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Ding Y, Zhang S, Guo Q, Leng J. Mitochondrial Diabetes Is Associated with the ND4 G11696A Mutation. Biomolecules 2023; 13:907. [PMID: 37371486 DOI: 10.3390/biom13060907] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/21/2023] [Accepted: 05/25/2023] [Indexed: 06/29/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a common endocrine disorder which remains a large challenge for clinicians. Previous studies have suggested that mitochondrial dysfunction plays an active role in T2DM progression, but a detailed mechanism is still elusive. In the current study, two Han Chinese families with maternally inherited T2DM were evaluated using clinical, genetic, molecular, and biochemical analyses. The mitochondrial genomes were PCR amplified and sequenced. Phylogenetic and bioinformatic analyses were used to assess the potential pathogenicity of mitochondrial DNA (mtDNA) mutations. Interestingly, the matrilineal relatives of these pedigrees exhibited variable severity of T2DM, in particular, the age at onset of T2DM varied from 26 to 65 years, with an average of 49 years. Sequence analysis revealed the presence of ND4 G11696A mutation, which resulted in the substitution of an isoleucine for valine at amino acid (AA) position 312. Indeed, this mutation was present in homoplasmy only in the maternal lineage, not in other members of these families, as well as 200 controls. Furthermore, the m.C5601T in the tRNAAla and novel m.T5813C in the tRNACys, showing high evolutional conservation, may contribute to the phenotypic expression of ND4 G11696A mutation. In addition, biochemical analysis revealed that cells with ND4 G11696A mutation exhibited higher levels of reactive oxygen species (ROS) productions than the controls. In contrast, the levels of mitochondrial membrane potential (MMP), ATP, mtDNA copy number (mtDNA-CN), Complex I activity, and NAD+/NADH ratio significantly decreased in cell lines carrying the m.G11696A and tRNA mutations, suggesting that these mutations affected the respiratory chain function and led to mitochondrial dysfunction that was involved in T2DM. Thus, our study broadened the clinical phenotypes of m.G11696A mutation.
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Affiliation(s)
- Yu Ding
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Shunrong Zhang
- Department of Geriatrics, Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Qinxian Guo
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
| | - Jianhang Leng
- Central Laboratory, Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou 310006, China
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2
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Carelli V, Newman NJ, Yu-Wai-Man P, Biousse V, Moster ML, Subramanian PS, Vignal-Clermont C, Wang AG, Donahue SP, Leroy BP, Sergott RC, Klopstock T, Sadun AA, Rebolleda Fernández G, Chwalisz BK, Banik R, Girmens JF, La Morgia C, DeBusk AA, Jurkute N, Priglinger C, Karanjia R, Josse C, Salzmann J, Montestruc F, Roux M, Taiel M, Sahel JA. Indirect Comparison of Lenadogene Nolparvovec Gene Therapy Versus Natural History in Patients with Leber Hereditary Optic Neuropathy Carrying the m.11778G>A MT-ND4 Mutation. Ophthalmol Ther 2023; 12:401-429. [PMID: 36449262 PMCID: PMC9834474 DOI: 10.1007/s40123-022-00611-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/28/2022] [Indexed: 12/05/2022] Open
Abstract
INTRODUCTION Lenadogene nolparvovec is a promising novel gene therapy for patients with Leber hereditary optic neuropathy (LHON) carrying the m.11778G>A ND4 mutation (MT-ND4). A previous pooled analysis of phase 3 studies showed an improvement in visual acuity of patients injected with lenadogene nolparvovec compared to natural history. Here, we report updated results by incorporating data from the latest phase 3 trial REFLECT in the pool, increasing the number of treated patients from 76 to 174. METHODS The visual acuity of 174 MT-ND4-carrying patients with LHON injected in one or both eyes with lenadogene nolparvovec from four pooled phase 3 studies (REVERSE, RESCUE and their long-term extension trial RESTORE; and REFLECT trial) was compared to the spontaneous evolution of an external control group of 208 matched patients from 11 natural history studies. RESULTS Treated patients showed a clinically relevant and sustained improvement in their visual acuity when compared to natural history. Mean improvement versus natural history was - 0.30 logMAR (+ 15 ETDRS letters equivalent) at last observation (P < 0.01) with a maximal follow-up of 3.9 years after injection. Most treated eyes were on-chart as compared to less than half of natural history eyes at 48 months after vision loss (89.6% versus 48.1%; P < 0.01) and at last observation (76.1% versus 44.4%; P < 0.01). When we adjusted for covariates of interest (gender, age of onset, ethnicity, and duration of follow-up), the estimated mean gain was - 0.43 logMAR (+ 21.5 ETDRS letters equivalent) versus natural history at last observation (P < 0.0001). Treatment effect was consistent across all phase 3 clinical trials. Analyses from REFLECT suggest a larger treatment effect in patients receiving bilateral injection compared to unilateral injection. CONCLUSION The efficacy of lenadogene nolparvovec in improving visual acuity in MT-ND4 LHON was confirmed in a large cohort of patients, compared to the spontaneous natural history decline. Bilateral injection of gene therapy may offer added benefits over unilateral injection. TRIAL REGISTRATION NUMBERS NCT02652780 (REVERSE); NCT02652767 (RESCUE); NCT03406104 (RESTORE); NCT03293524 (REFLECT); NCT03295071 (REALITY).
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Affiliation(s)
- Valerio Carelli
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura, 3, 40139, Bologna, BO, Italy.
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.
| | - Nancy J Newman
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Patrick Yu-Wai-Man
- Department of Clinical Neurosciences, Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
- Institute of Ophthalmology, University College London, London, UK
| | - Valerie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Neurological Surgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Mark L Moster
- Department of Neurology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
- Department of Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
| | - Prem S Subramanian
- Sue Anschutz-Rodgers University of Colorado Eye Center, University of Colorado School of Medicine, Aurora, CO, USA
| | - Catherine Vignal-Clermont
- Department of Neuro Ophthalmology and Emergencies, Rothschild Foundation Hospital, Paris, France
- Centre d'Investigation Clinique, Centre Hospitalier National d'Ophtalmologie des Quinze Vingts, Paris, France
| | - An-Guor Wang
- Department of Ophthalmology, Taipei Veterans General Hospital, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Sean P Donahue
- Department of Ophthalmology, Neurology, and Pediatrics, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN, USA
| | - Bart P Leroy
- Department of Ophthalmology and Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
- Department of Head & Skin, Ghent University, Ghent, Belgium
| | - Robert C Sergott
- Department of Neurology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
- Department of Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Alfredo A Sadun
- David Geffen, Doheny Eye Institute, School of Medicine, University of California, Los Angeles, CA, USA
| | | | - Bart K Chwalisz
- Department of Ophthalmology, Massachusetts Eye & Ear, Harvard Medical School, Boston, MA, USA
| | - Rudrani Banik
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jean François Girmens
- Centre d'Investigation Clinique, Centre Hospitalier National d'Ophtalmologie des Quinze Vingts, Paris, France
| | - Chiara La Morgia
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Via Altura, 3, 40139, Bologna, BO, Italy
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Adam A DeBusk
- Department of Neurology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
- Department of Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, USA
| | - Neringa Jurkute
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
- Institute of Ophthalmology, University College London, London, UK
- Department of Neuro-Ophthalmology, The National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Rustum Karanjia
- David Geffen, Doheny Eye Institute, School of Medicine, University of California, Los Angeles, CA, USA
- Department of Ophthalmology, University of Ottawa Eye, Ottawa, ON, Canada
| | - Constant Josse
- eXYSTAT, Data Management and Statistic, Malakoff, France
| | | | | | | | | | - José-Alain Sahel
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
- Rothschild Foundation Hospital, Paris, France
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Institut Hospitalo-Universitaire FOReSIGHT, INSERM-DGOS CIC 1423, Paris, France
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Tagliani S, Malaventura C, Ceccato C, Parmeggiani F, Suppiej A. Leber Mitochondrial Optic Neuropathy in Pediatric Females With Focus on Very Early Onset Cases. J Child Neurol 2023; 38:5-15. [PMID: 36659874 DOI: 10.1177/08830738221149962] [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: 01/21/2023]
Abstract
The aim of this study was to describe the phenotype of Leber hereditary optic neuropathy occurring in pediatric females. This disease generally affects young adult males, but it can occur also in females, and research data in this population is lacking. The very early onset can challenge the diagnosis and delay treatment. We searched PubMed through February 2021 and identified 226 pediatric females with genetically confirmed Leber hereditary optic neuropathy and added a new case of a 3-year-old female. The male-female ratio was 1.8:1; the mean onset age in females was 11 years with the onset at 3 years of age occurring in 3 females only. Acute onset with mild visual impairment was the most common presentation, associated with optic disc edema in 16%. Differential diagnoses are pseudotumor cerebri, optic nerve drusen and optic neuritis. The outcome is poor with partial recovery in 50%, despite some receiving Idebenone therapy.
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Affiliation(s)
- Sara Tagliani
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy
| | - Cristina Malaventura
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy
| | | | - Francesco Parmeggiani
- Department of Translational Medicine and for Romagna, 9299University of Ferrara, Ferrara, Italy.,ERN-EYE Network - Center for Retinitis Pigmentosa of Veneto Region, 196013Camposampiero Hospital, Padova, Italy
| | - Agnese Suppiej
- Department of Medical Sciences, Pediatric Section, University Hospital of Ferrara, Ferrara, Italy.,87812Robert Hollman Foundation, Padova, Italy.,ERN-EYE Network - Center for Retinitis Pigmentosa of Veneto Region, 196013Camposampiero Hospital, Padova, Italy
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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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Newman NJ, Yu-Wai-Man P, Carelli V, Biousse V, Moster ML, Vignal-Clermont C, Sergott RC, Klopstock T, Sadun AA, Girmens JF, La Morgia C, DeBusk AA, Jurkute N, Priglinger C, Karanjia R, Josse C, Salzmann J, Montestruc F, Roux M, Taiel M, Sahel JA. Intravitreal Gene Therapy vs. Natural History in Patients With Leber Hereditary Optic Neuropathy Carrying the m.11778G>A ND4 Mutation: Systematic Review and Indirect Comparison. Front Neurol 2021; 12:662838. [PMID: 34108929 PMCID: PMC8181419 DOI: 10.3389/fneur.2021.662838] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/25/2021] [Indexed: 01/22/2023] Open
Abstract
Objective: This work aimed to compare the evolution of visual outcomes in Leber hereditary optic neuropathy (LHON) patients treated with intravitreal gene therapy to the spontaneous evolution in prior natural history (NH) studies. Design: A combined analysis of two phase three randomized, double-masked, sham-controlled studies (REVERSE and RESCUE) and their joint long-term extension trial (CLIN06) evaluated the efficacy of rAAV2/2-ND4 vs. 11 pooled NH studies used as an external control. Subjects: The LHON subjects carried the m.11778G>A ND4 mutation and were aged ≥15 years at onset of vision loss. Methods: A total of 76 subjects received a single intravitreal rAAV2/2-ND4 injection in one eye and sham injection in the fellow eye within 1 year after vision loss in REVERSE and RESCUE. Both eyes were considered as treated due to the rAAV2/2-ND4 treatment efficacy observed in the contralateral eyes. Best corrected visual acuity (BCVA) from REVERSE, RESCUE, and CLIN06 up to 4.3 years after vision loss was compared to the visual acuity of 208 NH subjects matched for age and ND4 genotype. The NH subjects were from a LHON registry (REALITY) and from 10 NH studies. A locally estimated scatterplot smoothing (LOESS), non-parametric, local regression model was used to modelize visual acuity curves over time, and linear mixed model was used for statistical inferences. Main Outcome Measures: The main outcome measure was evolution of visual acuity from 12 months after vision loss, when REVERSE and RESCUE patients had been treated with rAAV2/2-ND4. Results: The LOESS curves showed that the BCVA of the treated patients progressively improved from month 12 to 52 after vision loss. At month 48, there was a statistically and clinically relevant difference in visual acuity of -0.33 logarithm of the minimal angle of resolution (LogMAR) (16.5 ETDRS letters equivalent) in favor of treated eyes vs. NH eyes (p < 0.01). Most treated eyes (88.7%) were on-chart at month 48 as compared to 48.1% of the NH eyes (p < 0.01). The treatment effect at last observation remained statistically and clinically significant when adjusted for age and duration of follow-up (-0.32 LogMAR, p < 0.0001). Conclusions: The m.11778G>A LHON patients treated with rAAV2/2-ND4 exhibited an improvement of visual acuity over more than 4 years after vision loss to a degree not demonstrated in NH studies. Clinical Trial Registration: NCT02652767, NCT02652780, NCT03406104, and NCT03295071.
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Affiliation(s)
- Nancy J. Newman
- Departments of Ophthalmology, Neurology and Neurological Surgery, Emory University School of Medicine, Atlanta, GA, United States
- *Correspondence: Nancy J. Newman
| | - Patrick Yu-Wai-Man
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
- Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, United Kingdom
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Valerio Carelli
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Unitá Operativa Compless Clinica Neurologica, Bologna, Italy
- Unit of Neurology, Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Valerie Biousse
- Departments of Ophthalmology, Neurology and Neurological Surgery, Emory University School of Medicine, Atlanta, GA, United States
| | - Mark L. Moster
- Departments of Neurology and Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, United States
| | - Catherine Vignal-Clermont
- Department of Neuro Ophthalmology and Emergencies, A. de Rothschild Foundation Hospital, Paris, France
- Centre d'investigation Clinique, Centre Hospitalier National d'Ophtalmologie des Quinze Vingts, Paris, France
| | - Robert C. Sergott
- Departments of Neurology and Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, United States
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
| | - Alfredo A. Sadun
- Doheny Eye Institute, School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jean-François Girmens
- Centre d'investigation Clinique, Centre Hospitalier National d'Ophtalmologie des Quinze Vingts, Paris, France
| | - Chiara La Morgia
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Unitá Operativa Compless Clinica Neurologica, Bologna, Italy
| | - Adam A. DeBusk
- Departments of Neurology and Ophthalmology, Wills Eye Hospital and Thomas Jefferson University, Philadelphia, PA, United States
| | - Neringa Jurkute
- Moorfields Eye Hospital National Health Service Foundation Trust, London, United Kingdom
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Rustum Karanjia
- Doheny Eye Institute, School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Ophthalmology, University of Ottawa Eye, Ottawa, ON, Canada
| | - Constant Josse
- eXYSTAT, Data Management and Statistic, Malakoff, France
| | | | | | | | | | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- A. de Rothschild Foundation Hospital, Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- CHNO des Quinze-Vingts, Institut Hospitalo-Universitaire FOReSIGHT, INSERM-DGOS CIC 1423, Paris, France
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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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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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Zhang Y, Tian Z, Yuan J, Liu C, Liu HL, Ma SQ, Li B. The Progress of Gene Therapy for Leber's Optic Hereditary Neuropathy. Curr Gene Ther 2019; 17:320-326. [PMID: 29189152 PMCID: PMC5902861 DOI: 10.2174/1566523218666171129204926] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/16/2017] [Accepted: 11/20/2017] [Indexed: 11/26/2022]
Abstract
Introduction: Leber’s Optic Hereditary Neuropathy (LHON) is a common cause of teenaged blindness in both eyes for which there is currently no effective treatment. In 1871, the German ophthal-mologist Theodor Leber was the first to describe the clinical characteristics of his namesake disease, and through unremitting efforts over the past 100 years, researchers have continued to increase their under-standing of LHON. In recent years, using gene therapy, several groups have obtained breakthroughs in the treatment of the disease. Conclusion: In this article, we will review the challenging journey that researchers faced towards our current understanding of LHON, and describe the transition of gene therapy research for LHON from the bench to bedside.
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Affiliation(s)
- Yong Zhang
- Department of Ophthalmology Shiyan, Hubei University of Medicine - Taihe Hospital, Hubei. China
| | - Zhen Tian
- Department of Ophthalmology Shiyan, Hubei University of Medicine - Taihe Hospital, Hubei. China
| | - Jiajia Yuan
- Department of Ophthalmology, Tongji Medical College, Huazhong University of Science and Technology - Tongji Hospital, Wuhan Shi. China
| | - Chang Liu
- Department of Ophthalmology, Tongji Medical College, Huazhong University of Science and Technology - Tongji Hospital, Wuhan Shi. China
| | - Hong Li Liu
- Department of Ophthalmology, Tongji Medical College, Huazhong University of Science and Technology - Tongji Hospital, Wuhan Shi. China
| | - Si Qi Ma
- Department of Ophthalmology, Tongji Medical College, Huazhong University of Science and Technology - Tongji Hospital, Wuhan Shi. China
| | - Bin Li
- Department of Ophthalmology Shiyan, Hubei University of Medicine - Taihe Hospital, Hubei. China
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9
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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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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: 12] [Impact Index Per Article: 1.7] [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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11
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Ji Y, Qiao L, Liang X, Zhu L, Gao Y, Zhang J, Jia Z, Wei QP, Liu X, Jiang P, Guan MX. Leber's hereditary optic neuropathy is potentially associated with a novel m.5587T>C mutation in two pedigrees. Mol Med Rep 2017; 16:8997-9004. [PMID: 28990081 DOI: 10.3892/mmr.2017.7734] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 07/21/2017] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial (mt)DNA mutations have been revealed to be associated with Leber's hereditary optic neuropathy (LHON). The present study conducted clinical, genetic and molecular evaluations of two Han Chinese families. A total of 4 (3 men and 1 female) out of 14 matrilineal relatives in the families exhibited visual impairment with variable severity and age of onset. The average age of onset of visual loss was 20.5 years old. Molecular analysis of the complete mitochondrial genome in these pedigrees demonstrated that the three primary mutations associated with LHON were not detected; however, the homoplasmic m.5587T>C mutation was identified, which was localized at the end of the mitochondrially encoded transfer (t)RNA alanine gene and may alter the tertiary structure of this tRNA. Subsequently, this structural alteration may result in tRNA metabolism failure. In addition, distinct sets of mtDNA polymorphisms belonging to haplogroup F1 were detected in both families tested. The findings of the present study suggested that the m.5587T>C mutation may be involved in the pathogenesis of visual impairment. In addition, the mtDNA variant m.15024G>A(p.C93H) in the mitochondrially encoded cytochrome B gene was detected in both families, which exhibited evolutionary conservation, indicating it may serve a potential modifying role in the development of visual impairment associated with m.5587T>C mutation in these families. Furthermore, other modifying factors, including nuclear modifier genes, and environmental and personal factors may also contribute to the development of LHON in subjects carrying this mutation.
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Affiliation(s)
- Yanchun Ji
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Lihua Qiao
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Xiaoyang Liang
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Ling Zhu
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Yinglong Gao
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325025, P.R. China
| | - Zidong Jia
- Institute of Genetics, Zhejiang University and Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Qi-Ping Wei
- Department of Ophthalmology, Beijing University of Chinese Medicine, Beijing 100029, P.R. China
| | - Xiaoling Liu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang 325025, P.R. China
| | - Pingping Jiang
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
| | - Min-Xin Guan
- Division of Clinical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, P.R. China
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12
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Ji J, Xu M, Huang Z, Li L, Zheng H, Yang S, Li S, Jin L, Ling X, Xia Y, Lu C, Wang X. Mitochondrial DNA sequencing and large-scale genotyping identifies MT-ND4 gene mutation m.11696G>A associated with idiopathic oligoasthenospermia. Oncotarget 2017; 8:52975-52982. [PMID: 28881787 PMCID: PMC5581086 DOI: 10.18632/oncotarget.17675] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/13/2017] [Indexed: 01/07/2023] Open
Abstract
Genetic variants of mitochondrial DNA (mtDNA) were implicated to be associated with male infertility. Our previous whole mitochondrial genome sequencing and association study has identified two susceptibility mtDNA variants for oligoasthenospermia in Han Chinese men. In this study, we tested promising associations in an extended validation using 670 idiopathic oligoasthenospermia cases and 793 healthy controls to identify additional risk variants. We found that the genetic variant of m.11696G>A showed significantly higher frequency in the case group than that in the control group (odds ratio (OR) 2.21, 95% CI 1.21-4.04) (P=7.90×10−3). To elucidate the exact role of the genetic variants in spermatogenesis, two main sperm parameters (sperm count and motility) were taken into account. We found that m.11696G>A was associated with low sperm motility, with the OR of 2.38 (95 % CI 1.27-4.46) (P =5.22×10−3). These results advance our understanding of the genetic susceptibility to oligoasthenospermia and more functional studies are needed to provide insights into its pathogenic mechanism.
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Affiliation(s)
- Juan Ji
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China.,Department of Children Health Care, Nanjing Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University, Nanjing 210029, China
| | - Miaofei Xu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China
| | - Zhenyao Huang
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China
| | - Lei Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Hongxiang Zheng
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Shuping Yang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Shilin Li
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xiufeng Ling
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Department of Children Health Care, Nanjing Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University, Nanjing 210029, China
| | - Yankai Xia
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China
| | - Chuncheng Lu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China
| | - Xinru Wang
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China.,Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 210029, China
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13
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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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14
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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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15
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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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16
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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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17
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Zhou HH, Dai XN, Lin B, Mi H, Liu XL, Zhao FX, Zhang JJ, Zhou XT, Sun YH, Wei QP, Qu J, Guan MX. [The analysis of Leber's hereditary optic neuropathy associated with mitochondrial tRNAAla C5601T mutation in seven Han Chinese families]. YI CHUAN = HEREDITAS 2012; 34:1031-42. [PMID: 22917908 DOI: 10.3724/sp.j.1005.2012.01031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We reported here the clinical, genetic, and molecular characterization of Leber's hereditary optic neuropathy (LHON) with C5601T mutation in seven Chinese families. The ophthalmologic examinations of seven Chinese families who were clinically diagnosed LHON were conducted. Strikingly, these families exhibited very low penetrance of visual impairment, and the penetrance was 9.5%, 14.3%, 4.5%, 8.3%, 10.0%, 22.2% and 25.0%. Meanwhile, entire mitochondrial genome of seven probands was amplified by PCR using 24 pairs of oligonucleotide primers with overlapping fragments. Molecular analysis of mitochondrial DNA (mtDNA) in these pedigrees revealed the absence of three common LHON associated G11778A, G3460A and T14484C mutations but the presence of homoplastic LHON associated tRNAAla C5601T mutation in probands and other matrilineal relatives. These mtDNA polymorphism sites belongs to the Asian haplogroups G2, G2a1, G2a1, G2, G2b, G2a1 and G2. By analyzing mitochondrial genome, seven LHON families all carry the C5601T mutation. The C5601T mutation occurs at the highly conserved nucleotide (conventional position 59) of tRNAAla, thereby contributing to the structural formation and stabilization of functional tRNAs and leading to mitochondrial dysfunction involved in visual impairment. The incomplete penetrance of visual loss in these seven Chinese pedigrees strongly indicates that the tRNAAla C5601T mutation was itself insufficient to produce a clinical phenotype. The lack of functional mtDNA variants in these pedigrees ruled out the role of mitochondrial background in the phenotypic expression of visual loss. Therefore, nuclear backgrounds and environmental factors seem to be modifying factors for the phenotypic manifestation of the tRNAAla C5601T mutation in the seven Chinese families.
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Affiliation(s)
- Hui-Hui Zhou
- Giuseppe Attardi Institute of Mitochondrial Biomedicine, Wenzhou Medical College, Wenzhou, China
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[The mitochondrial ND5 T12338C mutation may be associated with Leber's hereditary optic neuropathy in two Chinese families]. YI CHUAN = HEREDITAS 2011; 33:322-8. [PMID: 21482521 DOI: 10.3724/sp.j.1005.2011.00322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Leber's hereditary optic neuropathy (LHON) associated with mitochondrial DNA mutation is a maternally inherited eye disease. We reported here the clinical, genetic and molecular characterization of two Han Chinese families with Leber's hereditary optic neuropathy. Ophthalmologic examinations revealed that the variable severity and age-of-onset in visual impairment among probands and other matrilineal relatives of these families. Strikingly, there were extremely low penetrances of visual impairment in these families. Sequence analysis of complete mitochondrial genomes in these pedigrees identified the homoplasmic ND4 G11696A and ND5 T12338C mutation and distinct sets of polymorphism belonging to haplogroups F2. It is well known that mitochondrial DNA ND4 G11696A is associated with LHON. The ND5 T12338C mutation resulted in replacement of the first amino acid, translation-initiating methionine with a threonine, and shortening two amino acids of ND5. This mutation also locates in two nucleotides adjacent to the 3' end of the tRNALeu(Cun). Thus, this mutation may alter structural formation and stabilization of functional tRNA, thereby leading to a failure in protein synthesis and mitochondrial dysfunction involved in visual impairment. Therefore, the ND4 G11696A and ND5 T12338C mutation is likely associated with LHON in these two Chinese families. But these families exhibited extremely low penetrances of visual impairment. It suggests that other factors, such as nuclear modifier gene(s) or environmental factor(s), may play a role in the phenotypic expression of the LHON-associated ND4 G11696A and ND5 T12338C mutation.
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Leber's hereditary optic neuropathy is associated with the T12338C mutation in mitochondrial ND5 gene in six Han Chinese families. Ophthalmology 2010; 118:978-85. [PMID: 21131053 DOI: 10.1016/j.ophtha.2010.09.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 09/08/2010] [Accepted: 09/08/2010] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To investigate the molecular pathogenesis of Leber's hereditary optic neuropathy (LHON) in Chinese families. DESIGN Six Han Chinese families who seem to have maternally transmitted LHON were studied by clinical, genetic, and molecular evaluations. PARTICIPANTS One hundred twenty-seven subjects from 6 Chinese families with a wide range of age-at-onset and severity of visual impairment. METHODS All subjects underwent clinical examination, genetic evaluation, and molecular analysis of mitochondrial DNA (mtDNA). MAIN OUTCOME MEASURES The ophthalmologic examinations included visual acuity, visual field examination, visual evoked potentials, and fundus photography. The mtDNA analysis included the polymerase chain reaction (PCR) amplification of entire mtDNA and subsequent sequence determination. RESULTS Six families exhibited low penetrance of visual impairment, with an average of 10.8%. In particular, 9 (6 males/3 females) of 86 matrilineal relatives in these families exhibited variable severity and age at onset in visual dysfunction. The average age at onset of visual loss was 20 years. Molecular analysis of mtDNA in these families identified the homoplasmic ND5T12338C mutation and distinct set of variants belonging to the Asian haplogroup F2. The T12338C mutation is only present in the maternal lineage of those pedigrees and not in 178 Chinese controls. This mutation resulted in the replacement of the first amino acid, a translation-initiating methionine with a threonine, shortening 2 amino acids of ND5 polypeptide. The T12338C mutation is also located in 2 nucleotides adjacent to the 3' end of the tRNA(Leu(CUN)). Thus, this mutation may alter ND5 mRNA metabolism and the processing of RNA precursors. As a result, this mutation impairs respiratory function, leading to visual impairment. CONCLUSIONS Several lines of evidence suggest that the mitochondrial ND5T12338C mutation is associated with LHON. The tissue specificity of this mutation is likely due to the involvement of nuclear modifier genes. The identification of nuclear modifiers is important for the elucidation of the pathogenic mechanism of LHON and an open avenue for therapeutic interventions. The T12338C mutation should be added to the list of inherited risk factors for future molecular diagnosis. Our findings are helpful for counseling families with LHON.
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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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Zhang J, Zhou X, Zhou J, Li C, Zhao F, Wang Y, Meng Y, Wang J, Yuan M, Cai W, Tong Y, Sun YH, Yang L, Qu J, Guan MX. Mitochondrial ND6 T14502C variant may modulate the phenotypic expression of LHON-associated G11778A mutation in four Chinese families. Biochem Biophys Res Commun 2010; 399:647-53. [PMID: 20691156 DOI: 10.1016/j.bbrc.2010.07.135] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 07/30/2010] [Indexed: 10/19/2022]
Abstract
We report here the clinical, genetic, and molecular evaluations of four Han Chinese families with Leber's hereditary optic neuropathy. Thirty-one (20 males/11 females) of 83 matrilineal relatives in these families exhibited the variable severity and age-at-onset in visual impairment. The average age-of-onset of vision loss was 22years old. Strikingly, these penetrances of visual impairment in these Chinese families were higher than those in other 11 Chinese pedigrees carrying the only ND4 G11778A mutation. Molecular analysis identified the known G11778A mutation and distinct sets of variants belonging to the Asian haplogroups M10a and M7c2. Of these, the T14502C mutation caused the substitution of a highly conserved isoleucine for valine at position 58 in ND6. This mutation has been associated with LHON in other Chinese families with very low penetrance of LHON. Thus, the deficient activities of complex I, caused by G11778A mutation, would be worsened by the T14502C mutation in these four Chinese families. As a result, mitochondrial dysfunctions would lead to the high penetrance and expressivity of visual loss in these Chinese families carrying both G11778A and T14502C mutations than other 11 Chinese families carrying only G11778A mutation. These data suggested that the T14502C variant may modulate the phenotypic manifestation of the G11778A mutation in these Chinese pedigrees.
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Affiliation(s)
- Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Zhou X, Zhang H, Zhao F, Ji Y, Tong Y, Zhang J, Zhang Y, Yang L, Qian Y, Lu F, Qu J, Guan MX. Very high penetrance and occurrence of Leber's hereditary optic neuropathy in a large Han Chinese pedigree carrying the ND4 G11778A mutation. Mol Genet Metab 2010; 100:379-84. [PMID: 20627642 PMCID: PMC2906641 DOI: 10.1016/j.ymgme.2010.04.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 04/22/2010] [Accepted: 04/22/2010] [Indexed: 02/06/2023]
Abstract
We report here the clinical, genetics and molecular characterization of a five-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON). Strikingly, this family exhibits very high penetrance and occurrence of optic neuropathy. In particular, 25 (10 males/15 females) of 30 matrilineal relatives exhibited the variable severity, ranging from profound to mild of visual impairment. This penetrance of optic neuropathy in this Chinese family is much higher than those in many families with LHON worldwide. The age-at-onset for visual impairment in matrilineal relatives in this Chinese family varied from 7 to 24years old, with the average of 15 years old. Furthermore, the ratio between affected male and female matrilineal relatives is 1:1.5 in the Chinese family. This observation is in contrast with the typical features in LHON pedigrees that there was predominance of affected males in LHON in many families from different ethnic origins. Molecular analysis of mitochondrial genome identified the known ND4 G11778A mutation and 51 variants, belonging to Asian haplogroup C4a1. The absence of other known secondary LHON-associated and functionally significant mtDNA mutations in this Chinese family suggested that mitochondrial variants may not play an important role in the phenotypic manifestation of the G11778A mutation in this Chinese family. Therefore, nuclear modifier gene(s) may be responsible for very high penetrance and occurrence of optic neuropathy in this Chinese pedigree.
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Affiliation(s)
- Xiangtian Zhou
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Hongxing Zhang
- Department of Ophthalmology, Jinan Second People’s Hospital, Jinan, Shandong, China
| | - Fuxin Zhao
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yanchun Ji
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China
| | - Juanjuan Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yu Zhang
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Li Yang
- Divisions of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Yaping Qian
- Divisions of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- Giuseppe Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Divisions of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
- Corresponding authors: Min-Xin Guan, Ph.D., Division of Human Genetics, Cincinnati Children’s Hospital Medical, Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA; Telephone: (513) 636-3337; Fax: (513) 636-3486;
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Kumar M, Tanwar M, Saxena R, Sharma P, Dada R. Identification of novel mitochondrial mutations in Leber's hereditary optic neuropathy. Mol Vis 2010; 16:782-92. [PMID: 20454697 PMCID: PMC2862244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 04/26/2010] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To screen mitochondrial DNA (mtDNA) variations in Leber hereditary optic neuropathy (LHON). METHODS Ten LHON patients were selected from neuro-ophthalmology clinics of All India Institute of Medical Sciences (AIIMS), New Delhi, India. Clinical evaluation included slit-lamp biomicroscopy, fundus examination, and neuroimaging. DNA was isolated from whole blood samples. The entire coding region of the mitochondrial genome was amplified by PCR in ten patients and 20 controls. The full mtDNA genome except D-loop was sequenced. All sequences were analyzed against mitochondrial reference sequence NC_012920. RESULTS MtDNA sequencing revealed a total of 30 nucleotide variations in the ten LHON patients and 29 in the 20 controls. Of 30 changes, 30.00% (9/30) were nonsynonymous, and the remaining 70.00% (21/30) were synonymous. In controls, a total of five changes were nonsynonymous. Out of the total 14 nonsynonymous changes observed in cases and controls, four (p.A52T in nicotinamide adenine dinucleotide [NADH] dehydrogenase [ND1] protein; p.L128Q in ND2; p.W48R in ATPase6; p.R340H in ND4 protein) were pathogenic. Four patients were positive for either of pathogenic changes. In total, 16.66% (5/30) variations were novel out of which 40.00% (2/5) were nonsynonymous. All novel variations were submitted to the GenBank database, and accession numbers were obtained. Primary LHON mutations in complex I genes have been considered a hallmark feature of LHON patients, and primary LHON mutations were present in two cases in this study. Mutations in complex I genes (ND genes) account for 50%-90% of LHON pedigrees in different ethnic pedigrees. In this study the highest numbers of changes were also present in complex I genes (46.66%; 14/30) followed by complex IV (30.00%; 9/30), complex III (16.66%; 5/30), and then complex V (6.66%; 2/30). Complex I had 5/30 (16.66%) nonsynonymous changes, complex III had 1/30 (3.33%), complex IV had 1/30 (3.33%), and complex V had 2/30 (6.66%) nonsynonymous changes. Nonsynonymous mutations in cytochrome c oxidase (COX) genes have been reported previously in LHON patients. Nonsynonymous mtDNA variations may adversely affect the respiratory chain and impair the oxidative phosphorylation (OXPHOS) pathway, resulting in low ATP production and elevated reactive oxygen species (ROS) levels, which cause oxidative stress. It has previously been reported that oxidative stress (OS) leads to oxidative damage of cellular macromolecules, such as mitochondrial and nuclear DNA, proteins, and lipids along with energy depletion and a local imbalance of calcium homeostasis, resulting in neuronal degeneration. OS is the underlying etiology in several ocular diseases and also plays an essential role in LHON. CONCLUSIONS A total of five novel mtDNA variations were identified in this study. Nonsynonymous mtDNA variations may adversely affect the respiratory chain and impair the OXPHOS pathway, resulting in low ATP production and elevated ROS levels. OS further damages both nuclear and mtDNA. This preliminary study describes mtDNA sequence variations in a relatively small number of LHON patients of north Indian ethnic origin. However, these results should be confirmed in other populations. Early diagnosis of mtDNA variations and prompt anti-oxidant administration in these cases may delay OS-induced injury to retinal ganglion cells (RGCs) and hence improve visual prognosis.
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Affiliation(s)
- Manoj Kumar
- Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Mukesh Tanwar
- Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rohit Saxena
- Dr. R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Pradeep Sharma
- Dr. R.P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rima Dada
- Laboratory for Molecular Reproduction and Genetics, Department of Anatomy, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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Qu J, Wang Y, Tong Y, Zhou X, Zhao F, Yang L, Zhang S, Zhang J, West CE, Guan MX. Leber's hereditary optic neuropathy affects only female matrilineal relatives in two Chinese families. Invest Ophthalmol Vis Sci 2010; 51:4906-12. [PMID: 20435583 DOI: 10.1167/iovs.09-5027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE The purpose of this study was to investigate the role of modifier factors in the expression of Leber's hereditary optic neuropathy (LHON). METHODS Thirty-five subjects from two Han Chinese families with maternally transmitted LHON underwent a clinical and genetic evaluation and molecular analysis of mitochondrial (mt)DNA. RESULTS Matrilineal relatives in the two Chinese families exhibited a wide range of severity in visual impairment, from blindness to nearly normal vision. Very strikingly, all nine affected individuals of 21 matrilineal relatives (13 females/8 males) were female, which translates to 33% and 57% of penetrance for optic neuropathy in the two families. The average age at onset was 22 and 25 years. These observations were in contrast with typical features in many LHON pedigrees that have a predominance of affected males. Molecular analysis of their mtDNAs identified the homoplasmic ND4 G11778A mutation and distinct sets of variants belonging to the Asian haplogroups M1 and M10a. Of other variants, the L175F variant in CO3; the I58V variant in ND6; and the I189V, L292R, and S297A variants in CYTB were located at highly conserved residues of polypeptides. CONCLUSIONS Only female matrilineal relatives with a wide range of penetrance, severity, and age at onset of optic neuropathy in these two Chinese pedigrees showed the involvement of X-linked or autosomal recessive modifier genes in the phenotypic manifestation of the G11778A mutation. Furthermore, mitochondrial haplogroup-specific variants, together with epigenetic and environmental factors, may contribute to the phenotypic manifestation of the primary LHON-associated G11778A mutation in these pedigrees.
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Affiliation(s)
- Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China.
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Zhang YM, Ji YC, Liu XL, Zhou XT, Zhao FX, Sun YH, Wei QP, Zhang JJ, Liu Y, Qu J, Guan MX. [Leber's hereditary optic neuropathy may be associated with the mitochondrial tRNAGlu A14693G mutation in three Chinese families]. YI CHUAN = HEREDITAS 2010; 32:353-9. [PMID: 20423889 DOI: 10.3724/sp.j.1005.2010.00353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We reported here the clinical, genetic and molecular characterization of three Han Chinese families with Leber's hereditary optic neuropathy. Ophthalmologic examinations revealed the variable severity and age-at-onset of visual loss among probands and other matrilineal relatives of these families. Strikingly, these families exhibited extremely low penetrances of visual impairment. Sequence analysis of complete mitochondrial genomes in these pedigrees identified the known homoplasmic tRNAGlu A14693G mutation and distinct sets of polymorphism belonging to haplogroups Y1b, Y1 and Y1, respectively. The A14693G mutation occurs at the extremely conserved nucleotide (conventional position 54) of tRNAGlu. Thus, this mutation may alter structural formation and stabilization of functional tRNAs, thereby leading to a failure in tRNA metabolism and mitochondrial dysfunction involved in visual impairment. However, none of other variants showed the evolutionary conservation and functional significance. These observations suggested that the tRNAGlu A14693G mutation may be involved in the pathogenesis of optic neuropathy in these families.
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Affiliation(s)
- Yong-Mei Zhang
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, China
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Tong Y, Sun YH, Zhou X, Zhao F, Mao Y, Wei QP, Yang L, Qu J, Guan MX. Very low penetrance of Leber's hereditary optic neuropathy in five Han Chinese families carrying the ND1 G3460A mutation. Mol Genet Metab 2010; 99:417-24. [PMID: 20053576 PMCID: PMC2839065 DOI: 10.1016/j.ymgme.2009.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/03/2009] [Accepted: 12/04/2009] [Indexed: 11/26/2022]
Abstract
We report here the clinical, genetic, and molecular characterization of five Han Chinese families with Leber's hereditary optic neuropathy (LHON). Strikingly, there were very low penetrances of visual impairment in these Chinese families, ranging from 4.2% to 22.2%, with an average of 10.2%. In particular, only 7 (4 males/3 females) of 106 matrilineal relatives in these families exhibited the variable severity and age-at-onset in visual dysfunction. The age-at-onset for visual impairment in matrilineal relatives in these families, varied from 20 to 25 years, with an average of 21.8 years old. Molecular analysis of mitochondrial genomes identified the homoplasmic ND1 G3460A mutation and distinct sets of variants, belonging to the Asian haplogroups B5b, C4a1, D5, F1, and R9, respectively. This suggests that the G3640A mutation occurred sporadically and multiplied through evolution of the mtDNA in China. However, there was the absence of known secondary LHON-associated mtDNA mutations in these Chinese families. Very low penetrance of visual loss in these five Chinese pedigrees strongly indicated that the G3640A mutation was itself insufficient to develop the optic neuropathy. The absence of secondary LHON mtDNA mutations suggest that these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the G3640A mutation in those Chinese families with low penetrance of vision loss. However, nuclear modifier genes, epigenetic and environmental factors appear to be modifier factors for the phenotypic manifestation of the G3640A mutation in these Chinese families.
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Affiliation(s)
- Yi Tong
- School of Ophthalmology and Optometry, and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
- Giuseppe Attardi Institute of Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
- The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350005, China
| | - Yan-Hong Sun
- Department of Ophthalmology, Dongfang Hospital, Beijing University of Chinese Medicine and Pharmacology, Beijing 100078, China
| | - Xiangtian Zhou
- School of Ophthalmology and Optometry, and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
| | - Fuxin Zhao
- School of Ophthalmology and Optometry, and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
| | - Yijian Mao
- School of Ophthalmology and Optometry, and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
| | - Qi-ping Wei
- Department of Ophthalmology, Dongfang Hospital, Beijing University of Chinese Medicine and Pharmacology, Beijing 100078, China
| | - Li Yang
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Jia Qu
- School of Ophthalmology and Optometry, and Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
- Giuseppe Attardi Institute of Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
- Corresponding authors. Addresses: Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. Fax: +1 513 636 3486 (M.-X. Guan), School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China (J. Qu). (J. Qu), , (M.-X. Guan)
| | - Min-Xin Guan
- Giuseppe Attardi Institute of Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
- Corresponding authors. Addresses: Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA. Fax: +1 513 636 3486 (M.-X. Guan), School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China (J. Qu). (J. Qu), , (M.-X. Guan)
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Liu Y, Zhuang SL, Tong Y, Qu J, Zhou XT, Zhao FX, Zhang JJ, Zhang YM, Zhang Y, Guan MX. [Leber's hereditary optic neuropathy and limbs abnormity claudication may be associated with the mitochondrial ND1 T3866C mutation]. YI CHUAN = HEREDITAS 2010; 32:141-7. [PMID: 20176558 DOI: 10.3724/sp.j.1005.2010.00141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mutations in mitochondrial DNA have been associated with a wide spectrum of clinical abnormalities. We reported here the clinical, genetic and molecular characterization of a five-generation Han Chinese pedigree with Leber's Hereditary Optic Neuropathy (LHON) and limbs abnormity claudication. Of 27 matrilineal relatives, four exhibited only LHON, one suffered from only limbs abnormity claudication, and four had both LHON and limbs abnormity claudication. Sequence analysis of mitochondrial genome in this family identified the known T3866C mutation in ND1 gene and other 43 variants belonging to the Asian haplogroup D4a3. The T3866C (I187T) mutation resulted in the replacement of isoleucine at position 187 with theronine. The isoleucine at position 187 located at one of transmembrane domain in ND1 polypeptide. The isoleucine at position 187 was extremely conserved among 29 organisms, while other variants showed no evolutionarily conservation. Furthermore, the T3866C was absence in 135 Chinese control subjects. The T3866C mutation likely alters the complex I activity, which causes mitochondrial dysfunction associated with LHON and limbs abnormity claudication. Therefore, the T3866C mutation is likely associated with LHON and limbs abnormity claudication.
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Affiliation(s)
- Yan Liu
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, China.
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Qu J, Zhou X, Zhao F, Liu X, Zhang M, Sun YH, Liang M, Yuan M, Liu Q, Tong Y, Wei QP, Yang L, Guan MX. Low penetrance of Leber's hereditary optic neuropathy in ten Han Chinese families carrying the ND6 T11484C mutation. Biochim Biophys Acta Gen Subj 2009; 1800:305-12. [PMID: 19733221 DOI: 10.1016/j.bbagen.2009.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 08/22/2009] [Accepted: 08/26/2009] [Indexed: 11/27/2022]
Abstract
BACKGROUND Leber's hereditary optic neuropathy (LHON) is a maternally inherited disorder. The purpose of this investigation is to understand the role of mitochondrial haplotypes in the development of LHON associated with ND6 T14484C mutation in Chinese families. METHODS One hundred fourteen subjects from ten Han Chinese families with LHON were studied by the clinical and genetic evaluation as well as molecular and biochemical analyses of mitochondrial DNA (mtDNA). RESULTS Clinical evaluation revealed that ten families exhibited extremely low penetrance of visual impairment, with an average of 10%. In particular, ten (8 males/2 females) of 114 matrilineal relatives in these families exhibited the variable severity and age-at-onset in visual dysfunction. The average age-of-onset of vision loss was 19 years old. Molecular analysis of mitochondrial DNA (mtDNA) identified the homoplasmic T14484C mutation and distinct sets of variants, belonging to the Asian haplogroups B5b, D4, D4g1b, G3a2, R11, R11a and Z3, respectively. However, there was the absence of secondary LHON-associated mtDNA mutations in these ten Chinese families. CONCLUSION The low penetrance of vision loss in these Chinese pedigrees strongly indicated that the T14484C mutation was itself insufficient to produce a clinical phenotype. The absence of secondary LHON mtDNA mutations suggests that these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the T14484C mutation in those Chinese families with low penentrace of vision loss. However, nuclear modifier genes and environmental factors appear to be modifier factors for the phenotypic manifestation of the T14484C mutation in these Chinese families.
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Affiliation(s)
- Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China.
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Zhao F, Guan M, Zhou X, Yuan M, Liang M, Liu Q, Liu Y, Zhang Y, Yang L, Tong Y, Wei QP, Sun YH, Qu J, Guan MX. Leber's hereditary optic neuropathy is associated with mitochondrial ND6 T14502C mutation. Biochem Biophys Res Commun 2009; 389:466-72. [PMID: 19732751 DOI: 10.1016/j.bbrc.2009.08.168] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Accepted: 08/31/2009] [Indexed: 11/17/2022]
Abstract
We report here the clinical, genetic, and molecular characterization of three Chinese families with Leber's hereditary optic neuropathy (LHON). There were variable severity and age of onset in visual impairment among these families. Strikingly, there were extremely low penetrances of visual impairment in these Chinese families. Sequence analysis of complete mitochondrial genomes in these pedigrees showed the homoplasmic T14502C (I58V) mutation, which localized at a highly conserved isoleucine at position 58 of ND6, and distinct sets of mtDNA polymorphisms belonging to haplogroups M10a, F1a1, and H2. The occurrence of T14502C mutation in these several genetically unrelated subjects affected by visual impairment strongly indicates that this mutation is involved in the pathogenesis of visual impairment. Here, mtDNA variants I187T in the ND1, A122V in CO1, S99A in the A6, and V254I in CO3 exhibited an evolutionary conservation, indicating a potential modifying role in the development of visual impairment associated with T14502C mutation in those families. Furthermore, nuclear modifier gene(s) or environmental factor(s) may play a role in the phenotypic manifestation of the LHON-associated T14502C mutation in these Chinese families.
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Affiliation(s)
- Fuxin Zhao
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Yang J, Zhu Y, Chen L, Zhang H, Tong Y, Huang D, Zhang Z, Chen S, Han X, Ma X. Novel A14841G mutation is associated with high penetrance of LHON/C4171A family. Biochem Biophys Res Commun 2009; 386:693-6. [DOI: 10.1016/j.bbrc.2009.06.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
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Yang J, Zhu Y, Tong Y, Chen L, Liu L, Zhang Z, Wang X, Huang D, Qiu W, Zhuang S, Ma X. Confirmation of the mitochondrial ND1 gene mutation G3635A as a primary LHON mutation. Biochem Biophys Res Commun 2009; 386:50-4. [DOI: 10.1016/j.bbrc.2009.05.127] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Accepted: 05/28/2009] [Indexed: 01/30/2023]
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The novel G10680A mutation is associated with complete penetrance of the LHON/T14484C family. Mitochondrion 2009; 9:273-8. [DOI: 10.1016/j.mito.2009.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 03/29/2009] [Accepted: 04/15/2009] [Indexed: 01/31/2023]
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Bortot B, Barbi E, Biffi S, Angelini C, Faleschini E, Severini G, Carrozzi M. Two novel cosegregating mutations in tRNAMet and COX III, in a patient with exercise intolerance and autoimmune polyendocrinopathy. Mitochondrion 2009; 9:123-9. [DOI: 10.1016/j.mito.2009.01.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 11/27/2008] [Accepted: 01/12/2009] [Indexed: 01/25/2023]
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Liang M, Guan M, Zhao F, Zhou X, Yuan M, Tong Y, Yang L, Wei QP, Sun YH, Lu F, Qu J, Guan MX. Leber's hereditary optic neuropathy is associated with mitochondrial ND1 T3394C mutation. Biochem Biophys Res Commun 2009; 383:286-92. [PMID: 19324017 DOI: 10.1016/j.bbrc.2009.03.097] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Accepted: 03/18/2009] [Indexed: 12/22/2022]
Abstract
We report here the clinical, genetic and molecular characterization of four Chinese families with Leber's hereditary optic neuropathy (LHON). There were variable severity and age-of-onset in visual impairment among these families. Strikingly, there were extremely low penetrances of visual impairment in these Chinese families. Sequence analysis of complete mitochondrial genomes in these pedigrees showed the homoplasmic T3394C (Y30H) mutation, which localized at a highly conserved tyrosine at position 30 of ND1, and distinct sets of mtDNA polymorphisms belonging to haplogroups D4b and M9a. The occurrence of T3394C mutation in these several genetically unrelated subjects affected by visual impairment strongly indicates that this mutation is involved in the pathogenesis of visual impairment. However, there was the absence of functionally significant mtDNA mutations in these four Chinese pedigrees carrying the T3394C mutation. Therefore, nuclear modifier gene(s) or environmental factor(s) may play a role in the phenotypic expression of the LHON-associated T3394C mutation.
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Affiliation(s)
- Min Liang
- Wenzhou Medical College, Zhejiang, China
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Qu J, Zhou X, Zhang J, Zhao F, Sun YH, Tong Y, Wei QP, Cai W, Yang L, West CE, Guan MX. Extremely low penetrance of Leber's hereditary optic neuropathy in 8 Han Chinese families carrying the ND4 G11778A mutation. Ophthalmology 2009; 116:558-564.e3. [PMID: 19167085 DOI: 10.1016/j.ophtha.2008.10.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 10/18/2008] [Accepted: 10/22/2008] [Indexed: 02/03/2023] Open
Abstract
PURPOSE To investigate the role of mitochondrial haplotypes in the development of Leber's hereditary optic neuropathy (LHON) associated with the ND4 G11778A mutation in Chinese families. DESIGN Eight Han Chinese families with maternally transmitted LHON were studied using clinical, genetic, and molecular evaluations. PARTICIPANTS One hundred sixty-seven subjects from 8 Chinese families with a wide age range and severity of visual impairment. METHODS All subjects underwent the clinical and genetic evaluation, as well as molecular analysis of mitochondrial DNA (mtDNA). MAIN OUTCOME MEASURES The ophthalmologic examinations included visual acuity, visual field examination, visual evoked potentials, and fundus photography. Mitochondrial DNA analysis included the polymerase chain reaction amplification of the entire mtDNA and subsequent sequence determination. RESULTS Eight families exhibited extremely low penetrance of visual impairment, with the average of 13%. In particular, 14 (12 males and 2 females) of 119 matrilineal relatives in these families exhibited the variable severity and age at onset in visual dysfunction. The average age of onset of vision loss was 17 years. Molecular analysis of mtDNA identified the homoplasimic ND4 G11778A mutation and distinct sets of variants belonging to the Asian haplogroups M8a2, D4g2, B4a1c, B5b, N9a1, D4b2b, C, and M7b1. However, there was an absence of secondary LHON-associated mtDNA mutations in these 8 Chinese families. CONCLUSIONS The extremely low penetrance of vision loss in these 8 Chinese pedigrees strongly indicates that the G11778A mutation was itself insufficient to produce a clinical phenotype. The absence of secondary LHON mtDNA mutations suggest that these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the G11778A mutation in those Chinese families with very low penentrace of vision loss. However, nuclear backgrounds and environmental factors seem to be modifying factors for the phenotypic manifestation of the G11778A mutation in these Chinese families.
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Affiliation(s)
- Jia Qu
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, China
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Ji Y, Zhang AM, Jia X, Zhang YP, Xiao X, Li S, Guo X, Bandelt HJ, Zhang Q, Yao YG. Mitochondrial DNA haplogroups M7b1'2 and M8a affect clinical expression of leber hereditary optic neuropathy in Chinese families with the m.11778G-->a mutation. Am J Hum Genet 2008; 83:760-8. [PMID: 19026397 DOI: 10.1016/j.ajhg.2008.11.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 10/27/2008] [Accepted: 11/06/2008] [Indexed: 02/01/2023] Open
Abstract
Leber hereditary optic neuropathy (LHON) is the most extensively studied mitochondrial disease, with the majority of the cases being caused by one of three primary mitochondrial DNA (mtDNA) mutations. Incomplete disease penetrance and gender bias are two features of LHON and indicate involvement of additional genetic or environmental factors in the pathogenesis of the disorder. Haplogroups J, K, and H have been shown to influence the clinical expression of LHON in subjects harboring primary mutations in European families. However, whether mtDNA haplogroups would affect the penetrance of LHON in East Asian families has not been evaluated yet. By studying the penetrance of LHON in 1859 individuals from 182 Chinese families (including one from Cambodia) with the m.11778G-->A mutation, we found that haplogroup M7b1'2 significantly increases the risk of visual loss, whereas M8a has a protective effect. Analyses of the complete mtDNA sequences from LHON families with m.11778G-->A narrow the association of disease expression to m.12811T-->C (Y159H) in the NADH dehydrogenase 5 gene (MT-ND5) in haplogroup M7b1'2 and suggest that the specific combination of amino acid changes (A20T-T53I) in the ATP synthase 6 protein (MT-ATP6) caused by m.8584G-->A and m.8684C-->T might account for the beneficial background effect of M8a. Protein secondary-structure prediction for the MT-ATP6 with the two M8a-specific amino acid changes further supported our inferences. These findings will assist in further understanding the pathogenesis of LHON and guide future genetic counseling in East Asian patients with m.11778G-->A.
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Mitochondrial variants may influence the phenotypic manifestation of Leber's hereditary optic neuropathy-associated ND4 G11778A mutation. J Genet Genomics 2008; 35:649-55. [DOI: 10.1016/s1673-8527(08)60086-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 10/02/2008] [Accepted: 10/07/2008] [Indexed: 11/24/2022]
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Maternally inherited hypertension is associated with the mitochondrial tRNA(Ile) A4295G mutation in a Chinese family. Biochem Biophys Res Commun 2008; 367:906-11. [PMID: 18177739 DOI: 10.1016/j.bbrc.2007.12.150] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Accepted: 12/21/2007] [Indexed: 11/21/2022]
Abstract
Mutations in mitochondrial DNA have been associated with cardiovascular disease. We report here the clinical, genetic, and molecular characterization of one three-generation Han Chinese family with maternally transmitted hypertension. All matrilineal relatives in this family exhibited the variable degree of hypertension at the age at onset of 36 to 56 years old. Sequence analysis of the complete mitochondrial DNA in this pedigree revealed the presence of the known hypertension-associated tRNA(Ile) A4295G mutation and 33 other variants, belonging to the Asian haplogroup D4j. The A4295G mutation, which is extraordinarily conserved from bacteria to human mitochondria, is located at immediately 3' end to the anticodon, corresponding to conventional position 37 of tRNA(Ile). The occurrence of the A4295G mutation in several genetically unrelated pedigrees affected by cardiovascular disease but the absence of 242 Chinese controls strongly indicates that this mutation is involved in the pathogenesis of cardiovascular disease. Of other variants, the tRNA(Glu) A14693G and ND1 G11696A mutations were implicated to be associated with other mitochondrial disorders. The A14693G mutation, which is a highly conserved nucleoside at the TpsiC-loop of tRNA(Glu), has been implicated to be important for tRNA structure and function. Furthermore, the ND4 G11696A mutation was associated with Leber's hereditary optic neuropathy. Therefore, the combination of the A4295G mutation in the tRNA(Ile) gene with the ND4 G11696A mutation and tRNA(Glu) A14693G mutation may contribute to the high penetrance of hypertension in this Chinese family.
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Liao Z, Zhao J, Zhu Y, Yang L, Yang A, Sun D, Zhao Z, Wang X, Tao Z, Tang X, Wang J, Guan M, Chen J, Li Z, Lu J, Guan MX. The ND4 G11696A mutation may influence the phenotypic manifestation of the deafness-associated 12S rRNA A1555G mutation in a four-generation Chinese family. Biochem Biophys Res Commun 2007; 362:670-6. [PMID: 17723226 PMCID: PMC2696936 DOI: 10.1016/j.bbrc.2007.08.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 08/04/2007] [Indexed: 11/28/2022]
Abstract
We report here the clinical, genetic and molecular characterization of a large Han Chinese family with aminoglycoside-induced and nonsyndromic hearing loss. The penetrance of hearing loss (affected matrilineal relatives/total matrilineal relatives) in this pedigree was 53%, when aminoglycoside-induced deafness was included. When the effect of aminoglycosides was excluded, the penetrance of hearing loss in this pedigree was 42%. These matrilineal relatives exhibited a wide range of severity of hearing loss, varying from profound to normal hearing. Furthermore, these affected matrilineal relatives shared some common features: bilateral hearing loss of high frequencies and symmetries. Sequence analysis of mitochondrial DNA (mtDNA) in the pedigree identified the homoplasmic 12S rRNA A1555G mutation and other 35 variants belonging to Eastern Asian haplogroup D4. Of these, the V313I (G11696A) mutation in ND4 was associated with vision loss. However, the extremely low penetrance of visual loss, and the mild biochemical defect and the presence of one/167 Chinese controls indicted that the G11696A mutation is itself not sufficient to produce a clinical phenotype. Thus, the G11696A mutation may act in synergy with the primary deafness-associated 12S rRNA A1555G mutation in this Chinese family, thereby increasing the penetrance and expressivity of hearing loss in this Chinese pedigree.
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Affiliation(s)
- Zhisu Liao
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jianyue Zhao
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Yi Zhu
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Li Yang
- Division of Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Aifen Yang
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Dongmei Sun
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Zhongnong Zhao
- The Second Hospital of Shaoxing City, Shaoxing, Zhejiang, China
| | - Xinjian Wang
- Division of Human Genetics and Center for Hearing and Deafness Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Zhihua Tao
- Department of Laboratory Medicine, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Xiaowen Tang
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jindan Wang
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Minqiang Guan
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jiafu Chen
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Zhiyuan Li
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jianxin Lu
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Min-Xin Guan
- Department of Otolaryngology, the First Affiliated Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
- Deparment of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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Wei QP, Zhou X, Yang L, Sun YH, Zhou J, Li G, Jiang R, Lu F, Qu J, Guan MX. The coexistence of mitochondrial ND6 T14484C and 12S rRNA A1555G mutations in a Chinese family with Leber’s hereditary optic neuropathy and hearing loss. Biochem Biophys Res Commun 2007; 357:910-6. [PMID: 17452034 DOI: 10.1016/j.bbrc.2007.04.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Accepted: 04/04/2007] [Indexed: 10/23/2022]
Abstract
We report here the clinical, genetic and molecular characterization of one three-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON) and hearing loss. Four of 14 matrilineal relatives exhibited the moderate central vision loss at the average age of 12.5 years. Of these, one subject exhibited both LHON and mild hearing impairment. Sequence analysis of the complete mitochondrial genomes in the pedigree showed the presence of homoplasmic LHON-associated ND6 T14484C mutation, deafness-associated 12S rRNA A1555 mutation and 47 other variants belonging to Eastern Asian haplogroup H2. None of other mitochondrial variants was evolutionarily conserved and functional significance. Therefore, the coexistence of the A1555G mutation and T14484C mutations in this Chinese family indicate that the A1555G mutation may play a synergistic role in the phenotypic manifestation of LHON associated ND6 T14484C mutation. However, the incomplete penetrance of vision and hearing loss suggests the involvement of nuclear modifier genes and environmental factors in the phenotypic expression of these mtDNA mutations.
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Affiliation(s)
- Qi-Ping Wei
- Department of Ophthalmology, Dongfang Hospital, Beijing University of Chinese Medicine and Pharmacology, Beijing 100078, China
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Tong Y, Mao Y, Zhou X, Yang L, Zhang J, Cai W, Zhao F, Wang X, Lu F, Qu J, Guan MX. The mitochondrial tRNAGlu A14693G mutation may influence the phenotypic manifestation of ND1 G3460A mutation in a Chinese family with Leber’s hereditary optic neuropathy. Biochem Biophys Res Commun 2007; 357:524-30. [PMID: 17434142 DOI: 10.1016/j.bbrc.2007.03.189] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 03/29/2007] [Indexed: 11/17/2022]
Abstract
We report here the clinical, genetic, and molecular characterization of one Han Chinese family with maternally transmitted Leber's hereditary optic neuropathy (LHON). Three of seven matrilineal relatives in this family exhibited the variable degree of central vision loss at the age of 12, 14, and 16 years old, respectively. Sequence analysis of the complete mitochondrial DNA in this pedigree revealed the presence of the ND1 G3460A mutation and 47 other variants, belonging to the Asian haplogroup M7b2. The G3460A mutation is present at homoplasmy in matrilineal relatives of this Chinese family. Of other variants, the homoplasmic A14693G mutation is of special interest as it was implicated to be associated with other mitochondrial disorders. This mutation is located at the TpsiC-loop, at conventional position 54 of tRNA(Glu). The uridine at this position (U54), which is highly conserved from bacteria to human mitochondria, has been implicated to be important for tRNA structure and function. Thus, the A14693G mutation may alter the tertiary structure of this tRNA, cause a failure in this tRNA metabolism, thereby worsening the mitochondrial dysfunction associated with the primary G3460A mutation. Therefore, the tRNA(Glu) A14693G mutation may have a potential modifier role in the phenotypic manifestation of the primary LHON-associated G3460A mutation in this Chinese family.
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Affiliation(s)
- Yi Tong
- School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China
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