrophy with positive mitochondrial DNA (mtDNA) mutations were considered to demonstrate childhood-onset LHON. The non-childhood-onset group included 47 patients with genetically confirmed LHON who experienced disease onset later than 13 years of age. The type of mtDNA mutation, visual acuity (VA), color vision, fundus photography, retinal nerve fiber layer (RNFL) thickness, and visual field were investigated. RESULTS Sequence analysis of the mitochondrial genome revealed five different kinds of LHON-associated mtDNA mutations among our childhood-onset patients, including m.11778G>A (58.8%), m.3496G>T (11.8%), m.3497C>T (5.9%), m.11696G>A (5.9%), and m.14502T>C (5.9%). The mean final best-corrected VA in the childhood-onset group was better than that in the non-childhood-onset group with the value of logMAR 0.29 (0.09-0.75) vs. 0.55 (0.27-1.29) (expressed as median (interquartile range); p = 0.05). Spontaneous visual recovery was observed in 35.3% of the childhood-onset group but in only 12.8% of the non-childhood-onset group (p = 0.04). Eight patients (47.1%) showed interocular asymmetry of the disease, with two presenting true unilateral involvement of the optic nerve and the other six patients demonstrating unilateral subclinical manifestations with bilateral optic atrophy. CONCLUSION Involvement of secondary mitochondrial mutations was confirmed in patients with childhood-onset LHON. Characteristic clinical features of childhood-onset LHON included a higher proportion of subacute or insidious onset of symptoms, better VA, higher spontaneous recovery, and asymmetrical ocular involvement.
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Affiliation(s)
- Ye Jin Ahn
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 06591, Republic of Korea
| | - Yooyeon Park
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 06591, Republic of Korea
| | - Sun Young Shin
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 06591, Republic of Korea
| | - Hyojin Chae
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Myungshin Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Shin Hae Park
- Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, 222, Banpo-daero, Seocho-gu, Seoul, 06591, Republic of Korea.
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21
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Ding Y, Ye YF, Li MY, Xia BH, Leng JH. Mitochondrial tRNAAla 5601C>T variant may affect the clinical expression of the LHON‑related ND4 11778G>A mutation in a family. Mol Med Rep 2019; 21:201-208. [PMID: 31939618 PMCID: PMC6896293 DOI: 10.3892/mmr.2019.10844] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/09/2019] [Indexed: 01/21/2023] Open
Abstract
Certain mutations in mitochondrial DNA (mtDNA) are associated with Leber's hereditary optic neuropathy (LHON). In particular, the well-known NADH dehydrogenase 4 (ND4) m.11778G>A mutation is one of the most common LHON-associated primary mutations worldwide. However, how specific mtDNA mutations, or variants, affect LHON penetrance is not fully understood. The aim of the current study was to explore the relationship between mtDNA mutations and LHON, and to provide useful information for early detection and prevention of this disease. Following the molecular characterization of a Han Chinese family with maternally inherited LHON, four out of eight matrilineal relatives demonstrated varying degrees of both visual impairment and age of onset. Through PCR amplification of mitochondrial genomes and direct Sanger sequencing analysis, a homoplasmic mitochondrial-encoded ND4 m.11778G>A mutation, alongside a set of genetic variations belonging to human mtDNA haplogroup B5b1 were identified. Among these sequence variants, alanine transfer RNA (tRNA)Ala m.5601C>T was of particular interest. This variant occurred at position 59 in the TψC loop and altered the base pairing, which led to mitochondrial RNA (mt-RNA) metabolism failure and defects in mitochondrial protein synthesis. Bioinformatics analysis suggested that the m.5601C>T variant altered tRNAAla structure. Therefore, impaired mitochondrial functions caused by the ND4 m.11778G>A mutation may be enhanced by the mt-tRNAAla m.5601C>T variant. These findings suggested that the tRNAAla m.5601C>T variant might modulate the clinical manifestation of the LHON-associated primary mutation.
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Affiliation(s)
- Yu Ding
- Central Laboratory, School of Medicine, Hangzhou First People's Hospital, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Yu-Feng Ye
- Department of Ophthalmology, School of Medicine, Hangzhou First People's Hospital, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
| | - Mei-Ya Li
- Analytical Testing Center, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Bo-Hou Xia
- Department of Pharmacy, Hunan Chinese Medical University, Changsha, Hunan 410208, P.R. China
| | - Jian-Hang Leng
- Central Laboratory, School of Medicine, Hangzhou First People's Hospital, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
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22
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Lyu Y, Xu M, Chen J, Ji Y, Guan MX, Zhang J. Frequency and spectrum of MT-TT variants associated with Leber's hereditary optic neuropathy in a Chinese cohort of subjects. MITOCHONDRIAL DNA PART B-RESOURCES 2019; 4:2266-2280. [PMID: 33365504 PMCID: PMC7687527 DOI: 10.1080/23802359.2019.1627921] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease. In our previous investigations, we have reported the spectrum and frequency of mitochondrial MT-ND1, MT-ND4 and MT-ND6 gene in Chinese LHON population. This study aimed to assess the molecular epidemiology of MT-TT mutations in Chinese families with LHON. A cohort of 352 Chinese Han probands lacking the known LHON-associated mtDNA mutations and 376 control subjects underwent molecular analysis of mtDNA. All variants were evaluated for evolutionary conservation, structural and functional consequences. Fifteen variants were identified in the MT-TT gene by mitochondrial genome analysis of LHON pedigrees, which was substantially higher than that of individuals from general Chinese populations. The incidences of the two known LHON-associated mutations, m.15927G > A and m.15951A > G, were 2.27% and 1.14%, respectively. Nine putative LHON-associated variants were identified in 20 probands, translated into 2.1% cases of this cohort. Moreover, mtDNAs in 41 probands carrying the MT-TT mutation(s) were widely dispersed among nine Eastern Asian haplogroups. Our results suggest that the MT-TT gene is a mutational hotspot for these 352 Chinese families lacking the known LHON-associated mutations. These data further showed the molecular epidemiology of MT-TT mutations in Chinese Han LHON pedigrees.
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Affiliation(s)
- Yuanyuan Lyu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,School of Laboratory Medicine and Life Sciences, Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Man Xu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,School of Laboratory Medicine and Life Sciences, Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jie Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,School of Laboratory Medicine and Life Sciences, Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - YanChun Ji
- School of Medicine, Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Min-Xin Guan
- School of Laboratory Medicine and Life Sciences, Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China.,School of Medicine, Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China.,School of Laboratory Medicine and Life Sciences, Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
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23
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Multilocus Mitochondrial Mutations Do Not Directly Affect the Efficacy of Gene Therapy for Leber Hereditary Optic Neuropathy. J Neuroophthalmol 2019; 40:22-29. [PMID: 31246675 DOI: 10.1097/wno.0000000000000797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Clinical trials of gene therapy for Leber hereditary optic neuropathy (LHON) were conducted in 9 volunteers with the mitochondrial mutation, G11778A in ND4. The purpose of this study was to investigate whether multilocus mitochondrial mutations directly influence the efficacy of gene therapy for LHON. METHODS Nine volunteers with LHON participated in a clinical trial with intravitreal injection of an adenoviral vector expressing wild-type ND4. Patients were subsequently divided into 2 groups: according to the differences in therapy efficacy and based on improvements in visual acuity. Full mitochondrial DNA sequences of the 2 groups of patients were generated and compared using PubMed, PolyPhen, and PROVEAN. Furthermore, the association between the detected mutations and clinical effects of gene therapy was analyzed. RESULTS Best-corrected visual acuity (BCVA) significantly improved (≥0.3 log of minimum angle of resolution [logMAR]) in 7 patients 6 months after gene therapy, whereas there was no significant change in BCVA (<0.3 logMAR) of the remaining 2 patients. All 9 patients carried the G1178A mutation in addition to other nonsynonymous mutations. Among these mutations, some were predicted to be neutral and deleterious. Meanwhile, different mitochondrial mutations in the group in which treatment was ineffective, compared with those in responders, were at nucleotide positions 6569 (CO1; Patient 3), 9641 (CO3; Patient 3), and 4491 (ND2; Patient 5). CONCLUSIONS Detection of the 3 primary mitochondrial mutations causing LHON is sufficient for screening before gene therapy; sequencing of the entire mitochondrial genome is unnecessary before treatment. Patients with LHON can respond to targeted gene therapy irrespective of additional multilocus mitochondrial mutations.
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Zhang J, Ji Y, Lu Y, Fu R, Xu M, Liu X, Guan MX. Leber's hereditary optic neuropathy (LHON)-associated ND5 12338T > C mutation altered the assembly and function of complex I, apoptosis and mitophagy. Hum Mol Genet 2019; 27:1999-2011. [PMID: 29579248 DOI: 10.1093/hmg/ddy107] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/19/2018] [Indexed: 02/04/2023] Open
Abstract
Mutations in mitochondrial DNA (mtDNA) have been associated with Leber's hereditary optic neuropathy (LHON) and their pathophysiology remains poorly understood. In this study, we demonstrated that a missense mutation (m.12338T>C, p.1M>T) in the ND5 gene contributed to the pathogenesis of LHON. The m.12338T>C mutation affected the first methionine (Met1) with a threonine and shortened two amino acids of ND5. We therefore hypothesized that the mutated ND5 perturbed the structure and function of complex I. Using the cybrid cell models, generated by fusing mtDNA-less (ρ°) cells with enucleated cells from LHON patients carrying the m.12338T>C mutation and a control subject belonging to the same mtDNA haplogroup, we demonstrated that the m.12338T>C mutation caused the reduction of ND5 polypeptide, perturbed assemble and activity of complex I. Furthermore, the m.12338T>C mutation caused respiratory deficiency, diminished mitochondrial adenosine triphosphate levels and membrane potential and increased the production of reactive oxygen species. The m.12338T>C mutation promoted apoptosis, evidenced by elevated release of cytochrome c into cytosol and increased levels of apoptosis-activated proteins: caspases 9, 3, 7 and Poly ADP ribose polymerase in the cybrids carrying the m.12338T>C mutation, as compared with control cybrids. Moreover, we also document the involvement of m.12338T>C mutation in decreased mitophagy, as showed by reduced levels of autophagy protein light chain 3 and accumulation of autophagic substrate p62 in the in mutant cybrids as compared with control cybrids. These data demonstrated the direct link between mitochondrial dysfunction caused by complex I mutation and apoptosis or mitophagy. Our findings may provide new insights into the pathophysiology of LHON.
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Affiliation(s)
- Juanjuan Zhang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yuanyuan Lu
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Runing Fu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Man Xu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310052, China.,Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.,School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325600, China.,Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China.,Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China
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25
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Guo H, Li S, Dai L, Huang X, Yu T, Yin Z, Bai Y. Genetic analysis in a cohort of patients with hereditary optic neuropathies in Southwest of China. Mitochondrion 2018; 46:327-333. [PMID: 30201499 DOI: 10.1016/j.mito.2018.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 02/25/2018] [Accepted: 09/04/2018] [Indexed: 11/16/2022]
Abstract
We report the results of molecular screening in 121 patients with suspected hereditary optic neuropathies. The 34 primary and 9 secondary LHON mutations were screened in all the patients. In the familial cases, OPA1 was also tested when negative finding for the mtDNA mutations screening. Molecular defects were identified in 35 patients (28.9% of screened patients). Among these, 33 patients (94.3%) had an mtDNA mutation, including m.11778G > A (69.7%), m.14484 T > C, m.3460G > A, m.3635G > A, m.14502 T > C and three secondary mutations m.3316G > A, m.3394 T > C, m.3497C > T. Two novel OPA1 mutations, c.1301 T > G (p.Leu434Arg) and c.985-1G > A (IVS9-1G > A), were also detected in families with the evidence of father-to-son transmission. In conclusion, we reported the results of the molecular screening of 121 patients with hereditary optic neuropathies from southwest of China. Our results highlight the importance of investigating LHON-causing mtDNA mutations and OPA1 mutations in cases of suspected hereditary optic neuropathy.
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Affiliation(s)
- Hong Guo
- Department of Medical Genetics, Army Medical University, 30#, Gaotanyan St., Shapingba District, Chongqing 400038, PR China
| | - Shiying Li
- Southwest Eye Hospital, Southwest Hospital, Army Medical University, 30#, Gaotanyan St., Shapingba District 400038, Chongqing, PR China
| | - Limeng Dai
- Department of Medical Genetics, Army Medical University, 30#, Gaotanyan St., Shapingba District, Chongqing 400038, PR China
| | - Xiaoyong Huang
- Southwest Eye Hospital, Southwest Hospital, Army Medical University, 30#, Gaotanyan St., Shapingba District 400038, Chongqing, PR China
| | - Tao Yu
- Southwest Eye Hospital, Southwest Hospital, Army Medical University, 30#, Gaotanyan St., Shapingba District 400038, Chongqing, PR China
| | - Zhengqin Yin
- Southwest Eye Hospital, Southwest Hospital, Army Medical University, 30#, Gaotanyan St., Shapingba District 400038, Chongqing, PR China.
| | - Yun Bai
- Department of Medical Genetics, Army Medical University, 30#, Gaotanyan St., Shapingba District, Chongqing 400038, PR China.
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Abstract
SIGNIFICANCE We identified a missense mutation, m.11778G>A (p.R340H), in the mitochondrially encoded NADH dehydrogenase 4 gene (ND4) in eight patients and three asymptomatic carriers, even though the incidence of this has been considered low in Chinese population. These results have implications for the families' genetic counseling and clinical management. PURPOSE Leber hereditary optic neuropathy (LHON OMIM 535000) is one of the most common inherited optic neuropathies. The aim of this study was to identify the genetic cause in two Han Chinese families with LHON. METHODS We used Sanger sequencing to identify the genetic cause of two Han Chinese families from Hunan, China, with LHON. RESULTS The patients in these two families presented with typical LHON, with male patients experiencing more severe phenotypes. A missense mutation, m.11778G>A (p.R340H), in the ND4 gene was identified in eight patients and three asymptomatic carriers, even though the incidence of this has been considered low in Chinese population. CONCLUSIONS Eight of 11 family members (72.7%) manifested some vision loss, which is far higher percentage than reported in other studies. The variant is predicted to be the disease-causing mutation and results in seriously abnormal function of complex I subunits of the mitochondrial respiratory chain. These results have implications for the families' genetic counseling and clinical management and help to develop new LHON target-gene therapy strategies.
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Zhang J, Ji Y, Liu X, Chen J, Wang B, Zhang M, Guan MX. Leber's hereditary optic neuropathy caused by a mutation in mitochondrial tRNA Thr in eight Chinese pedigrees. Mitochondrion 2017; 42:84-91. [PMID: 29225014 DOI: 10.1016/j.mito.2017.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/09/2017] [Accepted: 12/06/2017] [Indexed: 01/09/2023]
Abstract
PURPOSE The purpose of this study was to investigate the pathophysiology underlying Leber's hereditary optic neuropathy (LHON)-associated mitochondrial tRNA mutation. METHODS Severn hundred ninety-seven Han Chinese subjects underwent clinical and genetic evaluation and analysis of mitochondrial DNA (mtDNA). The cybrid cell lines were constructed by transferring mitochondria from lymphoblastoid cell lines derived from a Chinese family into mtDNA-less (ρo) cells. These cell lines were assayed by tRNA Northern blot and Western blot analyses, respiratory enzymatic activities, the rate of ATP production and the generation of reactive oxygen species. RESULTS The tRNAThr 15927G>A mutation was identified in eight probands with suggestively maternal inheritance among 352 Han Chinese probands lacking these known LHON-associated mtDNA mutations. The m.15927G>A mutation affected a highly conserved guanine at position 42 at the anticodon-stem of tRNAThr, destabilizing the conservative base pairing (28C-42G). We therefore hypothesized that the m.15927G>A mutation, and altered the structure and function of tRNAThr. Northern blot analysis revealed 60% decrease in the steady-state level of tRNAThr in the mutant cell lines. Western blot analysis showed the variable reductions of 4 mtDNA encoding proteins, especially for marked decrease of ND1 and CYTB observed in mutant cell lines. Furthermore, we demonstrated that the m.15927G>A mutation decreased the activities of mitochondrial complexes I and III, markedly diminished mitochondrial ATP levels, and increased the production of reactive oxygen species in the mutant cells. CONCLUSIONS Our data demonstrated the first mitochondrial tRNA mutation leading to LHON. Our findings may provide new insights into the understanding of pathophysiology of LHON.
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Affiliation(s)
- Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, Zhejiang Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jie Chen
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Bibin Wang
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Min-Xin Guan
- Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Division of Medical Genetics and Genomics, Zhejiang Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China.
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28
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Dai Y, Wang C, Nie Z, Han J, Chen T, Zhao X, Ai C, Ji Y, Gao T, Jiang P. Mutation analysis of Leber's hereditary optic neuropathy using a multi-gene panel. Biomed Rep 2017; 8:51-58. [PMID: 29387390 DOI: 10.3892/br.2017.1014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/02/2017] [Indexed: 12/22/2022] Open
Abstract
The present study investigates the spectrum and incidence of mitochondrial DNA (mtDNA) mutations associated with Leber's hereditary optic neuropathy (LHON) in a Han population using a multi-gene panel with 46 LHON-associated mutations among 13 mitochondrial genes. A total of 23 mutations were observed in a cohort of 275 patients and 281 control subjects using multi-gene panel analysis. The causative mutations associated with LHON were identified to be m.11778G>A, m.14484T>C, m.3460 G>A, m.3635G>A, m.3866T>C and m.3733G>A, responsible for 70.55% cases in the patient cohort. The secondary mutations in the Chinese LHON population were m.12811T>C, m.11696 G>A, m.3316G>A, m.3394T>C, m.14502T>C, m.3497C>T, m.3571C>T, m.12338T>C, m.14693A>G, m.4216T>C and m.15951A>G, with incidences of 5.09, 4.36, 4.00, 4.00, 4.00, 2.55, 1.82, 1.82, 1.45, 1.09 and 1.09%, respectively. Besides three hotspot genes, MT-ND1, MT-ND4 and MT-ND6, MT-ND5 also had a high incidence of secondary mutations. Those mutations reported as rare causative mutations in a European LHON population, m.3376G>A, m.3700G>A and m.4171C>A, m.10663T>C, m.13051G>A, m.14482C>G/A, m.14495A>G and m.14568C>T were undetected in the present study. The primary and secondary mutations associated with LHON in the present multi-gene panel will advance the current understanding of the clinical phenotype of LHON, and provide useful information for early diagnosis.
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Affiliation(s)
- Yu Dai
- The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Chenghui Wang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China.,Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Zhipeng Nie
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China.,Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Jiamin Han
- Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Ting Chen
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Xiaoxu Zhao
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China.,Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Cheng Ai
- Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Tao Gao
- The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China.,Institute of Genetics, Zhejiang University, and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
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Manickam AH, Michael MJ, Ramasamy S. Mitochondrial genetics and therapeutic overview of Leber's hereditary optic neuropathy. Indian J Ophthalmol 2017; 65:1087-1092. [PMID: 29133631 PMCID: PMC5700573 DOI: 10.4103/ijo.ijo_358_17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 09/09/2017] [Indexed: 12/22/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a common inherited mitochondrial disorder that is characterized by the degeneration of the optic nerves, leading to vision loss. The major mutations in the mitochondrial genes ND1, ND4, and ND6 of LHON subjects are found to increase the oxidative stress experienced by the optic nerve cell, thereby leading to nerve cell damage. Accurate treatments are not available and drugs that are commercially available like Idebenone, EPI-743, and Bendavia with their antioxidant role help in reducing the oxidative stress experienced by the cell thereby preventing the progression of the disease. Genetic counseling plays an effective role in making the family members aware of the inheritance pattern of the disease. Gene therapy is an alternative for curing the disease but is still under study. This review focuses on the role of mitochondrial genes in causing LHON and therapeutics available for treating the disease. A systematic search has been adopted in various databases using the keywords "LHON," "mitochondria," "ND1," "ND4," "ND6," and "therapy" and the following review on mitochondrial genetics and therapeutics of LHON has been developed with obtained articles from 1988 to 2017.
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Affiliation(s)
- Agaath Hedina Manickam
- Molecular Genetics and Cancer Biology Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tami Nadu, India
| | - Minu Jenifer Michael
- Molecular Genetics and Cancer Biology Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tami Nadu, India
| | - Sivasamy Ramasamy
- Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tami Nadu, India
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Genetic and Clinical Analyses of DOA and LHON in 304 Chinese Patients with Suspected Childhood-Onset Hereditary Optic Neuropathy. PLoS One 2017; 12:e0170090. [PMID: 28081242 PMCID: PMC5230780 DOI: 10.1371/journal.pone.0170090] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/28/2016] [Indexed: 02/08/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) and dominant optic atrophy (DOA), the most common forms of hereditary optic neuropathy, are easily confused, and it is difficult to distinguish one from the other in the clinic, especially in young children. The present study was designed to survey the mutation spectrum of common pathogenic genes (OPA1, OPA3 and mtDNA genes) and to analyze the genotype-phenotype characteristics of Chinese patients with suspected childhood-onset hereditary optic neuropathy. Genomic DNA and clinical data were collected from 304 unrelated Chinese probands with suspected hereditary optic neuropathy with an age of onset below 14 years. Sanger sequencing was used to screen variants in the coding and adjacent regions of OPA1, OPA3 and the three primary LHON-related mutation sites in mitochondrial DNA (mtDNA) (m.3460G>A, m.11778G>A and m.14484T>C). All patients underwent a complete ophthalmic examination and were compared with age-matched controls. We identified 89/304 (29.3%) primary mtDNA mutations related to LHON in 304 probands, including 76 mutations at m.11778 (76/89, 85.4% of all mtDNA mutations), four at m.3460 (4/89, 4.5%) and nine at m.14484 (9/89, 10.1%). This result was similar to the mutation frequency among Chinese patients with LHON of any age. Screening of OPA1 revealed 23 pathogenic variants, including 11 novel and 12 known pathogenic mutations. This study expanded the OPA1 mutation spectrum, and our results showed that OPA1 mutation is another common cause of childhood-onset hereditary optic neuropathy in Chinese pediatric patients, especially those with disease onset during preschool age.
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Bi R, Logan I, Yao YG. Leber Hereditary Optic Neuropathy: A Mitochondrial Disease Unique in Many Ways. Handb Exp Pharmacol 2017; 240:309-336. [PMID: 27787713 DOI: 10.1007/164_2016_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Leber hereditary optic neuropathy (LHON) was the first mitochondrial disease to be identified as being caused by mutations in the mitochondrial DNA (mtDNA). This disease has been studied extensively in the past two decades, particularly in Brazilian, Chinese and European populations; and many primary mutations have been reported. However, the disease is enigmatic with many unique features, and there still are several important questions to be resolved. The incomplete penetrance, the male-biased disease expression and the prevalence in young adults all defy a proper explanation. It has been reported that the development of LHON is affected by the interaction between mtDNA mutations, mtDNA haplogroup background, nuclear genes, environmental factors and epigenetics. Furthermore, with the help of new animal models for LHON that have been created in recent years, we are continuing to learn more about the mechanism of this disease. The stage has now been reached at which there is a good understanding of both the genetic basis of the disease and its epidemiology, but just how the blindness that follows from the death of cells in the optic nerve can be prevented remains to be a pharmacological challenge. In this chapter, we summarize the progress that has been made in various recent studies on LHON, focusing on the molecular pathogenic mechanisms, clinical features, biochemical effects, the pharmacology and its treatment.
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Affiliation(s)
- Rui Bi
- Division of Medical Genetics & Evolutionary Medicine, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | | | - Yong-Gang Yao
- Division of Medical Genetics & Evolutionary Medicine, Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
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Whole mitochondrial genome analysis in South Indian patients with Leber's hereditary optic neuropathy. Mitochondrion 2016; 36:21-28. [PMID: 27989883 DOI: 10.1016/j.mito.2016.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/22/2016] [Accepted: 10/26/2016] [Indexed: 11/27/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) is a mitochondrial DNA (mtDNA) associated neurodegenerative disorder of retinal ganglion cells. In this study, whole mitochondrial genome sequencing of 75 LHON patients and 40 controls was performed to identify the mutation frequency and haplogroup background of South Indian population. Analysis of mtDNA revealed 559 different variants in LHON patients, including 7 pathogenic mutations, 30 private, and 22 other disease associated variants. A significantly higher (p=0.0008) overall variation load per individual was noted among LHON patients versus controls. We reported for the first time, the association of M haplogroup (p=0.028) with LHON in this cohort.
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Xie S, Zhang J, Sun J, Zhang M, Zhao F, Wei QP, Tong Y, Liu X, Zhou X, Jiang P, Ji Y, Guan MX. Mitochondrial haplogroup D4j specific variant m.11696G > a(MT-ND4) may increase the penetrance and expressivity of the LHON-associated m.11778G > a mutation in Chinese pedigrees. Mitochondrial DNA A DNA Mapp Seq Anal 2016; 28:434-441. [PMID: 27159682 DOI: 10.3109/19401736.2015.1136304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Leber's hereditary optic neuropathy (LHON) is one of the most common mitochondrial disorders. We report here the clinical, genetic and molecular analysis of mitochondrial DNA (mtDNA) in eight Han Chinese families carrying the known mitochondrial 11778G > A(MT-ND4) mutation. Thirty-seven (26 males/11 females) of 77 matrilineal relatives in these families exhibited the variable severity and age-at-onset of optic neuropathy. The penetrances were from 25% to 75%, with the average of 42%, and the age-at-onset for visual impairment varied from 10 to 25 years, with the average of 17 in these Chinese pedigrees. Molecular analysis of their mtDNA identified distinct sets of variants belonging to the Eastern Asian haplogroupD4j. Except the known m.11778G > A mutation, the m.11696G > A(MT-ND4) mutation caused the substitution of an isoleucine for valineat amino acid position 313, located in a predicted transmembrane region of ND4. And, it is reported that the m.11696G > A mutation was associated with LHON, and appeared to contribute to higher penetrance in these nine Chinese families than other Chinese families carrying only the m.11778G > A mutation. Therefore, the mitochondrial haplogroup D4j specific m.11696G > A mutation may act in synergy with the primary LHON-associated m.11778G > A mutation, thereby increasing the penetrance and expressivity of visual loss in these Chinese families.
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Affiliation(s)
- Shipeng Xie
- a Department of Ophthalmology , Xingtai Eye Hospital , Xingtai , Hebei , China
| | - Juanjuan Zhang
- b Institute of Genetics , Zhejiang University School of Medicine , Hangzhou , Zhejiang , China.,c School of Ophthalmology and Optometry , Wenzhou Medical University , Wenzhou , Zhejiang , China
| | - Jiji Sun
- b Institute of Genetics , Zhejiang University School of Medicine , Hangzhou , Zhejiang , China
| | - Minglian Zhang
- a Department of Ophthalmology , Xingtai Eye Hospital , Xingtai , Hebei , China
| | - Fuxin Zhao
- c School of Ophthalmology and Optometry , Wenzhou Medical University , Wenzhou , Zhejiang , China.,d Attardi Institute of Mitochondrial Biomedicine , Wenzhou Medical University , Wenzhou , Zhejiang , China
| | - Qi-Ping Wei
- e Department of Ophthalmology , Dongfang Hospital, Beijing University of Chinese Medicine and Pharmacology , Beijing , China
| | - Yi Tong
- c School of Ophthalmology and Optometry , Wenzhou Medical University , Wenzhou , Zhejiang , China
| | - Xiaoling Liu
- c School of Ophthalmology and Optometry , Wenzhou Medical University , Wenzhou , Zhejiang , China
| | - Xiangtian Zhou
- c School of Ophthalmology and Optometry , Wenzhou Medical University , Wenzhou , Zhejiang , China
| | - Pingping Jiang
- b Institute of Genetics , Zhejiang University School of Medicine , Hangzhou , Zhejiang , China.,f Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Zhejiang University , Hangzhou , China
| | - Yanchun Ji
- b Institute of Genetics , Zhejiang University School of Medicine , Hangzhou , Zhejiang , China
| | - Min-Xin Guan
- a Department of Ophthalmology , Xingtai Eye Hospital , Xingtai , Hebei , China.,f Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases , Zhejiang University , Hangzhou , China.,g Division of Pathology , Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA
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Jiang P, Jin X, Peng Y, Wang M, Liu H, Liu X, Zhang Z, Ji Y, Zhang J, Liang M, Zhao F, Sun YH, Zhang M, Zhou X, Chen Y, Mo JQ, Huang T, Qu J, Guan MX. The exome sequencing identified the mutation in YARS2 encoding the mitochondrial tyrosyl-tRNA synthetase as a nuclear modifier for the phenotypic manifestation of Leber's hereditary optic neuropathy-associated mitochondrial DNA mutation. Hum Mol Genet 2015; 25:584-96. [PMID: 26647310 DOI: 10.1093/hmg/ddv498] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/01/2015] [Indexed: 01/18/2023] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is the most common mitochondrial disorder. Nuclear modifier genes are proposed to modify the phenotypic expression of LHON-associated mitochondrial DNA (mtDNA) mutations. By using an exome sequencing approach, we identified a LHON susceptibility allele (c.572G>T, p.191Gly>Val) in YARS2 gene encoding mitochondrial tyrosyl-tRNA synthetase, which interacts with m.11778G>A mutation to cause visual failure. We performed functional assays by using lymphoblastoid cell lines derived from members of Chinese families (asymptomatic individuals carrying m.11778G>A mutation, or both m.11778G>A and heterozygous p.191Gly>Val mutations and symptomatic subjects harboring m.11778G>A and homozygous p.191Gly>Val mutations) and controls lacking these mutations. The 191Gly>Val mutation reduced the YARS2 protein level in the mutant cells. The aminoacylated efficiency and steady-state level of tRNA(Tyr) were markedly decreased in the cell lines derived from patients both carrying homozygous YARS2 p.191Gly>Val and m.11778G>A mutations. The failure in tRNA(Tyr) metabolism impaired mitochondrial translation, especially for polypeptides with high content of tyrosine codon such as ND4, ND5, ND6 and COX2 in cells lines carrying homozygous YARS2 p.191Gly>Val and m.11778G>A mutations. The YARS2 p.191Gly>Val mutation worsened the respiratory phenotypes associated with m.11778G>A mutation, especially reducing activities of complexes I and IV. The respiratory deficiency altered the efficiency of mitochondrial ATP synthesis and increased the production of reactive oxygen species. Thus, mutated YARS2 aggravates mitochondrial dysfunctions associated with the m.11778G>A mutation, exceeding the threshold for the expression of blindness phenotype. Our findings provided new insights into the pathophysiology of LHON that were manifested by interaction between mtDNA mutation and mutated nuclear-modifier YARS2.
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Affiliation(s)
- Pingping Jiang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Xiaofen Jin
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Yanyan Peng
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Meng Wang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Hao Liu
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Zengjun Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Juanjuan Zhang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min Liang
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China
| | - Fuxin Zhao
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yan-Hong Sun
- Department of Ophthalmology, Beijing University of Chinese Medicine and Pharmacology, Beijing, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China and
| | - Xiangtian Zhou
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Ye Chen
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China
| | - Jun Qin Mo
- Department of Pathology, Rady Children's Hospital, University of California School of Medicine, San Diego, CA, USA
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China, Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, School of Medicine, Hangzhou, Zhejiang, China, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China,
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Remenyi V, Inczedy-Farkas G, Komlosi K, Horvath R, Maasz A, Janicsek I, Pentelenyi K, Gal A, Karcagi V, Melegh B, Molnar MJ. Retrospective assessment of the most common mitochondrial DNA mutations in a large Hungarian cohort of suspect mitochondrial cases. MITOCHONDRIAL DNA 2015; 26:572-8. [PMID: 24438288 DOI: 10.3109/19401736.2013.878901] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Prevalence estimations for mitochondrial disorders still vary widely and only few epidemiologic studies have been carried out so far. With the present work we aim to give a comprehensive overview about frequencies of the most common mitochondrial mutations in Hungarian patients. A total of 1328 patients were tested between 1999 and 2012. Among them, 882 were screened for the m.3243A > G, m.8344A > G, m.8993T > C/G mutations and deletions, 446 for LHON primary mutations. The mutation frequency in our cohort was 2.61% for the m.3243A > G, 1.47% for the m.8344A > G, 17.94% for Leber's Hereditary Optic Neuropathy (m.3460G > A, m.11778G > A, m.14484T > C) and 0.45% for the m.8993T > C/G substitutions. Single mtDNA deletions were detected in 14.97%, while multiple deletions in 6.01% of the cases. The mutation frequency in Hungarian patients suggestive of mitochondrial disease was similar to other Caucasian populations. Further retrospective studies of different populations are needed in order to accurately assess the importance of mitochondrial diseases and manage these patients.
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Affiliation(s)
- Viktoria Remenyi
- Institute of Genomic Medicine and Rare Disorders, Semmelweis University , Budapest , Hungary
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QIAO CHEN, WEI TANWEI, HU BO, PENG CHUNYAN, QIU XUEPING, WEI LI, YAN MING. Two families with Leber’s hereditary optic neuropathy carrying G11778A and T14502C mutations with haplogroup H2a2a1 in mitochondrial DNA. Mol Med Rep 2015; 12:3067-72. [DOI: 10.3892/mmr.2015.3714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 03/18/2015] [Indexed: 11/06/2022] Open
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Agarwal N, Hanumunthadu D, Afrasiabi M, Malaguarnera G, Cordeiro MF. Clinical update in optic nerve disorders. EXPERT REVIEW OF OPHTHALMOLOGY 2015. [DOI: 10.1586/17469899.2015.1003544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Zhang J, Jiang P, Jin X, Liu X, Zhang M, Xie S, Gao M, Zhang S, Sun YH, Zhu J, Ji Y, Wei QP, Tong Y, Guan MX. Leber's hereditary optic neuropathy caused by the homoplasmic ND1 m.3635G>A mutation in nine Han Chinese families. Mitochondrion 2014; 18:18-26. [PMID: 25194554 DOI: 10.1016/j.mito.2014.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 08/28/2014] [Accepted: 08/29/2014] [Indexed: 11/18/2022]
Abstract
In this report, we investigated the molecular mechanism underlying Leber's hereditary optic neuropathy (LHON)-associated mitochondrial m.3635G>A (p.S110N, ND1) mutation. A mutational screening of ND1 gene in a cohort of 1070 Han Chinese subjects LHON identified the m.3635G>A mutation in nine Chinese families with suggestively maternally transmitted LHON. Thirty-eight (22 males/16 females) of 162 matrilineal relatives in these families exhibited the variable severity and age-at-onset of optic neuropathy. Molecular analysis of their mitochondrial genomes identified the homoplasmic m.3635G>A mutation and distinct sets of polymorphisms belonging to the Asian haplogroups G2a1, R11a, D4, R11a, M7b2, G1a, F1a1, B4, and N9a3, respectively. Using cybrids constructed by transferring mitochondria from lymphoblastoid cell lines derived from one Chinese family into mtDNA-less (ρ(0)) cells, we showed ~27% decrease in the activity of NADH:ubiquinone oxidoreductase (complex I) in mutant cybrids carrying the m.3635G>A mutation, compared with control cybrids. The respiratory deficiency caused by the m.3635G>A mutation results in decreased efficiency of mitochondrial ATP synthesis. These mitochondrial dysfunctions caused an increase in the production of reactive oxygen species in the mutant cybrids. The data provide the direct evidence for the m.3635G>A mutation leading to LHON. Our findings may provide new insights into the understanding of pathophysiology of LHON.
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Affiliation(s)
- Juanjuan Zhang
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China; School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Pingping Jiang
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaofen Jin
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Shipeng Xie
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, Hebei, China
| | - Min Gao
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Sai Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yan-Hong Sun
- Department of Ophthalmology, Beijing University of Chinese Medicine and Pharmacology, Beijing, China
| | - Jinping Zhu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qi-Ping Wei
- Department of Ophthalmology, Beijing University of Chinese Medicine and Pharmacology, Beijing, China
| | - Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang, China; Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical University, Wenzhou, Zhejiang, China.
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Jančić J, Dejanović I, Samardžić J, Radovanović S, Pepić A, Kosanović-Jaković N, Ćetković M, Kostić V. Leber hereditary optic neuropathy in the population of Serbia. Eur J Paediatr Neurol 2014; 18:354-9. [PMID: 24508359 DOI: 10.1016/j.ejpn.2014.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 01/13/2014] [Accepted: 01/19/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder. However, few countries have published their population-based findings related to this multisystemic disease. THE AIM In order to get a better insight into the epidemiological and clinical picture of this maternally inherited disorder, we performed the first population-based clinical and molecular-genetic study of LHON in the Serbian population. METHODS Prospective study included patients who were diagnosed with LHON after detailed medical examination and molecular-genetic confirmation. RESULTS We identified 41 individuals from 12 genealogically unrelated families, carrying one of the three "primary" mitochondrial (mt) DNA point mutations associated with LHON. Fourteen of them were clinically affected, giving a minimum point prevalence of 1.9 per 1,000,000. The minimum point prevalence for mtDNA LHON mutations was 5.2 per 1,000,000. Male to female ratio was 6:1. Only one affected patient harboured mutant mtDNA in heteroplasmic condition. All patients were presented with common clinical findings. CONCLUSION We observed significantly lower prevalence and higher gender ratio than expected. However, frequencies of primary mutations, incidence of heteroplasmy and clinical findings are in accordance with other studies in Caucasoid populations. Our results might be a consequence of poor recognition and misdiagnosis due to lack of diagnostic possibilities of the entity in different region of our country or less likely be in part due to specific haplotype background of Serbian population which should be further investigated.
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Affiliation(s)
- Jasna Jančić
- Clinic of Neurology and Psychiatry for Children and Youth, Medical Faculty, University of Belgrade, Serbia.
| | - Ivana Dejanović
- Clinic of Neurology and Psychiatry for Children and Youth, Medical Faculty, University of Belgrade, Serbia
| | - Janko Samardžić
- Institute of Pharmacology and Toxicology, Medical Faculty, University of Belgrade, Serbia
| | | | - Ana Pepić
- Clinic of Neurology and Psychiatry for Children and Youth, Medical Faculty, University of Belgrade, Serbia
| | | | - Mila Ćetković
- Institute of Histology and Embryology, Medical Faculty, University of Belgrade, Serbia
| | - Vladimir Kostić
- Clinic of Neurology, Medical Faculty, University of Belgrade, Serbia
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Ji Y, Liang M, Zhang J, Zhang M, Zhu J, Meng X, Zhang S, Gao M, Zhao F, Wei QP, Jiang P, Tong Y, Liu X, Qin Mo J, Guan MX. Mitochondrial haplotypes may modulate the phenotypic manifestation of the LHON-associated ND1 G3460A mutation in Chinese families. J Hum Genet 2014; 59:134-40. [DOI: 10.1038/jhg.2013.134] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 11/01/2013] [Accepted: 12/10/2013] [Indexed: 11/09/2022]
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Zhang J, Zhao F, Fu Q, Liang M, Tong Y, Liu X, Lin B, Mi H, Zhang M, Wei QP, Xue L, Jiang P, Zhou X, Mo JQ, Huang T, Qu J, Guan MX. Mitochondrial haplotypes may modulate the phenotypic manifestation of the LHON-associated m.14484T>C (MT-ND6) mutation in Chinese families. Mitochondrion 2013; 13:772-81. [DOI: 10.1016/j.mito.2013.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 04/19/2013] [Accepted: 05/02/2013] [Indexed: 01/08/2023]
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Cui G, Ding H, Xu Y, Li B, Wang DW. Applications of the method of high resolution melting analysis for diagnosis of Leber's disease and the three primary mutation spectrum of LHON in the Han Chinese population. Gene 2012; 512:108-12. [PMID: 23063736 DOI: 10.1016/j.gene.2012.09.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 09/28/2012] [Accepted: 09/29/2012] [Indexed: 12/28/2022]
Abstract
Current screening methods, such as single strand conformational polymorphism (SSCP), denaturing high performance liquid chromatography (dHPLC) and direct DNA sequencing that are used for detecting mutation in Leber's hereditary optic neuropathy (LHON) subjects are time consuming and costly. Here we tested high-resolution melt (HRM) analysis for mtDNA primary mutations in LHON patients. In this study, we applied the high resolution melting (HRM) technology to screen mtDNA primary mutations in 50 LHON patients from their peripheral blood. In order to evaluate the reliability of this technique, we compared the results obtained by HRM and direct mtDNA sequencing. We also investigated the spectrum of three most common mtDNA mutations implicated in LHON in the Han Chinese population. The results showed HRM analysis differentiated all of the mtDNA primary mutations and identified 4 additional mtDNA mutations from 50 patients in the blind study. The prevalence of three primary mutations were 11778G>A (87.9%), 14484T>C (6.5%) and 3460G>A (1.7%) in the Han Chinese population. In conclusion, HRM analysis is a rapid, reliable, and low-cost tool for detecting mtDNA primary mutations and has practical applications in molecular genetics.
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Affiliation(s)
- Guanglin Cui
- The Institute of Hypertension and Department of Internal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan People's Republic of China
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Zhang AM, Jia X, Guo X, Zhang Q, Yao YG. Mitochondrial DNA mutation m.10680G > A is associated with Leber hereditary optic neuropathy in Chinese patients. J Transl Med 2012; 10:43. [PMID: 22400981 PMCID: PMC3372436 DOI: 10.1186/1479-5876-10-43] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 03/09/2012] [Indexed: 01/01/2023] Open
Abstract
Background Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder with gender biased and incomplete penetrance. The majority of LHON patients are caused by one of the three primary mutations (m.3460G > A, m.11778G > A and m.14484T > C). Rare pathogenic mutations have been occasionally reported in LHON patients. Methods We screened mutation m.10680G > A in the MT-ND4L gene in 774 Chinese patients with clinical features of LHON but lacked the three primary mutations by using allele specific PCR (AS-PCR). Patients with m.10680G > A were further determined entire mtDNA genome sequence. Results The optimal AS-PCR could detect as low as 10% heteroplasmy of mutation m.10680G > A. Two patients (Le1263 and Le1330) were identified to harbor m.10680G > A. Analysis of the complete mtDNA sequences of the probands suggested that they belonged to haplogroups B4a1 and D6a1. There was no other potentially pathogenic mutation, except for a few private yet reported variants in the MT-ND1 and MT-ND5 genes, in the two lineages. A search in reported mtDNA genome data set (n = 9277; excluding Chinese LHON patients) identified no individual with m.10680G > A. Frequency of m.10680G > A in Chinese LHON patients analyzed in this study and our previous studies (3/784) was significantly higher than that of the general populations (0/9277) (P = 0.0005). Conclusion Taken together, we speculated that m.10680G > A may be a rare pathogenic mutation for LHON in Chinese. This mutation should be included in future clinical diagnosis.
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Affiliation(s)
- A-Mei Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
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Shu L, Zhang YM, Huang XX, Chen CY, Zhang XN. Complete mitochondrial DNA sequence analysis in two southern Chinese pedigrees with Leber hereditary optic neuropathy revealed secondary mutations along with the primary mutation. Int J Ophthalmol 2012; 5:28-31. [PMID: 22553750 DOI: 10.3980/j.issn.2222-3959.2012.01.06] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 01/10/2012] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate mitochondrial factors associated with Leber hereditary optic neuropathy (LHON) through complete sequencing and analysis of the mitochondrial genome of Chinese patients with this disease. METHODS Two unrelated southern Chinese families with LHON and 10 matched healthy controls were recruited, and their entire mitochondrial DNA (mtDNA) was amplified and sequenced with the universal M13 primer. Then DNA sequence analysis and variation identification were perfomed by DNAssist and Chromas 2 software and compared with authoritative databases such as Mitomap. RESULTS Mutational analysis of mtDNA in these two Chinese pedigrees revealed one common LHON-associated mutation, G11778A (Arg→His), in the MT-ND4 gene. In addition, there were two secondary mutations in Pedigree 1: C3497T (Ala→Val), and C3571T (Leu→Phe) in the MT-ND1 gene, which have not been reported; and two secondary mutations occurred in Pedigree 2: A10398G (Thr→Ala) in the MT-ND3 gene, and T14502C (Ile→Val) in the MT-ND6 gene. Three polymorphisms, A73G, G94A and A263G in the mtDNA control region, were also found. CONCLUSION Our study confirmed that the known MT-ND4*G11778A mutation is the most significant cause of LHON. The C3497T and C3571T mutations in Pedigree 1 were also both at hot-spots of MT-ND1; they may affect the respiratory chain in coordination with the primary mutation G11778A. In Pedigree 2, the two secondary mutations A10398G of MT-ND3 and T14502C of MT-ND6 may influence mitochondrial respiratory complex I, leading to the mitochondrial respiratory chain dysfunction which results in optic atrophy together with G11778A. Therefore, not only the common primary LHON mutation is responsible for the visual atrophy, but other secondary mtDNA mutations should also be considered when giving genetic counseling.
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Affiliation(s)
- Lei Shu
- Hangzhou Red Cross Hospital, Hangzhou 310003, Zhejiang Province, China
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Zhang AM, Jia X, Bi R, Salas A, Li S, Xiao X, Wang P, Guo X, Kong QP, Zhang Q, Yao YG. Mitochondrial DNA haplogroup background affects LHON, but not suspected LHON, in Chinese patients. PLoS One 2011; 6:e27750. [PMID: 22110754 PMCID: PMC3216987 DOI: 10.1371/journal.pone.0027750] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 10/24/2011] [Indexed: 02/07/2023] Open
Abstract
Recent studies have shown that mtDNA background could affect the clinical expression of Leber hereditary optic neuropathy (LHON). We analyzed the mitochondrial DNA (mtDNA) variation of 304 Chinese patients with m.11778G>A (sample #1) and of 843 suspected LHON patients who lack the three primary mutations (sample #2) to discern mtDNA haplogroup effect on disease onset. Haplogroup frequencies in the patient group was compared to frequencies in the general Han Chinese population (n = 1,689; sample #3). The overall matrilineal composition of the suspected LHON population resembles that of the general Han Chinese population, suggesting no association with mtDNA haplogroup. In contrast, analysis of these LHON patients confirms mtDNA haplogroup effect on LHON. Specifically, the LHON sample significantly differs from the general Han Chinese and suspected LHON populations by harboring an extremely lower frequency of haplogroup R9, in particular of its main sub-haplogroup F (#1 vs. #3, P-value = 1.46×10−17, OR = 0.051, 95% CI: 0.016–0.162; #1 vs. #2, P-value = 4.44×10−17, OR = 0.049, 95% CI: 0.015–0.154; in both cases, adjusted P-value <10−5) and higher frequencies of M7b (#1 vs. #3, adjusted P-value = 0.001 and #1 vs. #2, adjusted P-value = 0.004). Our result shows that mtDNA background affects LHON in Chinese patients with m.11778G>A but not suspected LHON. Haplogroup F has a protective effect against LHON, while M7b is a risk factor.
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Affiliation(s)
- A-Mei Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Rui Bi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Antonio Salas
- Unidade de Xenética, Instituto de Medicina Legal and Departamento de Anatomía Patolóxica e Ciencias Forenses, Facultade de Medicina, Universidade de Santiago de Compostela, Galicia, Spain
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiangming Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qing-Peng Kong
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- * E-mail: (QZ); (Y-GY)
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, China
- * E-mail: (QZ); (Y-GY)
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Zhang AM, Bandelt HJ, Jia X, Zhang W, Li S, Yu D, Wang D, Zhuang XY, Zhang Q, Yao YG. Is mitochondrial tRNA(phe) variant m.593T>C a synergistically pathogenic mutation in Chinese LHON families with m.11778G>A? PLoS One 2011; 6:e26511. [PMID: 22039503 PMCID: PMC3198432 DOI: 10.1371/journal.pone.0026511] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Accepted: 09/28/2011] [Indexed: 01/28/2023] Open
Abstract
Mitochondrial transfer RNA (mt-tRNA) mutations have been reported to be associated with a variety of diseases. In a previous paper that studied the mtDNA background effect on clinical expression of Leber's hereditary optic neuropathy (LHON) in 182 Chinese families with m.11778G>A, we found a strikingly high frequency (7/182) of m.593T>C in the mitochondrially encoded tRNA phenylalanine (MT-TF) gene in unrelated LHON patients. To determine the potential role of m.593T>C in LHON, we compared the frequency of this variant in 479 LHON patients with m.11778G>A, 843 patients with clinical features of LHON but without the three known primary mutations, and 2374 Han Chinese from the general populations. The frequency of m.593T>C was higher in LHON patients (14/479) than in suspected LHON subjects (12/843) or in general controls (49/2374), but the difference was not statistically significant. The overall penetrance of LHON in families with both m.11778G>A and m.593T>C (44.6%) was also substantially higher than that of families with only m.11778G>A (32.9%) (P = 0.083). Secondary structure prediction of the MT-TF gene with the wild type or m.593T>C showed that this nucleotide change decreases the free energy. Electrophoretic mobility of the MT-TF genes with the wild type or m.593T>C transcribed in vitro further confirmed the change of secondary structure in the presence of this variant. Although our results could suggest a modest synergistic effect of variant m.593T>C on the LHON causing mutation m.11778G>A, the lack of statistical significance probably due to the relatively small sample size analyzed, makes necessary more studies to confirm this effect.
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Affiliation(s)
- A-Mei Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | | | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wen Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Dandan Yu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Dong Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Xin-Ying Zhuang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
- * E-mail: (QZ); (YGY)
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan, China
- * E-mail: (QZ); (YGY)
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mtDNA m.3635G>A may be classified as a common primary mutation for Leber hereditary optic neuropathy in the Chinese population. Biochem Biophys Res Commun 2010; 403:237-41. [DOI: 10.1016/j.bbrc.2010.11.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 11/04/2010] [Indexed: 02/08/2023]
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Screening the three LHON primary mutations in the general Chinese population by using an optimized multiplex allele-specific PCR. Clin Chim Acta 2010; 411:1671-4. [DOI: 10.1016/j.cca.2010.06.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 06/24/2010] [Accepted: 06/25/2010] [Indexed: 02/07/2023]
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Yu D, Jia X, Zhang AM, Li S, Zou Y, Zhang Q, Yao YG. Mitochondrial DNA sequence variation and haplogroup distribution in Chinese patients with LHON and m.14484T>C. PLoS One 2010; 5:e13426. [PMID: 20976138 PMCID: PMC2956641 DOI: 10.1371/journal.pone.0013426] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 09/22/2010] [Indexed: 12/28/2022] Open
Abstract
Background Leber hereditary optic neuropathy (LHON, MIM 535000) is one of the most common mitochondrial genetic disorders caused by three primary mtDNA mutations (m.3460G>A, m.11778G>A and m. 14484T>C). The clinical expression of LHON is affected by many additional factors, e.g. mtDNA background, nuclear genes, and environmental factors. Hitherto, there is no comprehensive study of Chinese LHON patients with m.14484T>C. Methodology/Principal Findings In this study, we analyzed the mtDNA sequence variations and haplogroup distribution pattern of the largest number of Chinese LHON patients with m.14484T>C to date. We first determined the complete mtDNA sequences in eleven LHON probands with m.14484T>C, to discern the potentially pathogenic mutations that co-segregate with m.14484T>C. We then dissected the matrilineal structure of 52 patients with m.14484T>C (including 14 from unrelated families and 38 sporadic cases) and compared it with the reported Han Chinese from general populations. Complete mtDNA sequencing showed that the eleven matrilines belonged to nine haplogroups including Y2, C4a, M8a, M10a1a, G1a1, G2a1, G2b2, D5a2a1, and D5c. We did not identify putatively pathogenic mutation that was co-segregated with m.14484T>C in these lineages based on the evolutionary analysis. Compared with the reported Han Chinese from general populations, the LHON patients with m.14484T>C had significantly higher frequency of haplogroups C, G, M10, and Y, but a lower frequency of haplogroup F. Intriguingly, we also observed a lower prevalence of F lineages in LHON subjects with m.11778G>A in our previous study, suggesting that this haplogroup may enact similar role during the onset of LHON in the presence of m.14484T>C or m.11778G>A. Conclusions/Significance Our current study provided a comprehensive profile regarding the mtDNA variation and background of Chinese patients with LHON and m.14484T>C. Matrilineal background might affect the expression of LHON in Chinese patients with m.14484T>C.
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Affiliation(s)
- Dandan Yu
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - A-Mei Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yang Zou
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
- * E-mail: (Y-GY); (QZ)
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- * E-mail: (Y-GY); (QZ)
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Zhang M, Zhou X, Li C, Zhao F, Zhang J, Yuan M, Sun YH, Wang J, Tong Y, Liang M, Yang L, Cai W, Wang L, Qu J, Guan MX. Mitochondrial haplogroup M9a specific variant ND1 T3394C may have a modifying role in the phenotypic expression of the LHON-associated ND4 G11778A mutation. Mol Genet Metab 2010; 101:192-9. [PMID: 20728388 DOI: 10.1016/j.ymgme.2010.07.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 07/26/2010] [Indexed: 11/18/2022]
Abstract
We report here the clinical, genetic and molecular characterization of four Han Chinese families with Leber's hereditary optic neuropathy (LHON). The penetrances of optic neuropathy in these Chinese pedigrees were 38%, 38%, 44% and 56%. This observation is in contrast with the previously identified 14 Chinese families with very low penetrance of LHON. The age-at-onset for visual impairment in matrilineal relatives in these Chinese families varied from 18 to 30years. Furthermore, the ratios between affected male and female matrilineal relatives in these families were 3:0, 3:0, 3:1 and 2:3, respectively. Molecular analysis of mitochondrial genomes identified the known ND4 G11778A mutation and distinct sets of variants belonging to the Asian haplogroups M9a. Of these, the ND1 T3394C mutation caused the substitution of a highly conserved histidine for tyrosine (Y30H) at amino acid position 30. This mutation was associated with LHON in other families with low penetrance of optic neuropathy and other clinical abnormalities. The presence of both G11778A and T3394C mutations appears to contribute to higher penetrance of optic neuropathy in these four Chinese families than other Chinese families carrying only the G11778A mutation. Therefore, the mitochondrial haplogroup M9a specific variant T3394C may modulate the phenotypic manifestation of LHON-associated G11778A mutation in these Chinese pedigrees.
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Affiliation(s)
- Minglian Zhang
- Department of Ophthalmology, Xingtai Eye Hospital, Xingtai, Hebei, China
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