1
|
Lopriore P, Palermo G, Meli A, Bellini G, Benevento E, Montano V, Siciliano G, Mancuso M, Ceravolo R. Mitochondrial Parkinsonism: A Practical Guide to Genes and Clinical Diagnosis. Mov Disord Clin Pract 2024. [PMID: 38943319 DOI: 10.1002/mdc3.14148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 04/19/2024] [Accepted: 06/01/2024] [Indexed: 07/01/2024] Open
Abstract
BACKGROUND Primary mitochondrial diseases (PMDs) are the most common inborn errors of energy metabolism, with a combined prevalence of 1 in 4300. They can result from mutations in either nuclear DNA (nDNA) or mitochondrial DNA (mtDNA). These disorders are multisystemic and mainly affect high energy-demanding tissues, such as muscle and the central nervous system (CNS). Among many clinical features of CNS involvement, parkinsonism is one of the most common movement disorders in PMDs. METHODS This review provides a pragmatic educational overview of the most recent advances in the field of mitochondrial parkinsonism, from pathophysiology and genetic etiologies to phenotype and diagnosis. RESULTS mtDNA maintenance and mitochondrial dynamics alterations represent the principal mechanisms underlying mitochondrial parkinsonism. It can be present in isolation, alongside other movement disorders or, more commonly, as part of a multisystemic phenotype. Mutations in several nuclear-encoded genes (ie, POLG, TWNK, SPG7, and OPA1) and, more rarely, mtDNA mutations, are responsible for mitochondrial parkinsonism. Progressive external opthalmoplegia and optic atrophy may guide genetic etiology identification. CONCLUSION A comprehensive deep-phenotyping approach is needed to reach a diagnosis of mitochondrial parkinsonism, which lacks distinctive clinical features and exemplifies the intricate genotype-phenotype interplay of PMDs.
Collapse
Affiliation(s)
- Piervito Lopriore
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Giovanni Palermo
- Unit of Neurology, Department of Clinical and Experimental Medicine, Center for Neurodegenerative Diseases-Parkinson's Disease and Movement Disorders, University of Pisa, Pisa, Italy
| | - Adriana Meli
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Gabriele Bellini
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Unit of Neurology, Department of Clinical and Experimental Medicine, Center for Neurodegenerative Diseases-Parkinson's Disease and Movement Disorders, University of Pisa, Pisa, Italy
| | - Elena Benevento
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Unit of Neurology, Department of Clinical and Experimental Medicine, Center for Neurodegenerative Diseases-Parkinson's Disease and Movement Disorders, University of Pisa, Pisa, Italy
| | - Vincenzo Montano
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Gabriele Siciliano
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Michelangelo Mancuso
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Roberto Ceravolo
- Unit of Neurology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
- Unit of Neurology, Department of Clinical and Experimental Medicine, Center for Neurodegenerative Diseases-Parkinson's Disease and Movement Disorders, University of Pisa, Pisa, Italy
| |
Collapse
|
2
|
Amore G, Romagnoli M, Carbonelli M, Cascavilla ML, De Negri AM, Carta A, Parisi V, Di Renzo A, Schiavi C, Lenzetti C, Zenesini C, Ormanbekova D, Palombo F, Fiorini C, Caporali L, Carelli V, Barboni P, La Morgia C. AFG3L2 and ACO2-Linked Dominant Optic Atrophy: Genotype-Phenotype Characterization Compared to OPA1 Patients. Am J Ophthalmol 2024; 262:114-124. [PMID: 38278202 DOI: 10.1016/j.ajo.2024.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 12/28/2023] [Accepted: 01/10/2024] [Indexed: 01/28/2024]
Abstract
PURPOSE Heterozygous mutations in the AFG3L2 gene (encoding a mitochondrial protease indirectly reflecting on OPA1 cleavage) and ACO2 gene (encoding the mitochondrial enzyme aconitase) are associated with isolated forms of Dominant Optic Atrophy (DOA). We aimed at describing their neuro-ophthalmological phenotype as compared with classic OPA1-related DOA. DESIGN Cross-sectional study. METHODS The following neuro-ophthalmological parameters were collected: logMAR visual acuity (VA), color vision, mean deviation and foveal threshold at visual fields, average and sectorial retinal nerve fiber layer (RNFL), and ganglion cell layer (GCL) thickness on optical coherence tomography. ACO2 and AFG3L2 patients were compared with an age- and sex-matched group of OPA1 patients with a 1:2 ratio. All eyes were analyzed using a clustered Wilcoxon rank sum test with the Rosner-Glynn-Lee method. RESULTS A total of 44 eyes from 23 ACO2 patients and 26 eyes from 13 AFG3L2 patients were compared with 143 eyes from 72 OPA1 patients. All cases presented with bilateral temporal-predominant optic atrophy with various degree of visual impairment. Comparison between AFG3L2 and OPA1 failed to reveal any significant difference. ACO2 patients compared to both AFG3L2 and OPA1 presented overall higher values of nasal RNFL thickness (P = .029, P = .023), average thickness (P = .012, P = .0007), and sectorial GCL thickness. These results were confirmed also comparing separately affected and subclinical patients. CONCLUSIONS Clinically, DOA remains a fairly homogeneous entity despite the growing genetic heterogeneity. ACO2 seems to be associated with an overall better preservation of retinal ganglion cells, probably depending on the different pathogenic mechanism involving mtDNA maintenance, as opposed to AFG3L2, which is involved in OPA1 processing and is virtually indistinguishable from classic OPA1-DOA.
Collapse
Affiliation(s)
- Giulia Amore
- From the Department of Biomedical and Neuromotor Sciences (G.A., M.C., V.C., C.L.M.), University of Bologna, Bologna, Italy; Ophthalmology Unit (G.A., C.S.), IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
| | - Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Michele Carbonelli
- From the Department of Biomedical and Neuromotor Sciences (G.A., M.C., V.C., C.L.M.), University of Bologna, Bologna, Italy
| | - Maria Lucia Cascavilla
- Department of Ophthalmology (M.L.C., P.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | | | - Arturo Carta
- Ophthalmology Unit (A.C.), University Hospital of Parma, University of Parma, Parma, Italy
| | | | | | - Costantino Schiavi
- Ophthalmology Unit (G.A., C.S.), IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Chiara Lenzetti
- Department of Surgery and Translational Medicine (C.L.), Eye Clinic, Careggi University Hospital, University of Florence, Florence, Italy
| | - Corrado Zenesini
- IRCCS Istituto delle Scienze Neurologiche di Bologna (C.Z.), Unità di Epidemiologia e Statistica, Bologna, Italy
| | - Danara Ormanbekova
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Flavia Palombo
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Claudio Fiorini
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Valerio Carelli
- From the Department of Biomedical and Neuromotor Sciences (G.A., M.C., V.C., C.L.M.), University of Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., D.O., F.P., C.F.L.C.V.C.), Programma di Neurogenetica, Bologna, Italy
| | - Piero Barboni
- Department of Ophthalmology (M.L.C., P.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Chiara La Morgia
- From the Department of Biomedical and Neuromotor Sciences (G.A., M.C., V.C., C.L.M.), University of Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (C.L.M.), UOC Clinica Neurologica, Bologna, Italy
| |
Collapse
|
3
|
Gupta PR, O'Connell K, Sullivan JM, Huckfeldt RM. RTN4IP1-associated non-syndromic optic neuropathy and rod-cone dystrophy. Ophthalmic Genet 2024:1-5. [PMID: 38224077 DOI: 10.1080/13816810.2024.2303683] [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: 07/19/2023] [Accepted: 01/05/2024] [Indexed: 01/16/2024]
Abstract
BACKGROUND Biallelic variants in RTN4IP1 are a well-established cause of syndromic and nonsyndromic early-onset autosomal recessive optic neuropathy. They have more recently been reported to cause a concomitant but later-onset rod-cone dystrophy with or without syndromic features. METHODS A comprehensive evaluation was performed that included assessment of visual and retinal function, clinical examination, and retinal imaging. Childhood ophthalmic records as well as the results of genetic testing were evaluated. RESULTS A 24-year-old female described longstanding reduced visual acuity with more recent subjective impairment of dark adaptation. Visual acuity was subnormal in both eyes. Goldmann kinetic perimetry demonstrated scotomas in a pattern consistent with the presence of both optic neuropathy and rod-cone dystrophy with fundus exam as well as retinal imaging showing corroborating findings. Full-field electroretinography further confirmed the presence of a rod-cone dystrophy. Genetic testing demonstrated biallelic variants in RTN4IP1, one of which was novel, in association with the ocular findings. CONCLUSIONS RTN4IP1-associated early-onset bilateral optic neuropathy with rod-cone dystrophy is a recently described clinical entity with limited reports available to-date. The present case provides additional support for this dual phenotype and identifies a novel causative variant.
Collapse
Affiliation(s)
- Priya R Gupta
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Kaitlin O'Connell
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Jack M Sullivan
- Ira G. Ross Eye Institute (Department of Ophthalmology), Jacobs School of Medicine and Biomedical Sciences, University of Buffalo, Buffalo, New York, USA
- Department of Ophthalmology, VA Western NY Healthcare System, Buffalo, New York, USA
| | - Rachel M Huckfeldt
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
4
|
Rákosníková T, Kelifová S, Štufková H, Lokvencová K, Lišková P, Kousal B, Honzík T, Hansíková H, Martínek V, Tesařová M. Case report: A rare variant m.4135T>C in the MT-ND1 gene leads to Leber hereditary optic neuropathy and altered respiratory chain supercomplexes. Front Genet 2023; 14:1182288. [PMID: 37274791 PMCID: PMC10233053 DOI: 10.3389/fgene.2023.1182288] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/28/2023] [Indexed: 06/07/2023] Open
Abstract
Leber hereditary optic neuropathy is a primary mitochondrial disease characterized by acute visual loss due to the degeneration of retinal ganglion cells. In this study, we describe a patient carrying a rare missense heteroplasmic variant in MT-ND1, NC_012920.1:m.4135T>C (p.Tyr277His) manifesting with a typical bilateral painless decrease of the visual function, triggered by physical exercise or higher ambient temperature. Functional studies in muscle and fibroblasts show that amino acid substitution Tyr277 with His leads to only a negligibly decreased level of respiratory chain complex I (CI), but the formation of supercomplexes and the activity of the enzyme are disturbed noticeably. Our data indicate that although CI is successfully assembled in the patient's mitochondria, its function is hampered by the m.4135T>C variant, probably by stabilizing CI in its inactive form. We conclude that the m.4135T>C variant together with a combination of external factors is necessary to manifest the phenotype.
Collapse
Affiliation(s)
- Tereza Rákosníková
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Silvie Kelifová
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Hana Štufková
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Kateřina Lokvencová
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Petra Lišková
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Bohdan Kousal
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Tomáš Honzík
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Hana Hansíková
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| | - Václav Martínek
- Department of Biochemistry, Faculty of Science, Charles University, Prague, Czechia
| | - Markéta Tesařová
- Laboratory for Study of Mitochondrial Disorders, Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czechia
| |
Collapse
|
5
|
Newman NJ, Yu-Wai-Man P, Biousse V, Carelli V. Understanding the molecular basis and pathogenesis of hereditary optic neuropathies: towards improved diagnosis and management. Lancet Neurol 2023; 22:172-188. [PMID: 36155660 DOI: 10.1016/s1474-4422(22)00174-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 03/30/2022] [Accepted: 04/13/2022] [Indexed: 01/25/2023]
Abstract
Hereditary optic neuropathies result from defects in the human genome, both nuclear and mitochondrial. The two main and most recognised phenotypes are dominant optic atrophy and Leber hereditary optic neuropathy. Advances in modern molecular diagnosis have expanded our knowledge of genotypes and phenotypes of inherited disorders that affect the optic nerve, either alone or in combination, with various forms of neurological and systemic degeneration. A unifying feature in the pathophysiology of these disorders appears to involve mitochondrial dysfunction, suggesting that the retinal ganglion cells and their axons are especially susceptible to perturbations in mitochondrial homoeostasis. As we better understand the pathogenesis behind these genetic diseases, aetiologically targeted therapies are emerging and entering into clinical trials, including treatments aimed at halting the cascade of neurodegeneration, replacing or editing the defective genes or their protein products, and potentially regenerating damaged optic nerves, as well as preventing generational disease transmission.
Collapse
MESH Headings
- Humans
- Optic Nerve Diseases/diagnosis
- Optic Nerve Diseases/genetics
- Optic Nerve Diseases/therapy
- Optic Atrophy, Hereditary, Leber/diagnosis
- Optic Atrophy, Hereditary, Leber/genetics
- Optic Atrophy, Hereditary, Leber/therapy
- Optic Atrophy, Autosomal Dominant/diagnosis
- Optic Atrophy, Autosomal Dominant/genetics
- Optic Atrophy, Autosomal Dominant/therapy
- Optic Nerve
- Mitochondria/genetics
- Mitochondria/metabolism
- Mitochondria/pathology
- DNA, Mitochondrial/genetics
Collapse
Affiliation(s)
- 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
- Cambridge Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, University College London, London, UK
| | - Valérie Biousse
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| |
Collapse
|
6
|
Abstract
Mitochondrial optic neuropathies have a leading role in the field of mitochondrial medicine ever since 1988, when the first mutation in mitochondrial DNA was associated with Leber's hereditary optic neuropathy (LHON). Autosomal dominant optic atrophy (DOA) was subsequently associated in 2000 with mutations in the nuclear DNA affecting the OPA1 gene. LHON and DOA are both characterized by selective neurodegeneration of retinal ganglion cells (RGCs) triggered by mitochondrial dysfunction. This is centered on respiratory complex I impairment in LHON and defective mitochondrial dynamics in OPA1-related DOA, leading to distinct clinical phenotypes. LHON is a subacute, rapid, severe loss of central vision involving both eyes within weeks or months, with age of onset between 15 and 35 years old. DOA is a more slowly progressive optic neuropathy, usually apparent in early childhood. LHON is characterized by marked incomplete penetrance and a clear male predilection. The introduction of next-generation sequencing has greatly expanded the genetic causes for other rare forms of mitochondrial optic neuropathies, including recessive and X-linked, further emphasizing the exquisite sensitivity of RGCs to compromised mitochondrial function. All forms of mitochondrial optic neuropathies, including LHON and DOA, can manifest either as pure optic atrophy or as a more severe multisystemic syndrome. Mitochondrial optic neuropathies are currently at the forefront of a number of therapeutic programs, including gene therapy, with idebenone being the only approved drug for a mitochondrial disorder.
Collapse
Affiliation(s)
- Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy.
| | - Chiara La Morgia
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy; IRCCS Istituto di Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Patrick Yu-Wai-Man
- John van Geest 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 NHS Foundation Trust, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
| |
Collapse
|
7
|
Manners DN, Gramegna LL, La Morgia C, Sighinolfi G, Fiscone C, Carbonelli M, Romagnoli M, Carelli V, Tonon C, Lodi R. Multishell Diffusion MR Tractography Yields Morphological and Microstructural Information of the Anterior Optic Pathway: A Proof-of-Concept Study in Patients with Leber’s Hereditary Optic Neuropathy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19116914. [PMID: 35682499 PMCID: PMC9180110 DOI: 10.3390/ijerph19116914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/23/2022] [Accepted: 05/27/2022] [Indexed: 12/04/2022]
Abstract
Tractography based on multishell diffusion-weighted magnetic resonance imaging (DWI) can be used to estimate the course of myelinated white matter tracts and nerves, yielding valuable information regarding normal anatomy and variability. DWI is sensitive to the local tissue microstructure, so tractography can be used to estimate tissue properties within nerve tracts at a resolution of millimeters. This study aimed to test the applicability of the method using a disease with a well-established pattern of myelinated nerve involvement. Eight patients with LHON and 13 age-matched healthy controls underwent tractography of the anterior optic pathway. Diffusion parameters were compared between groups, and for the patient group correlated with clinical/ophthalmological parameters. Tractography established the course of the anterior optic pathway in both patients and controls. Localized changes in fractional anisotropy were observed, and related to estimates of different tissue compartments within the nerve and tract. The proportion of different compartments correlated with markers of disease severity. The method described allows both anatomical localization and tissue characterization in vivo, permitting both visualization of variation at the individual level and statistical inference at the group level. It provides a valuable adjunct to ex vivo anatomical and histological study of normal variation and disease processes.
Collapse
Affiliation(s)
- David Neil Manners
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
- Correspondence:
| | - Laura Ludovica Gramegna
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| | - Giovanni Sighinolfi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
| | - Cristiana Fiscone
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
| | - Michele Carbonelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
| | - Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| | - Caterina Tonon
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| | - Raffaele Lodi
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40138 Bologna, Italy; (L.L.G.); (G.S.); (C.F.); (M.C.); (V.C.); (C.T.); (R.L.)
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, 40139 Bologna, Italy; (C.L.M.); (M.R.)
| |
Collapse
|
8
|
Barboni P, Amore G, Cascavilla ML, Battista M, Frontino G, Romagnoli M, Caporali L, Baldoli C, Gramegna LL, Sessagesimi E, Bonfanti R, Romagnoli A, Scotti R, Brambati M, Carbonelli M, Starace V, Fiorini C, Panebianco R, Parisi V, Tonon C, Bandello F, Carelli V, La Morgia C. The pattern of retinal ganglion cell loss in Wolfram syndrome is distinct from mitochondrial optic neuropathies. Am J Ophthalmol 2022; 241:206-216. [PMID: 35452662 DOI: 10.1016/j.ajo.2022.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/13/2022] [Accepted: 03/16/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE To describe the clinical phenotype of a cohort of Wolfram syndrome (WS) patients, focusing on the pattern of optic atrophy correlated with brain MRI measurements, as compared to OPA1-associated mitochondrial optic neuropathy. DESIGN Retrospective, comparative cohort study METHODS: 25 WS patients and 33 age-matched patients affected by OPA1-related Dominant Optic Atrophy (DOA). Ophthalmological, neurological, endocrinological and MRI data from WS patients were retrospectively retrieved. Ophthalmological data were compared to OPA1-related DOA and further analyzed for age dependency dividing patients in age quartiles. In a subgroup of WS patients, we correlated the structural damage assessed by optical coherence tomography (OCT) with brain MRI morphological measurements. Visual acuity (VA), visual field mean defect (MD), retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness assessed by OCT, MRI morphological measurements of anterior and posterior visual pathways. RESULTS In our cohort optic atrophy was present in 100% of WS patients. VA, MD and RNFL thickness loss were worse in WS patients with a faster decline since early age as compared to DOA patients, who displayed a more stable visual function over the years. Conversely, GCL sectors were overall thinner in DOA patients since early age compared to WS, in which GCL thickness started to decline later in life. The neuroradiological sub-analysis on 11 WS patients exhibited bilateral thinning of the anterior optic pathway, especially prechiasmatic optic nerves and optic tracts. Optic tract thinning was significantly correlated with the GCL thickness but not with RNFL parameters. CONCLUSIONS Our results showed a generally more severe and diffuse degeneration of both anterior and posterior visual pathways in WS, with fast deterioration of visual function and structural OCT parameters since early age. The pattern observed at OCT suggests that retinal ganglion cells axonal degeneration (i.e. RNFL) precedes of about a decade the cellular body atrophy (i.e. GCL). This differs substantially from DOA, in which a more stable visual function is evident with predominant early loss of GCL, indirectly supporting the lack of a primary mitochondrial dysfunction in WS.
Collapse
Affiliation(s)
- Piero Barboni
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy; Studio Oculistico d'Azeglio (P.B.), Bologna, Italy.
| | - Giulia Amore
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy
| | - Maria Lucia Cascavilla
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Marco Battista
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Giulio Frontino
- Department of Pediatrics (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy; Diabetes Research Institute (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy
| | - Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., L.C., C.F., V.C., C.L.M.), Programma di Neurogenetica, Bologna, Italy
| | - Leonardo Caporali
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., L.C., C.F., V.C., C.L.M.), Programma di Neurogenetica, Bologna, Italy
| | - Cristina Baldoli
- Neuroradiology Unit (C.B., R.S.), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Laura Ludovica Gramegna
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (L.L.G., E.S., C.T.), Functional and Molecular Neuroimaging Unit, Bologna, Italy
| | - Elisa Sessagesimi
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (L.L.G., E.S., C.T.), Functional and Molecular Neuroimaging Unit, Bologna, Italy
| | - Riccardo Bonfanti
- Department of Pediatrics (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy; Diabetes Research Institute (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy
| | - Andrea Romagnoli
- Department of Pediatrics (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy; Diabetes Research Institute (G.F., R.B., A.R.), IRCCS San Raffaele Hospital, Milan, Italy
| | - Roberta Scotti
- Neuroradiology Unit (C.B., R.S.), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Brambati
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Michele Carbonelli
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy
| | - Vincenzo Starace
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Claudio Fiorini
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., L.C., C.F., V.C., C.L.M.), Programma di Neurogenetica, Bologna, Italy
| | - Roberta Panebianco
- Department of Ophthalmology (R.P.), University of Catania, Catania, Italy
| | | | - Caterina Tonon
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (L.L.G., E.S., C.T.), Functional and Molecular Neuroimaging Unit, Bologna, Italy
| | - Francesco Bandello
- From the Department of Ophthalmology (P.B., M.L.C., M.Ba., M.Br., V.S., F.B.), University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Valerio Carelli
- Dipartimento di Scienze Biomediche e Neuromotorie (G.A., L.L.G., E.S., M.C., C.T., V.C.), Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., L.C., C.F., V.C., C.L.M.), Programma di Neurogenetica, Bologna, Italy
| | - Chiara La Morgia
- IRCCS Istituto delle Scienze Neurologiche di Bologna (M.R., L.C., C.F., V.C., C.L.M.), Programma di Neurogenetica, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna (C.L.M.), UOC Clinica Neurologica, Bologna, Italy
| |
Collapse
|
9
|
Zeviani M, Carelli V. Mitochondrial Retinopathies. Int J Mol Sci 2021; 23:210. [PMID: 35008635 PMCID: PMC8745158 DOI: 10.3390/ijms23010210] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/14/2021] [Accepted: 12/18/2021] [Indexed: 12/13/2022] Open
Abstract
The retina is an exquisite target for defects of oxidative phosphorylation (OXPHOS) associated with mitochondrial impairment. Retinal involvement occurs in two ways, retinal dystrophy (retinitis pigmentosa) and subacute or chronic optic atrophy, which are the most common clinical entities. Both can present as isolated or virtually exclusive conditions, or as part of more complex, frequently multisystem syndromes. In most cases, mutations of mtDNA have been found in association with mitochondrial retinopathy. The main genetic abnormalities of mtDNA include mutations associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) sometimes with earlier onset and increased severity (maternally inherited Leigh syndrome, MILS), single large-scale deletions determining Kearns-Sayre syndrome (KSS, of which retinal dystrophy is a cardinal symptom), and mutations, particularly in mtDNA-encoded ND genes, associated with Leber hereditary optic neuropathy (LHON). However, mutations in nuclear genes can also cause mitochondrial retinopathy, including autosomal recessive phenocopies of LHON, and slowly progressive optic atrophy caused by dominant or, more rarely, recessive, mutations in the fusion/mitochondrial shaping protein OPA1, encoded by a nuclear gene on chromosome 3q29.
Collapse
Affiliation(s)
- Massimo Zeviani
- Department of Neurosciences, The Clinical School, University of Padova, 35128 Padova, Italy
- Veneto Institute of Molecular Medicine, Via Orus 2, 35128 Padova, Italy
| | - Valerio Carelli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, 40139 Bologna, Italy
- Programma di Neurogenetica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura 6, 40139 Bologna, Italy
| |
Collapse
|
10
|
Strachan EL, Mac White-Begg D, Crean J, Reynolds AL, Kennedy BN, O'Sullivan NC. The Role of Mitochondria in Optic Atrophy With Autosomal Inheritance. Front Neurosci 2021; 15:784987. [PMID: 34867178 PMCID: PMC8634724 DOI: 10.3389/fnins.2021.784987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022] Open
Abstract
Optic atrophy (OA) with autosomal inheritance is a form of optic neuropathy characterized by the progressive and irreversible loss of vision. In some cases, this is accompanied by additional, typically neurological, extra-ocular symptoms. Underlying the loss of vision is the specific degeneration of the retinal ganglion cells (RGCs) which form the optic nerve. Whilst autosomal OA is genetically heterogenous, all currently identified causative genes appear to be associated with mitochondrial organization and function. However, it is unclear why RGCs are particularly vulnerable to mitochondrial aberration. Despite the relatively high prevalence of this disorder, there are currently no approved treatments. Combined with the lack of knowledge concerning the mechanisms through which aberrant mitochondrial function leads to RGC death, there remains a clear need for further research to identify the underlying mechanisms and develop treatments for this condition. This review summarizes the genes known to be causative of autosomal OA and the mitochondrial dysfunction caused by pathogenic mutations. Furthermore, we discuss the suitability of available in vivo models for autosomal OA with regards to both treatment development and furthering the understanding of autosomal OA pathology.
Collapse
Affiliation(s)
- Elin L Strachan
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Delphi Mac White-Begg
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - John Crean
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.,UCD Diabetes Complications Research Centre, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Alison L Reynolds
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Breandán N Kennedy
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| |
Collapse
|