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Tan YJ, Yong ACW, Foo JN, Lian MM, Lim WK, Dominguez J, Fong ZH, Narasimhalu K, Chiew HJ, Ng KP, Ting SKS, Kandiah N, Ng ASL. C9orf72 expansions are the most common cause of genetic frontotemporal dementia in a Southeast Asian cohort. Ann Clin Transl Neurol 2023; 10:568-578. [PMID: 36799407 PMCID: PMC10109321 DOI: 10.1002/acn3.51744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/18/2023] Open
Abstract
OBJECTIVE Frontotemporal dementia (FTD) encompasses a spectrum of neurodegenerative disorders, including behavioural variant FTD (bvFTD), semantic variant primary progressive aphasia (svPPA) and non-fluent variant PPA (nfvPPA). While a strong genetic component is implicated in FTD, genetic FTD in Asia is less frequently reported. We aimed to investigate the frequency of Southeast Asian FTD patients harbouring known genetic FTD variants. METHODS A total of 60 FTD-spectrum patients (25 familial and 35 sporadic) from Singapore and the Philippines were included. All underwent next-generation sequencing and repeat-primed PCR for C9orf72 expansion testing. Neurofilament light chain (NfL) levels were measured in a subset of patients. RESULTS Overall, 26.6% (16/60 cases) carried pathogenic or likely pathogenic variants in a FTD-related gene, including: MAPT Gln351Arg (n = 1); GRN Cys92Ter (n = 1), Ser301Ter (n = 2), c.462 + 1G > C (n = 1); C9orf72 expansion (35-70 repeats; n = 8); TREM2 Arg47Cys (n = 1); and OPTN frameshift insertion (n = 2). Genetic mutations accounted for 48% (12/25) of patients with familial FTD, and 11.4% (4/35) of patients with sporadic FTD. C9orf72 repeat expansions were the most common genetic mutation (13.3%, 8/60), followed by GRN (6.7%, 4/60) variants. Within mutation carriers, plasma NfL was highest in a C9orf72 expansion carrier, and CSF NfL was highest in a GRN splice variant carrier. INTERPRETATION In our cohort, genetic mutations are present in one-quarter of FTD-spectrum cases, and up to half of those with family history. Our findings highlight the importance of wider implementation of genetic testing in FTD patients from Southeast Asia.
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Affiliation(s)
- Yi Jayne Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Alisa C W Yong
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Jia Nee Foo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Human Genetics, Genome Institute of Singapore, A*STAR, Singapore, Singapore
| | - Michelle M Lian
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Weng Khong Lim
- Singhealth Duke-NUS Institute of Precision Medicine, Singapore, Singapore.,Cancer & Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore
| | | | - Zhi Hui Fong
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Kaavya Narasimhalu
- Singhealth Duke-NUS Institute of Precision Medicine, Singapore, Singapore.,Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore
| | - Hui Jin Chiew
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Kok Pin Ng
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Simon K S Ting
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore
| | - Nagaendran Kandiah
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Adeline S L Ng
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore.,Neuroscience and Behavioural Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
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Genetic landscape of early-onset dementia in Hungary. Neurol Sci 2022; 43:5289-5300. [PMID: 35752680 PMCID: PMC9385840 DOI: 10.1007/s10072-022-06168-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/24/2022] [Indexed: 10/31/2022]
Abstract
Abstract
Introduction
Early-onset dementias (EOD) are predominantly genetically determined, but the underlying disease-causing alterations are often unknown. The most frequent forms of EODs are early-onset Alzheimer’s disease (EOAD) and frontotemporal dementia (FTD).
Patients
This study included 120 Hungarian patients with EOD (48 familial and 72 sporadic) which had a diagnosis of EOAD (n = 49), FTD (n = 49), or atypical dementia (n = 22).
Results
Monogenic dementia was detected in 15.8% of the patients. A pathogenic hexanucleotide repeat expansion in the C9ORF72 gene was present in 6.7% of cases and disease-causing variants were detected in other known AD or FTD genes in 6.7% of cases (APP, PSEN1, PSEN2, GRN). A compound heterozygous alteration of the TREM2 gene was identified in one patient and heterozygous damaging variants in the CSF1R and PRNP genes were detected in two other cases. In two patients, the coexistence of several heterozygous damaging rare variants associated with neurodegeneration was detected (1.7%). The APOE genotype had a high odds ratio for both the APOE ɛ4/3 and the ɛ4/4 genotype (OR = 2.7 (95%CI = 1.3–5.9) and OR = 6.5 (95%CI = 1.4–29.2), respectively). In TREM2, SORL1, and ABCA7 genes, 5 different rare damaging variants were detected as genetic risk factors. These alterations were not present in the control group.
Conclusion
Based on our observations, a comprehensive, targeted panel of next-generation sequencing (NGS) testing investigating several neurodegeneration-associated genes may accelerate the path to achieve the proper genetic diagnosis since phenotypes are present on a spectrum. This can also reveal hidden correlations and overlaps in neurodegenerative diseases that would remain concealed in separated genetic testing.
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Dominguez J, Ng A, Yu J, Guevarra AC, Daroy ML, Alfon A, Catindig JA, Dizon M, Santiago J, Del Moral MC, Yu J, Jamerlan A, Ligsay A, Bagyinszky E, An SS, Kim S. Autosomal Dominant Frontotemporal Lobar Degeneration in a Filipino Family with Progranulin Mutation. Dement Geriatr Cogn Disord 2021; 49:557-564. [PMID: 33486486 DOI: 10.1159/000510106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/10/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Compared to Western populations, familial frontotemporal lobar degeneration (FTLD) is rare among Asians. Progranulin (GRN) gene mutation, which is a major cause of FTLD, is likewise rare. We present a family with FTLD from the Philippines with an autosomal dominant pattern of inheritance and GRN mutation and briefly review reports of GRN mutations in Asia. CASE PRESENTATION The proband is 66 years old with progressive nonfluent aphasia (PNFA)-corticobasal syndrome . We assessed 3 generations of her pedigree and found 11 affected relatives with heterogenous phenotypes, usually behavioral variant frontotemporal dementia (FTD) and PNFA. Neuroimaging showed atrophy and hypometabolism consistent with FTD syndromes. White matter hyperintensities were seen in affected members even in the absence of vascular risk factors. A GRN mutation R110X was found in 6 members, 3 with symptoms and 3 were asymptomatic. Plasma GRN was low (<112 ng/mL) in all mutation carriers. No mutations were found in microtubule-associated protein tau, APP, PSEN1, and PSEN2 genes, and all were APOE3. CONCLUSION This is the first Filipino family with autosomal dominant FTD documented with GRN mutation. Identifying families and cohorts would contribute to therapeutic developments in an area with FTD-GRN.
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Affiliation(s)
- Jacqueline Dominguez
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines,
| | - Arlene Ng
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Jeryl Yu
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Anne Cristine Guevarra
- Research and Biotechnology Division, St. Luke's Medical Center, Quezon City, Philippines
| | - Maria Luisa Daroy
- Research and Biotechnology Division, St. Luke's Medical Center, Quezon City, Philippines
| | - Alicia Alfon
- Research and Biotechnology Division, St. Luke's Medical Center, Quezon City, Philippines
| | - Joseree-Ann Catindig
- Memory Center-Institute for Neurosciences, St. Luke's Medical Center, Taguig City, Philippines
| | - Mercedes Dizon
- Institute of Radiology, St. Luke's Medical Center, Quezon City, Philippines
| | - Jonas Santiago
- PET Center, St. Luke's Medical Center, Quezon City, Philippines
| | | | - Justine Yu
- Memory Center-Institute for Neurosciences, St. Luke's Medical Center, Taguig City, Philippines
| | - Angelo Jamerlan
- Department of Bionano Technology, Gachon University, Seongnam, Republic of Korea
| | - Antonio Ligsay
- Section of Clinical Research, St. Luke's Medical Center - College of Medicine, Quezon City, Philippines
| | - Eva Bagyinszky
- Department of Industrial and Environmental Engineering, Gachon University, Seongnam, Republic of Korea
| | - Seong Soo An
- Department of Bionano Technology, Gachon University, Seongnam, Republic of Korea
| | - Sangyun Kim
- Department of Neurology, Seoul National University College of Medicine & Neurocognitive Behavior Center, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
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Duran-Aniotz C, Orellana P, Leon Rodriguez T, Henriquez F, Cabello V, Aguirre-Pinto MF, Escobedo T, Takada LT, Pina-Escudero SD, Lopez O, Yokoyama JS, Ibanez A, Parra MA, Slachevsky A. Systematic Review: Genetic, Neuroimaging, and Fluids Biomarkers for Frontotemporal Dementia Across Latin America Countries. Front Neurol 2021; 12:663407. [PMID: 34248820 PMCID: PMC8263937 DOI: 10.3389/fneur.2021.663407] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/27/2021] [Indexed: 11/13/2022] Open
Abstract
Frontotemporal dementia (FTD) includes a group of clinically, genetically, and pathologically heterogeneous neurodegenerative disorders, affecting the fronto-insular-temporal regions of the brain. Clinically, FTD is characterized by progressive deficits in behavior, executive function, and language and its diagnosis relies mainly on the clinical expertise of the physician/consensus group and the use of neuropsychological tests and/or structural/functional neuroimaging, depending on local availability. The modest correlation between clinical findings and FTD neuropathology makes the diagnosis difficult using clinical criteria and often leads to underdiagnosis or misdiagnosis, primarily due to lack of recognition or awareness of FTD as a disease and symptom overlap with psychiatric disorders. Despite advances in understanding the underlying neuropathology of FTD, accurate and sensitive diagnosis for this disease is still lacking. One of the major challenges is to improve diagnosis in FTD patients as early as possible. In this context, biomarkers have emerged as useful methods to provide and/or complement clinical diagnosis for this complex syndrome, although more evidence is needed to incorporate most of them into clinical practice. However, most biomarker studies have been performed using North American or European populations, with little representation of the Latin American and the Caribbean (LAC) region. In the LAC region, there are additional challenges, particularly the lack of awareness and knowledge about FTD, even in specialists. Also, LAC genetic heritage and cultures are complex, and both likely influence clinical presentations and may modify baseline biomarker levels. Even more, due to diagnostic delay, the clinical presentation might be further complicated by both neurological and psychiatric comorbidity, such as vascular brain damage, substance abuse, mood disorders, among others. This systematic review provides a brief update and an overview of the current knowledge on genetic, neuroimaging, and fluid biomarkers for FTD in LAC countries. Our review highlights the need for extensive research on biomarkers in FTD in LAC to contribute to a more comprehensive understanding of the disease and its associated biomarkers. Dementia research is certainly reduced in the LAC region, highlighting an urgent need for harmonized, innovative, and cross-regional studies with a global perspective across multiple areas of dementia knowledge.
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Affiliation(s)
- Claudia Duran-Aniotz
- Latin American Institute for Brain Health (BrainLat), Universidad Adolfo Ibanez, Santiago, Chile
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibanez, Santiago, Chile
| | - Paulina Orellana
- Latin American Institute for Brain Health (BrainLat), Universidad Adolfo Ibanez, Santiago, Chile
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibanez, Santiago, Chile
| | - Tomas Leon Rodriguez
- Trinity College, Global Brain Health Institute, Dublin, Ireland
- Memory and Neuropsychiatric Clinic (CMYN) Neurology Department, Hospital del Salvador and Faculty of Medicine, University of Chile, Santiago, Chile
| | - Fernando Henriquez
- Neuropsychology and Clinical Neuroscience Laboratory (LANNEC), Physiopathology Department - Institute of Biomedical Sciences (ICBM), Neuroscience and East Neuroscience Departments, Faculty of Medicine, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - Victoria Cabello
- Neuropsychology and Clinical Neuroscience Laboratory (LANNEC), Physiopathology Department - Institute of Biomedical Sciences (ICBM), Neuroscience and East Neuroscience Departments, Faculty of Medicine, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | | | - Tamara Escobedo
- Latin American Institute for Brain Health (BrainLat), Universidad Adolfo Ibanez, Santiago, Chile
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibanez, Santiago, Chile
| | - Leonel T. Takada
- Cognitive and Behavioral Neurology Unit - Department of Neurology, University of São Paulo, São Paulo, Brazil
| | - Stefanie D. Pina-Escudero
- Global Brain Health Institute (GBHI), University of California San Francisco (UCSF), San Francisco, CA, United States
- UCSF Department of Neurology, Memory and Aging Center, UCSF, San Francisco, CA, United States
| | - Oscar Lopez
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jennifer S. Yokoyama
- Global Brain Health Institute (GBHI), University of California San Francisco (UCSF), San Francisco, CA, United States
- UCSF Department of Neurology, Memory and Aging Center, UCSF, San Francisco, CA, United States
| | - Agustin Ibanez
- Latin American Institute for Brain Health (BrainLat), Universidad Adolfo Ibanez, Santiago, Chile
- Center for Social and Cognitive Neuroscience (CSCN), School of Psychology, Universidad Adolfo Ibanez, Santiago, Chile
- Trinity College, Global Brain Health Institute, Dublin, Ireland
- Global Brain Health Institute (GBHI), University of California San Francisco (UCSF), San Francisco, CA, United States
- Cognitive Neuroscience Center (CNC), Universidad de San Andrés, & National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
| | - Mario A. Parra
- School of Psychological Sciences and Health, University of Strathclyde, Glasgow, United Kingdom
| | - Andrea Slachevsky
- Memory and Neuropsychiatric Clinic (CMYN) Neurology Department, Hospital del Salvador and Faculty of Medicine, University of Chile, Santiago, Chile
- Neuropsychology and Clinical Neuroscience Laboratory (LANNEC), Physiopathology Department - Institute of Biomedical Sciences (ICBM), Neuroscience and East Neuroscience Departments, Faculty of Medicine, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
- Cognitive and Behavioral Neurology Unit - Department of Neurology, University of São Paulo, São Paulo, Brazil
- Department of Neurology and Psychiatry, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
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5
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Samanci B, Bilgiç B, Gelişin Ö, Tepgeç F, Guven G, Tüfekçioğlu Z, Alaylıoğlu M, Hanagasi HA, Gürvit H, Guerreiro R, Hardy J, Emre M. TREM2 variants as a possible cause of frontotemporal dementia with distinct neuroimaging features. Eur J Neurol 2021; 28:2603-2613. [PMID: 33969597 DOI: 10.1111/ene.14908] [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: 03/16/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Nasu-Hakola disease (NHD) is a rare, autosomal recessive disorder characterized by skeletal and neurological symptoms. Behavioral symptoms with cognitive impairment may mimic the behavioral variant of frontotemporal dementia (bvFTD) and other early-onset dementias. Our patients were analyzed and the literature was reviewed to delineate neurological and neuroimaging findings suggestive of NHD. METHOD Fourteen patients carrying a pathogenic mutation in the TREM2 gene were found in our database. Demographic, clinical, laboratory and radiological data were retrieved and analyzed. RESULTS The presenting clinical picture was behavioral changes with cognitive decline resembling bvFTD in all patients. The mean age was 37.1 ± 4.97 years and the mean duration of the disease was 8.9 ± 3.51 years. Only two patients had typical bone cysts. Seven patients had bilateral calcification of the basal ganglia in computed tomography of the brain. Magnetic resonance imaging of the brain revealed severe atrophy of the corpus callosum, enlargement of the ventricles, atrophy of the caudate nuclei and periventricular white matter changes in all patients. Symmetrical global atrophy of the brain mainly affecting frontoparietal and lateral temporal regions were observed in all cases, and 13 patients had atrophy of the hippocampus. Cerebrospinal fluid examination of 10 patients showed elevated protein levels in six and the presence of oligoclonal bands in four patients. CONCLUSION A combination of white matter changes, enlarged ventricles, atrophy of the caudate nuclei and thinning of the corpus callosum in magnetic resonance imaging strongly suggests NHD in patients with FTD syndrome. Molecular genetic analysis should be performed in suspected cases, and families should receive genetic counseling.
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Affiliation(s)
- Bedia Samanci
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Başar Bilgiç
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Özlem Gelişin
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Fatih Tepgeç
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Gamze Guven
- Department of Genetics, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Zeynep Tüfekçioğlu
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Merve Alaylıoğlu
- Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Hasmet A Hanagasi
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Hakan Gürvit
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Rita Guerreiro
- Center for Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - John Hardy
- Department of Neurodegenerative Disorders, Institute of Neurology, University College London, London, UK
| | - Murat Emre
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
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6
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Dominguez J, Yu JT, Tan YJ, Ng A, De Guzman MF, Natividad B, Daroy ML, Cano J, Yu J, Lian MM, Zeng L, Lim WK, Foo JN, Ng ASL. Novel Optineurin Frameshift Insertion in a Family With Frontotemporal Dementia and Parkinsonism Without Amyotrophic Lateral Sclerosis. Front Neurol 2021; 12:645913. [PMID: 34093394 PMCID: PMC8170397 DOI: 10.3389/fneur.2021.645913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/12/2021] [Indexed: 12/30/2022] Open
Abstract
Frontotemporal Dementia (FTD) is a common cause of Young Onset Dementia and has diverse clinical manifestations involving behavior, executive function, language and motor function, including parkinsonism. Up to 50% of FTD patients report a positive family history, supporting a strong genetic basis, particularly in cases with both FTD and amyotrophic lateral sclerosis (FTD-ALS). Mutations in three genes are associated with the majority of familial FTD (fFTD) cases - microtubule associated protein tau gene (MAPT), granulin precursor (GRN), and hexanucleotide repeat expansions in chromosome 9 open reading frame 72- SMCR8complex subunit (C9orf72) while mutations in other genes such as optineurin (OPTN) have rarely been reported. Mutations in OPTN have been reported mostly in familial and sporadic cases of ALS, or in rare cases of FTD-ALS, but not in association with pure or predominant FTD and/or parkinsonian phenotype. Here, we report for the first time, a family from the Philippines with four members harboring a novel frameshift insertion at OPTN (Chr 10:13166090 G>GA) p.Lys328GluTer11, three of whom presented with FTD-related phenotypes. Additionally, one sibling heterozygous for the frameshift insertion had a predominantly parkinsonian phenotype resembling corticobasal syndrome, but it remains to be determined if this phenotype is related to the frameshift insertion. Notably, none of the affected members showed any evidence of motor neuron disease or ALS at the time of writing, both clinically and on electrophysiological testing, expanding the phenotypic spectrum of OPTN mutations. Close follow-up of mutation carriers for the development of new clinical features and wider investigation of additional family members with further genetic analyses will be conducted to investigate the possibility of other genetic modifiers in this family which could explain phenotypic heterogeneity.
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Affiliation(s)
- Jacqueline Dominguez
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Jeryl Tan Yu
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Yi Jayne Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - Arlene Ng
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Ma Fe De Guzman
- Research and Biotechnology Division, St Luke's Medical Centre, Quezon, Philippines
| | - Boots Natividad
- Research and Biotechnology Division, St Luke's Medical Centre, Quezon, Philippines
| | - Ma Luisa Daroy
- Research and Biotechnology Division, St Luke's Medical Centre, Quezon, Philippines
| | - Jemellee Cano
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Justine Yu
- Institute for Neurosciences, St. Luke's Medical Center, Quezon City, Philippines
| | - Michelle M Lian
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Li Zeng
- Neural Stem Cell Research Lab, Research Department, National Neuroscience Institute, Singapore, Singapore.,Neuroscience and Behavioural Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
| | - Weng Khong Lim
- Singhealth Duke-NUS Institute of Precision Medicine, Singapore, Singapore.,Cancer & Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore
| | - Jia Nee Foo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Human Genetics, Genome Institute of Singapore, ASTAR, Singapore, Singapore
| | - Adeline S L Ng
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore.,Neuroscience and Behavioural Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
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7
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The Role of White Matter Dysfunction and Leukoencephalopathy/Leukodystrophy Genes in the Aetiology of Frontotemporal Dementias: Implications for Novel Approaches to Therapeutics. Int J Mol Sci 2021; 22:ijms22052541. [PMID: 33802612 PMCID: PMC7961524 DOI: 10.3390/ijms22052541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/22/2021] [Accepted: 03/01/2021] [Indexed: 01/01/2023] Open
Abstract
Frontotemporal dementia (FTD) is a common cause of presenile dementia and is characterized by behavioural and/or language changes and progressive cognitive deficits. Genetics is an important component in the aetiology of FTD, with positive family history of dementia reported for 40% of cases. This review synthesizes current knowledge of the known major FTD genes, including C9orf72 (chromosome 9 open reading frame 72), MAPT (microtubule-associated protein tau) and GRN (granulin), and their impact on neuronal and glial pathology. Further, evidence for white matter dysfunction in the aetiology of FTD and the clinical, neuroimaging and genetic overlap between FTD and leukodystrophy/leukoencephalopathy are discussed. The review highlights the role of common variants and mutations in genes such as CSF1R (colony-stimulating factor 1 receptor), CYP27A1 (cytochrome P450 family 27 subfamily A member 1), TREM2 (triggering receptor expressed on myeloid cells 2) and TMEM106B (transmembrane protein 106B) that play an integral role in microglia and oligodendrocyte function. Finally, pharmacological and non-pharmacological approaches for enhancing remyelination are discussed in terms of future treatments of FTD.
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8
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A novel homozygous mutation in TREM2 found in a Chinese early-onset dementia family with mild bone involvement. Neurobiol Aging 2020; 86:201.e1-201.e7. [DOI: 10.1016/j.neurobiolaging.2019.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 12/12/2018] [Accepted: 01/12/2019] [Indexed: 12/15/2022]
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9
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Dean HB, Roberson ED, Song Y. Neurodegenerative Disease-Associated Variants in TREM2 Destabilize the Apical Ligand-Binding Region of the Immunoglobulin Domain. Front Neurol 2019; 10:1252. [PMID: 32021611 PMCID: PMC6985895 DOI: 10.3389/fneur.2019.01252] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/11/2019] [Indexed: 01/22/2023] Open
Abstract
Single nucleotide variations in Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) have been linked to both late-onset Alzheimer's disease and behavioral variant frontotemporal dementia (FTD), the latter presenting either in isolation or with cystic bone lesions in a condition called Nasu-Hakola disease. Models of the extracellular domain of TREM2 show that Nasu-Hakola disease-associated mutations are grossly inactivating by truncation, frameshift, or unfolding, that Alzheimer's disease (AD)-associated variants localize to a putative ligand-interacting region (PLIR) on the extracellular surface, and that FTD-associated variants are found in the hydrophobic core. However, while these disease-associated residues are predicted to play some role in disrupting ligand binding to the extracellular domain of TREM2, how they ultimately lead to disease remains unknown. Here, we used in silico molecular modeling to investigate all-atom models of TREM2 and characterize the effects on conformation and dynamical motion of AD-associated R47H and R62H as well as FTD-associated T96K, D86V, and T66M variants compared to the benign N68K variant and the common variant. Our model, which is based on a published 2.2 Å resolution crystal structure of the TREM2 extracellular domain, finds that both AD- and FTD-associated variants cause localized instability in three loops adjacent to the PLIR that correspond to the complementarity-determining regions (CDRs) of antibodies. This instability ultimately disrupts tethering between these CDRs and the core of the immunoglobulin domain, exposing a group of otherwise-buried, negatively charged residues. This instability and exposure of negatively charged residues is most severe following introduction of the T66M variant that has been described as causing FTD even in the heterozygous state and is less severe following introduction of variants that are less strongly tied to FTD or of those associated with AD. Thus, our results provide further evidence that the proposed loss-of-function caused by neurodegenerative disease-associated variants may be driven by altered conformational stability of the ligand-interacting CDR and, ultimately, loss of affinity or specificity for TREM2 ligands.
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Affiliation(s)
- Hunter B Dean
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States.,Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States.,Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, United States.,Alzheimer's Disease Center, University of Alabama at Birmingham, Birmingham, AL, United States.,Medical Scientist Training Program, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Erik D Roberson
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States.,Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, United States.,Alzheimer's Disease Center, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Yuhua Song
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, United States
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Ciani M, Benussi L, Bonvicini C, Ghidoni R. Genome Wide Association Study and Next Generation Sequencing: A Glimmer of Light Toward New Possible Horizons in Frontotemporal Dementia Research. Front Neurosci 2019; 13:506. [PMID: 31156380 PMCID: PMC6532367 DOI: 10.3389/fnins.2019.00506] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/02/2019] [Indexed: 12/12/2022] Open
Abstract
Frontotemporal Dementia (FTD) is a focal neurodegenerative disease, with a strong genetic background, that causes early onset dementia. The present knowledge about the risk loci and causative mutations of FTD mainly derives from genetic linkage analysis, studies of candidate genes, Genome-Wide Association Studies (GWAS) and Next-Generation Sequencing (NGS) applications. In this review, we report recent insights into the genetics of FTD, and, specifically, the results achieved thanks to GWAS and NGS approaches. Linkage studies of large FTD pedigrees have prompted the identification of causal mutations in different genes: mutations in C9orf72, MAPT, and GRN genes explain the large majority of cases with a high family history of the disease. In cases with a less clear inheritance, GWAS and NGS have contributed to further understand the genetic picture of FTD. GWAS identified several common genetic variants with a modest risk effect. Of interest, many of these variants are in genes belonging to the endo-lysosomal pathway, the immune response and neuronal survival. On the opposite, the NGS approach allowed the identification of rare variants with a strong risk effect. These variants were identified in known FTD-associated genes and again in genes involved in the endo-lysosomal pathway and in the immune response. Interestingly, both approaches demonstrated that several genes are associated to multiple neurodegenerative disorders including FTD. Thanks to these complementary approaches, the genetic picture of FTD is becoming more clear and novel key molecular processes are emerging. This will foster opportunities to move toward prevention and therapy for this incurable disease.
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Affiliation(s)
- Miriam Ciani
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.,Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Luisa Benussi
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Cristian Bonvicini
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Roberta Ghidoni
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
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Abstract
Purpose of review In this review we highlight recent advances in the human genetics of frontotemporal dementia (FTD). In addition to providing a broad survey of genes implicated in FTD in the last several years, we also discuss variation in genes implicated in both hereditary leukodystrophies and risk for FTD (e.g., TREM2, TMEM106B, CSF1R, AARS2, NOTCH3). Recent findings Over the past five years, genetic variation in approximately 50 genes has been confirmed or suggested to cause or influence risk for FTD and FTD-spectrum disorders. We first give background and discuss recent findings related to C9ORF72, GRN and MAPT, the genes most commonly implicated in FTD. We then provide a broad overview of other FTD-associated genes and go on to discuss new findings in FTD genetics in East Asian populations, including pathogenic variation in CHCHD10, which may represent a frequent cause of disease in Chinese populations. Finally, we consider recent insights gleaned from genome-wide association and genetic pleiotropy studies. Summary Recent genetic discoveries highlight cellular pathways involving autophagy, the endolysosomal system and neuroinflammation, and reveal an intriguing overlap between genes that confer risk for leukodystrophy and FTD.
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The role of TREM2 in Alzheimer's disease and other neurodegenerative disorders. Lancet Neurol 2018; 17:721-730. [PMID: 30033062 DOI: 10.1016/s1474-4422(18)30232-1] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is a genetically complex disorder; rare variants in the triggering receptor expressed on myeloid cells 2 (TREM2) gene have been shown to as much as triple an individual's risk of developing Alzheimer's disease. TREM2 is a transmembrane receptor expressed in cells of the myeloid lineage, and its association with Alzheimer's disease supports the involvement of immune and inflammatory pathways in the cause of the disease, rather than as a consequence of the disease. TREM2 variants associated with Alzheimer's disease induce partial loss of function of the TREM2 protein and alter the behaviour of microglial cells, including their response to amyloid plaques. TREM2 variants have also been shown to cause polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy and frontotemporal dementia. Although the low frequency of TREM2 variants makes it difficult to establish robust genotype-phenotype correlations, such studies are essential to enable a comprehensive understanding of the role of TREM2 in different neurological diseases, with the ultimate goal of developing novel therapeutic approaches.
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