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Rajan-Babu IS, Dolzhenko E, Eberle MA, Friedman JM. Sequence composition changes in short tandem repeats: heterogeneity, detection, mechanisms and clinical implications. Nat Rev Genet 2024:10.1038/s41576-024-00696-z. [PMID: 38467784 DOI: 10.1038/s41576-024-00696-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2024] [Indexed: 03/13/2024]
Abstract
Short tandem repeats (STRs) are a class of repetitive elements, composed of tandem arrays of 1-6 base pair sequence motifs, that comprise a substantial fraction of the human genome. STR expansions can cause a wide range of neurological and neuromuscular conditions, known as repeat expansion disorders, whose age of onset, severity, penetrance and/or clinical phenotype are influenced by the length of the repeats and their sequence composition. The presence of non-canonical motifs, depending on the type, frequency and position within the repeat tract, can alter clinical outcomes by modifying somatic and intergenerational repeat stability, gene expression and mutant transcript-mediated and/or protein-mediated toxicities. Here, we review the diverse structural conformations of repeat expansions, technological advances for the characterization of changes in sequence composition, their clinical correlations and the impact on disease mechanisms.
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Affiliation(s)
- Indhu-Shree Rajan-Babu
- Department of Medical Genetics, The University of British Columbia, and Children's & Women's Hospital, Vancouver, British Columbia, Canada.
| | | | | | - Jan M Friedman
- Department of Medical Genetics, The University of British Columbia, and Children's & Women's Hospital, Vancouver, British Columbia, Canada
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada
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2
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Kim R, Seong MW, Oh B, Shin HS, Lee JS, Park S, Jang M, Jeon B, Kim HJ, Lee JY. Analysis of HTT CAG repeat expansion among healthy individuals and patients with chorea in Korea. Parkinsonism Relat Disord 2024; 118:105930. [PMID: 37992538 DOI: 10.1016/j.parkreldis.2023.105930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/24/2023]
Abstract
BACKGROUND Although the epidemiology of Huntington's disease (HD) in Korea differs notably from that in Western countries, the genetic disparities between these regions remain unclear. OBJECTIVE To investigate the characteristics and clinical significance of cytosine-adenine-guanine (CAG) repeat size associated with HD in the Korean population. METHODS We analyzed the CAG repeat lengths of the HTT gene in 941 healthy individuals (1,882 alleles) and 954 patients with chorea (1,908 alleles) from two referral hospitals in Korea. We presented normative CAG repeat length data for the Korean population and computed the reduced penetrance (36-39 CAG) and intermediate allele (27-35 CAG) frequencies in the two groups. Furthermore, we investigated the relationship between intermediate alleles and chorea development using logistic regression models in individuals aged ≥55 years. RESULTS The mean (±standard deviation) CAG repeat length in healthy individuals was 17.5 ± 2.0, with a reduced penetrance allele frequency of 0.05 % (1/1882) and intermediate allele frequency of 0.69 % (13/1882). We identified 213 patients with genetically confirmed HD whose CAG repeat length ranged from 39 to 140, with a mean of 45.2 ± 7.9 in the longer allele. Compared with normal CAG repeat alleles, intermediate CAG repeat alleles were significantly related to a higher risk of developing chorea (age of onset range, 63-84 years) in individuals aged ≥55 years. CONCLUSIONS This study provides insights into the specific characteristics of CAG repeat lengths in the HTT gene in the Korean population. The reduced penetrance and intermediate allele frequencies in the Korean general population seem to be lower than those reported in Western populations. The presence of intermediate alleles may increase the risk of chorea in the Korean elderly population, which requires further large-scale investigations.
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Affiliation(s)
- Ryul Kim
- Department of Neurology, Inha University Hospital, Inha University College of Medicine, Incheon, South Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea; Cancer Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Bumjo Oh
- Department of Familial Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, South Korea
| | - Ho Seop Shin
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Jee-Soo Lee
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Sangmin Park
- Department of Neurology, Daejeon Eulji Medical Center, Eulji University College of Medicine, Daejeon, South Korea
| | - Mihee Jang
- Department of Neurology, JMH Seoul Neurologic Clinic, Seoul, South Korea
| | - Beomseok Jeon
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Han-Joon Kim
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea.
| | - Jee-Young Lee
- Department of Neurology, Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, South Korea.
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Goldman JS, Uhlmann WR, Naini AB, Klitzman RL, Marder KS. Genetic Testing of HTT Modifiers for Huntington's Disease: Considerations for Clinical Guidelines. Mov Disord 2023; 38:2151-2154. [PMID: 37975739 DOI: 10.1002/mds.29650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/24/2023] [Accepted: 10/16/2023] [Indexed: 11/19/2023] Open
Affiliation(s)
- Jill S Goldman
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
| | - Wendy R Uhlmann
- Departments of Internal Medicine and Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Ali B Naini
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA
| | - Robert L Klitzman
- Department of Psychiatry, Columbia University Irving Medical Center, Mailman School of Public Health, Columbia University, New York, New York, USA
| | - Karen S Marder
- Department of Neurology, Columbia University Irving Medical Center, New York, New York, USA
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Lammert DB, Bang J, Stafstrom CE. Pearls & Oy-sters: Epilepsy Is a Key Feature of Pediatric-Onset Huntington Disease. Neurology 2023; 101:e2051-e2055. [PMID: 37652706 PMCID: PMC10662976 DOI: 10.1212/wnl.0000000000207867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/26/2023] [Indexed: 09/02/2023] Open
Abstract
Pediatric-onset Huntington disease (PoHD) presents differently from adult-onset disease. Children typically exhibit regression in school performance, psychiatric features such as inattention, and oral motor dysfunction. Unlike adult-onset HD, in which seizures occur at approximately the rate of the general public, at least half of children with HD develop epilepsy, and seizures can be a presenting feature of PoHD. Here we present the case of a 10-year-old boy with a history of language delay, motor regression, oral motor dysfunction, and tremor who presented with a first lifetime seizure. Given a family history of Huntington disease in his father, PoHD was considered, and a pathogenic allele with 88 repeats was confirmed in the child. As symptoms progressed, history alone could not differentiate abnormal movements from seizures. Continuous video electroencephalography helped to demonstrate epileptic myoclonic jerks and guide treatment.
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Affiliation(s)
- Dawn B Lammert
- From the Department of Neurology (D.B.L., C.E.S.), Division of Pediatric Neurology, Johns Hopkins University School of Medicine; and Department of Neurology (J.B.), Johns Hopkins University School of Medicine, Baltimore, MD.
| | - Jee Bang
- From the Department of Neurology (D.B.L., C.E.S.), Division of Pediatric Neurology, Johns Hopkins University School of Medicine; and Department of Neurology (J.B.), Johns Hopkins University School of Medicine, Baltimore, MD
| | - Carl E Stafstrom
- From the Department of Neurology (D.B.L., C.E.S.), Division of Pediatric Neurology, Johns Hopkins University School of Medicine; and Department of Neurology (J.B.), Johns Hopkins University School of Medicine, Baltimore, MD
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5
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Burgunder JM. Mechanisms underlying phenotypic variation in neurogenetic disorders. Nat Rev Neurol 2023:10.1038/s41582-023-00811-4. [PMID: 37202496 DOI: 10.1038/s41582-023-00811-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2023] [Indexed: 05/20/2023]
Abstract
Neurological diseases associated with pathogenic variants in a specific gene, or even with a specific pathogenic variant, can show profound phenotypic variation with regard to symptom presentation, age at onset and disease course. Highlighting examples from a range of neurogenetic disorders, this Review explores emerging mechanisms that are involved in this variability, including environmental, genetic and epigenetic factors that influence the expressivity and penetrance of pathogenic variants. Environmental factors, some of which can potentially be modified to prevent disease, include trauma, stress and metabolic changes. Dynamic patterns of pathogenic variants might explain some of the phenotypic variations, for example, in the case of disorders caused by DNA repeat expansions such as Huntington disease (HD). An important role for modifier genes has also been identified in some neurogenetic disorders, including HD, spinocerebellar ataxia and X-linked dystonia-parkinsonism. In other disorders, such as spastic paraplegia, the basis for most of the phenotypic variability remains unclear. Epigenetic factors have been implicated in disorders such as SGCE-related myoclonus-dystonia and HD. Knowledge of the mechanisms underlying phenotypic variation is already starting to influence management strategies and clinical trials for neurogenetic disorders.
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6
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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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Kalia LV, Nimmo GAM, Mestre TA. Genetic Testing in Clinical Movement Disorders: A Case-Based Review. Semin Neurol 2023; 43:147-155. [PMID: 36854393 DOI: 10.1055/s-0043-1763507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Genetics are fundamental to understanding the pathophysiology of neurological disease, including movement disorders. Genetic testing in clinical practice has changed dramatically over the last few decades. While the likelihood of establishing an etiological diagnosis is greater now with increased access to testing and more advanced technologies, clinicians face challenges when deciding whether to test, then selecting the appropriate test, and ultimately interpreting and sharing the results with patients and families. In this review, we use a case-based approach to cover core aspects of genetic testing for the neurologist, namely, genetic testing in Parkinson's disease, interpretation of inconclusive genetic test reports, and genetic testing for repeat expansion disorders using Huntington disease as a prototype.
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Affiliation(s)
- Lorraine V Kalia
- Division of Neurology, Department of Medicine, Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic and Krembil Research Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Graeme A M Nimmo
- Fred A. Litwin Family Centre for Genetic Medicine, Department of Medicine, Mount Sinai Hospital and Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Tiago A Mestre
- Division of Neurology, Department of Medicine, Ottawa Hospital Research Institute, University of Ottawa Brain and Mind Research Institute, The Ottawa Hospital, Ottawa, Ontario Canada
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8
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Points to consider in the detection of germline structural variants using next-generation sequencing: A statement of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2023; 25:100316. [PMID: 36507974 DOI: 10.1016/j.gim.2022.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 12/14/2022] Open
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9
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Zhu X, Zhang Y, Yu Z, Yu L, Huang W, Sun S, Li Y, Wang M, Li Y, Sun L, Yang Q, Deng F, Shao X, Liu L, Liu C, Qin Y, Feng S, Zhu H, Yang F, Zheng W, Zheng W, Zhong R, Hou L, Mao J, Wang F, Ding J. The Clinical and Genetic Features in Chinese Children With Steroid-Resistant or Early-Onset Nephrotic Syndrome: A Multicenter Cohort Study. Front Med (Lausanne) 2022; 9:885178. [PMID: 35755072 PMCID: PMC9218096 DOI: 10.3389/fmed.2022.885178] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is one of the major causes of end-stage kidney disease (ESKD) in children and young adults. For approximately 30% of children with SRNS results from a genetic cause. In this study, genotype-phenotype correlations in a cohort of 283 pediatric patients with SRNS or early-onset NS (nephrotic syndrome presenting within the first year of life) from 23 major pediatric nephrology centers in China were analyzed. All patients were performed with next-generation sequencing and Sanger sequencing. The overall mutation detection rate was 37.5% (106 of 283 patients). WT1 was the most frequently detected mutation, followed by NPHS1, NPHS2, and ADCK4, and these four major causative genes (WT1, NPHS1, NPHS2, and ADCK4) account for 73.6% of patients with monogenic SRNS. Thirteen of 106 individuals (12.3%) carried mutations in ADCK4 that function within the coenzyme Q10 biosynthesis pathway. In the higher frequently ADCK4-related SRNS, two mutations, c.737G>A (p.S246N) and c.748G>C (p.D250H), were the most prevalent. Our study provides not only definitive diagnosis but also facilitate available targeted treatment for SRNS, and prediction of prognosis and renal outcome. Our indications for genetic testing are patients with FSGS, initial SRNS, cases of positive family history or those with extra-renal manifestations.
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Affiliation(s)
- Xiujuan Zhu
- Department of Nephrology, The Children Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yanqin Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zihua Yu
- Department of Pediatrics, Fuzong Clinical Medical College, Fujian Medical University, Fuzhou, China
| | - Li Yu
- Department of Pediatrics, Guangzhou First People's Hospital, Guangzhou, China
| | - Wenyan Huang
- Department of Nephrology and Rheumatology, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Shuzhen Sun
- Department of Pediatric Nephrology and Rheumatism and Immunology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Yingjie Li
- Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Mo Wang
- Department of Nephrology, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Yongzhen Li
- Department of Pediatrics, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liangzhong Sun
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qing Yang
- Department of Nephrology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Fang Deng
- Department of Nephrology, Anhui Provincial Children's Hospital, Hefei, China
| | - Xiaoshan Shao
- Department of Nephrology and Immunization, Guiyang Maternal and Child Health Care Hospital, Guiyang, China
| | - Ling Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Hebei Province, Shijiazhuang, China
| | - Cuihua Liu
- Department of Nephrology and Rheumatology, Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
- Zhengzhou Key Laboratory of Pediatric Kidney Disease Research, Zhengzhou, China
| | - Yuanhan Qin
- Department of Pediatrics, The First Hospital of Guangxi Medical University, Nanning, China
| | - Shipin Feng
- Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Hongtao Zhu
- Department of Pediatrics, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Fang Yang
- Department of Pediatrics, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Weimin Zheng
- Department of Nephrology, Jiangxi Provincial Children's Hospital, The Affiliated Children's Hospital Nanchang University, Nanchang, China
| | - Wanqi Zheng
- Department of Pediatrics, The Second Hospital of Dalian Medical University, Dalian, China
| | - Rirong Zhong
- Department of Pediatrics, Fujian Provincial Hospital, Fuzhou, China
| | - Ling Hou
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Jianhua Mao
- Department of Nephrology, The Children Hospital of Zhejiang University School of Medicine, Hangzhou, China
- *Correspondence: Jianhua Mao
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Fang Wang
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
- Jie Ding
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Kaye J, Reisine T, Finkbeiner S. Huntington's disease mouse models: unraveling the pathology caused by CAG repeat expansion. Fac Rev 2021; 10:77. [PMID: 34746930 PMCID: PMC8546598 DOI: 10.12703/r/10-77] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disease that results in motor and cognitive dysfunction, leading to early death. HD is caused by an expansion of CAG repeats in the huntingtin gene (HTT). Here, we review the mouse models of HD. They have been used extensively to better understand the molecular and cellular basis of disease pathogenesis as well as to provide non-human subjects to test the efficacy of potential therapeutics. The first and best-studied in vivo rodent model of HD is the R6/2 mouse, in which a transgene containing the promoter and exon 1 fragment of human HTT with 150 CAG repeats was inserted into the mouse genome. R6/2 mice express rapid, robust behavioral pathologies and display a number of degenerative abnormalities in neuronal populations most vulnerable in HD. The first conditional full-length mutant huntingtin (mHTT) mouse model of HD was the bacterial artificial chromosome (BAC) transgenic mouse model of HD (BACHD), which expresses human full-length mHTT with a mixture of 97 CAG-CAA repeats under the control of endogenous HTT regulatory machinery. It has been useful in identifying the role of mHTT in specific neuronal populations in degenerative processes. In the knock-in (KI) model of HD, the expanded human CAG repeats and human exon 1 are inserted into the mouse Htt locus, so a chimera of the full-length mouse protein with the N-terminal human portion is expressed. Many of aspects of the pathology and behavioral deficits in the KI model better mimic disease characteristics found in HD patients than other models. Accordingly, some have proposed that these mice may be preferable models of the disease over others. Indeed, as our understanding of HD advances, so will the design of animal models to test and develop HD therapies.
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Affiliation(s)
- Julia Kaye
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, USA
| | - Terry Reisine
- Independent Scientific Consultant, Santa Cruz, CA, USA
| | - Steve Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, USA
- Taube/Koret Center for Neurodegenerative Disease Research, Gladstone Institutes, San Francisco, CA, USA
- Department of Neurology and Physiology, University of California, San Francisco, CA, USA
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11
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Jiao B, Liu H, Guo L, Xiao X, Liao X, Zhou Y, Weng L, Zhou L, Wang X, Jiang Y, Yang Q, Zhu Y, Zhou L, Zhang W, Wang J, Yan X, Li J, Tang B, Shen L. The role of genetics in neurodegenerative dementia: a large cohort study in South China. NPJ Genom Med 2021; 6:69. [PMID: 34389718 PMCID: PMC8363644 DOI: 10.1038/s41525-021-00235-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/30/2021] [Indexed: 02/07/2023] Open
Abstract
Neurodegenerative dementias are a group of diseases with highly heterogeneous pathology and complicated etiology. There exist potential genetic component overlaps between different neurodegenerative dementias. Here, 1795 patients with neurodegenerative dementias from South China were enrolled, including 1592 with Alzheimer's disease (AD), 110 with frontotemporal dementia (FTD), and 93 with dementia with Lewy bodies (DLB). Genes targeted sequencing analysis were performed. According to the American College of Medical Genetics (ACMG) guidelines, 39 pathogenic/likely pathogenic (P/LP) variants were identified in 47 unrelated patients in 14 different genes, including PSEN1, PSEN2, APP, MAPT, GRN, CHCHD10, TBK1, VCP, HTRA1, OPTN, SQSTM1, SIGMAR1, and abnormal repeat expansions in C9orf72 and HTT. Overall, 33.3% (13/39) of the variants were novel, the identified P/LP variants were seen in 2.2% (35/1592) and 10.9% (12/110) of AD and FTD cases, respectively. The overall molecular diagnostic rate was 2.6%. Among them, PSEN1 was the most frequently mutated gene (46.8%, 22/47), followed by PSEN2 and APP. Additionally, the age at onset of patients with P/LP variants (51.4 years), ranging from 30 to 83 years, was ~10 years earlier than those without P/LP variants (p < 0.05). This study sheds insight into the genetic spectrum and clinical manifestations of neurodegenerative dementias in South China, further expands the existing repertoire of P/LP variants involved in known dementia-associated genes. It provides a new perspective for basic research on genetic pathogenesis and novel guiding for clinical practice of neurodegenerative dementia.
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Affiliation(s)
- Bin Jiao
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Hui Liu
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lina Guo
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xuewen Xiao
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xinxin Liao
- grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Yafang Zhou
- grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Ling Weng
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Lu Zhou
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xin Wang
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yaling Jiang
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qijie Yang
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yuan Zhu
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lin Zhou
- grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China ,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Weiwei Zhang
- grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Department of Radiology, Xiangya Hospital, Central South University, Changsha, China
| | - Junling Wang
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Xinxiang Yan
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Jinchen Li
- grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Beisha Tang
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
| | - Lu Shen
- grid.216417.70000 0001 0379 7164Department of Neurology, Xiangya Hospital, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164National Clinical Research Center for Geriatric Disorders, Central South University, Changsha, China ,grid.216417.70000 0001 0379 7164Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China ,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China ,grid.216417.70000 0001 0379 7164Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China ,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
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12
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De Luca A, Morella A, Consoli F, Fanelli S, Thibert JR, Statt S, Latham GJ, Squitieri F. A Novel Triplet-Primed PCR Assay to Detect the Full Range of Trinucleotide CAG Repeats in the Huntingtin Gene ( HTT). Int J Mol Sci 2021; 22:ijms22041689. [PMID: 33567536 PMCID: PMC7916029 DOI: 10.3390/ijms22041689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 02/07/2023] Open
Abstract
The expanded CAG repeat number in HTT gene causes Huntington disease (HD), which is a severe, dominant neurodegenerative illness. The accurate determination of the expanded allele size is crucial to confirm the genetic status in symptomatic and presymptomatic at-risk subjects and avoid genetic polymorphism-related false-negative diagnoses. Precise CAG repeat number determination is critical to discriminate the cutoff between unexpanded and intermediate mutable alleles (IAs, 27–35 CAG) as well as between IAs and pathological, low-penetrance alleles (i.e., 36–39 CAG repeats), and it is also critical to detect large repeat expansions causing pediatric HD variants. We analyzed the HTT-CAG repeat number of 14 DNA reference materials and of a DNA collection of 43 additional samples carrying unexpanded, IAs, low and complete penetrance alleles, including large (>60 repeats) and very large (>100 repeats) expansions using a novel triplet-primed PCR-based assay, the AmplideX PCR/CE HTT Kit. The results demonstrate that the method accurately genotypes both normal and expanded HTT-CAG repeat numbers and reveals previously undisclosed and very large CAG expansions >200 repeats. We also show that this technique can improve genetic test reliability and accuracy by detecting CAG expansions in samples with sequence variations within or adjacent to the repeat tract that cause allele drop-outs or inaccuracies using other PCR methods.
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Affiliation(s)
- Alessandro De Luca
- Medical Genetics Division, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (A.D.L.); (A.M.); (F.C.)
| | - Annunziata Morella
- Medical Genetics Division, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (A.D.L.); (A.M.); (F.C.)
| | - Federica Consoli
- Medical Genetics Division, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (A.D.L.); (A.M.); (F.C.)
| | - Sergio Fanelli
- Huntington and Rare Diseases Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Julie R. Thibert
- Asuragen, Inc., Austin, TX 78744, USA; (J.R.T.); (S.S.); (G.J.L.)
| | - Sarah Statt
- Asuragen, Inc., Austin, TX 78744, USA; (J.R.T.); (S.S.); (G.J.L.)
| | - Gary J. Latham
- Asuragen, Inc., Austin, TX 78744, USA; (J.R.T.); (S.S.); (G.J.L.)
| | - Ferdinando Squitieri
- Huntington and Rare Diseases Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
- Correspondence: ; Tel.: +39-06-44160536
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13
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Dewan R, Chia R, Ding J, Hickman RA, Stein TD, Abramzon Y, Ahmed S, Sabir MS, Portley MK, Tucci A, Ibáñez K, Shankaracharya FNU, Keagle P, Rossi G, Caroppo P, Tagliavini F, Waldo ML, Johansson PM, Nilsson CF, Rowe JB, Benussi L, Binetti G, Ghidoni R, Jabbari E, Viollet C, Glass JD, Singleton AB, Silani V, Ross OA, Ryten M, Torkamani A, Tanaka T, Ferrucci L, Resnick SM, Pickering-Brown S, Brady CB, Kowal N, Hardy JA, Van Deerlin V, Vonsattel JP, Harms MB, Morris HR, Ferrari R, Landers JE, Chiò A, Gibbs JR, Dalgard CL, Scholz SW, Traynor BJ. Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis. Neuron 2021; 109:448-460.e4. [PMID: 33242422 PMCID: PMC7864894 DOI: 10.1016/j.neuron.2020.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/02/2020] [Accepted: 11/04/2020] [Indexed: 02/01/2023]
Abstract
We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered.
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Affiliation(s)
- Ramita Dewan
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Ruth Chia
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Jinhui Ding
- Computational Biology Group, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Richard A Hickman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Thor D Stein
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA 02118, USA; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA 02118, USA; Research and Development Service, Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA; Department of Veterans Affairs Medical Center, Bedford, MA 01730, USA
| | - Yevgeniya Abramzon
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA; Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK
| | - Sarah Ahmed
- Neurodegenerative Diseases Research Unit, Laboratory of Neurogenetics, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Marya S Sabir
- Neurodegenerative Diseases Research Unit, Laboratory of Neurogenetics, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Makayla K Portley
- Neurodegenerative Diseases Research Unit, Laboratory of Neurogenetics, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
| | - Arianna Tucci
- Clinical Pharmacology, William Harvey Research Institute, School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - Kristina Ibáñez
- Clinical Pharmacology, William Harvey Research Institute, School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, UK
| | - F N U Shankaracharya
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Pamela Keagle
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Giacomina Rossi
- Division of Neurology V and Neuropathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | - Paola Caroppo
- Division of Neurology V and Neuropathology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | - Fabrizio Tagliavini
- Scientific Directorate, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan 20133, Italy
| | - Maria L Waldo
- Division of Clinical Sciences Helsingborg, Department of Clinical Sciences Lund, Lund University, Lund 221 84, Sweden
| | - Per M Johansson
- Division of Clinical Sciences Helsingborg, Department of Clinical Sciences Lund, Lund University, Lund 221 84, Sweden; Department of Internal Medicine, Sahlgrenska Academy, University of Gottenburg, Gottenburg 413 45, Sweden
| | - Christer F Nilsson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Skåne University Hospital, 205 02 Malmö, Sweden
| | - James B Rowe
- Cambridge University Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, Cambridge Biomedical Campus, Cambridge CB2 02Z, UK
| | - Luisa Benussi
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia 25125, Italy
| | - Giuliano Binetti
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia 25125, Italy; MAC Memory Clinic, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia 25125, Italy
| | - Roberta Ghidoni
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia 25125, Italy
| | - Edwin Jabbari
- Department of Neurology, Royal Free Hospital, London NW3 2PF, UK; Department of Clinical and Movement Neuroscience, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Coralie Viollet
- Department of Anatomy, Physiology and Genetics, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Jonathan D Glass
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew B Singleton
- Molecular Genetics Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Vincenzo Silani
- Department of Neurology - Stroke Unit and Laboratory of Neuroscience, IRCCS Istituto Auxologico Italiano, Milan 20149, Italy; Department of Pathophysiology and Transplantation, Dino Ferrari Center, Università degli Studi di Milano, Milan 20122, Italy
| | - Owen A Ross
- Department of Neuroscience & Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Mina Ryten
- Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK; Genetics and Genomic Medicine, Great Ormond Street Institute of Child Health, University College London, London WC1E 6BT, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, University College London, London WC1N 3JH, UK
| | - Ali Torkamani
- The Scripps Translational Science Institute, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Toshiko Tanaka
- Longitudinal Studies Section, National Institute on Aging, Baltimore, MD 21224, USA
| | - Luigi Ferrucci
- Longitudinal Studies Section, National Institute on Aging, Baltimore, MD 21224, USA
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, MD 21224, USA
| | - Stuart Pickering-Brown
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Christopher B Brady
- Department of Neurology & Program in Behavioral Neuroscience, Boston University School of Medicine, Boston, MA 02118, USA; Research and Development Service, Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA
| | - Neil Kowal
- Department of Neurology, Veterans Affairs Boston Healthcare System, Boston, MA 02130, USA; Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - John A Hardy
- Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK; Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; UK Dementia Research Institute at UCL and Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK; NINR University College London Hospitals Biomedical Research Centre, University College London, London W1T 7DN, UK; Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Vivianna Van Deerlin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jean Paul Vonsattel
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Matthew B Harms
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Huw R Morris
- Department of Neurology, Royal Free Hospital, London NW3 2PF, UK; Department of Clinical and Movement Neuroscience, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Raffaele Ferrari
- Department of Neurology, Royal Free Hospital, London NW3 2PF, UK
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Adriano Chiò
- Rita Levi Montalcini Department of Neuroscience, University of Turin, Turin 10126, Italy; Institute of Cognitive Sciences and Technologies, C.N.R., Rome 00185, Italy; Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Turin 10126, Italy
| | - J Raphael Gibbs
- Computational Biology Group, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA
| | - Clifton L Dalgard
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA; The American Genome Center, Collaborative Health Initiative Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Sonja W Scholz
- Neurodegenerative Diseases Research Unit, Laboratory of Neurogenetics, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA; Department of Neurology, Johns Hopkins University Medical Center, Baltimore, MD 21287, USA
| | - Bryan J Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD 20892, USA; Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, University College London, London WC1N 1PJ, UK; Department of Neurology, Johns Hopkins University Medical Center, Baltimore, MD 21287, USA.
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14
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Abstract
Objectives. Pheochromocytoma (PCC) is a neuroendocrine tumor derived from chromaffin tissue more frequently found in the adrenal medulla. Many discoveries over the last decade have significantly improved our understanding of PCC.Methods. We retrospectively reviewed all patients with a histological diagnosis of PCC at the Centro Hospitalar Universitario de Sao Joao, a tertiary and university hospital in Oporto, Portugal, between January 2009 and December 2017.Results. The study group included 33 patients. In most cases the diagnosis was suspected with more than half of patients presenting with hypertension and the third diagnosed during the work-up of an adrenal incidentaloma. About half of the patients was referred for genetic testing and 6 patients had a positive inherited susceptibility genetic pathogenic variant associated with classic cancer predisposition syndromes and also associated with newly described genes. In the incidentaloma group, genetic testing was performed in 3 (9%) patients with only 1 positive result. In the suspected group, 15 (45%) genetic tests were performed.Conclusions. In contrast to other studies, where only a minority of patients with PCC were referred for genetic counselling, in our study 54% of patients was referred for genetic testing. This study suggests that clinicians were correctly recognizing the need to refer young patients and patients with positive family history. However, opportunities for genetic testing are frequently missed due to low referral rates in patients with apparently sporadic PCC, particularly older than 30 years old. It is imperative that all the providers involved in the multidisciplinary care of patients with pheochromocytomas are aware of the genetic disorders associated with these unique tumors.
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15
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Cardiac electrical remodeling and neurodegenerative diseases association. Life Sci 2020; 267:118976. [PMID: 33387579 DOI: 10.1016/j.lfs.2020.118976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/01/2020] [Accepted: 12/22/2020] [Indexed: 11/30/2022]
Abstract
Cardiac impairment contributes significantly to the mortality associated with several neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), primarily recognized as brain pathologies. These diseases may be caused by aggregation of a misfolded protein, most often, in the brain, although new evidence also reveals peripheral abnormalities. After characterization of the cardiac involvement in neurodegenerative diseases, several studies concentrated on elucidating the cause of the impaired cardiac function. However, most of the current knowledge is focused on the mechanical aspects of the heart rather than the electrical disturbances. The main objective of this review is to summarize the most recent advances in the elucidation of cardiac electrical remodeling in the neurodegenerative environment. We aimed to determine a crosstalk between the heart and the brain in three neurodegenerative conditions: AD, PD, and HD. We found that the most studies demonstrated important alterations in the electrocardiogram (ECG) of patients with neurodegeneration and in animal models of the conditions. We also showed that little is described when considering excitability disruptions in cardiomyocytes, for example, action potential impairments. It is a matter of contention whether central nervous system abnormalities or the peripheral ones increase the risk of heart diseases in patients with neurodegenerative conditions. To determine this notion, there is a need for new heart studies focusing specifically on the cardiac electrophysiology (e.g., ECG and cardiomyocyte excitability). This review could serve as an important guide in designing novel accurate approaches targeting the heart in neuronal conditions.
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16
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Goldman J, Xie S, Green D, Naini A, Mansukhani MM, Marder K. Predictive testing for neurodegenerative diseases in the age of next-generation sequencing. J Genet Couns 2020; 30:10.1002/jgc4.1342. [PMID: 33090625 PMCID: PMC10699540 DOI: 10.1002/jgc4.1342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 11/09/2022]
Abstract
The availability and cost of next-generation sequencing (NSG) now allow testing large numbers of genes simultaneously. However, the gold standard for predictive testing has been to test only for a known family mutation or confirmed family disease. The goal of this study was to investigate the psychological impact of predictive testing for autosomal dominant neurodegenerative diseases without a known family mutation using next-generation sequencing panels compared to single-gene testing of a known family mutation. Fourteen individuals from families with a known mutation and 10 individuals with unknown family mutations participated. Participants completed questionnaires on demographics, genetic knowledge, and psychological measures of anxiety, depression, perceived personal control, rumination, and intolerance to uncertainty at baseline and 1 and 6 months after receiving results. Decision regret was measured 1 and 6 months after receiving results. Participants completed a modified Huntington disease genetic testing protocol with genetic counseling and neurological and psychological evaluation. Genetic testing of either the known family mutation or an NGS panel of neurodegenerative disease genes was performed. Semi-structured interviews were performed at 6 months post-results about their experience. Two-sample t tests were performed on data collected at each time point to identify significant between-group differences in demographic variables, baseline psychological scores, and baseline genetic knowledge scores. Within-group change over time was assessed by a mixed-effects model. Results of this study indicate that NGS panels for predictive testing for neurodegenerative disease are safe and beneficial to participants when performed within a modified HD protocol. Though significant differences in psychological outcomes were found, these differences may have been driven by genetic results and baseline psychological differences between individuals within the groups. Participants did not regret their decision to test and were largely pleased with the testing protocol.
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Affiliation(s)
- Jill Goldman
- Dept. of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Columbia University Irving Medical Center, New York, NY, USA
| | - Shanghong Xie
- Dept. of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, USA
| | - Dina Green
- Clinical Genetics Service, Memorial Sloane Kettering Cancer Center, New York, NY, USA
| | - Ali Naini
- Dept. of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Mahesh M. Mansukhani
- Dept. of Pathology and Cell Biology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
| | - Karen Marder
- Dept. of Neurology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA
- Columbia University Irving Medical Center, New York, NY, USA
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17
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Svrzikapa N, Longo KA, Prasad N, Boyanapalli R, Brown JM, Dorset D, Yourstone S, Powers J, Levy SE, Morris AJ, Vargeese C, Goyal J. Investigational Assay for Haplotype Phasing of the Huntingtin Gene. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 19:162-173. [PMID: 33209959 PMCID: PMC7648085 DOI: 10.1016/j.omtm.2020.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/04/2020] [Indexed: 01/20/2023]
Abstract
Novel treatments for Huntington's disease (HD), a progressive neurodegenerative disorder, include selective targeting of the mutant allele of the huntingtin gene (mHTT) carrying the abnormally expanded disease-causing cytosine-adenine-guanine (CAG) repeat. WVE-120101 and WVE-120102 are investigational stereopure antisense oligonucleotides that enable selective suppression of mHTT by targeting single-nucleotide polymorphisms (SNPs) that are in haplotype phase with the CAG repeat expansion. Recently developed long-read sequencing technologies can capture CAG expansions and distant SNPs of interest and potentially facilitate haplotype-based identification of patients for clinical trials of oligonucleotide therapies. However, improved methods are needed to phase SNPs with CAG repeat expansions directly and reliably without need for familial genotype/haplotype data. Our haplotype phasing method uses single-molecule real-time sequencing and a custom algorithm to determine with confidence bases at SNPs on mutant alleles, even without familial data. Herein, we summarize this methodology and validate the approach using patient-derived samples with known phasing results. Comparison of experimentally measured CAG repeat lengths, heterozygosity, and phasing with previously determined results showed improved performance. Our methodology enables the haplotype phasing of SNPs of interest and the disease-causing, expanded CAG repeat of the huntingtin gene, enabling accurate identification of patients with HD eligible for allele-selective clinical studies.
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Affiliation(s)
- Nenad Svrzikapa
- Wave Life Sciences Ltd., Cambridge, MA 02138, USA.,Department of Paediatrics, Medical Sciences Division, University of Oxford, Oxford OX3 9DU, UK
| | | | - Nripesh Prasad
- HudsonAlpha Discovery, Discovery Life Sciences, Huntsville, AL 35806, USA.,Genomic Services Laboratory, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | | | | | - Daniel Dorset
- HudsonAlpha Discovery, Discovery Life Sciences, Huntsville, AL 35806, USA.,Genomic Services Laboratory, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | | | - Jason Powers
- Q Solutions
- EA Genomics, LLC, Morrisville, NC 27560, USA
| | - Shawn E Levy
- HudsonAlpha Discovery, Discovery Life Sciences, Huntsville, AL 35806, USA.,Genomic Services Laboratory, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | | | | | - Jaya Goyal
- Wave Life Sciences Ltd., Cambridge, MA 02138, USA
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18
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Kim KY, Kim TH, Seong MW, Park SS, Moon JS, Ko JS. Mutation spectrum and biochemical features in infants with neonatal Dubin-Johnson syndrome. BMC Pediatr 2020; 20:369. [PMID: 32758197 PMCID: PMC7404915 DOI: 10.1186/s12887-020-02260-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/27/2020] [Indexed: 01/06/2023] Open
Abstract
Background Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder presenting as isolated direct hyperbilirubinemia.DJS is rarely diagnosed in the neonatal period. The purpose of this study was to clarify the clinical features of neonatal DJS and to analyze the genetic mutation of adenosine triphosphate-binding cassette subfamily C member 2 (ABCC2). Methods From 2013 to 2018, 135 infants with neonatal cholestasis at Seoul National University Hospital were enrolled. Genetic analysis was performed by neonatal cholestasis gene panel. To clarify the characteristics of neonatal DJS, the clinical and laboratory results of 6 DJS infants and 129 infants with neonatal cholestasis from other causes were compared. Results A total of 8 different ABCC2 variants were identified among the 12 alleles of DJS. The most common variant was p.Arg768Trp (33.4%), followed by p.Arg100Ter (16.8%). Three novel variants were identified (p.Gly693Glu, p.Thr394Arg, and p.Asn718Ser). Aspartate transaminase (AST) and alanine transaminase (ALT) levels were significantly lower in infants with DJS than in infants with neonatal cholestasis from other causes. Direct bilirubin and total bilirubin were significantly higher in the infants with DJS. Conclusions We found three novel variants in 6 Korean infants with DJS. When AST and ALT levels are normal in infants with neonatal cholestasis, genetic analysis of ABCC2 permits an accurate diagnosis.
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Affiliation(s)
- Kwang Yeon Kim
- Department of Pediatrics, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-Gu, 110-769, Seoul, Korea
| | - Tae Hyeong Kim
- Department of Pediatrics, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-Gu, 110-769, Seoul, Korea
| | - Moon-Woo Seong
- Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Sung Sup Park
- Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Soo Moon
- Department of Pediatrics, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-Gu, 110-769, Seoul, Korea
| | - Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-Gu, 110-769, Seoul, Korea.
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19
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Zhao M, Cheah FSH, Tan ASC, Lian M, Phang GP, Agarwal A, Chong SS. Robust Preimplantation Genetic Testing of Huntington Disease by Combined Triplet-Primed PCR Analysis of the HTT CAG Repeat and Multi-Microsatellite Haplotyping. Sci Rep 2019; 9:16481. [PMID: 31712634 PMCID: PMC6848083 DOI: 10.1038/s41598-019-52769-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/23/2019] [Indexed: 12/13/2022] Open
Abstract
Huntington disease (HD) is a lethal neurodegenerative disorder caused by expansion of a CAG repeat within the huntingtin (HTT) gene. Disease prevention can be facilitated by preimplantation genetic testing for this monogenic disorder (PGT-M). We developed a strategy for HD PGT-M, involving whole genome amplification (WGA) followed by combined triplet-primed PCR (TP-PCR) for HTT CAG repeat expansion detection and multi-microsatellite marker genotyping for disease haplotype phasing. The strategy was validated and tested pre-clinically in a simulated PGT-M case before clinical application in five cycles of a PGT-M case. The assay reliably and correctly diagnosed all embryos, even where allele dropout (ADO) occurred at the HTT CAG repeat locus or at one or more linked markers. Ten of the 27 embryos analyzed were diagnosed as unaffected. Four embryo transfers were performed, two of which involved fresh cycle double embryo transfers and two were frozen-thawed single embryo transfers. Pregnancies were achieved from each of the frozen-thawed single embryo transfers and confirmed to be unaffected by amniocentesis, culminating in live births at term. This strategy enhances diagnostic confidence for PGT-M of HD and can also be employed in situations where disease haplotype phase cannot be established prior to the start of PGT-M.
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Affiliation(s)
- Mingjue Zhao
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Felicia Siew Hong Cheah
- Preimplantation Genetic Diagnosis Center, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Arnold Sia Chye Tan
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Preimplantation Genetic Diagnosis Center, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Mulias Lian
- Preimplantation Genetic Diagnosis Center, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Gui Ping Phang
- Preimplantation Genetic Diagnosis Center, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore
| | - Anupriya Agarwal
- Clinic for Human Reproduction, Department of Obstetrics and Gynecology, National University Hospital, Singapore, Singapore
| | - Samuel S Chong
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Preimplantation Genetic Diagnosis Center, Khoo Teck Puat - National University Children's Medical Institute, National University Health System, Singapore, Singapore. .,Molecular Diagnosis Center and Clinical Cytogenetics Service, Department of Laboratory Medicine, National University Hospital, Singapore, Singapore.
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20
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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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21
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Butz H, Patócs A. Brief Summary of the Most Important Molecular Genetic Methods (PCR, qPCR, Microarray, Next-Generation Sequencing, etc.). EXPERIENTIA SUPPLEMENTUM (2012) 2019; 111:33-52. [PMID: 31588527 DOI: 10.1007/978-3-030-25905-1_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular genetic methods have become an organic part of everyday clinical practice. In the past, molecular diagnostic tests were carried out for genetic diagnosis of a particular monogenic disease. In these situations the tests itself were used for identification of one particular genetic alteration (e.g., point mutation or deletion) of the gene of interest. Later, parallel with the development of the technology, the focus has shifted by allowing investigating at once targeted gene panels and even the whole exome/genome behind a suspected genetic disorder. Historically for these purposes, array-based methods (oligonucleotide arrays) and then next-generation sequencing-based methods have been used. High-throughput methods have been fundamentally transforming the everyday, routine genetic diagnostics, but older molecular techniques still have a role in clinical genetics. Here, we summarize the most important molecular genetic methods and shed light to the advantages and disadvantages of their application in routine diagnostics. We mainly focus on methods used for detection of germline alterations.
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Affiliation(s)
- Henriett Butz
- Department of Laboratory Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- "Lendület" Hereditary Endocrine Tumors Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary
| | - Attila Patócs
- Department of Laboratory Medicine, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
- "Lendület" Hereditary Endocrine Tumors Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.
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22
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Bram E, Javanmardi K, Nicholson K, Culp K, Thibert JR, Kemppainen J, Le V, Schlageter A, Hadd A, Latham GJ. Comprehensive genotyping of the C9orf72 hexanucleotide repeat region in 2095 ALS samples from the NINDS collection using a two-mode, long-read PCR assay. Amyotroph Lateral Scler Frontotemporal Degener 2018; 20:107-114. [PMID: 30430876 DOI: 10.1080/21678421.2018.1522353] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Expansion of the G4C2 repeat tract in the C9orf72 gene is linked to frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we provide comprehensive genotyping of the C9orf72 repeat region for the National Institute of Neurological Disorders and Stroke (NINDS) ALS collection (n = 2095), using a novel bimodal PCR assay capable of amplifying nearly 100% GC-rich sequences. METHODS A single-tube 3-primer PCR assay mode, resolved using capillary electrophoresis, was used for sizing up to 145 repeats with single-repeat accuracy, for detecting expansions irrespective of their overall size, and for flagging confounding 3' sequence variations (SVs). A modified two-primer PCR mode, resolved via agarose gel electrophoresis, provided further size information for hyper-expanded samples (>145 repeats) up to ∼5.8 kb amplicons (∼950 G4C2 repeats). RESULTS Within the evaluated cohort, 177 (8.4%) samples were expanded, with 175 (99%) samples being hyper-expanded. 3'-SVs were identified in 64 (3.1%) samples, and were most common in expanded alleles. Genotypes of all 606 (29%) homozygous samples were confirmed using an orthogonal PCR assay. CONCLUSION This study and PCR method may improve and standardize molecular characterization of the C9orf72 locus, and have the potential to inform phenotype-genotype correlations and therapeutic development in ALS/FTD.
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23
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Chheda P, Chanekar M, Salunkhe Y, Dama T, Pais A, Pande S, Bendre R, Shah N. A Study of Triplet-Primed PCR for Identification of CAG Repeat Expansion in the HTT Gene in a Cohort of 503 Indian Cases with Huntington's Disease Symptoms. Mol Diagn Ther 2018; 22:353-359. [PMID: 29619771 DOI: 10.1007/s40291-018-0327-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder with an average age at onset of 40 years. It is a polyglutamine (polyQ) disorder that is caused by an increase in the number of CAG repeats in the huntingtin (HTT) gene. Genetic tests that accurately determine the number of CAG repeats are performed for confirmation of diagnosis, predictive testing of persons at genetic risk for inheriting HD, and prenatal testing. The aim of our study was to evaluate efficacy of triplet-primed polymerase chain reaction (TP-PCR) for routine diagnosis of HD in suspected cases from India. METHODS We evaluated a combination of CAG flanking PCR and triplet-primed PCR for estimation of CAG repeats in 503 cases with clinical suspicion of HD. RESULTS There were 250 cases (49.7%) that showed the presence of expanded alleles, with 241 (47.9%) being fully penetrant alleles and nine (1.8%) in the reduced penetrance category. There were seven juvenile cases with an age of onset of < 20 years, with the longest allele comprising 106 CAG repeats found in an 8-year-old male patient. The results demonstrated an inverse (R = - 0.67) relationship between CAG length and age at clinical onset. CONCLUSION Our study on pan-Indian cases is one of the largest studies reported so far in India and focuses on the most accurate and comprehensive molecular diagnostic evaluation of HD.
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Affiliation(s)
- Pratiksha Chheda
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India.
| | - Milind Chanekar
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India
| | - Yogita Salunkhe
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India
| | - Tavisha Dama
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India
| | - Anurita Pais
- Genetics Department, Metropolis Healthcare Ltd, Mumbai, 400 070, India
| | - Shailesh Pande
- Genetics Department, Metropolis Healthcare Ltd, Mumbai, 400 070, India
| | - Rajesh Bendre
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India
| | - Nilesh Shah
- Department of Molecular Pathology, Metropolis Healthcare Ltd, Commercial Building A, Unit No. 409 to 416, 4th Floor, Kohinoor City, Near Kohinoor Mall, Kirol Road, Kurla-W, Mumbai, 400 070, India
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24
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Aganzo M, Montojo MT, López de Las Hazas MC, Martínez-Descals A, Ricote-Vila M, Sanz R, González-Peralta I, Martín-Hernández R, de Dios O, Garcés C, Galdón A, Lorenzo Ó, Tomás-Zapico C, Dávalos A, Vázquez C, González N. Customized Dietary Intervention Avoids Unintentional Weight Loss and Modulates Circulating miRNAs Footprint in Huntington's Disease. Mol Nutr Food Res 2018; 62:e1800619. [PMID: 30359470 DOI: 10.1002/mnfr.201800619] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/02/2018] [Indexed: 12/25/2022]
Abstract
SCOPE Huntington's disease (HD) is a rare progressive neurodegenerative disorder of genetic origin, with no definitive treatment. Unintentional weight loss (UWL) is a clinical feature of symptomatic HD subjects. To prevent UWL, a customized HD diet is designed and its impact on plasma miRNA HD footprint and neurological parameters is examined. METHODS AND RESULTS Eleven participants are included, BMI ≤ 18 kg m-2 or UWL of 5% in 6 months or 10% in a year. Diet design is based on nutritional surveys and interviews of participants and caregivers and on published literature review. Twelve-month dietary intervention, with follow-up every 3 months, induces high diet adherence, which manages to curb UWL in all participants (73% gained weight). Noticeable increases in fat mass and leptin levels are obtained. The results also show significant decrease in the expression of 19 miRNAs, which are previously reported to be upregulated in HD-patients versus healthy controls: revealing hsa-miR-338-3p, hsa-miR-128-3p, hsa-miR-23a-3p, and hsa-miR-24-3p as potential HD-biomarkers. The diminished expression of hsa-miR-100-5p reflects the general maintenance of the functional status. Cognitive status is improved in six of 11 participants, while only three present better motor-score values. CONCLUSION A customized HD-diet prevents UWL and modified miRNAs HD-footprint. The normalization of miRNA values suggests its potentially use as HD-biomarkers.
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Affiliation(s)
- Miguel Aganzo
- Division of Endocrinology, Fundación Jiménez Díaz, 28040, Madrid, Spain
| | - María-Teresa Montojo
- Department of Neurology, Movement Disorders Unit, Fundación Jiménez Díaz, 28040, Madrid, Spain
| | - María-Carmen López de Las Hazas
- Laboratory of Epigenetics of Lipid Metabolism, Instituto Madrileño de Estudios Avanzados (IMDEA)-Alimentación, CEI UAM+CSIC, Madrid, Spain
| | | | - Marta Ricote-Vila
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), UAM, Madrid, Spain
| | - Raúl Sanz
- Centros de Estudios Genéticcos ATG Medical, Madrid, Spain
| | - Irene González-Peralta
- Centros de Estudios Genéticcos ATG Medical, Madrid, Spain.,Escuela Superior de Ciencias Experimentales y Tecnología. URJC, Madrid, Spain
| | - Roberto Martín-Hernández
- Laboratory of Epigenetics of Lipid Metabolism, Instituto Madrileño de Estudios Avanzados (IMDEA)-Alimentación, CEI UAM+CSIC, Madrid, Spain
| | | | | | - Alba Galdón
- Division of Endocrinology, Fundación Jiménez Díaz, 28040, Madrid, Spain
| | - Óscar Lorenzo
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), UAM, Madrid, Spain
| | - Cristina Tomás-Zapico
- Department of Functional Biology, Physiology Area, Faculty of Medicine, University of Oviedo, Oviedo, Spain
| | - Alberto Dávalos
- Laboratory of Epigenetics of Lipid Metabolism, Instituto Madrileño de Estudios Avanzados (IMDEA)-Alimentación, CEI UAM+CSIC, Madrid, Spain
| | - Clotilde Vázquez
- Division of Endocrinology, Fundación Jiménez Díaz, 28040, Madrid, Spain
| | - Nieves González
- Renal, Vascular and Diabetes Research Laboratory, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz (IIS-FJD), UAM, Madrid, Spain.,Centros de Estudios Genéticcos ATG Medical, Madrid, Spain.,Spanish Biomedical Research Network in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
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25
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Carrassi E, Pugliatti M, Govoni V, Sensi M, Casetta I, Granieri E. Epidemiological Study of Huntington's Disease in the Province of Ferrara, Italy. Neuroepidemiology 2017; 49:18-23. [PMID: 28803251 DOI: 10.1159/000479697] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/19/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by the abnormal expansion of CAG triplet repeat. We aimed to reappraise HD epidemiology in a northern Italian population, in relation to introduction of genetic testing. METHODS Through ICD-9M code 333.4 and medical fare exemption code RF0080, HD cases were identified from administrative health data and medical records from the Units of Neurology and Genetics, Ferrara University Hospital, and from other provincial neurological structures. RESULTS HD mean annual incidence rate in 1990-2009 was 0.3 per 100,000 (95% CI 0.2-0.5). All incident cases were found to have symptoms of the disease's classic form, and neither juvenile nor the rigid Westphal variant was detected. The mean (SD) age at onset was 50.2 (12.7 years; range 32-82 years), 54.9 (14.6) for men and 45.8 (9.4) for women. On prevalence day, December 31, 2014, HD prevalence was 4.2 per 100,000 (95% CI 2.4-7.0), with a male:female ratio of 1:2. CONCLUSIONS The prevalence and incidence of HD in our population were lower than the prevalence and incidence reported for other European and Italian populations, but higher compared to those of Asia, Africa, and Eastern Europe. Compared to previous studies, HD incidence and prevalence did not change significantly.
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Affiliation(s)
- Erika Carrassi
- Department of Biomedical and Specialty Surgery, Section of Neurology, University of Ferrara, Ferrara, Italy
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26
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Zhao M, Cheah FSH, Chen M, Lee CG, Law HY, Chong SS. Improved high sensitivity screen for Huntington disease using a one-step triplet-primed PCR and melting curve assay. PLoS One 2017; 12:e0180984. [PMID: 28700716 PMCID: PMC5507316 DOI: 10.1371/journal.pone.0180984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 05/22/2017] [Indexed: 11/19/2022] Open
Abstract
Molecular diagnosis of Huntington disease (HD) is currently performed by fluorescent repeat-flanking or triplet-primed PCR (TP-PCR) with capillary electrophoresis (CE). However, CE requires multiple post-PCR steps and may result in high cost in high-throughput settings. We previously described a cost-effective single-step molecular screening strategy employing the use of melting curve analysis (MCA). However, because it relies on repeat-flanking PCR, its efficiency in detecting expansion mutations decreases with increasing size of the repeat, which could lead to false-negative results. To address this pitfall, we have developed an improved screening assay coupling TP-PCR, which has been shown in CE-based assays to detect all expanded alleles regardless of size, with MCA in a rapid one-step assay. A companion protocol for rapid size confirmation of expansion-positive samples is also described. The assay was optimized on 30 genotype-known DNAs, and two plasmids pHTT(CAG)26 and pHTT(CAG)33 were used to establish the threshold temperatures (TTs) distinguishing normal from expansion-positive samples. In contrast to repeat-flanking PCR MCA, TP-PCR MCA displayed much higher sensitivity for detecting large expansions. All 30 DNAs generated distinct melt peak Tms which correlated well with each sample's larger allele. Normal samples were clearly distinguished from affected samples. The companion sizing protocol accurately sized even the largest expanded allele of ~180 CAGs. Blinded analysis of 69 clinical samples enriched for HD demonstrated 100% assay sensitivity and specificity in sample segregation. The assay targets the HTT CAG repeat specifically, tolerates a wide range of input DNA, and works well using DNA from saliva and buccal swab in addition to blood. Therefore, rapid, accurate, reliable, and high-throughput detection/exclusion of HD can be achieved using this one-step screening assay, at less than half the cost of fluorescent PCR with CE.
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Affiliation(s)
- Mingjue Zhao
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Felicia S. H. Cheah
- Khoo Teck Puat – National University Children’s Medical Institute, National University Health System, Singapore, Singapore
| | - Min Chen
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Caroline G. Lee
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Division of Medical Sciences, National Cancer Center, Singapore, Singapore
- Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Hai-Yang Law
- Department of Pediatric Medicine, KK Women’s and Children’s Hospital, Singapore, Singapore
| | - Samuel S. Chong
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Khoo Teck Puat – National University Children’s Medical Institute, National University Health System, Singapore, Singapore
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
- * E-mail:
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27
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Miller CR, Mambo NC, Dong J, Campbell GA. A Case of Previously Unsuspected Huntington Disease Diagnosed at Autopsy. Acad Forensic Pathol 2017; 7:136-144. [PMID: 31239966 DOI: 10.23907/2017.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 12/20/2016] [Indexed: 11/12/2022]
Abstract
Huntington disease (HD) is a neurodegenerative disorder with a worldwide prevalence of four to ten per 100 000. It is characterized by choreiform movements, behavioral/psychiatric disturbances, and eventual cognitive decline. Symptoms usually present between 30 and 50 years of age and the diagnosis is based on the combination of clinical symptoms, family history, and genetic testing. A variation of HD, juvenile Huntington disease (JHD), presents earlier, with more severe symptoms and with a worse prognosis. Symptoms are different in JHD, with personality changes and learning difficulties being the predominant presenting features. Seizures are common in JHD, and chorea is uncommon; movement disorders at presentation of JHD are predominantly nonchoreiform. The inheritance pattern for both HD and JHD is autosomal dominant and the disease is caused by an elongation of the CAG repeat in the huntingtin gene. There are many published case reports of Huntington disease that were confirmed at autopsy, but to our knowledge, there are no reports in the literature where the diagnosis of Huntington disease was first made at autopsy. We present a case of a 28-year-old African-American male who was in a state of neglect due to a lifetime of abuse, cognitive difficulties, and seizures, whose cause of death was pneumonia. The gross autopsy findings included bilateral caudate nucleus atrophy and lateral ventricular dilation. Microscopically, severe bilateral neuronal loss and gliosis of the caudate and putamen nuclei were seen. Genetic testing for the number of CAG repeats confirmed the diagnosis and was consistent with JHD.
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Affiliation(s)
| | | | - Jianli Dong
- University of Texas Medical Branch at Galveston - Pathology
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28
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Pagan F, Torres-Yaghi Y, Altshuler M. The diagnosis and natural history of Huntington disease. HUNTINGTON DISEASE 2017; 144:63-67. [DOI: 10.1016/b978-0-12-801893-4.00005-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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29
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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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30
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Kay C, Tirado-Hurtado I, Cornejo-Olivas M, Collins JA, Wright G, Inca-Martinez M, Veliz-Otani D, Ketelaar ME, Slama RA, Ross CJ, Mazzetti P, Hayden MR. The targetable A1 Huntington disease haplotype has distinct Amerindian and European origins in Latin America. Eur J Hum Genet 2016; 25:332-340. [PMID: 28000697 DOI: 10.1038/ejhg.2016.169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 10/24/2016] [Accepted: 11/15/2016] [Indexed: 11/09/2022] Open
Abstract
Huntington disease (HD) is a dominant neurodegenerative disorder caused by a CAG repeat expansion in the Huntingtin (HTT) gene. HD occurs worldwide, but the causative mutation is found on different HTT haplotypes in distinct ethnic groups. In Latin America, HD is thought to have European origins, but indigenous Amerindian ancestry has not been investigated. Here, we report dense HTT haplotypes in 62 mestizo Peruvian HD families, 17 HD families from across Latin America, and 42 controls of defined Peruvian Amerindian ethnicity to determine the origin of HD in populations of admixed Amerindian and European descent. HD in Peru occurs most frequently on the A1 HTT haplotype (73%), as in Europe, but on an unexpected indigenous variant also found in Amerindian controls. This Amerindian A1 HTT haplotype predominates over the European A1 variant among geographically disparate Latin American controls and in HD families from across Latin America, supporting an indigenous origin of the HD mutation in mestizo American populations. We also show that a proportion of HD mutations in Peru occur on a C1 HTT haplotype of putative Amerindian origin (14%). The majority of HD mutations in Latin America may therefore occur on haplotypes of Amerindian ancestry rather than on haplotypes resulting from European admixture. Despite the distinct ethnic ancestry of Amerindian and European A1 HTT, alleles on the parent A1 HTT haplotype allow for development of identical antisense molecules to selectively silence the HD mutation in the greatest proportion of patients in both Latin American and European populations.
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Affiliation(s)
- Chris Kay
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Indira Tirado-Hurtado
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Jennifer A Collins
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Galen Wright
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Miguel Inca-Martinez
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Diego Veliz-Otani
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Maria E Ketelaar
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Ramy A Slama
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Colin J Ross
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
| | - Pilar Mazzetti
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurologicas, Lima, Peru
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4 Canada
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31
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Kay C, Collins JA, Miedzybrodzka Z, Madore SJ, Gordon ES, Gerry N, Davidson M, Slama RA, Hayden MR. Huntington disease reduced penetrance alleles occur at high frequency in the general population. Neurology 2016; 87:282-8. [PMID: 27335115 DOI: 10.1212/wnl.0000000000002858] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/16/2016] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE To directly estimate the frequency and penetrance of CAG repeat alleles associated with Huntington disease (HD) in the general population. METHODS CAG repeat length was evaluated in 7,315 individuals from 3 population-based cohorts from British Columbia, the United States, and Scotland. The frequency of ≥36 CAG alleles was assessed out of a total of 14,630 alleles. The general population frequency of reduced penetrance alleles (36-39 CAG) was compared to the prevalence of patients with HD with genetically confirmed 36-39 CAG from a multisource clinical ascertainment in British Columbia, Canada. The penetrance of 36-38 CAG repeat alleles for HD was estimated for individuals ≥65 years of age and compared against previously reported clinical penetrance estimates. RESULTS A total of 18 of 7,315 individuals had ≥36 CAG, revealing that approximately 1 in 400 individuals from the general population have an expanded CAG repeat associated with HD (0.246%). Individuals with CAG 36-37 genotypes are the most common (36, 0.096%; 37, 0.082%; 38, 0.027%; 39, 0.000%; ≥40, 0.041%). General population CAG 36-38 penetrance rates are lower than penetrance rates extrapolated from clinical cohorts. CONCLUSION HD alleles with a CAG repeat length of 36-38 occur at high frequency in the general population. The infrequent diagnosis of HD at this CAG length is likely due to low penetrance. Another important contributing factor may be reduced ascertainment of HD in those of older age.
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Affiliation(s)
- Chris Kay
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Jennifer A Collins
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Zosia Miedzybrodzka
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Steven J Madore
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Erynn S Gordon
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Norman Gerry
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Mark Davidson
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Ramy A Slama
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ
| | - Michael R Hayden
- From the Centre for Molecular Medicine and Therapeutics (C.K., J.A.C., R.A.S., M.R.H.), University of British Columbia, Canada; Medical Genetics Group (Z.M., M.D.), School of Medicine and Dentistry, University of Aberdeen, UK; and Molecular Biology Group (S.J.M., E.S.G., N.G.), Coriell Institute for Medical Research, Camden, NJ.
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Zhao M, Lee CG, Law HY, Chong SS. Enhanced Detection and Sizing of the HTT CAG Repeat Expansion in Huntington Disease Using an Improved Triplet-Primed PCR Assay. NEURODEGENER DIS 2016; 16:348-51. [PMID: 27207688 DOI: 10.1159/000444714] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 02/16/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Accurate determination of the CAG repeat number is crucial for diagnostic and predictive testing for Huntington disease (HD). Current PCR-based assays can accurately size up to ∼110 HTT CAG repeats. OBJECTIVE To develop an improved assay capable of detecting larger CAG repeat expansions. METHODS A triplet-primed PCR (TP-PCR) assay was optimized and validated on 14 HD reference DNAs, including a sample carrying a large expansion of ∼180 CAG repeats. RESULTS All 14 HD reference samples showed 100% concordance with the previously verified allele sizes. For alleles under 45 CAGs, identical repeat sizes were obtained, while alleles larger than 46 CAGs were sized to within ±1 CAG. The improved TP-PCR assay successfully detected the ∼180 CAG repeat allele in an affected sample. CONCLUSION This method extends the detection limit of large expanded alleles to at least ∼175-180 CAG repeats, thus reducing the likelihood of requiring Southern blot analysis for any HD-affected sample.
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Affiliation(s)
- Mingjue Zhao
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Green KM, Linsalata AE, Todd PK. RAN translation-What makes it run? Brain Res 2016; 1647:30-42. [PMID: 27060770 DOI: 10.1016/j.brainres.2016.04.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 03/24/2016] [Accepted: 04/01/2016] [Indexed: 12/14/2022]
Abstract
Nucleotide-repeat expansions underlie a heterogeneous group of neurodegenerative and neuromuscular disorders for which there are currently no effective therapies. Recently, it was discovered that such repetitive RNA motifs can support translation initiation in the absence of an AUG start codon across a wide variety of sequence contexts, and that the products of these atypical translation initiation events contribute to neuronal toxicity. This review examines what we currently know and do not know about repeat associated non-AUG (RAN) translation in the context of established canonical and non-canonical mechanisms of translation initiation. We highlight recent findings related to RAN translation in three repeat expansion disorders: CGG repeats in fragile X-associated tremor ataxia syndrome (FXTAS), GGGGCC repeats in C9orf72 associated amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) and CAG repeats in Huntington disease. These studies suggest that mechanistic differences may exist for RAN translation dependent on repeat type, repeat reading frame, and the surrounding sequence context, but that for at least some repeats, RAN translation retains a dependence on some of the canonical translational initiation machinery. This article is part of a Special Issue entitled SI:RNA Metabolism in Disease.
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Affiliation(s)
- Katelyn M Green
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Alexander E Linsalata
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Peter K Todd
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, United States; Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, United States; Veterans Affairs Medical Center, Ann Arbor, MI, United States.
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Baake V, Hart EP, Bos R, Roos RAC. Participants at the Leiden Site of the REGISTRY Study: A Demographic Approach. J Huntingtons Dis 2016; 5:83-90. [PMID: 27003663 DOI: 10.3233/jhd-150157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND REGISTRY is the largest European observational study of Huntington's disease (HD). The Leiden University Medical Center (LUMC) in The Netherlands is the largest recruiting site. OBJECTIVE The aim of this paper is to give an overview of the baseline characteristics of all Leiden participants from the start of the study in 2005 until the close of REGISTRY at the LUMC in September 2014. METHODS The Leiden cohort is described in two different ways: CAG repeat length and presence of motor signs. RESULTS Division into groups based on prolonged CAG length revealed that the cohort consists of 4 intermediate - (27-35 CAG), 22 reduced penetrance - (36-39 CAG), 465 full penetrance - (>39 CAG) and 60 control participants (<27 CAG). The second way of dividing the participants based on present or absent of motor signs, showed that 170 pre-motormanifest - and 317 motormanifest participants were enrolled. CONCLUSION The Leiden REGISTRY cohort at baseline is mainly characterized by full penetrance gene expansion carriers who have been clinically diagnosed with HD but who remain relatively functionally independent. For the majority of these participants, disease onset was based on motor signs followed by psychiatric and cognitive signs.
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Affiliation(s)
- Verena Baake
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
| | - Ellen P Hart
- Center for Human Drug Research, Leiden, The Netherlands
| | - Reineke Bos
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
| | - Raymund A C Roos
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
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López-Díaz JA, Ruíz-Díaz G, Ortega-Blanco JA. [A case of Huntington disease in primary care: The role of the physician]. Semergen 2016; 42:e157-e159. [PMID: 26924685 DOI: 10.1016/j.semerg.2016.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 10/22/2022]
Affiliation(s)
- J A López-Díaz
- Medicina de Familia y Comunitaria, Centro de Salud Molino de la Vega, Huelva, España.
| | - G Ruíz-Díaz
- Medicina de Familia y Comunitaria, Centro de Salud Molino de la Vega, Huelva, España
| | - J A Ortega-Blanco
- Medicina de Familia y Comunitaria, Centro de Salud Molino de la Vega, Huelva, España
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Bastepe M, Xin W. Huntington Disease: Molecular Diagnostics Approach. ACTA ACUST UNITED AC 2015; 87:9.26.1-9.26.23. [DOI: 10.1002/0471142905.hg0926s87] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Murat Bastepe
- Neurogenetics DNA Diagnostic Laboratory, Department of Neurology, Massachusetts General Hospital and Harvard Medical School Boston Massachusetts
- Genetics Training Program, Harvard Medical School Boston Massachusetts
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School Boston Massachusetts
| | - Winnie Xin
- Neurogenetics DNA Diagnostic Laboratory, Department of Neurology, Massachusetts General Hospital and Harvard Medical School Boston Massachusetts
- Center for Human Genetic Research, Massachusetts General Hospital and Harvard Medical School Boston Massachusetts
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Ungar WJ. Next Generation Sequencing and Health Technology Assessment in Autism Spectrum Disorder. JOURNAL OF THE CANADIAN ACADEMY OF CHILD AND ADOLESCENT PSYCHIATRY = JOURNAL DE L'ACADEMIE CANADIENNE DE PSYCHIATRIE DE L'ENFANT ET DE L'ADOLESCENT 2015; 24:123-127. [PMID: 26379724 PMCID: PMC4558983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 05/26/2015] [Indexed: 06/05/2023]
Abstract
Next generation sequencing (NGS) is a new genome-based technology showing great promise in delineating the genetic basis of autism thus facilitating diagnosis and in the future, the selection of treatment. NGS can have a targeted use as well as provide clinically important findings from medically actionable variants regarding the risk of other disorders. As more is learned about the genomic basis of autism, the clinical utility of the risk information will increase. But at what cost? As the medical management that ensues from primary and secondary (incidental) findings grows, there will be increased pressure on sub-specialists with a longer and more circuitous pathway to care. This will result in higher costs to health care systems and to families. Health technology assessment is needed to measure the additional costs associated with NGS compared to standard care and to weigh these costs against additional health benefits. Well-designed data collection systems should be implemented early in clinical translation of this technology to enable assessment of clinical utility and cost-effectiveness and to generate high quality evidence to inform clinical and budget allocation decision-making.
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Affiliation(s)
- Wendy J. Ungar
- Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario
- Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario
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