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Kortazar-Zubizarreta I, Manero-Azua A, Afonso-Agüera J, Perez de Nanclares G. C9ORF72 Gene GGGGCC Hexanucleotide Expansion: A High Clinical Variability from Amyotrophic Lateral Sclerosis to Frontotemporal Dementia. J Pers Med 2023; 13:1396. [PMID: 37763163 PMCID: PMC10532825 DOI: 10.3390/jpm13091396] [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: 09/02/2023] [Revised: 09/15/2023] [Accepted: 09/16/2023] [Indexed: 09/29/2023] Open
Abstract
The expanded GGGGCC hexanucleotide repeat (HRE) in the non-coding region of the C9ORF72 gene (C9ORF72-HRE) is the most common genetic cause of familial forms of amyotrophic lateral sclerosis (ALS), FTD, and concurrent ALS and FTD (ALS-FTD), in addition to contributing to the sporadic forms of these diseases. Both syndromes overlap not only genetically, but also sharing similar clinical and neuropathological findings, being considered as a spectrum. In this paper we describe the clinical-genetic findings in a Basque family with different manifestations within the spectrum, our difficulties in reaching the diagnosis, and a narrative review, carried out as a consequence, of the main features associated with C9ORF72-HRE. Family members underwent a detailed clinical assessment, neurological examination, and genetic analysis by repeat-primed PCR. We studied 10 relatives of a symptomatic carrier of the C9ORF72-HRE expansion. Two of them presented the expansion in the pathological range, one of them was symptomatic whereas the other one remained asymptomatic at 72 years. Given the great intrafamilial clinical variability of C9ORF72-HRE, the characterization of patients and family members with particular clinical and genetic subgroups within ALS and FTD becomes a bottleneck for medication development, in particular for genetically focused medicines for ALS and FTD.
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Affiliation(s)
- Izaro Kortazar-Zubizarreta
- Department of Neurology, Bioaraba Health Research Institute, Araba University Hospital-Txagorritxu, 01009 Vitoria-Gasteiz, Spain
| | - Africa Manero-Azua
- Molecular (Epi) Genetics Laboratory, Bioaraba Health Research Institute, Araba University Hospital, 01009 Vitoria-Gasteiz, Spain; (A.M.-A.); (G.P.d.N.)
| | - Juan Afonso-Agüera
- Department of Neurology, Central University Hospital of Asturias, 33006 Oviedo, Spain;
| | - Guiomar Perez de Nanclares
- Molecular (Epi) Genetics Laboratory, Bioaraba Health Research Institute, Araba University Hospital, 01009 Vitoria-Gasteiz, Spain; (A.M.-A.); (G.P.d.N.)
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2
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Vinceti G, Gallingani C, Zucchi E, Martinelli I, Gianferrari G, Simonini C, Bedin R, Chiari A, Zamboni G, Mandrioli J. Young Onset Alzheimer's Disease Associated with C9ORF72 Hexanucleotide Expansion: Further Evidence for a Still Unsolved Association. Genes (Basel) 2023; 14:genes14040930. [PMID: 37107688 PMCID: PMC10138077 DOI: 10.3390/genes14040930] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/29/2023] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are recognized as part of a disease continuum (FTD-ALS spectrum), in which the most common genetic cause is chromosome 9 open reading frame 72 (C9ORF72) gene hexanucleotide repeat expansion. The clinical phenotype of patients carrying this expansion varies widely and includes diseases beyond the FTD-ALS spectrum. Although a few cases of patients with C9ORF72 expansion and a clinical or biomarker-supported diagnosis of Alzheimer's disease (AD) have been described, they have been considered too sparse to establish a definite association between the C9ORF72 expansion and AD pathology. Here, we describe a C9ORF72 family with pleomorphic phenotypical expressions: a 54-year-old woman showing cognitive impairment and behavioral disturbances with both neuroimaging and cerebrospinal fluid (CSF) biomarkers consistent with AD pathology, her 49-year-old brother with typical FTD-ALS, and their 63-year-old mother with the behavioral variant of FTD and CSF biomarkers suggestive of AD pathology. The young onset of disease in all three family members and their different phenotypes and biomarker profiles make the simple co-occurrence of different diseases an extremely unlikely explanation. Our report adds to previous findings and may contribute to further expanding the spectrum of diseases associated with C9ORF72 expansion.
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Affiliation(s)
- Giulia Vinceti
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
| | - Chiara Gallingani
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Elisabetta Zucchi
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Ilaria Martinelli
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Giulia Gianferrari
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Cecilia Simonini
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Roberta Bedin
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
| | - Annalisa Chiari
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
| | - Giovanna Zamboni
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Jessica Mandrioli
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
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Zecca C, Tortelli R, Carrera P, Dell'Abate MT, Logroscino G, Ferrari M. Genotype-phenotype correlation in the spectrum of frontotemporal dementia-parkinsonian syndromes and advanced diagnostic approaches. Crit Rev Clin Lab Sci 2022; 60:171-188. [PMID: 36510705 DOI: 10.1080/10408363.2022.2150833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The term frontotemporal dementia (FTD) refers to a group of progressive neurodegenerative disorders characterized mainly by atrophy of the frontal and anterior temporal lobes. Based on clinical presentation, three main clinical syndromes have traditionally been described: behavioral variant frontotemporal dementia (bvFTD), non-fluent/agrammatic primary progressive aphasia (nfPPA), and semantic variant PPA (svPPA). However, over the last 20 years, it has been recognized that cognitive phenotypes often overlap with motor phenotypes, either motor neuron diseases or parkinsonian signs and/or syndromes like progressive supranuclear palsy (PSP) and cortico-basal syndrome (CBS). Furthermore, FTD-related genes are characterized by genetic pleiotropy and can cause, even in the same family, pure motor phenotypes, findings that underlie the clinical continuum of the spectrum, which has pure cognitive and pure motor phenotypes as the extremes. The genotype-phenotype correlation of the spectrum, FTD-motor neuron disease, has been well defined and extensively investigated, while the continuum, FTD-parkinsonism, lacks a comprehensive review. In this narrative review, we describe the current knowledge about the genotype-phenotype correlation of the spectrum, FTD-parkinsonism, focusing on the phenotypes that are less frequent than bvFTD, namely nfPPA, svPPA, PSP, CBS, and cognitive-motor overlapping phenotypes (i.e. PPA + PSP). From a pathological point of view, they are characterized mainly by the presence of phosphorylated-tau inclusions, either 4 R or 3 R. The genetic correlate of the spectrum can be heterogeneous, although some variants seem to lead preferentially to specific clinical syndromes. Furthermore, we critically review the contribution of genome-wide association studies (GWAS) and next-generation sequencing (NGS) in disentangling the complex heritability of the FTD-parkinsonism spectrum and in defining the genotype-phenotype correlation of the entire clinical scenario, owing to the ability of these techniques to test multiple genes, and so to allow detailed investigations of the overlapping phenotypes. Finally, we conclude with the importance of a detailed genetic characterization and we offer to patients and families the chance to be included in future randomized clinical trials focused on autosomal dominant forms of FTLD.
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Affiliation(s)
- Chiara Zecca
- Department of Clinical Research in Neurology, Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro", Pia Fondazione Card G. Panico Hospital, Tricase, Italy
| | - Rosanna Tortelli
- Neuroscience and Rare Diseases Discovery and Translational Area, Roche Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Paola Carrera
- Unit of Genomics for Human Disease Diagnosis and Clinical Molecular Biology Laboratory, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Teresa Dell'Abate
- Department of Clinical Research in Neurology, Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro", Pia Fondazione Card G. Panico Hospital, Tricase, Italy
| | - Giancarlo Logroscino
- Department of Clinical Research in Neurology, Center for Neurodegenerative Diseases and the Aging Brain, University of Bari "Aldo Moro", Pia Fondazione Card G. Panico Hospital, Tricase, Italy.,Department of Basic Medicine Sciences, Neuroscience, and Sense Organs, University of Bari "Aldo Moro", Bari, Italy
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Clinical Update on C9orf72: Frontotemporal Dementia, Amyotrophic Lateral Sclerosis, and Beyond. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1281:67-76. [PMID: 33433869 DOI: 10.1007/978-3-030-51140-1_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The identification of C9orf72 gene has led to important scientific progresses and has considerably changed our clinical practice. However, a decade after C9orf72 discovery, some important clinical questions remain unsolved. The reliable cutoff for the pathogenic repeat number and the implication of intermediate alleles in frontotemporal dementia, amyotrophic lateral sclerosis, or in other diseases are still uncertain. The occurrence of an anticipation phenomenon - at the clinical and molecular levels - in C9orf72 kindreds is still debated as well, and the factors driving age at onset and phenotype variability are largely unknown. All these questions have a significant impact not only in clinical practice for diagnosis and genetic counseling but also in a research context for the initiation of therapeutic trials. In this chapter, we will address all those issues and summarize the recent updates about clinical aspects of C9orf72 disease, focusing on both the common and the less typical phenotypes.
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Ramos EM, Dokuru DR, Van Berlo V, Wojta K, Wang Q, Huang AY, Miller ZA, Karydas AM, Bigio EH, Rogalski E, Weintraub S, Rader B, Miller BL, Gorno-Tempini ML, Mesulam MM, Coppola G. Genetic screen in a large series of patients with primary progressive aphasia. Alzheimers Dement 2019; 15:553-560. [PMID: 30599136 PMCID: PMC6480353 DOI: 10.1016/j.jalz.2018.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 10/05/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Primary progressive aphasia (PPA) is a neurological syndrome, associated with both frontotemporal dementia and Alzheimer's disease, in which progressive language impairment emerges as the most salient clinical feature during the initial stages of disease. METHODS We screened the main genes associated with Alzheimer's disease and frontotemporal dementia for pathogenic and risk variants in a cohort of 403 PPA cases. RESULTS In this case series study, 14 (3.5%) cases carried (likely) pathogenic variants: four C9orf72 expansions, nine GRN, and one TARDBP mutation. Rare risk variants, TREM2 R47H and MAPT A152T, were associated with a three- to seven-fold increase in risk for PPA. DISCUSSION Our results show that while pathogenic variants within the most common dementia genes were rarely associated with PPA, these were found almost exclusively in GRN and C9orf72, suggesting that PPA is more TDP43- than tau-related in our series. This is consistent with the finding that PPA frequency in dominantly inherited dementias is the highest in kindreds with GRN variants.
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Affiliation(s)
- Eliana Marisa Ramos
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Deepika Reddy Dokuru
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Victoria Van Berlo
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Kevin Wojta
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Qing Wang
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Alden Y Huang
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, USA
| | - Zachary A Miller
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Anna M Karydas
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Eileen H Bigio
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University, Chicago, IL, USA
| | - Emily Rogalski
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University, Chicago, IL, USA
| | - Sandra Weintraub
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University, Chicago, IL, USA
| | - Benjamin Rader
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University, Chicago, IL, USA
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Maria Luisa Gorno-Tempini
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Marek-Marsel Mesulam
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Northwestern University, Chicago, IL, USA
| | - Giovanni Coppola
- Department of Psychiatry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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Risacher SL, Saykin AJ. Neuroimaging in aging and neurologic diseases. HANDBOOK OF CLINICAL NEUROLOGY 2019; 167:191-227. [PMID: 31753134 DOI: 10.1016/b978-0-12-804766-8.00012-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Neuroimaging biomarkers for neurologic diseases are important tools, both for understanding pathology associated with cognitive and clinical symptoms and for differential diagnosis. This chapter explores neuroimaging measures, including structural and functional measures from magnetic resonance imaging (MRI) and molecular measures primarily from positron emission tomography (PET), in healthy aging adults and in a number of neurologic diseases. The spectrum covers neuroimaging measures from normal aging to a variety of dementias: late-onset Alzheimer's disease [AD; including mild cognitive impairment (MCI)], familial and nonfamilial early-onset AD, atypical AD syndromes, posterior cortical atrophy (PCA), logopenic aphasia (lvPPA), cerebral amyloid angiopathy (CAA), vascular dementia (VaD), sporadic and familial behavioral-variant frontotemporal dementia (bvFTD), semantic dementia (SD), progressive nonfluent aphasia (PNFA), frontotemporal dementia with motor neuron disease (FTD-MND), frontotemporal dementia with amyotrophic lateral sclerosis (FTD-ALS), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), Parkinson's disease (PD) with and without dementia, and multiple systems atrophy (MSA). We also include a discussion of the appropriate use criteria (AUC) for amyloid imaging and conclude with a discussion of differential diagnosis of neurologic dementia disorders in the context of neuroimaging.
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Affiliation(s)
- Shannon L Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States.
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Castelnovo V, Caminiti SP, Riva N, Magnani G, Silani V, Perani D. Heterogeneous brain FDG-PET metabolic patterns in patients with C9orf72 mutation. Neurol Sci 2018; 40:515-521. [PMID: 30554355 DOI: 10.1007/s10072-018-3685-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 12/10/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The hexanucleotide repeat expansion in C9orf72 is an associated genetic cause in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In the "ALS/FTD" spectrum prevails clinical heterogeneity and an in vivo knowledge of the underling brain dysfunction in patients carrying C9orf72 mutation remain limited and only described at group level. The study aimed to assess the brain metabolic alterations characterizing patients with C9orf72 mutation using FDG-PET in single individuals. METHODS We applied a validated statistical parametric mapping (SPM) voxel-based procedure for FDG-PET data to obtain maps of brain relative hypometabolism and hypermetabolism at single-subject level in six FTD/ALS patients carrying the C9orf72 mutation. RESULTS Clinical diagnoses classified the patients as right semantic variant of frontotemporal dementia (one case, C9svFTD), behavioral variant of frontotemporal dementia (two cases, C9bvFTD), and bulbar amyotrophic lateral sclerosis (three cases, C9bALS). The FDG-PET SPM revealed a prevalent frontal hypometabolism in C9bvFTD cases, and right temporal polar and lateral involvement in C9svFTD, consistent with the clinical diagnosis. There was a quite comparable occipital and cerebellar hypermetabolism in these cases. The three C9bALS patients showed variable patterns of hypo- and hypermetabolism. CONCLUSIONS The present work is the first in vivo FDG-PET study showing the heterogeneous patterns of brain regional hypo- and hypermetabolism in single patients sharing C9orf72 mutation. Brain hypometabolism was consistent with the clinical phenotypes, supporting the diagnostic importance of neuroimaging functional biomarkers to capture at single-subject level specific brain dysfunction.
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Affiliation(s)
- Veronica Castelnovo
- Vita-Salute San Raffaele University, Milan, Italy.,Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Silvia Paola Caminiti
- Vita-Salute San Raffaele University, Milan, Italy.,In vivo Structural and Molecular Neuroimaging Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Nilo Riva
- Department of Neurology, San Raffaele Hospital, Milan, Italy
| | | | - Vincenzo Silani
- Department of Neurology and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Milan, Italy.,Department of Pathophysiology and Transplantation, "Dino Ferrari" Center, Università degli Studi di Milano, Milan, Italy
| | - Daniela Perani
- Vita-Salute San Raffaele University, Milan, Italy. .,In vivo Structural and Molecular Neuroimaging Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy. .,Nuclear Medicine Unit, San Raffaele Hospital, Milan, Italy.
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Abstract
PURPOSE Primary progressive aphasia (PPA) is a neurological syndrome in which language functions become progressively impaired with relative sparing of memory and other instrumental functions. The pathologic causes of PPA are heterogeneous, but studies suggest that logopenic PPA (LPA) is underpinned by Alzheimer disease (AD) pathology in a high proportion of cases. The purposes of this descriptive and retrospective study were to characterize F-florbetapir PET imaging in a group of patients with a clinical syndrome of PPA, to determine the value of clinical characterization based on language phenotype in predicting the underlying pathology of PPA with F-florbetapir, and to quantify amyloid load in PPA subjects classified as "positive" F-florbetapir scans. Then, we compare the quantification and distribution of F-florbetapir uptake with those of typical, predominantly amnestic AD patients. METHODS We conducted a PET study with F-florbetapir in a cohort of 12 right-handed patients diagnosed with PPA: 3 patients with semantic-variant PPA, 5 with nonfluent PPA, 1 with LPA, and 3 unclassifiable patients. We evaluated amyloid deposition between APP groups and 11 patients with typical amnestic AD. RESULTS Among the 12 patients with PPA syndrome, 8 (66.7%) were considered as amyloid positive. One of the 3 patients with semantic-variant PPA was F-florbetapir positive. In contrast, 4 of the 5 nonfluent-variant PPA, 2 of the 3 unclassifiable cases and the single patient with LPA were F-florbetapir positive. A significantly higher F-florbetapir uptake was observed in PPA F-florbetapir-positive patients compared with typical AD patients. This difference was observed in all regions of interest, except in posterior cingulate and temporal cortex. CONCLUSIONS These results suggest that F-florbetapir PET may be useful in a routine clinical procedure to improve the reliability of identifying AD pathology in patients with PPA syndrome, with different clinical subtypes of the PPA syndrome.
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Pasanen P, Myllykangas L, Pöyhönen M, Kiviharju A, Siitonen M, Hardy J, Bras J, Paetau A, Tienari PJ, Guerreiro R, Verkkoniemi-Ahola A. Genetics of dementia in a Finnish cohort. Eur J Hum Genet 2018; 26:827-837. [PMID: 29476165 DOI: 10.1038/s41431-018-0117-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 12/03/2017] [Accepted: 02/01/2018] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the two most common neurodegenerative dementias. Variants in APP, PSEN1 and PSEN2 are typically linked to early-onset AD, and several genetic risk loci are associated with late-onset AD. Inherited FTD can be caused by hexanucleotide expansions in C9orf72, or variants in GRN, MAPT or CHMP2B. Several other genes have also been linked to FTD or FTD with motor neuron disease. Here we describe a cohort of 60 Finnish families with possible inherited dementia. Our aim was to clarify the genetic background of dementia in this cohort by analysing both known dementia-associated genes (APOE, APP, C9ORF72, GRN, PSEN1 and PSEN2) and searching for rare or novel segregating variants with exome sequencing. C9orf72 repeat expansions were detected in 12 (20%) of the 60 families, including, in addition to FTD, a family with neuropathologically verified AD. Twelve families (10 with AD and 2 with FTD) with representative samples from affected and unaffected subjects and without C9orf72 expansions were selected for whole-exome sequencing. Exome sequencing did not reveal any variants that could be regarded unequivocally causative, but revealed potentially damaging variants in UNC13C and MARCH4.
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Affiliation(s)
- Petra Pasanen
- Department of Medical Biochemistry and Genetics, Institute of Biomedicine, University of Turku, Turku, Finland. .,Tyks Genetics and Saske, Department of Medical Genetics, Turku University Hospital, Turku, Finland.
| | - Liisa Myllykangas
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Minna Pöyhönen
- Department of Clinical Genetics, Helsinki University Central Hospital, Helsinki, Finland.,Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| | - Anna Kiviharju
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Maija Siitonen
- Department of Medical Biochemistry and Genetics, Institute of Biomedicine, University of Turku, Turku, Finland
| | - John Hardy
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK
| | - Jose Bras
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute at UCL, London, UK.,Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Anders Paetau
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Pentti J Tienari
- Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland.,Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Rita Guerreiro
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute at UCL, London, UK.,Department of Medical Sciences and Institute of Biomedicine - iBiMED, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Auli Verkkoniemi-Ahola
- Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Chi S, Jiang T, Tan L, Yu JT. Distinct neurological disorders with C9orf72 mutations: genetics, pathogenesis, and therapy. Neurosci Biobehav Rev 2016; 66:127-42. [PMID: 27139021 DOI: 10.1016/j.neubiorev.2016.03.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 12/12/2022]
Abstract
The G4C2 repeat expansion within C9orf72 has been recently identified as the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. This mutation has also been detected in a variety of other neurological diseases with distinct clinical manifestations. The exact mechanisms of how this mutation leads to the wide spectrum of clinical syndromes remain unknown. A series of molecular changes together with some potential modifiers may play a key role. Nucleolar stress, nucleocytoplasmic transport defect, oxidative damage, inhibited stress granules assembly, activated endoplasmic reticulum stress, and inhibited proteasome activity are mechanisms that contribute to the pathogenesis of these diseases. Additional mutations, epigenetic modifiers, and repeat size are potential modifiers that modulate specific phenotypes on the basis of the molecular changes. Here, we summarize distinct C9orf72-related neurological disorders and their corresponding neuropathological changes. Then, we elucidate the existing molecular knowledge and the potential modifiers. Finally, we detail the main target of treatment aiming at controlling expanded RNA transcripts.
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Affiliation(s)
- Song Chi
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, China; Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China
| | - Teng Jiang
- Department of Neurology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Lan Tan
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China.
| | - Jin-Tai Yu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong, China.
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Rostgaard N, Waldemar G, Nielsen JE, Simonsen AH. Cerebrospinal Fluid Biomarkers in Familial Forms of Alzheimer's Disease and Frontotemporal Dementia. Dement Geriatr Cogn Disord 2016; 40:54-62. [PMID: 25998699 DOI: 10.1159/000381828] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/21/2015] [Indexed: 11/19/2022] Open
Abstract
As dementia is a fast-growing health care problem, it is becoming an increasingly urgent need to provide an early diagnosis in order to offer patients the best medical treatment and care. Validated biomarkers which reflect the pathology and disease progression are essential for diagnosis and are important when developing new therapies. Today, the core protein biomarkers amyloid-β42, total tau and phosphorylated tau in the cerebrospinal fluid (CSF) are used to diagnose Alzheimer's disease (AD), because these biomarkers have shown to reflect the underlying amyloid and tau pathology. However, the biomarkers have proved insufficient predictors of dementias with a different pathology, e.g. frontotemporal dementia (FTD); furthermore, the biomarkers are not useful for early AD diagnosis. Familial dementias with a known disease-causing mutation can be extremely valuable to study; yet the biomarker profiles in patients with familial dementias are not clear. This review summarizes CSF biomarker findings from studies on symptomatic and presymptomatic individuals carrying a mutation in one of the genes known to cause early-onset familial AD or FTD. In conclusion, the biomarker profile of inherited AD is quite similar between carriers of different mutations as well as similar to the profile found in sporadic AD, whereas familial FTD does not seem to have a clear biomarker profile. Hence, new biomarkers are needed for FTD.
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Affiliation(s)
- Nina Rostgaard
- Danish Dementia Research Centre, Department of Neurology, Section 6911, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Benussi A, Padovani A, Borroni B. Phenotypic Heterogeneity of Monogenic Frontotemporal Dementia. Front Aging Neurosci 2015; 7:171. [PMID: 26388768 PMCID: PMC4555036 DOI: 10.3389/fnagi.2015.00171] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 08/19/2015] [Indexed: 12/12/2022] Open
Abstract
Frontotemporal dementia (FTD) is a genetically and pathologically heterogeneous disorder characterized by personality changes, language impairment, and deficits of executive functions associated with frontal and temporal lobe degeneration. Different phenotypes have been defined on the basis of presenting clinical symptoms, i.e., the behavioral variant of FTD, the agrammatic variant of primary progressive aphasia, and the semantic variant of PPA. Some patients have an associated movement disorder, either parkinsonism, as in progressive supranuclear palsy and corticobasal syndrome, or motor neuron disease (FTD-MND). A family history of dementia is found in 40% of cases of FTD and about 10% have a clear autosomal-dominant inheritance. Genetic studies have identified several genes associated with monogenic FTD: microtubule-associated protein tau, progranulin, TAR DNA-binding protein 43, valosin-containing protein, charged multivesicular body protein 2B, fused in sarcoma, and the hexanucleotide repeat expansion in intron 1 of the chromosome 9 open reading frame 72. Patients often present with an extensive phenotypic variability, even among different members of the same kindred carrying an identical disease mutation. The objective of the present work is to review and evaluate available literature data in order to highlight recent advances in clinical, biological, and neuroimaging features of monogenic frontotemporal lobar degeneration and try to identify different mechanisms underlying the extreme phenotypic heterogeneity that characterizes this disease.
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Affiliation(s)
- Alberto Benussi
- Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Alessandro Padovani
- Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Barbara Borroni
- Centre for Ageing Brain and Neurodegenerative Disorders, Neurology Unit, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
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Le Ber I. Frontotemporal lobar dementia and amyotrophic lateral sclerosis associated with c9orf72 expansion. Rev Neurol (Paris) 2015; 171:475-81. [PMID: 26032484 DOI: 10.1016/j.neurol.2015.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 04/24/2015] [Accepted: 04/24/2015] [Indexed: 12/12/2022]
Abstract
An intronic GGGGCC repeat expansion in c9orf72 gene has been identified as the most common genetic cause of frontotemporal lobar dementia (FTLD), amyotrophic lateral sclerosis (ALS) and FTLD-ALS. The discovery of c9orf72 gene has led to important scientific progresses and has considerably changed our clinical practice over the last few years. This paper summarizes the common and less typical phenotypes associated with c9orf72 expansion, the complex pathological pattern characterized by p62/dipeptide repeat aggregates, as well as the pathological mechanisms by which the expansion might produce neurodegeneration implicating loss-of-function, RNA toxicity, RNA-binding protein sequestration and accumulation of dipeptide repeats. We also discuss the recommendations and limits for genetic testing and counseling in clinical practice.
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Affiliation(s)
- I Le Ber
- Institut du cerveau et de la moelle épinière (ICM), Inserm U1127, CNRS UMR 7225, Sorbonne Universités, Université Pierre-et-Marie-Curie, université Paris 06, UPMC-P6 UMR S 1127, hôpital Pitié-Salpêtrière, 75013 Paris, France; Centre de référence des rémences rares, hôpital de la Pitié-Salpêtrière, AP-HP, 75013 Paris, France; Département des maladies du système nerveux, hôpital de la Pitié-Salpêtrière, AP-HP, 75013 Paris, France.
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