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Pengo M, Squitieri F. Beyond CAG Repeats: The Multifaceted Role of Genetics in Huntington Disease. Genes (Basel) 2024; 15:807. [PMID: 38927742 PMCID: PMC11203031 DOI: 10.3390/genes15060807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/11/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG expansion on the huntingtin (HTT) gene and is characterized by progressive motor, cognitive, and neuropsychiatric decline. Recently, new genetic factors besides CAG repeats have been implicated in the disease pathogenesis. Most genetic modifiers are involved in DNA repair pathways and, as the cause of the loss of CAA interruption in the HTT gene, they exert their main influence through somatic expansion. However, this mechanism might not be the only driver of HD pathogenesis, and future studies are warranted in this field. The aim of the present review is to dissect the many faces of genetics in HD pathogenesis, from cis- and trans-acting genetic modifiers to RNA toxicity, mitochondrial DNA mutations, and epigenetics factors. Exploring genetic modifiers of HD onset and progression appears crucial to elucidate not only disease pathogenesis, but also to improve disease prediction and prevention, develop biomarkers of disease progression and response to therapies, and recognize new therapeutic opportunities. Since the same genetic mechanisms are also described in other repeat expansion diseases, their implications might encompass the whole spectrum of these disorders.
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Affiliation(s)
- Marta Pengo
- Department of Molecular and Translational Medicine, University of Brescia, 25121 Brescia, Italy;
| | - Ferdinando Squitieri
- Centre for Neurological Rare Diseases (CMNR), Fondazione Lega Italiana Ricerca Huntington (LIRH), 00161 Rome, Italy
- Huntington and Rare Diseases Unit, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
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Novy C, Busk ØL, Tysnes OB, Landa SS, Aanjesen TN, Alstadhaug KB, Bjerknes TL, Bjørnå IK, Bråthen G, Dahl E, Demic N, Fahlström M, Flemmen HØ, Hallerstig E, HogenEsch I, Kampman MT, Kleveland G, Kvernmo HB, Ljøstad U, Maniaol A, Morsund AH, Nakken O, Olsen CG, Schlüter K, Utvik MS, Yaseen R, Holla ØL, Holmøy T, Høyer H. Repeat expansions in AR, ATXN1, ATXN2 and HTT in Norwegian patients diagnosed with amyotrophic lateral sclerosis. Brain Commun 2024; 6:fcae087. [PMID: 38585669 PMCID: PMC10998343 DOI: 10.1093/braincomms/fcae087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/23/2024] [Accepted: 03/12/2024] [Indexed: 04/09/2024] Open
Abstract
Genetic repeat expansions cause neuronal degeneration in amyotrophic lateral sclerosis as well as other neurodegenerative disorders such as spinocerebellar ataxia, Huntington's disease and Kennedy's disease. Repeat expansions in the same gene can cause multiple clinical phenotypes. We aimed to characterize repeat expansions in a Norwegian amyotrophic lateral sclerosis cohort. Norwegian amyotrophic lateral sclerosis patients (n = 414) and neurologically healthy controls adjusted for age and gender (n = 713) were investigated for repeat expansions in AR, ATXN1, ATXN2 and HTT using short read exome sequencing and the ExpansionHunter software. Five amyotrophic lateral sclerosis patients (1.2%) and two controls (0.3%) carried ≥36 repeats in HTT (P = 0.032), and seven amyotrophic lateral sclerosis patients (1.7%) and three controls (0.4%) carried ≥29 repeats in ATXN2 (P = 0.038). One male diagnosed with amyotrophic lateral sclerosis carried a pathogenic repeat expansion in AR, and his diagnosis was revised to Kennedy's disease. In ATXN1, 50 amyotrophic lateral sclerosis patients (12.1%) and 96 controls (13.5%) carried ≥33 repeats (P = 0.753). None of the patients with repeat expansions in ATXN2 or HTT had signs of Huntington's disease or spinocerebellar ataxia type 2, based on a re-evaluation of medical records. The diagnosis of amyotrophic lateral sclerosis was confirmed in all patients, with the exception of one patient who had primary lateral sclerosis. Our findings indicate that repeat expansions in HTT and ATXN2 are associated with increased likelihood of developing amyotrophic lateral sclerosis. Further studies are required to investigate the potential relationship between HTT repeat expansions and amyotrophic lateral sclerosis.
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Affiliation(s)
- Camilla Novy
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
| | - Øyvind L Busk
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Ole-Bjørn Tysnes
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, 5009 Bergen, Norway
| | - Sigve S Landa
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Tori N Aanjesen
- Department of Neurology, Akershus University Hospital, 1478 Lørenskog, Norway
| | | | - Tale L Bjerknes
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, 5009 Bergen, Norway
- Institute of Clinical Medicine, University of Bergen, 5007 Bergen, Norway
| | - Ingrid K Bjørnå
- Department of Neurology, Vestre Viken Hospital Trust, 3004 Drammen, Norway
| | - Geir Bråthen
- Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim University Hospital, 7030 Trondheim, Norway
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, 7034 Trondheim, Norway
| | - Elin Dahl
- Department of Neurology, Telemark Hospital Trust, 3710 Skien, Norway
| | - Natasha Demic
- Department of Neurology, Vestfold Hospital Trust, 3103 Tønsberg, Norway
| | - Maria Fahlström
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Heidi Ø Flemmen
- Department of Neurology, Telemark Hospital Trust, 3710 Skien, Norway
| | - Erika Hallerstig
- Department of Neurology, Østfold Hospital Trust, 1714 Grålum, Norway
| | - Ineke HogenEsch
- Department of Neurology, Fonna Hospital Trust, 5528 Haugesund, Norway
| | - Margitta T Kampman
- Department of Neurology, University Hospital of North Norway, 9019 Tromsø, Norway
| | - Grethe Kleveland
- Department of Neurology, Innlandet Hospital Trust, 2609 Lillehammer, Norway
| | - Helene B Kvernmo
- Department of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim University Hospital, 7030 Trondheim, Norway
- Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, 7034 Trondheim, Norway
| | - Unn Ljøstad
- Institute of Clinical Medicine, University of Bergen, 5007 Bergen, Norway
- Department of Neurology, Sørlandet Hospital Trust, 4615 Kristiansand, Norway
| | - Angelina Maniaol
- Department of Neurology, Oslo University Hospital, 0450 Oslo, Norway
| | | | - Ola Nakken
- Department of Neurology, Akershus University Hospital, 1478 Lørenskog, Norway
| | - Cathrine G Olsen
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
| | - Katrin Schlüter
- Department of Neurology, Stavanger University Hospital, 4019 Stavanger, Norway
| | - May-Sissel Utvik
- Department of Neurology, Namsos Hospital Trust, 7803 Namsos, Norway
| | - Ryaz Yaseen
- Department of Neurology, Oslo University Hospital, 0450 Oslo, Norway
| | - Øystein L Holla
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Trygve Holmøy
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway
- Department of Neurology, Akershus University Hospital, 1478 Lørenskog, Norway
| | - Helle Høyer
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
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Solís-Añez E, Salles PA, Rojas N, Benavides O, Chaná-Cuevas P. Huntington's Disease in Chile: Epidemiological and Genetic Aspects. Neuroepidemiology 2023; 57:176-184. [PMID: 37121230 DOI: 10.1159/000528961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 12/20/2022] [Indexed: 05/02/2023] Open
Abstract
INTRODUCTION Huntington's disease (HD) is a neurodegenerative, autosomal dominant disabling condition due to an expansion of the CAG trinucleotide in the HTT gene. Motor, psychiatric, and cognitive disorders characterize it. Chilean reports on HD in the era of molecular diagnosis were wanted. METHODS This is a retrospective analysis of a prospective cohort of patients with HD seen at the Center for Movement Disorders (CETRAM) in Chile between 2013 and 2019. Sociodemographic, genotype, and neuropsychiatric features were investigated. RESULTS One hundred three probands with HD were identified. The majority (63.1%) were born in the metropolitan region, followed by the VIII and V regions with 8.73% and 7.76%, respectively. When pedigrees were analyzed, ninety unrelated families encompassing 1,007 individuals were identified; among relatives, other 35 manifested HD, and 106 died of HD. Besides, five hundred seventy-nine individuals were at genetic risk. The minimum estimated prevalence of HD in Chile in 2019 was 0.72 × 100,000 inhabitants. The mean CAG repeats (CAGR) of 47.2 ± 10.74 for the expanded allele and 17.93 ± 2.05 for the normal allele. The mean age of onset was 41.39 ± 13.47 years. Juvenile cases represented 7.8% of this cohort, and 4.9% had a late onset. There was a negative correlation between the age of onset and the CAGR of the expanded allele (r =-0.84 p < 0.0001). Besides, 79.6% had a family history of HD. CONCLUSIONS This is the first report characterizing genetics, motor, and neuropsychiatric features in patients with HD in Chile. The mean length of CAGR expansion of the abnormal allele was similar to previous reports in North America (i.e., Mexico and Canada) and higher than that reported in the neighboring country of Argentina. According to previous estimations, the minimal prevalence of HD in Chile may be lower than expected.
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Affiliation(s)
| | - Philippe A Salles
- Center for Movement Disorders CETRAM, University of Santiago de Chile, Santiago, Chile,
| | - Natalia Rojas
- Center for Movement Disorders CETRAM, University of Santiago de Chile, Santiago, Chile
| | - Olga Benavides
- Neurology Department, Dr. Eloisa Díaz La Florida Metropolitan Hospital, Santiago, Chile
| | - Pedro Chaná-Cuevas
- Center for Movement Disorders CETRAM, University of Santiago de Chile, Santiago, Chile
- Faculty of Medical Sciences, University of Santiago de Chile, Santiago, Chile
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Palaiogeorgou AM, Papakonstantinou E, Golfinopoulou R, Sigala M, Mitsis T, Papageorgiou L, Diakou I, Pierouli K, Dragoumani K, Spandidos DA, Bacopoulou F, Chrousos GP, Eliopoulos E, Vlachakis D. Recent approaches on Huntington's disease (Review). Biomed Rep 2022; 18:5. [PMID: 36544856 PMCID: PMC9756286 DOI: 10.3892/br.2022.1587] [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: 08/14/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder characterized by severe motor, cognitive and psychiatric symptoms. Patients of all ages can present with a dysfunction of the nervous system, which leads to the progressive loss of movement control and disabilities in speech, swallowing, communications, etc. The molecular basis of the disease is well-known, as HD is related to a mutated gene, a trinucleotide expansion, which encodes to the huntingtin protein. This protein is linked to neurogenesis and the loss of its function leads to neurodegenerative disorders. Although the genetic cause of the disorder has been known for decades, no effective treatment is yet available to prevent onset or to eliminate the progression of symptoms. Thus, the present review focused on the development of novel methods for the timely and accurate diagnosis of HD in an aim to aid the development of therapies which may reduce the severity of the symptoms and control their progression. The majority of the therapies include gene-silencing mechanisms of the mutated huntingtin gene aiming to suppress its expression, and the use of various substances as drugs with highly promising results. In the present review, the latest approaches on the diagnosis of HD are discussed along with the need for genetic counseling and an up-to-date presentation of the applied treatments.
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Affiliation(s)
- Anastasia Marina Palaiogeorgou
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Eleni Papakonstantinou
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Rebecca Golfinopoulou
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Markezina Sigala
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Thanasis Mitsis
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Louis Papageorgiou
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Io Diakou
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Katerina Pierouli
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Konstantina Dragoumani
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Flora Bacopoulou
- University Research Institute of Maternal and Child Health and Precision Medicine, and UNESCO Chair on Adolescent Health Care, National and Kapodistrian University of Athens, ‘Aghia Sophia’ Children's Hospital, 11527 Athens, Greece
| | - George P. Chrousos
- University Research Institute of Maternal and Child Health and Precision Medicine, and UNESCO Chair on Adolescent Health Care, National and Kapodistrian University of Athens, ‘Aghia Sophia’ Children's Hospital, 11527 Athens, Greece
| | - Elias Eliopoulos
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Dimitrios Vlachakis
- Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece,University Research Institute of Maternal and Child Health and Precision Medicine, and UNESCO Chair on Adolescent Health Care, National and Kapodistrian University of Athens, ‘Aghia Sophia’ Children's Hospital, 11527 Athens, Greece,Division of Endocrinology and Metabolism, Center of Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece,Correspondence to: Dr Dimitrios Vlachakis, Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece
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Rocha NP, Charron O, Colpo GD, Latham LB, Patino JE, Stimming EF, Freeman L, Teixeira AL. Cerebral blood flow is associated with markers of neurodegeneration in Huntington’s disease. Parkinsonism Relat Disord 2022; 102:79-85. [DOI: 10.1016/j.parkreldis.2022.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 07/21/2022] [Accepted: 07/30/2022] [Indexed: 10/16/2022]
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Karwacka M, Olejniczak M. Advances in Modeling Polyglutamine Diseases Using Genome Editing Tools. Cells 2022; 11:cells11030517. [PMID: 35159326 PMCID: PMC8834129 DOI: 10.3390/cells11030517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 11/18/2022] Open
Abstract
Polyglutamine (polyQ) diseases, including Huntington’s disease, are a group of late-onset progressive neurological disorders caused by CAG repeat expansions. Although recently, many studies have investigated the pathological features and development of polyQ diseases, many questions remain unanswered. The advancement of new gene-editing technologies, especially the CRISPR-Cas9 technique, has undeniable value for the generation of relevant polyQ models, which substantially support the research process. Here, we review how these tools have been used to correct disease-causing mutations or create isogenic cell lines with different numbers of CAG repeats. We characterize various cellular models such as HEK 293 cells, patient-derived fibroblasts, human embryonic stem cells (hESCs), induced pluripotent stem cells (iPSCs) and animal models generated with the use of genome-editing technology.
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Nikitina M, Bragina E, Nazarenko M, Alifirova V. The role of alleles with an intermediate number of trinucleotide repeats in Parkinson’s disease and other neurodegenerative disorders. Zh Nevrol Psikhiatr Im S S Korsakova 2022; 122:42-50. [DOI: 10.17116/jnevro202212207142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Islam J, So KH, Kc E, Moon HC, Kim A, Hyun SH, Kim S, Park YS. Transplantation of human embryonic stem cells alleviates motor dysfunction in AAV2-Htt171-82Q transfected rat model of Huntington's disease. Stem Cell Res Ther 2021; 12:585. [PMID: 34809707 PMCID: PMC8607638 DOI: 10.1186/s13287-021-02653-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Human embryonic stem cells (hESCs) transplantation had shown to provide a potential source of cells in neurodegenerative disease studies and lead to behavioral recovery in lentivirus transfected or, toxin-induced Huntington's disease (HD) rodent model. Here, we aimed to observe if transplantation of superparamagnetic iron oxide nanoparticle (SPION)-labeled hESCs could migrate in the neural degenerated area and improve motor dysfunction in an AAV2-Htt171-82Q transfected Huntington rat model. METHODS All animals were randomly allocated into three groups at first: HD group, sham group, and control group. After six weeks, the animals of the HD group and sham group were again divided into two subgroups depending on animals receiving either ipsilateral or contralateral hESCs transplantation. We performed cylinder test and stepping test every two weeks after AAV2-Htt171-82Q injection and hESCs transplantation. Stem cell tracking was performed once per two weeks using T2 and T2*-weighted images at 4.7 Tesla MRI. We also performed immunohistochemistry and immunofluorescence staining to detect the presence of hESCs markers, huntingtin protein aggregations, and iron in the striatum. RESULTS After hESCs transplantation, the Htt virus-injected rats exhibited significant behavioral improvement in behavioral tests. SPION labeled hESCs showed migration with hypointense signal in MRI. The cells were positive with βIII-tubulin, GABA, and DARPP32. CONCLUSION Collectively, our results suggested that hESCs transplantation can be a potential treatment for motor dysfunction of Huntington's disease.
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Affiliation(s)
- Jaisan Islam
- Department of Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Kyoung Ha So
- Institute for Stem Cell & Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Elina Kc
- Department of Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyeong Cheol Moon
- Department of Neurosurgery, Gammaknife Icon Center, Chungbuk National University Hospital, Cheongju, Republic of Korea
| | - Aryun Kim
- Department of Neurology, Chungbuk National University Hospital, Cheongju, Republic of Korea
| | - Sang Hwan Hyun
- Institute for Stem Cell & Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
- Laboratory of Veterinary Embryology and Biotechnology (VETEMBIO), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Soochong Kim
- Institute for Stem Cell & Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea
| | - Young Seok Park
- Department of Neuroscience, College of Medicine, Chungbuk National University, Cheongju, Republic of Korea.
- Institute for Stem Cell & Regenerative Medicine (ISCRM), College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
- Department of Neurosurgery, Gammaknife Icon Center, Chungbuk National University Hospital, Cheongju, Republic of Korea.
- Department of Neurosurgery, Chungbuk National University Hospital, College of Medicine, Chungbuk National University, 776, 1 Sunhwanro, Seowon-gu, Cheongju-si, Chungbuk, 28644, Republic of Korea.
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Huntington's disease: lessons from prion disorders. J Neurol 2021; 268:3493-3504. [PMID: 33625583 DOI: 10.1007/s00415-021-10418-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
Decades of research on the prion protein and its associated diseases have caused a paradigm shift in our understanding of infectious agents. More recent years have been marked by a surge of studies supporting the application of these findings to a broad array of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Here, we present evidence to suggest that Huntington's disease, a monogenic disorder of the central nervous system, shares features with prion disorders and that, it too, may be governed by similar mechanisms. We further posit that these similarities could suggest that, like other common neurodegenerative disorders, sporadic forms of Huntington's disease may exist.
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Despotov K, Zádori D, Veres G, Jakab K, Gárdián G, Tóth E, Kincses TZ, Vécsei L, Ajtay A, Bereczki D, Klivényi P. Genetic epidemiological characteristics of a Hungarian subpopulation of patients with Huntington's disease. BMC Neurol 2021; 21:79. [PMID: 33602179 PMCID: PMC7890867 DOI: 10.1186/s12883-021-02089-9] [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: 07/03/2020] [Accepted: 02/02/2021] [Indexed: 11/22/2022] Open
Abstract
Background Recent advances in therapeutic options may prevent deterioration related to Huntington’s disease (HD), even at the pre-symptomatic stage. Be that as it may, a well-characterized patient population is essential for screening and monitoring outcome. Accordingly, the aim of this study was to describe the characteristics of a Hungarian subpopulation of HD patients and mutation carriers diagnosed at the University of Szeged. Methods We conducted a search for International Classification of Diseases (ICD) code G10H0 in the local medical database for the period of 1 January 1998 to 31 December 2018. Results We identified 90 HD cases (male: 45, female: 45) and 34 asymptomatic carriers (male: 15, female: 19). The median age of onset was 45 years (range: 16–79). There were 3 cases of juvenile onset (3.3%), and 7 of late disease onset (7.8%). The median repeat length was 43 (range: 36–70) for the pathological and 19 for the non-pathological alleles (range: 9–35). 17.5% of the pathological alleles were in the decreased penetrance range, while 7% of non-pathological alleles were intermediate. Conclusions The genetic and clinical features of the population examined in the present study were in line with the previous Hungarian study, as well as with international literature. The exceptions were the higher ratio of reduced penetrance and intermediate alleles. Supplementary Information The online version contains supplementary material available at 10.1186/s12883-021-02089-9.
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Affiliation(s)
- Katalin Despotov
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Dénes Zádori
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Gábor Veres
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Katalin Jakab
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Gabriella Gárdián
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Eszter Tóth
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - Tamás Zsigmond Kincses
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - László Vécsei
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary
| | - András Ajtay
- Department of Neurology, Semmelweis University, Budapest, Hungary.,MTA-SE Neuroepidemiological Research Group, Budapest, Hungary
| | - Dániel Bereczki
- Department of Neurology, Semmelweis University, Budapest, Hungary.,MTA-SE Neuroepidemiological Research Group, Budapest, Hungary
| | - Péter Klivényi
- Department of Neurology, University of Szeged, 6 Semmelweis Street, Szeged, 6725, Hungary.
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Frequency of the loss of CAA interruption in the HTT CAG tract and implications for Huntington disease in the reduced penetrance range. Genet Med 2020; 22:2108-2113. [PMID: 32741964 PMCID: PMC7708297 DOI: 10.1038/s41436-020-0917-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 11/27/2022] Open
Abstract
Purpose In some Huntington disease (HD) patients, the “loss of interruption” (LOI) variant eliminates an interrupting codon in the HTT CAG-repeat tract, which causes earlier age of onset (AOO). The magnitude of this effect is uncertain, since previous studies included few LOI carriers, and the variant also causes CAG size misestimation. We developed a rapid LOI detection screen, enabling unbiased frequency estimation among manifest HD patients. Additionally, we combined published data with clinical data from newly identified patients to accurately characterize the LOI’s effect on AOO. Methods We developed a LOI detection polymerase chain reaction (PCR) assay, and screened patients to estimate the frequency of the LOI variant and its effect on AOO. Results Mean onset for LOI carriers (n = 49) is 20.4 years earlier than expected based on diagnosed CAG size. After correcting for CAG size underestimation, the variant is still associated with onset 9.5 years earlier. The LOI is present in 1.02% of symptomatic HD patients, and in 32.2% of symptomatic reduced penetrance (RP) range patients (36–39 CAGs). Conclusion The LOI causes significantly earlier onset, greater than expected by CAG length, particularly in persons with 36–39 CAG repeats. Detection of this variant has implications for HD families, especially for those in the RP range.
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Sundblom J, Niemelä V, Ghazarian M, Strand AS, Bergdahl IA, Jansson JH, Söderberg S, Stattin EL. High frequency of intermediary alleles in the HTT gene in Northern Sweden - The Swedish Huntingtin Alleles and Phenotype (SHAPE) study. Sci Rep 2020; 10:9853. [PMID: 32555394 PMCID: PMC7299994 DOI: 10.1038/s41598-020-66643-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/20/2020] [Indexed: 11/08/2022] Open
Abstract
Trinucleotide (CAG) repeat expansions longer than 39 in the huntingtin (HTT) gene cause Huntington's disease (HD). The frequency of intermediate alleles (IA) with a length of 27-35 in the general population is not fully known, but studied in specific materials connected to the incidence of HD. The Swedish Huntingtin Alleles and Phenotype (SHAPE) study aims to assess the frequency of trinucleotide repeat expansions in the HTT gene in north Sweden. 8260 individuals unselected for HD from the counties of Norr- and Västerbotten in the north of Sweden were included. DNA samples were obtained and analysis of the HTT gene was performed, yielding data on HTT gene expansion length in 7379 individuals. A high frequency of intermediate alleles, 6.8%, was seen. Also, individuals with repeat numbers lower than ever previously reported (<5) were found. These results suggest a high frequency of HD in the norther parts of Sweden. Subsequent analyses may elucidate the influence of IA:s on traits other than HD.
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Affiliation(s)
- Jimmy Sundblom
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden.
| | - Valter Niemelä
- Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden
| | - Maria Ghazarian
- Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden
| | - Ann-Sofi Strand
- Science for Life Laboratory (SciLifeLab), Department of Immunology, Genetics, and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Jan-Håkan Jansson
- Department of Public Health and Clinical Medicine, Research Unit Skellefteå, Umeå University, Umeå, Sweden
| | - Stefan Söderberg
- Department of Public Health and Clinical Medicine, Heart Centre, Umeå University, Umeå, Sweden
| | - Eva-Lena Stattin
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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13
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Franklin GL, Meira AT, Camargo CHF, Teive HAG. Comment on: “Investigation of intermediate CAG alleles of the HTT in the general population of Rio de Janeiro, Brazil, in comparison with a sample of Huntington disease‐affected families.”. Mol Genet Genomic Med 2020; 8:e1243. [PMID: 32253809 PMCID: PMC7284025 DOI: 10.1002/mgg3.1243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 03/20/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Gustavo L. Franklin
- Movement Disorders Unit Neurology Service Internal Medicine Department Federal University of Paraná Curitiba Paraná Brazil
| | - Alex T. Meira
- Movement Disorders Unit Neurology Service Internal Medicine Department Federal University of Paraná Curitiba Paraná Brazil
| | - Carlos H. F. Camargo
- Movement Disorders Unit Neurology Service Internal Medicine Department Federal University of Paraná Curitiba Paraná Brazil
| | - Hélio A. G. Teive
- Movement Disorders Unit Neurology Service Internal Medicine Department Federal University of Paraná Curitiba Paraná Brazil
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14
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Jevtic SD, Provias JP. Case report and literature review of Huntington disease with intermediate CAG expansion. BMJ Neurol Open 2020; 2:e000027. [PMID: 33681777 PMCID: PMC7871728 DOI: 10.1136/bmjno-2019-000027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2020] [Indexed: 01/08/2023] Open
Abstract
Background Huntington disease (HD) is a genetically inherited neurodegenerative disorder that classically involves a trinucleotide CAG repeat expansion on chromosome 4, with 36 repeats or greater being disease identifying. It generally presents between the age of 30 and 40 years old and is characterised by severe caudate/striatum degeneration with huntingtin protein aggregation. We present here the case of a patient in her early 80s who presented with 5-year history of worsening chorea and family history of HD but an intermediate length CAG expansion. Methods Genetic testing of CAG repeats on chromosome 4. Postmortem brain tissue was obtained and stained using immunohistochemistry for amyloid-beta, tau and glial fibrillary acidic protein (GFAP). Sections from the caudate/putamen were also analysed by p62 immunofluorescence. All sections were reviewed by trained neuropathologists. Results On genetic testing the patient was found to have a 28 CAG repeat on the longest expansion. Microscopic analysis revealed significant neuronal atrophy in the caudate and putamen with gliosis. Immunofluorescent staining demonstrated minimal intranuclear p62 inclusions suggesting little huntingtin aggregation present. Furthermore, there was significant amyloid-beta pathology (Thal-IV stage) and tau involvement in the medial temporal lobe (Braak stage II). Conclusion This case provides clinical and pathological evidence to support an emerging clinical entity involving HD presentation in late age with an intermediate CAG repeat.
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Affiliation(s)
- Stefan D Jevtic
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John P Provias
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.,Laboratory Medicine and Pathology - Neuropathology, Hamilton Health Sciences, Hamilton, Ontario, Canada
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15
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Niemann N, Jankovic J. Juvenile parkinsonism: Differential diagnosis, genetics, and treatment. Parkinsonism Relat Disord 2019; 67:74-89. [DOI: 10.1016/j.parkreldis.2019.06.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/24/2019] [Accepted: 06/28/2019] [Indexed: 12/12/2022]
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16
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Parkinsonism with a Hint of Huntington's from 29 CAG Repeats in HTT. Brain Sci 2019; 9:brainsci9100245. [PMID: 31546689 PMCID: PMC6826852 DOI: 10.3390/brainsci9100245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 01/09/2023] Open
Abstract
Huntington's disease is caused by at least 36 cytosine-adenine-guanine (CAG) repeats in an HTT gene allele, but repeat tracts in the intermediate range (27-35 repeats) also display a subtle phenotype. This patient had a slightly elongated CAG repeat tract (29 repeats), a prominent family history of Parkinson's disease (PD), and a clinical phenotype mostly consistent with PD, but early dystonia and poor levodopa response. Neurophysiological test results were more consistent with Huntington's disease (HD) than PD. It is suggested that the intermediate allele modulated the clinical phenotype of PD in this patient.
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17
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Savitt D, Jankovic J. Clinical phenotype in carriers of intermediate alleles in the huntingtin gene. J Neurol Sci 2019; 402:57-61. [DOI: 10.1016/j.jns.2019.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 04/17/2019] [Accepted: 05/12/2019] [Indexed: 12/20/2022]
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18
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Migliore S, Jankovic J, Squitieri F. Genetic Counseling in Huntington's Disease: Potential New Challenges on Horizon? Front Neurol 2019; 10:453. [PMID: 31114543 PMCID: PMC6503085 DOI: 10.3389/fneur.2019.00453] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 04/15/2019] [Indexed: 01/08/2023] Open
Abstract
Huntington's disease (HD) is a rare, hereditary, neurodegenerative and dominantly transmitted disorder affecting about 10 out of 100,000 people in Western Countries. The genetic cause is a CAG repeat expansion in the huntingtin gene (HTT), which is unstable and may further increase its length in subsequent generations, so called anticipation. Mutation repeat length coupled with other gene modifiers and environmental factors contribute to the age at onset in the offspring. Considering the unpredictability of age at onset and of clinical prognosis in HD, the accurate interpretation, a proper psychological support and a scientifically sound and compassionate communication of the genetic test result are crucial in the context of Good Clinical Practice and when considering further potential disease-modifying therapies. We discuss various genetic test scenarios that require a particularly careful attention in psychological and genetic counseling and expect that the counseling procedures will require a constant update.
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Affiliation(s)
- Simone Migliore
- Huntington and Rare Diseases Unit, Fondazione IRCCS Casa Sollievo Della Sofferenza Research Hospital, San Giovanni Rotondo, Italy
| | - Joseph Jankovic
- Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX, United States
| | - Ferdinando Squitieri
- Huntington and Rare Diseases Unit, Fondazione IRCCS Casa Sollievo Della Sofferenza Research Hospital, San Giovanni Rotondo, Italy
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19
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Lane RM, Smith A, Baumann T, Gleichmann M, Norris D, Bennett CF, Kordasiewicz H. Translating Antisense Technology into a Treatment for Huntington's Disease. Methods Mol Biol 2019; 1780:497-523. [PMID: 29856033 DOI: 10.1007/978-1-4939-7825-0_23] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Advances in molecular biology and genetics have been used to elucidate the fundamental genetic mechanisms underlying central nervous system (CNS) diseases, yet disease-modifying therapies are currently unavailable for most CNS conditions. Antisense oligonucleotides (ASOs) are synthetic single stranded chains of nucleic acids that bind to a specific sequence on ribonucleic acid (RNA) and regulate posttranscriptional gene expression. Decreased gene expression with ASOs might be able to reduce production of the disease-causing protein underlying dominantly inherited neurodegenerative disorders. Huntington's disease (HD), which is caused by a CAG repeat expansion in exon 1 of the huntingtin (HTT) gene and leads to the pathogenic expansion of a polyglutamine (PolyQ ) tract in the N terminus of the huntingtin protein (Htt), is a prime candidate for ASO therapy.State-of-the art translational science techniques can be applied to the development of an ASO targeting HTT RNA, allowing for a data-driven, stepwise progression through the drug development process. A deep and wide-ranging understanding of the basic, preclinical, clinical, and epidemiologic components of drug development will improve the likelihood of success. This includes characterizing the natural history of the disease, including evolution of biomarkers indexing the underlying pathology; using predictive preclinical models to assess the putative gain-of-function of mutant Htt protein and any loss-of-function of the wild-type protein; characterizing toxicokinetic and pharmacodynamic effects of ASOs in predictive animal models; developing sensitive and reliable biomarkers to monitor target engagement and effects on pathology that translate from animal models to patients with HD; establishing a drug delivery method that ensures reliable distribution to relevant CNS tissue; and designing clinical trials that move expeditiously from proof of concept to proof of efficacy. This review focuses on the translational science techniques that allow for efficient and informed development of an ASO for the treatment of HD.
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Affiliation(s)
| | - Anne Smith
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | | | | | - Dan Norris
- Ionis Pharmaceuticals, Carlsbad, CA, USA
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20
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Soares TR, Reis SD, Pinho BR, Duchen MR, Oliveira JMA. Targeting the proteostasis network in Huntington's disease. Ageing Res Rev 2019; 49:92-103. [PMID: 30502498 PMCID: PMC6320389 DOI: 10.1016/j.arr.2018.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/19/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion mutation in the huntingtin protein. Expansions above 40 polyglutamine repeats are invariably fatal, following a symptomatic period characterised by choreiform movements, behavioural abnormalities, and cognitive decline. While mutant huntingtin (mHtt) is widely expressed from early life, most patients with HD present in mid-adulthood, highlighting the role of ageing in disease pathogenesis. mHtt undergoes proteolytic cleavage, misfolding, accumulation, and aggregation into inclusion bodies. The emerging model of HD pathogenesis proposes that the chronic production of misfolded mHtt overwhelms the chaperone machinery, diverting other misfolded clients to the proteasome and the autophagy pathways, ultimately leading to a global collapse of the proteostasis network. Multiple converging hypotheses also implicate ageing and its impact in the dysfunction of organelles as additional contributing factors to the collapse of proteostasis in HD. In particular, mitochondrial function is required to sustain the activity of ATP-dependent chaperones and proteolytic machinery. Recent studies elucidating mitochondria-endoplasmic reticulum interactions and uncovering a dedicated proteostasis machinery in mitochondria, suggest that mitochondria play a more active role in the maintenance of cellular proteostasis than previously thought. The enhancement of cytosolic proteostasis pathways shows promise for HD treatment, protecting cells from the detrimental effects of mHtt accumulation. In this review, we consider how mHtt and its post translational modifications interfere with protein quality control pathways, and how the pharmacological and genetic modulation of components of the proteostasis network impact disease phenotypes in cellular and in vivo HD models.
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Affiliation(s)
- Tânia R Soares
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Sara D Reis
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Brígida R Pinho
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK
| | - Jorge M A Oliveira
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK.
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Solís-Maldonado M, Miró MP, Acuña AI, Covarrubias-Pinto A, Loaiza A, Mayorga G, Beltrán FA, Cepeda C, Levine MS, Concha II, Bátiz LF, Carrasco MA, Castro MA. Altered lactate metabolism in Huntington's disease is dependent on GLUT3 expression. CNS Neurosci Ther 2018; 24:343-352. [PMID: 29582588 DOI: 10.1111/cns.12837] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/31/2018] [Accepted: 02/11/2018] [Indexed: 12/15/2022] Open
Abstract
AIMS Huntington's disease (HD) is a neurodegenerative disorder characterized by progressive abnormalities in cognitive function, mental state, and motor control. HD is characterized by a failure in brain energy metabolism. It has been proposed that monocarboxylates, such as lactate, support brain activity. During neuronal synaptic activity, ascorbic acid released from glial cells stimulates lactate and inhibits glucose transport. The aim of this study was to evaluate the expression and function of monocarboxylate transporters (MCTs) in two HD models. METHODS Using immunofluorescence, qPCR, and Western blot analyses, we explored mRNA and protein levels of MCTs in the striatum of R6/2 animals and HdhQ7/111 cells. We also evaluated MCT function in HdhQ7/111 cells using radioactive tracers and the fluorescent lactate sensor Laconic. RESULTS We found no significant differences in the mRNA or protein levels of neuronal MCTs. Functional analyses revealed that neuronal MCT2 had a high catalytic efficiency in HD cells. Ascorbic acid did not stimulate lactate uptake in HD cells. Ascorbic acid was also unable to inhibit glucose transport in HD cells because they exhibit decreased expression of the neuronal glucose transporter GLUT3. CONCLUSION We demonstrate that stimulation of lactate uptake by ascorbic acid is a consequence of inhibiting glucose transport. Supporting this, lactate transport stimulation by ascorbic acid in HD cells was completely restored by overexpressing GLUT3. Therefore, alterations in GLUT3 expression could be responsible for inefficient use of lactate in HD neurons, contributing to the metabolic failure observed in HD.
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Affiliation(s)
- Macarena Solís-Maldonado
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - María Paz Miró
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Aníbal I Acuña
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Adriana Covarrubias-Pinto
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Anitsi Loaiza
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Gonzalo Mayorga
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Felipe A Beltrán
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behaviour, Brain Research Institute, The David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Michael S Levine
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behaviour, Brain Research Institute, The David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Ilona I Concha
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Luis Federico Bátiz
- Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile.,Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.,Centro de Investigación Biomédica (CIB), Facultad de Medicina, Universidad de Los Andes, Santiago, Chile.,Research Initiative for Brain Rejuvenation (ReBrain), Valdivia, Chile
| | - Mónica A Carrasco
- Research Initiative for Brain Rejuvenation (ReBrain), Valdivia, Chile.,Departamento de Ciencias Básicas Biomédicas, Facultad de Ciencias de la Salud, Universidad de Talca, Talca, Chile
| | - Maite A Castro
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile.,Research Initiative for Brain Rejuvenation (ReBrain), Valdivia, Chile
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22
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Jankovic J, Squitieri F. Letter re: Huntington disease reduced penetrance alleles occur at high frequency in the general population. Neurology 2017; 88:334. [DOI: 10.1212/wnl.0000000000003527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Hayden MR, Kay C. Author response: Huntington disease reduced penetrance alleles occur at high frequency in the general population. Neurology 2017; 88:334-335. [DOI: 10.1212/wnl.0000000000003528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Nance MA. Genetic counseling and testing for Huntington's disease: A historical review. Am J Med Genet B Neuropsychiatr Genet 2017; 174:75-92. [PMID: 27174011 DOI: 10.1002/ajmg.b.32453] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/15/2016] [Indexed: 12/26/2022]
Abstract
This manuscript describes the ways in which genetic counseling has evolved since John Pearson and Sheldon Reed first promoted "a genetic education" in the 1950s as a voluntary, non-directive clinical tool for permitting individual decision making. It reviews how the emergence of Huntington's disease (HD) registries and patient support organizations, genetic testing, and the discovery of a disease-causing CAG repeat expansion changed the contours of genetic counseling for families with HD. It also reviews the guidelines, outcomes, ethical and laboratory challenges, and uptake of predictive, prenatal, and preimplantation testing, and it casts a vision for how clinicians can better make use of genetic counseling to reach a broader pool of families that may be affected by HD and to ensure that genetic counseling is associated with the best levels of care. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Martha A Nance
- Struthers Parkinson's Center, Golden Valley, Minnesota.,Hennepin County Medical Center, Minneapolis, Minnesota
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25
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Raper J, Bosinger S, Johnson Z, Tharp G, Moran SP, Chan AWS. Increased irritability, anxiety, and immune reactivity in transgenic Huntington's disease monkeys. Brain Behav Immun 2016; 58:181-190. [PMID: 27395434 PMCID: PMC5067193 DOI: 10.1016/j.bbi.2016.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 12/20/2022] Open
Abstract
Although the most notable clinical symptoms of Huntington's disease (HD) are motor disturbances and brain atrophy, other symptoms include cognitive dysfunction, emotional and hormonal dysregulation. Emotional dysregulation (irritability, anger/aggression, and anxiety) and increased inflammation are early emerging symptoms which can be detected decades before the onset of motor symptoms in HD patients. Despite the advances in understanding the genetic causes of HD there is still no cure or preventative treatment. Thus, to better understand the pathogenesis of HD and develop effective treatments, a holistic understanding of HD is needed, as well as animal models that replicate the full spectrum of HD symptoms. The current study examined the emotional, hormonal, and gene expression responses to an acute stressor of adult male transgenic HD rhesus monkeys (n=2) as compared to wild-type controls (n=2). Results revealed that HD monkeys expressed increased anxiety and irritability/aggression as compared to controls. Reactive cortisol response to the stressor was similar between groups. However, HD monkeys exhibited increased pro-inflammatory cytokines and higher induction of immune pathway genes as compared to controls. Overall, results reveal that HD monkeys exhibit these early emerging symptoms of HD and may be an effective animal model to facilitate the development of new therapeutics for HD patients.
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Affiliation(s)
- Jessica Raper
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA; Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA 30322, USA.
| | - Steven Bosinger
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA.
| | - Zachary Johnson
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA.
| | - Gregory Tharp
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA.
| | - Sean P Moran
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA.
| | - Anthony W S Chan
- Yerkes National Primate Research Center, 954 Gatewood Rd NE, Atlanta, GA 30329, USA; Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA.
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26
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Chan AWS, Jiang J, Chen Y, Li C, Prucha MS, Hu Y, Chi T, Moran S, Rahim T, Li S, Li X, Zola SM, Testa CM, Mao H, Villalba R, Smith Y, Zhang X, Bachevalier J. Progressive cognitive deficit, motor impairment and striatal pathology in a transgenic Huntington disease monkey model from infancy to adulthood. PLoS One 2015; 10:e0122335. [PMID: 25966278 PMCID: PMC4428630 DOI: 10.1371/journal.pone.0122335] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/10/2015] [Indexed: 02/02/2023] Open
Abstract
One of the roadblocks to developing effective therapeutics for Huntington disease (HD) is the lack of animal models that develop progressive clinical traits comparable to those seen in patients. Here we report a longitudinal study that encompasses cognitive and motor assessment, and neuroimaging of a group of transgenic HD and control monkeys from infancy to adulthood. Along with progressive cognitive and motor impairment, neuroimaging revealed a progressive reduction in striatal volume. Magnetic resonance spectroscopy at 48 months of age revealed a decrease of N-acetylaspartate (NAA), further suggesting neuronal damage/loss in the striatum. Postmortem neuropathological analyses revealed significant neuronal loss in the striatum. Our results indicate that HD monkeys share similar disease patterns with HD patients, making them potentially suitable as a preclinical HD animal model.
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Affiliation(s)
- Anthony W. S. Chan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Jie Jiang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Yiju Chen
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Chunxia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Melinda S. Prucha
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Yijuan Hu
- Department of Biostatistics and Bioinformatics, Emory University School of Public Health, Atlanta, Georgia, United States of America
| | - Tim Chi
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Sean Moran
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Tayeb Rahim
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Shihua Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Xiaojiang Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Stuart M. Zola
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Claudia M. Testa
- Department of Neurology and Parkinson’s and Movement Disorders Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Hui Mao
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Rosa Villalba
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Yoland Smith
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Xiaodong Zhang
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia, United States of America
| | - Jocelyne Bachevalier
- Department of Psychology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Center, Emory University, Atlanta, Georgia, United States of America
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27
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Uhlmann WR, Peñaherrera MS, Robinson WP, Milunsky JM, Nicholson JM, Albin RL. Biallelic mutations in huntington disease: A new case with just one affected parent, review of the literature and terminology. Am J Med Genet A 2015; 167A:1152-60. [DOI: 10.1002/ajmg.a.37009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/22/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Wendy R. Uhlmann
- Division of Molecular Medicine and Genetics; Department of Internal Medicine; University of Michigan; Ann Arbor Michigan
- Department of Human Genetics; University of Michigan; Ann Arbor Michigan
| | - Maria S. Peñaherrera
- Department of Medical Genetics; University of British Columbia; Vancouver British Columbia
- Child and Family Research Institute; Vancouver British Columbia
| | - Wendy P. Robinson
- Department of Medical Genetics; University of British Columbia; Vancouver British Columbia
- Child and Family Research Institute; Vancouver British Columbia
| | | | - Jane M. Nicholson
- Division of Molecular Medicine and Genetics; Department of Internal Medicine; University of Michigan; Ann Arbor Michigan
- Department of Obstetrics and Gynecology; University of Michigan; Ann Arbor Michigan
| | - Roger L. Albin
- Department of Neurology; University of Michigan; Ann Arbor Michigan
- VA Ann Arbor Healthcare System; Geriatrics Research, Education, and Clinical Center; Ann Arbor Michigan
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28
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Semaka A, Kay C, Belfroid RDM, Bijlsma EK, Losekoot M, van Langen IM, van Maarle MC, Oosterloo M, Hayden MR, van Belzen MJ. A new mutation for Huntington disease following maternal transmission of an intermediate allele. Eur J Med Genet 2014; 58:28-30. [PMID: 25464109 DOI: 10.1016/j.ejmg.2014.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
Abstract
New mutations for Huntington disease (HD) originate from CAG repeat expansion of intermediate alleles (27-35 CAG). Expansions of such alleles into the pathological range (≥ 36 CAG) have been exclusively observed in paternal transmission. We report the occurrence of a new mutation that defies the paternal expansion bias normally observed in HD. A maternal intermediate allele with 33 CAG repeats expanded in transmission to 48 CAG repeats causing a de novo case of HD in the family. Retrospectively, the mother presented with cognitive decline, but HD was never considered in the differential diagnosis. She was diagnosed with dementia and testing for HD was only performed after her daughter had been diagnosed. This observation of an intermediate allele expanding into the full penetrance HD range after maternal transmission has important implications for genetic counselling of females with intermediate repeats.
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Affiliation(s)
- Alicia Semaka
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - René D M Belfroid
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Monique Losekoot
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Irene M van Langen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Merel C van Maarle
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Mayke Oosterloo
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Martine J van Belzen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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29
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Trinucleotide expansion in disease: why is there a length threshold? Curr Opin Genet Dev 2014; 26:131-40. [PMID: 25282113 DOI: 10.1016/j.gde.2014.07.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 11/24/2022]
Abstract
Trinucleotide repeats (TNRs) expansion disorders are severe neurodegenerative and neuromuscular disorders that arise from inheriting a long tract (30-50 copies) of a trinucleotide unit within or near an expressed gene (Figure 1a). The mutation is referred to as 'trinucleotide expansion' since the number of triplet units in a mutated gene is greater than the number found in the normal gene. Expansion becomes obvious once the number of repeating units passes a critical threshold length, but what happens at the threshold to render the repeating tract unstable? Here we discuss DNA-dependent and RNA-dependent models by which a particular DNA length permits a rapid transition to an unstable state.
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30
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Ross CA, Aylward EH, Wild EJ, Langbehn DR, Long JD, Warner JH, Scahill RI, Leavitt BR, Stout JC, Paulsen JS, Reilmann R, Unschuld PG, Wexler A, Margolis RL, Tabrizi SJ. Huntington disease: natural history, biomarkers and prospects for therapeutics. Nat Rev Neurol 2014; 10:204-16. [PMID: 24614516 DOI: 10.1038/nrneurol.2014.24] [Citation(s) in RCA: 659] [Impact Index Per Article: 65.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Huntington disease (HD) can be seen as a model neurodegenerative disorder, in that it is caused by a single genetic mutation and is amenable to predictive genetic testing, with estimation of years to predicted onset, enabling the entire range of disease natural history to be studied. Structural neuroimaging biomarkers show that progressive regional brain atrophy begins many years before the emergence of diagnosable signs and symptoms of HD, and continues steadily during the symptomatic or 'manifest' period. The continued development of functional, neurochemical and other biomarkers raises hopes that these biomarkers might be useful for future trials of disease-modifying therapeutics to delay the onset and slow the progression of HD. Such advances could herald a new era of personalized preventive therapeutics. We describe the natural history of HD, including the timing of emergence of motor, cognitive and emotional impairments, and the techniques that are used to assess these features. Building on this information, we review recent progress in the development of biomarkers for HD, and potential future roles of these biomarkers in clinical trials.
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Affiliation(s)
- Christopher A Ross
- Division of Neurobiology, Johns Hopkins University, 600 North Wolfe Street, Baltimore, MD 21287, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | - Russell L Margolis
- Division of Neurobiology, Johns Hopkins University, 600 North Wolfe Street, Baltimore, MD 21287, USA
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31
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Chandra A, Johri A, Beal MF. Prospects for neuroprotective therapies in prodromal Huntington's disease. Mov Disord 2014; 29:285-93. [PMID: 24573776 DOI: 10.1002/mds.25835] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/14/2014] [Accepted: 01/16/2014] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is a prototypical dominantly inherited neurodegenerative disorder characterized by progressive cognitive deterioration, psychiatric disturbances, and a movement disorder. The genetic cause of the illness is a CAG repeat expansion in the huntingtin gene, which leads to a polyglutamine expansion in the huntingtin protein. The exact mechanism by which mutant huntingtin causes HD is unknown, but it causes abnormalities in gene transcription as well as both mitochondrial dysfunction and oxidative damage. Because the penetrance of HD is complete with CAG repeats greater than 39, patients can be diagnosed well before disease onset with genetic testing. Longitudinal studies of HD patients before disease onset have shown that subtle cognitive and motor deficits occur as much as 10 years before onset, as do reductions in glucose utilization and striatal atrophy. An increase in inflammation, as shown by elevated interleukin-6, occurs approximately 15 years before onset. Detection of these abnormalities may be useful in defining an optimal time for disease intervention to try to slow or halt the degenerative process. Although reducing gene expression with small interfering RNA or short hairpin RNA is an attractive approach, other approaches targeting energy metabolism, inflammation, and oxidative damage may be more easily and rapidly moved into the clinic. The recent PREQUEL study of coenzyme Q10 in presymptomatic gene carriers showed the feasibility of carrying out clinical trials to slow or halt onset of HD. We review both the earliest detectable clinical and laboratory manifestations of HD, as well as potential neuroprotective therapies that could be utilized in presymptomatic HD.
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Affiliation(s)
- Abhishek Chandra
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, New York, USA
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32
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Semaka A, Hayden M. Evidence-based genetic counselling implications for Huntington disease intermediate allele predictive test results. Clin Genet 2014; 85:303-11. [DOI: 10.1111/cge.12324] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 11/29/2022]
Affiliation(s)
- A. Semaka
- Centre for Molecular Medicine and Therapeutics; University of British Columbia; Vancouver British Columbia Canada
| | - M.R. Hayden
- Centre for Molecular Medicine and Therapeutics; University of British Columbia; Vancouver British Columbia Canada
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33
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Semaka A, Kay C, Doty CN, Collins JA, Tam N, Hayden MR. High frequency of intermediate alleles on Huntington disease-associated haplotypes in British Columbia's general population. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:864-71. [PMID: 24038799 DOI: 10.1002/ajmg.b.32193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 07/11/2013] [Indexed: 11/08/2022]
Abstract
Intermediate alleles (27-35 CAG, IAs) for Huntington disease (HD) usually do not confer the disease phenotype but are prone to CAG repeat instability. Consequently, offspring are at-risk of inheriting an expanded allele in the HD range (≥36 CAG). IAs that expand into a new mutation have been hypothesized to be more susceptible to instability compared to IAs identified on the non-HD side of a family from the general population. Frequency estimates for IAs are limited and have largely been determined using clinical samples of HD or related disorders, which may result in an ascertainment bias. This study aimed to establish the frequency of IAs in a sample of a British Columbia's (B.C.) general population with no known association to HD and examine the haplotype of new mutation and general population IAs. CAG sizing was performed on 1,600 DNA samples from B.C.'s general population. Haplotypes were determined using 22 tagging SNPs across the HTT gene. 5.8% of individuals were found to have an IA, of which 60% were on HD-associated haplotypes. There was no difference in the haplotype distribution of new mutation and general population IAs. These findings suggest that IAs are relatively frequent in the general population and are often found on haplotypes associated with expanded CAG lengths. There is likely no difference in the propensity of new mutation and general population IAs to expand into the disease range given that they are both found on disease-associated haplotypes. These findings have important implications for clinical practice.
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Affiliation(s)
- Alicia Semaka
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
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34
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Jimenez-Shahed J, Jankovic J. Tetrabenazine for treatment of chorea associated with Huntington's disease and other potential indications. Expert Opin Orphan Drugs 2013. [DOI: 10.1517/21678707.2013.787358] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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