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Gazit I, Hecht I, Weiner C, Kotlyar A, Almer Z, Bakshi E, Or L, Volkov H, Feldman B, Maharshak I, Michelson M, Goldenberg-Cohen N, Pras E. Variants in the WDR45 Gene Within the OPA-2 Locus Associate With Isolated X-Linked Optic Atrophy. Invest Ophthalmol Vis Sci 2023; 64:17. [PMID: 37819743 PMCID: PMC10573587 DOI: 10.1167/iovs.64.13.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023] Open
Abstract
Purpose To describe clinical and molecular findings of two families with X-linked optic atrophy and present two new pathogenic variants in the WDR45 gene. Methods Case series and molecular analysis of two families of Jewish Ashkenazi descent with early onset bilateral optic atrophy. Whole-exome sequencing (WES) and bioinformatic analysis were performed, followed by Sanger sequencing and segregation analysis. Results In both families, male siblings (three in family 1, two in family 2) had early-onset isolated bilateral optic atrophy. The sibling's healthy mother (and in the second family also one healthy sister) had a mild presentation, suggesting a carrier state and an X-linked inheritance pattern. All participants were otherwise healthy, apart from mild learning disabilities and autism spectrum disorder in two siblings of the second family. Variants in known optic atrophy genes were excluded. Analysis revealed a point variant in the WDR45 gene-a missense variant in the first family, NM_001029896.2:c.107C>A; NP_001025067.1:p.Pro36His (variant ID: 1704205), and a splice site variant in the second family, NM_001029896.2:c.236-1G>T; NP_009006.2:p.Val80Leu (variant ID: 1704204), located on Xp11.23 (OPA2 locus). Both variants are novel and predicted as pathogenic. In both families, the variant was seen with full segregation with the disease, occurring in all affected male participants and in one allele of the carrier females, as well as none of the healthy participants. Conclusions Among two families with isolated X-linked optic atrophy, molecular analysis revealed novel variants in the WDR45 gene in full segregation with the disease. This gene resides within the OPA2 locus, previously described to associate with X-linked optic atrophy. Taken together, these findings suggest that certain pathogenic variants in the WDR45 gene are associated with isolated X-linked optic atrophy.
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Affiliation(s)
- Inbal Gazit
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Idan Hecht
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Matlow's Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
| | - Chen Weiner
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Matlow's Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
| | - Alina Kotlyar
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Matlow's Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
| | - Zina Almer
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
| | - Erez Bakshi
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lior Or
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hadas Volkov
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Barak Feldman
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Idit Maharshak
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Ophthalmology, Edith Wolfson Medical Center, Holon, Israel
| | - Marina Michelson
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
- The Genetic Institute of Maccabi Health Medicinal Organization, Tel Aviv, Israel
| | - Nitza Goldenberg-Cohen
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel, and the Department of Ophthalmology, Bnai Zion Medical Center, Haifa, Israel
| | - Eran Pras
- Department of Ophthalmology, Shamir Medical Center, Zerifin, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Matlow's Ophthalmo-genetics Laboratory, Shamir Medical Center, Zerifin, Israel
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Horvath R, Medina J, Reilly MM, Shy ME, Zuchner S. Peripheral neuropathy in mitochondrial disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 194:99-116. [PMID: 36813324 DOI: 10.1016/b978-0-12-821751-1.00014-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Mitochondria are essential for the health and viability of both motor and sensory neurons and their axons. Processes that disrupt their normal distribution and transport along axons will likely cause peripheral neuropathies. Similarly, mutations in mtDNA or nuclear encoded genes result in neuropathies that either stand alone or are part of multisystem disorders. This chapter focuses on the more common genetic forms and characteristic clinical phenotypes of "mitochondrial" peripheral neuropathies. We also explain how these various mitochondrial abnormalities cause peripheral neuropathy. In a patient with a neuropathy either due to a mutation in a nuclear or an mtDNA gene, clinical investigations aim to characterize the neuropathy and make an accurate diagnosis. In some patients, this may be relatively straightforward, where a clinical assessment and nerve conduction studies followed by genetic testing is all that is needed. In others, multiple investigations including a muscle biopsy, CNS imaging, CSF analysis, and a wide range of metabolic and genetic tests in blood and muscle may be needed to establish diagnosis.
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Affiliation(s)
- Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, John van Geest Centre for Brain Repair, Cambridge, United Kingdom.
| | - Jessica Medina
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Stephan Zuchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, United States
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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.
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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
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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: 30] [Impact Index Per Article: 10.0] [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.
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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
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McMacken G, Lochmüller H, Bansagi B, Pyle A, Lochmüller A, Chinnery PF, Laurie S, Beltran S, Matalonga L, Horvath R. Behr syndrome and hypertrophic cardiomyopathy in a family with a novel UCHL1 deletion. J Neurol 2020; 267:3643-3649. [PMID: 32656641 PMCID: PMC7674332 DOI: 10.1007/s00415-020-10059-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND Behr syndrome is a clinically distinct, but genetically heterogeneous disorder characterized by optic atrophy, progressive spastic paraparesis, and motor neuropathy often associated with ataxia. The molecular diagnosis is based on gene panel testing or whole-exome/genome sequencing. METHODS Here, we report the clinical presentation of two siblings with a novel genetic form of Behr syndrome. We performed whole-exome sequencing in the two patients and their mother. RESULTS Both patients had a childhood-onset, slowly progressive disease resembling Behr syndrome, starting with visual impairment, followed by progressive spasticity, weakness, and atrophy of the lower legs and ataxia. They also developed scoliosis, leading to respiratory problems. In their late 30's, both siblings developed a hypertrophic cardiomyopathy and died of sudden cardiac death at age 43 and 40, respectively. Whole-exome sequencing identified the novel homozygous c.627_629del; p.(Gly210del) deletion in UCHL1. CONCLUSIONS The presentation of our patients raises the possibility that hypertrophic cardiomyopathy may be an additional feature of the clinical syndrome associated with UCHL1 mutations, and highlights the importance of cardiac follow-up and treatment in neurodegenerative disease associated with UCHL1 mutations.
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Affiliation(s)
- Grace McMacken
- Department of Neurosciences, Royal Victoria Hospital, Belfast, UK
| | - Hanns Lochmüller
- Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
- Division of Neurology, Department of Medicine, Children's Hospital of Eastern Ontario Research Institute, The Ottawa Hospital and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Boglarka Bansagi
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Angela Pyle
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | | | - Patrick F Chinnery
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Steve Laurie
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Sergi Beltran
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Leslie Matalonga
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK.
- Department of Clinical Neurosciences, University of Cambridge School of Clinical Medicine, John Van Geest Cambridge Centre for Brain Repair, Robinson Way, Cambridge, CB2 0PY, UK.
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Bevan RJ, Williams PA, Waters CT, Thirgood R, Mui A, Seto S, Good M, Morgan JE, Votruba M, Erchova I. OPA1 deficiency accelerates hippocampal synaptic remodelling and age-related deficits in learning and memory. Brain Commun 2020; 2:fcaa101. [PMID: 33094281 PMCID: PMC7566495 DOI: 10.1093/braincomms/fcaa101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 04/09/2020] [Accepted: 05/27/2020] [Indexed: 12/13/2022] Open
Abstract
A healthy mitochondrial network is essential for the maintenance of neuronal synaptic integrity. Mitochondrial and metabolic dysfunction contributes to the pathogenesis of many neurodegenerative diseases including dementia. OPA1 is the master regulator of mitochondrial fusion and fission and is likely to play an important role during neurodegenerative events. To explore this, we quantified hippocampal dendritic and synaptic integrity and the learning and memory performance of aged Opa1 haploinsufficient mice carrying the Opa1Q285X mutation (B6; C3-Opa1Q285STOP ; Opa1+/- ). We demonstrate that heterozygous loss of Opa1 results in premature age-related loss of spines in hippocampal pyramidal CA1 neurons and a reduction in synaptic density in the hippocampus. This loss is associated with subtle memory deficits in both spatial novelty and object recognition. We hypothesize that metabolic failure to maintain normal neuronal activity at the level of a single spine leads to premature age-related memory deficits. These results highlight the importance of mitochondrial homeostasis for maintenance of neuronal function during ageing.
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Affiliation(s)
- Ryan J Bevan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Polhemsgatan 50, 112 82 Stockholm, Sweden
| | - Caroline T Waters
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Rebecca Thirgood
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Amanda Mui
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Sharon Seto
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Mark Good
- School of Psychology, Cardiff University, Tower Building, 70 Park Place, Cardiff, CF10 3AT, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
| | - Irina Erchova
- School of Optometry and Vision Sciences, Cardiff University, Maindy Rd, Cardiff, CF24 4HQ, UK
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Dušek P, Školoudík D, Roth J, Dušek P. Mitochondrial membrane protein-associated neurodegeneration: a case report and literature review. Neurocase 2018; 24:161-165. [PMID: 30088953 DOI: 10.1080/13554794.2018.1506038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondrial membrane protein-associated neurodegeneration (MPAN) is an autosomal recessive disorder caused by mutation in the C19orf12 gene. We report a compound heterozygous c.[32C>T];[205G>A;424A>G] (p.[Thr11Met];[Gly69Arg;Lys142Glu]) Czech patient who manifested with right foot dystonia, impaired handwriting, attention deficit, and signs of iron accumulation on brain MRI. Gradually, he developed dysarthria, spastic-dystonic gait, pedes cavi, and atrophy of leg muscles. Additionally, we report demographic parameters, clinical signs, and allelic frequencies of C19orf12 mutations of all published MPAN cases. We compared the most frequent mutations, p.Thr11Met and p.Gly69ArgfsX10; the latter was associated with younger age at onset and more frequent optic atrophy in homozygotes.
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Affiliation(s)
- Pavel Dušek
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic
| | - David Školoudík
- b Center of Research and Science, Faculty of Health Sciences , Palacký University , Olomouc , Czech Republic
| | - Jan Roth
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic
| | - Petr Dušek
- a Department of Neurology, Centre of Clinical Neurosciences, 1st Faculty of Medicine , Charles University and General University Hospital , Prague , Czech Republic.,c Department of Radiology, First Faculty of Medicine , Charles Universityand GeneralUniversity Hospital in Prague , Prague , Czech Republic
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Finsterer J, Mancuso M, Pareyson D, Burgunder JM, Klopstock T. Mitochondrial disorders of the retinal ganglion cells and the optic nerve. Mitochondrion 2017; 42:1-10. [PMID: 29054473 DOI: 10.1016/j.mito.2017.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 10/02/2017] [Accepted: 10/06/2017] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To summarise and discuss recent findings and future perspectives concerning mitochondrial disorders (MIDs) affecting the retinal ganglion cells and the optic nerve (mitochondrial optic neuropathy. MON). METHOD Literature review. RESULTS MON in MIDs is more frequent than usually anticipated. MON may occur in specific as well as non-specific MIDs. In specific and non-specific MIDs, MON may be a prominent or non-prominent phenotypic feature and due to mutations in genes located either in the mitochondrial DNA (mtDNA) or the nuclear DNA (nDNA). Clinically, MON manifests with painless, bilateral or unilateral, slowly or rapidly progressive visual impairment and visual field defects. In some cases, visual impairment may spontaneously recover. The most frequent MIDs with MON include LHON due to mutations in mtDNA-located genes and autosomal dominant optic atrophy (ADOA) or autosomal recessive optic atrophy (AROA) due to mutations in nuclear genes. Instrumental investigations for diagnosing MON include fundoscopy, measurement of visual acuity, visual fields, and color vision, visually-evoked potentials, optical coherence tomography, fluorescein angiography, electroretinography, and MRI of the orbita and cerebrum. In non-prominent MON, work-up of the muscle biopsy with transmission electron microscopy may indicate mitochondrial destruction. Treatment is mostly supportive but idebenone has been approved for LHON and experimental approaches are promising. CONCLUSIONS MON needs to be appreciated, requires extensive diagnostic work-up, and supportive treatment should be applied although loss of vision, as the most severe outcome, can often not be prevented.
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Affiliation(s)
| | - Michelangelo Mancuso
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Italy
| | - Davide Pareyson
- Department of Clinical Neurosciences, C. Besta Neurological Institute, IRCCS Foundation, Milan, Italy.
| | - Jean-Marc Burgunder
- Department of Neurology, University of Bern, Switzerland; Department of Neurology, Sun Yat Sen University, Guangzhou, China; Department of Neurology, Sichuan University, Chendgu, China.
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur Institute, Ludwig-Maximilians-Universität München, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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Olgiati S, Doğu O, Tufekcioglu Z, Diler Y, Saka E, Gultekin M, Kaleagasi H, Kuipers D, Graafland J, Breedveld GJ, Quadri M, Sürmeli R, Sünter G, Doğan T, Yalçın AD, Bilgiç B, Elibol B, Emre M, Hanagasi HA, Bonifati V. The p.Thr11Met mutation in c19orf12 is frequent among adult Turkish patients with MPAN. Parkinsonism Relat Disord 2017; 39:64-70. [PMID: 28347615 DOI: 10.1016/j.parkreldis.2017.03.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/13/2017] [Accepted: 03/17/2017] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Mutations in the C19orf12 gene cause mitochondrial membrane protein associated neurodegeneration (MPAN), an autosomal recessive form of neurodegeneration with brain iron accumulation (NBIA). A limited number of patients with C19orf12 mutations, particularly those with adult onset of symptoms, have been reported. METHODS We sequenced the entire coding region of C19orf12 in 15 Turkish adult probands with idiopathic NBIA. We also performed haplotype analysis in families with a recurrent C19orf12 mutation. Clinical features were collected using a standardized form. RESULTS Nine of our 15 probands (60%) carried the homozygous c.32C > T mutation in C19orf12 (predicted protein effect: p.Thr11Met). This homozygous mutation co-segregated with the disease in all affected relatives available for testing (16 homozygous subjects). Haplotypes across the C19orf12 locus were identical for a very small region, closest to the mutation, suggesting an old founder, or, two independent founders. The clinical phenotype was characterized by adult onset in most cases (mean 24.5 years, range 10-36), and broad spectrum, including prominent parkinsonism, pyramidal signs, psychiatric disturbances, cognitive decline, and motor axonal neuropathy, in various combinations. On T2- or susceptibility weighted-MRI images, all patients displayed bilateral hypointensities in globus pallidus and substantia nigra, without an eye-of-the-tiger sign; however, hyperintense streaking of the medial medullary lamina between the external and internal parts of globus pallidus was observed frequently. CONCLUSION The C19orf12 p.Thr11Met mutation is frequent among adult Turkish patients with MPAN. These findings contribute to the characterization of this important NBIA form, and have direct implications for genetic testing of patients of Turkish origin.
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Affiliation(s)
- Simone Olgiati
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Okan Doğu
- Department of Neurology, Medical Faculty, Mersin University, Mersin, Turkey
| | - Zeynep Tufekcioglu
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Yunus Diler
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Esen Saka
- Department of Neurology, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Murat Gultekin
- Department of Neurology, Erciyes University Faculty of Medicine, Kayseri, Turkey
| | - Hakan Kaleagasi
- Department of Neurology, Medical Faculty, Mersin University, Mersin, Turkey
| | - Demy Kuipers
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Josja Graafland
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Guido J Breedveld
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Marialuisa Quadri
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Reyhan Sürmeli
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Gülin Sünter
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | - Tuğrul Doğan
- Neurology Clinic, Ümraniye Research and Training Hospital, Istanbul, Turkey
| | | | - Başar Bilgiç
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Bülent Elibol
- Department of Neurology, Medical Faculty, Hacettepe University, Ankara, Turkey
| | - Murat Emre
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Hasmet A Hanagasi
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Vincenzo Bonifati
- Department of Clinical Genetics, Erasmus MC, Rotterdam, The Netherlands.
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Kim J, Liao YH, Ionita C, Bale AE, Darras B, Acsadi G. Mitochondrial Membrane Protein-Associated Neurodegeneration Mimicking Juvenile Amyotrophic Lateral Sclerosis. Pediatr Neurol 2016; 64:83-86. [PMID: 27671242 DOI: 10.1016/j.pediatrneurol.2016.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mitochondrial membrane protein associated neurodegeneration (MPAN) is the third most common subtype of neurodegeneration with brain iron accumulation (NBIA) and caused by mutations of the orphan gene C19ORF12 encoding a transmembrane mitochondrial protein. Like other NBIA disorders, the hallmark of neuropathology is iron deposition in the basal ganglia, but the clinical presentation is highly variable. METHODS We present the relevant clinical history, neurological examination, electrophysiological and neuroimaging tests of a currently ten-year-old girl. The genetic analysis was carried out by exome sequencing focused on known NBIA and juvenile amyotrophic lateral sclerosis (ALS) genes. RESULTS The patient presented at four years of age with progressive lower extremity weakness and generalized hypotonia. She was initially diagnosed with juvenile ALS based on clinical signs, negative brain magnetic resonance imaging (MRI) and electromyography findings. As the disease progressed, a repeat brain MRI showed iron deposition in the basal ganglia at nine years of age. Exome sequencing of genes known to be associated with NBIA revealed a compound heterozygous mutation of C19ORF12 gene. CONCLUSIONS A C19orf12 gene mutation should be considered in young children with clinical signs of progressive upper and lower motor neuron disease. Finding iron accumulation in the basal ganglia helps to focus the genetic testing, but it may not be apparent for several years.
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Affiliation(s)
- Jiyeon Kim
- University of Connecticut School of Medicine, Farmington, Connecticut
| | - Yu-Hsien Liao
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
| | | | - Allen E Bale
- Yale University School of Medicine, New Haven, Connecticut
| | - Basil Darras
- Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gyula Acsadi
- Children's Medical Center, University of Connecticut, Farmington, Connecticut.
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Gore E, Appleby BS, Cohen ML, DeBrosse SD, Leverenz JB, Miller BL, Siedlak SL, Zhu X, Lerner AJ. Clinical and imaging characteristics of late onset mitochondrial membrane protein-associated neurodegeneration (MPAN). Neurocase 2016; 22:476-483. [PMID: 27801611 PMCID: PMC5568540 DOI: 10.1080/13554794.2016.1247458] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 10/07/2016] [Indexed: 12/14/2022]
Abstract
Young onset dementias present significant diagnostic challenges. We present the case of a 35-year-old Kuwaiti man with social withdrawal, drowsiness, irritability, anxiety, aphasia, memory loss, hypereflexia, and Parkinsonism. Brain MRI showed bilateral symmetric gradient echo hypointensities in the globi pallidi and substantiae nigrae. Left cortical hypometabolism was seen on brain fluorodeoxyglucose positron emission tomography. A cortical brain biopsy revealed a high Lewy body burden. Genetic testing revealed a homozygous p.T11M mutation in the C19orf12 gene consistent with mitochondrial membrane protein-associated neurodegeneration. This is the oldest onset age of MPAN reported.
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Affiliation(s)
- Ethan Gore
- Department of Neurology, University Hospitals Case Medical Center, Beachwood, OH, USA
| | - Brian S. Appleby
- Departments of Neurology and Psychiatry, University Hospitals Case Medical Center, 3619 Park East Drive, Beachwood, OH, USA
| | - Mark L. Cohen
- Department of Pathology, University Hospitals Case Medical Center, Cleveland, OH, USA
| | - Suzanne D. DeBrosse
- Departments of Genetics and Genome Sciences, Pediatrics, and Neurology, University Hospitals Case Medical Center, Cleveland, OH, USA
| | - James B. Leverenz
- Cleveland Clinic Lou Ruvo Center for Brain Health, Cleveland, OH, USA
| | - Bruce L. Miller
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Sandra L. Siedlak
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Alan J. Lerner
- Department of Neurology, University Hospitals Case Medical Center, Beachwood, OH, USA
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Kinghorn KJ, Castillo-Quan JI. Mitochondrial dysfunction and defects in lipid homeostasis as therapeutic targets in neurodegeneration with brain iron accumulation. Rare Dis 2016; 4:e1128616. [PMID: 27141409 PMCID: PMC4838319 DOI: 10.1080/21675511.2015.1128616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/11/2015] [Accepted: 12/01/2015] [Indexed: 10/26/2022] Open
Abstract
The PLA2G6 gene encodes a group VIA calcium independent phospholipase A2 (iPLA2β), which hydrolyses glycerophospholipids to release fatty acids and lysophospholipids. Mutations in PLA2G6 are associated with a number of neurodegenerative disorders including neurodegeneration with brain iron accumulation (NBIA), infantile neuroaxonal dystrophy (INAD), and dystonia parkinsonism, collectively known as PLA2G6-associated neurodegeneration (PLAN). Recently Kinghorn et al. demonstrated in Drosophila and PLA2G6 mutant fibroblasts that loss of normal PLA2G6 activity is associated with mitochondrial dysfunction and mitochondrial lipid peroxidation. Furthermore, they were able to show the beneficial effects of deuterated polyunsaturated fatty acids (D-PUFAs), which reduce lipid peroxidation. D-PUFAs were able to rescue the locomotor deficits of flies lacking the fly ortholog of PLA2G6 (iPLA2-VIA), as well as the mitochondrial abnormalities in PLA2G6 mutant fibroblasts. This work demonstrated that the iPLA2-VIA knockout fly is a useful organism to dissect the mechanisms of pathogenesis of PLAN, and that further investigation is required to determine the therapeutic potential of D-PUFAs in patients with PLA2G6 mutations. The fruit fly has also been used to study some of the other genetic causes of NBIA, and here we also describe what is known about the mechanisms of pathogenesis of these NBIA variants. Mitochondrial dysfunction, defects in lipid metabolism, as well as defective Coenzyme A (CoA) biosynthesis, have all been implicated in some genetic forms of NBIA, including PANK2, CoASY, C12orf19 and FA2H.
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Affiliation(s)
- Kerri J Kinghorn
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
| | - Jorge Iván Castillo-Quan
- Institute of Healthy Ageing and Department of Genetics, Environment and Evolution, University College London, London, UK; Institute of Neurology, University College London, Queen Square, London, UK
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