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Cacheiro P, Pava D, Parkinson H, VanZanten M, Wilson R, Gunes O, The International Mouse Phenotyping Consortium, Smedley D. Computational identification of disease models through cross-species phenotype comparison. Dis Model Mech 2024; 17:dmm050604. [PMID: 38881316 PMCID: PMC11247498 DOI: 10.1242/dmm.050604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 06/11/2024] [Indexed: 06/18/2024] Open
Abstract
The use of standardised phenotyping screens to identify abnormal phenotypes in mouse knockouts, together with the use of ontologies to describe such phenotypic features, allows the implementation of an automated and unbiased pipeline to identify new models of disease by performing phenotype comparisons across species. Using data from the International Mouse Phenotyping Consortium (IMPC), approximately half of mouse mutants are able to mimic, at least partially, the human ortholog disease phenotypes as computed by the PhenoDigm algorithm. We found the number of phenotypic abnormalities in the mouse and the corresponding Mendelian disorder, the pleiotropy and severity of the disease, and the viability and zygosity status of the mouse knockout to be associated with the ability of mouse models to recapitulate the human disorder. An analysis of the IMPC impact on disease gene discovery through a publication-tracking system revealed that the resource has been implicated in at least 109 validated rare disease-gene associations over the last decade.
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Affiliation(s)
- Pilar Cacheiro
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Diego Pava
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Helen Parkinson
- European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Maya VanZanten
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Robert Wilson
- European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Osman Gunes
- European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | | | - Damian Smedley
- William Harvey Research Institute, Queen Mary University of London, London, EC1M 6BQ, UK
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Lail N, Pandey AK, Venkatesh S, Noland RD, Swanson G, Pain D, Branson HM, Suzuki CK, Yoon G. Child Neurology: Progressive Cerebellar Atrophy and Retinal Dystrophy: Clues to an Ultrarare ACO2-Related Neurometabolic Diagnosis. Neurology 2023; 101:e1567-e1571. [PMID: 37460232 PMCID: PMC10585704 DOI: 10.1212/wnl.0000000000207649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/31/2023] [Indexed: 10/11/2023] Open
Abstract
Pathogenic biallelic variants in ACO2, which encodes the enzyme mitochondrial aconitase, are associated with the very rare diagnosis of ACO2-related infantile cerebellar retinal degeneration (OMIM 614559). We describe the diagnostic odyssey of a 4-year-old female patient with profound global developmental delays, microcephaly, severe hypotonia, retinal dystrophy, seizures, and progressive cerebellar atrophy. Whole-exome sequencing revealed 2 variants in ACO2; c.2105_2106delAG (p.Gln702ArgfsX9), a likely pathogenic variant, and c.988C>T (p.Pro330Ser) which was classified as a variant of uncertain significance (VUS). While the VUS was confirmed to be maternally inherited, the phase of the other variant could not be confirmed due to lack of a paternal sample. Functional biochemical studies were performed on a research basis to clarify the interpretation of the VUS, which enabled clinical confirmation of the diagnosis of ACO2-related infantile cerebellar retinal degeneration for our patient.
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Affiliation(s)
- Noor Lail
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Ashutosh K Pandey
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Sundararajan Venkatesh
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Roberto D Noland
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Gabriel Swanson
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Debkumar Pain
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Helen M Branson
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Carolyn K Suzuki
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown
| | - Grace Yoon
- From the Division of Clinical and Metabolic Genetics (N.L., G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada; Department of Pharmacology, Physiology and Neuroscience (A.K.P., D.P.), and Department of Microbiology, Biochemistry and Molecular Genetics (S.V., R.D.N., G.S., C.K.S.), Rutgers-New Jersey Medical School, Newark; and Division of Neuroradiology (H.M.B.), Department of Diagnostic Imaging, and Division of Neurology (G.Y.), Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada. S. Venkatesh is now with Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown.
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3
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Hassan A. Episodic Ataxias: Primary and Secondary Etiologies, Treatment, and Classification Approaches. Tremor Other Hyperkinet Mov (N Y) 2023; 13:9. [PMID: 37008993 PMCID: PMC10064912 DOI: 10.5334/tohm.747] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/03/2023] [Indexed: 03/30/2023] Open
Abstract
Background Episodic ataxia (EA), characterized by recurrent attacks of cerebellar dysfunction, is the manifestation of a group of rare autosomal dominant inherited disorders. EA1 and EA2 are most frequently encountered, caused by mutations in KCNA1 and CACNA1A. EA3-8 are reported in rare families. Advances in genetic testing have broadened the KCNA1 and CACNA1A phenotypes, and detected EA as an unusual presentation of several other genetic disorders. Additionally, there are various secondary causes of EA and mimicking disorders. Together, these can pose diagnostic challenges for neurologists. Methods A systematic literature review was performed in October 2022 for 'episodic ataxia' and 'paroxysmal ataxia', restricted to publications in the last 10 years to focus on recent clinical advances. Clinical, genetic, and treatment characteristics were summarized. Results EA1 and EA2 phenotypes have further broadened. In particular, EA2 may be accompanied by other paroxysmal disorders of childhood with chronic neuropsychiatric features. New treatments for EA2 include dalfampridine and fampridine, in addition to 4-aminopyridine and acetazolamide. There are recent proposals for EA9-10. EA may also be caused by gene mutations associated with chronic ataxias (SCA-14, SCA-27, SCA-42, AOA2, CAPOS), epilepsy syndromes (KCNA2, SCN2A, PRRT2), GLUT-1, mitochondrial disorders (PDHA1, PDHX, ACO2), metabolic disorders (Maple syrup urine disease, Hartnup disease, type I citrullinemia, thiamine and biotin metabolism defects), and others. Secondary causes of EA are more commonly encountered than primary EA (vascular, inflammatory, toxic-metabolic). EA can be misdiagnosed as migraine, peripheral vestibular disorders, anxiety, and functional symptoms. Primary and secondary EA are frequently treatable which should prompt a search for the cause. Discussion EA may be overlooked or misdiagnosed for a variety of reasons, including phenotype-genotype variability and clinical overlap between primary and secondary causes. EA is highly treatable, so it is important to consider in the differential diagnosis of paroxysmal disorders. Classical EA1 and EA2 phenotypes prompt single gene test and treatment pathways. For atypical phenotypes, next generation genetic testing can aid diagnosis and guide treatment. Updated classification systems for EA are discussed which may assist diagnosis and management.
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4
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Cacheiro P, Westerberg CH, Mager J, Dickinson ME, Nutter LMJ, Muñoz-Fuentes V, Hsu CW, Van den Veyver IB, Flenniken AM, McKerlie C, Murray SA, Teboul L, Heaney JD, Lloyd KCK, Lanoue L, Braun RE, White JK, Creighton AK, Laurin V, Guo R, Qu D, Wells S, Cleak J, Bunton-Stasyshyn R, Stewart M, Harrisson J, Mason J, Haseli Mashhadi H, Parkinson H, Mallon AM, Smedley D. Mendelian gene identification through mouse embryo viability screening. Genome Med 2022; 14:119. [PMID: 36229886 PMCID: PMC9563108 DOI: 10.1186/s13073-022-01118-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 09/26/2022] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND The diagnostic rate of Mendelian disorders in sequencing studies continues to increase, along with the pace of novel disease gene discovery. However, variant interpretation in novel genes not currently associated with disease is particularly challenging and strategies combining gene functional evidence with approaches that evaluate the phenotypic similarities between patients and model organisms have proven successful. A full spectrum of intolerance to loss-of-function variation has been previously described, providing evidence that gene essentiality should not be considered as a simple and fixed binary property. METHODS Here we further dissected this spectrum by assessing the embryonic stage at which homozygous loss-of-function results in lethality in mice from the International Mouse Phenotyping Consortium, classifying the set of lethal genes into one of three windows of lethality: early, mid, or late gestation lethal. We studied the correlation between these windows of lethality and various gene features including expression across development, paralogy and constraint metrics together with human disease phenotypes. We explored a gene similarity approach for novel gene discovery and investigated unsolved cases from the 100,000 Genomes Project. RESULTS We found that genes in the early gestation lethal category have distinct characteristics and are enriched for genes linked with recessive forms of inherited metabolic disease. We identified several genes sharing multiple features with known biallelic forms of inborn errors of the metabolism and found signs of enrichment of biallelic predicted pathogenic variants among early gestation lethal genes in patients recruited under this disease category. We highlight two novel gene candidates with phenotypic overlap between the patients and the mouse knockouts. CONCLUSIONS Information on the developmental period at which embryonic lethality occurs in the knockout mouse may be used for novel disease gene discovery that helps to prioritise variants in unsolved rare disease cases.
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Affiliation(s)
- Pilar Cacheiro
- William Harvey Research Institute, Queen Mary University of London, London, UK
| | | | - Jesse Mager
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | - Mary E Dickinson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Lauryl M J Nutter
- The Hospital for Sick Children, The Centre for Phenogenomics, Toronto, Canada
| | - Violeta Muñoz-Fuentes
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, UK
| | - Chih-Wei Hsu
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, USA.,Department of Education, Innovation and Technology, Baylor College of Medicine, Houston, TX, USA
| | - Ignatia B Van den Veyver
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, USA
| | - Ann M Flenniken
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, The Centre for Phenogenomics, Toronto, Canada
| | - Colin McKerlie
- The Hospital for Sick Children, The Centre for Phenogenomics, Toronto, Canada
| | | | - Lydia Teboul
- The Mary Lyon Centre, MRC Harwell Institute, Harwell, Oxfordshire, UK
| | - Jason D Heaney
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - K C Kent Lloyd
- Mouse Biology Program, University of California Davis, Davis, CA, USA
| | - Louise Lanoue
- Mouse Biology Program, University of California Davis, Davis, CA, USA
| | | | | | - Amie K Creighton
- The Hospital for Sick Children, The Centre for Phenogenomics, Toronto, Canada
| | - Valerie Laurin
- The Hospital for Sick Children, The Centre for Phenogenomics, Toronto, Canada
| | - Ruolin Guo
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, The Centre for Phenogenomics, Toronto, Canada
| | - Dawei Qu
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, The Centre for Phenogenomics, Toronto, Canada
| | - Sara Wells
- The Mary Lyon Centre, MRC Harwell Institute, Harwell, Oxfordshire, UK
| | - James Cleak
- The Mary Lyon Centre, MRC Harwell Institute, Harwell, Oxfordshire, UK
| | | | - Michelle Stewart
- The Mary Lyon Centre, MRC Harwell Institute, Harwell, Oxfordshire, UK
| | - Jackie Harrisson
- The Mary Lyon Centre, MRC Harwell Institute, Harwell, Oxfordshire, UK
| | - Jeremy Mason
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, UK
| | - Hamed Haseli Mashhadi
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, UK
| | - Helen Parkinson
- European Molecular Biology Laboratory-European Bioinformatics Institute, Hinxton, UK
| | | | | | | | - Damian Smedley
- William Harvey Research Institute, Queen Mary University of London, London, UK.
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5
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Ha DJ, Park J, Seo GH, Lee K, Kwon YS, Lee JE, Kim SJ. Case Report: Infantile Cerebellar-Retinal Degeneration With Compound Heterozygous Variants in ACO2 Gene-Long-Term Follow-Up of a Sibling. Front Genet 2022; 13:729980. [PMID: 35368710 PMCID: PMC8965713 DOI: 10.3389/fgene.2022.729980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
Abstract
Infantile cerebellar-retinal degeneration (ICRD) is an extremely rare, infantile-onset neuro-degenerative disease, characterized by autosomal recessive inherited, global developmental delay (GDD), progressive cerebellar and cortical atrophy, and retinal degeneration. In 2012, a biallelic pathogenic variant in ACO2 gene (NM_001098.3) was found to be causative of this disease. To date, approximately 44 variants displaying various clinical features have been reported. Here, we report a case of two siblings with compound heterozygous variants in the ACO2 gene. Two siblings without perinatal problems were born to healthy non-consanguineous Korean parents. They showed GDD and seizures since infancy. Their first brain magnetic resonance imaging (MRI), electroencephalography, and metabolic workup revealed no abnormal findings. As they grew, they developed symptoms including ataxia, dysmetria, poor sitting balance, and myopia. Follow-up brain MRI findings revealed atrophy of the cerebellum and optic nerve. Through exome sequencing of both siblings and their parents, we identified the following compound heterozygous variants in the ACO2: c.85C > T (p.Arg29Trp) and c.2303C > A (p.Ala768Asp). These two variants were categorized as likely pathogenic based on ACMG/AMP guidelines. In conclusion, this case help to broaden the genetic and clinical spectrum of the ACO2 variants associated with ICRD. We have also documented the long-term clinical course and serial brain MRI findings for two patients with this extremely rare disease.
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Affiliation(s)
- Dong Jun Ha
- Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea
| | - Jisun Park
- Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea.,Northwest Gyeonggi Regional Center for Rare Disease, Inha University Hospital, Incheon, Korea
| | | | | | - Young Se Kwon
- Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea.,Northwest Gyeonggi Regional Center for Rare Disease, Inha University Hospital, Incheon, Korea
| | - Ji Eun Lee
- Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea.,Northwest Gyeonggi Regional Center for Rare Disease, Inha University Hospital, Incheon, Korea
| | - Su Jin Kim
- Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea.,Northwest Gyeonggi Regional Center for Rare Disease, Inha University Hospital, Incheon, Korea
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6
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Charif M, Gueguen N, Ferré M, Elkarhat Z, Khiati S, LeMao M, Chevrollier A, Desquiret-Dumas V, Goudenège D, Bris C, Kane S, Alban J, Chupin S, Wetterwald C, Caporali L, Tagliavini F, LaMorgia C, Carbonelli M, Jurkute N, Barakat A, Gohier P, Verny C, Barth M, Procaccio V, Bonneau D, Zanlonghi X, Meunier I, Weisschuh N, Schimpf-Linzenbold S, Tonagel F, Kellner U, Yu-Wai-Man P, Carelli V, Wissinger B, Amati-Bonneau P, Reynier P, Lenaers G. Dominant ACO2 mutations are a frequent cause of isolated optic atrophy. Brain Commun 2021; 3:fcab063. [PMID: 34056600 PMCID: PMC8152918 DOI: 10.1093/braincomms/fcab063] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/24/2022] Open
Abstract
Biallelic mutations in ACO2, encoding the mitochondrial aconitase 2, have been identified in individuals with neurodegenerative syndromes, including infantile cerebellar retinal degeneration and recessive optic neuropathies (locus OPA9). By screening European cohorts of individuals with genetically unsolved inherited optic neuropathies, we identified 61 cases harbouring variants in ACO2, among whom 50 carried dominant mutations, emphasizing for the first time the important contribution of ACO2 monoallelic pathogenic variants to dominant optic atrophy. Analysis of the ophthalmological and clinical data revealed that recessive cases are affected more severely than dominant cases, while not significantly earlier. In addition, 27% of the recessive cases and 11% of the dominant cases manifested with extraocular features in addition to optic atrophy. In silico analyses of ACO2 variants predicted their deleterious impacts on ACO2 biophysical properties. Skin derived fibroblasts from patients harbouring dominant and recessive ACO2 mutations revealed a reduction of ACO2 abundance and enzymatic activity, and the impairment of the mitochondrial respiration using citrate and pyruvate as substrates, while the addition of other Krebs cycle intermediates restored a normal respiration, suggesting a possible short-cut adaptation of the tricarboxylic citric acid cycle. Analysis of the mitochondrial genome abundance disclosed a significant reduction of the mitochondrial DNA amount in all ACO2 fibroblasts. Overall, our data position ACO2 as the third most frequently mutated gene in autosomal inherited optic neuropathies, after OPA1 and WFS1, and emphasize the crucial involvement of the first steps of the Krebs cycle in the maintenance and survival of retinal ganglion cells.
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Affiliation(s)
- Majida Charif
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Genetics and Immuno-Cell Therapy Team, Mohammed First University, Oujda, Morocco
| | - Naïg Gueguen
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Marc Ferré
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Zouhair Elkarhat
- Laboratory of Genomics and Human Genetics, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Salim Khiati
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Morgane LeMao
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Arnaud Chevrollier
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Valerie Desquiret-Dumas
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - David Goudenège
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Céline Bris
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Selma Kane
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Jennifer Alban
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Stéphanie Chupin
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | | | - Leonardo Caporali
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Francesca Tagliavini
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Chiara LaMorgia
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
| | - Michele Carbonelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Neringa Jurkute
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
- Cambridge Eye Unit, Addenbrooke’s Hospital, Cambridge University Hospitals, Cambridge, UK
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Abdelhamid Barakat
- Laboratory of Genomics and Human Genetics, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Philippe Gohier
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
| | - Christophe Verny
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Centre de référence des Maladies Neurogénétiques, Département de Neurologie, CHU d’Angers, Angers, France
| | - Magalie Barth
- Department of Pediatrics, Competence Center of Inherited Metabolic Disorders, Angers Hospital, Angers, France
| | - Vincent Procaccio
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Dominique Bonneau
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | | | - Isabelle Meunier
- National Center for Rare Diseases, Genetics of Sensory Diseases, University Hospital, Montpellier, France
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | | | - Felix Tonagel
- Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ulrich Kellner
- Rare Retinal Disease Center, AugenZentrum Siegburg, MVZ ADTC Siegburg GmbH, Siegburg, Germany
- RetinaScience, 53113 Bonn, Germany
| | - Patrick Yu-Wai-Man
- Moorfields Eye Hospital, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
- Cambridge Eye Unit, Addenbrooke’s Hospital, Cambridge University Hospitals, Cambridge, UK
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Valerio Carelli
- Unit of Neurology, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Patrizia Amati-Bonneau
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | - Pascal Reynier
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Département de Biochimie et Génétique, CHU d'Angers, Angers, France
| | | | - Guy Lenaers
- Université Angers, MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, SFR ICAT, Angers, France
- Correspondence to: Guy Lenaers MitoLab Team, Mitochondrial Medicine Research Centre, MitoVasc Unit, Université d'Angers UMR CNRS 6015, INSERM U1083, CHU Bât IRIS/IBS, Rue des Capucins 49933 Angers cedex 9, France E-mail:
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