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Clark LN, Gao Y, Wang GT, Hernandez N, Ashley-Koch A, Jankovic J, Ottman R, Leal SM, Rodriguez SMB, Louis ED. Whole genome sequencing identifies candidate genes for familial essential tremor and reveals biological pathways implicated in essential tremor aetiology. EBioMedicine 2022; 85:104290. [PMID: 36183486 PMCID: PMC9525816 DOI: 10.1016/j.ebiom.2022.104290] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 08/25/2022] [Accepted: 09/13/2022] [Indexed: 12/13/2022] Open
Abstract
Background Essential tremor (ET), one of the most common neurological disorders, has a phenotypically heterogeneous presentation characterized by bilateral kinetic tremor of the arms and, in some patients, tremor involving other body regions (e.g., head, voice). Genetic studies suggest that ET is genetically heterogeneous. Methods We analyzed whole genome sequence data (WGS) generated on 104 multi-generational white families with European ancestry affected by ET. Genome-wide parametric linkage and association scans were analyzed using adjusted logistic regression models through the application of the Pseudomarker software. To investigate the additional contribution of rare variants in familial ET, we also performed an aggregate variant non-parametric linkage (NPL) analysis using the collapsed haplotype method implemented in CHP-NPL software. Findings Parametric linkage analysis of common variants identified several loci with significant evidence of linkage (HLOD ≥3.6). Among the gene regions within the strongest ET linkage peaks were BTC (4q13.3, HLOD=4.53), N6AMT1 (21q21.3, HLOD=4.31), PCDH9 (13q21.32, HLOD=4.21), EYA1 (8q13.3, HLOD=4.04), RBFOX1 (16p13.3, HLOD=4.02), MAPT (17q21.31, HLOD=3.99) and SCARB2 (4q21.1, HLOD=3.65). CHP-NPL analysis identified fifteen additional genes with evidence of significant linkage (LOD ≥3.8). These genes include TUBB2A, VPS33B, STEAP1B, SPINK5, ZRANB1, TBC1D3C, PDPR, NPY4R, ETS2, ZNF736, SPATA21, ARL17A, PZP, BLK and CCDC94. In one ET family contributing to the linkage peak on chromosome 16p13.3, we identified a likely pathogenic heterozygous canonical splice acceptor variant in exon 2 of RBFOX1 (ENST00000547372; c.4-2A>G), that co-segregated with the ET phenotype in the family. Interpretation Linkage and association analyses of WGS identified several novel ET candidate genes, which are implicated in four major pathways that include 1) the epidermal growth factor receptor-phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha-AKT serine/threonine kinase 1 (EGFR-PI3K-AKT) and Mitogen-activated protein Kinase 1 (ERK) pathways, 2) Reactive oxygen species (ROS) and DNA repair, 3) gamma-aminobutyric acid-ergic (GABAergic) system and 4) RNA binding and regulation of RNA processes. Our study provides evidence for a possible overlap in the genetic architecture of ET, neurological disease, cancer and aging. The genes and pathways identified can be prioritized in future genetic and functional studies. Funding National Institutes of Health, NINDS, NS073872 (USA) and NIA AG058131(USA).
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Affiliation(s)
- Lorraine N Clark
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University Irving Medical Center, New York, NY, USA.
| | - Yizhe Gao
- The G.H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; The Center for Statistical Genetics, Columbia University Irving Medical Center, New York, NY, USA
| | - Gao T Wang
- The G.H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; The Center for Statistical Genetics, Columbia University Irving Medical Center, New York, NY, USA
| | - Nora Hernandez
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas TX, USA
| | - Allison Ashley-Koch
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - Joseph Jankovic
- Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston TX, USA
| | - Ruth Ottman
- The G.H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Epidemiology, Mailman School of Public Health, Columbia University Irving Medical Center, New York, NY, USA; Division of Translational Epidemiology, New York State Psychiatric Institute, New York, NY, USA
| | - Suzanne M Leal
- The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University Irving Medical Center, New York, NY, USA; The G.H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; The Center for Statistical Genetics, Columbia University Irving Medical Center, New York, NY, USA
| | - Sandra M Barral Rodriguez
- The Taub Institute for Research on Alzheimer's Disease and The Aging Brain, Columbia University Irving Medical Center, New York, NY, USA; The G.H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY, USA.
| | - Elan D Louis
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas TX, USA.
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Asif M, Mocanu ID, Abdullah U, Höhne W, Altmüller J, Makhdoom EUH, Thiele H, Baig SM, Nürnberg P, Graul-Neumann L, Hussain MS. A novel missense variant of SCN4A co-segregates with congenital essential tremor in a consanguineous Kurdish family. Am J Med Genet A 2021; 188:1251-1258. [PMID: 34913263 DOI: 10.1002/ajmg.a.62610] [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: 09/14/2021] [Revised: 11/10/2021] [Accepted: 11/30/2021] [Indexed: 11/09/2022]
Abstract
Essential tremor (ET) is a neurological disorder characterized by bilateral and symmetric postural, isometric, and kinetic tremors of forelimbs produced during voluntary movements. To date, only a single SCN4A variant has been suggested to cause ET. In continuation of the previous report on the association between SCN4A and ET in a family from Spain, we validated the pathogenicity of a novel SCN4A variant and its involvement in ET in a second family affected by this disease. We recruited a Kurdish family with four affected members manifesting congenital tremor. Using whole-exome sequencing, we identified a novel missense variant in SCN4A, NM_000334.4:c.4679C>T; p.(Pro1560Leu), thus corroborating SCN4A's role in ET. The residue is highly conserved across vertebrates and the substitution is predicted to be pathogenic by various in silico tools. Western blotting and immunocytochemistry performed in cells derived from one of the patients showed reduced immunoreactivity of SCN4A as compared to control cells. The study provides supportive evidence for the role of SCN4A in the etiology of ET and expands the phenotypic spectrum of channelopathies to this neurological disorder.
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Affiliation(s)
- Maria Asif
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | - Ionut Dragos Mocanu
- Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | - Uzma Abdullah
- University Institute of Biochemistry and Biotechnology (UIBB), PMAS-Arid Agriculture University, Rawalpindi, Pakistan
| | - Wolfgang Höhne
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Core Facility Genomics, Berlin, Germany.,Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Ehtisham Ul Haq Makhdoom
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany.,Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad, Pakistan.,Neurochemicalbiology and Genetics Laboratory (NGL), Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad, Pakistan
| | - Holger Thiele
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Shahid Mahmood Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE) College, PIEAS, Faisalabad, Pakistan.,Pakistan Science Foundation (PSF), Islamabad, Pakistan.,Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Luitgard Graul-Neumann
- Charité-Universitätsmedizin Berlin, Institut für Medizinische Genetik und Humangenetik, Berlin, Germany
| | - Muhammad Sajid Hussain
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.,Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
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Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Álvarez I, Pastor P, Agúndez JAG. Genomic Markers for Essential Tremor. Pharmaceuticals (Basel) 2021; 14:ph14060516. [PMID: 34072005 PMCID: PMC8226734 DOI: 10.3390/ph14060516] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/13/2022] Open
Abstract
There are many reports suggesting an important role of genetic factors in the etiopathogenesis of essential tremor (ET), encouraging continuing the research for possible genetic markers. Linkage studies in families with ET have identified 4 genes/loci for familial ET, although the responsible gene(s) have not been identified. Genome-wide association studies (GWAS) described several variants in LINGO1, SLC1A2, STK32B, PPARGC1A, and CTNNA3, related with ET, but none of them have been confirmed in replication studies. In addition, the case-control association studies performed for candidate variants have not convincingly linked any gene with the risk for ET. Exome studies described the association of several genes with familial ET (FUS, HTRA2, TENM4, SORT1, SCN11A, NOTCH2NLC, NOS3, KCNS2, HAPLN4, USP46, CACNA1G, SLIT3, CCDC183, MMP10, and GPR151), but they were found only in singular families and, again, not found in other families or other populations, suggesting that some can be private polymorphisms. The search for responsible genes for ET is still ongoing.
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Affiliation(s)
- Félix Javier Jiménez-Jiménez
- Section of Neurology, Hospital Universitario del Sureste, E28500 Arganda del Rey, Spain;
- Correspondence: ; Tel.: +34-636-96-83-95; Fax: +34-913-28-07-04
| | | | - Elena García-Martín
- ARADyAL Instituto de Salud Carlos III, University Institute of Molecular Pathology Biomarkers, University of Extremadura, E10071 Caceres, Spain; (E.G.-M.); (J.A.G.A.)
| | - Ignacio Álvarez
- Movement Disorders Unit, Department of Neurology, University Hospital Mútua de Terrassa, Fundació Docencia i Recerça Mútua de Terrassa, E08221 Terrassa, Spain; (I.Á.); (P.P.)
| | - Pau Pastor
- Movement Disorders Unit, Department of Neurology, University Hospital Mútua de Terrassa, Fundació Docencia i Recerça Mútua de Terrassa, E08221 Terrassa, Spain; (I.Á.); (P.P.)
| | - José A. G. Agúndez
- ARADyAL Instituto de Salud Carlos III, University Institute of Molecular Pathology Biomarkers, University of Extremadura, E10071 Caceres, Spain; (E.G.-M.); (J.A.G.A.)
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Magrinelli F, Latorre A, Balint B, Mackenzie M, Mulroy E, Stamelou M, Tinazzi M, Bhatia KP. Isolated and combined genetic tremor syndromes: a critical appraisal based on the 2018 MDS criteria. Parkinsonism Relat Disord 2020; 77:121-140. [PMID: 32818815 DOI: 10.1016/j.parkreldis.2020.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 04/13/2020] [Accepted: 04/18/2020] [Indexed: 12/12/2022]
Abstract
The 2018 consensus statement on the classification of tremors proposes a two-axis categorization scheme based on clinical features and etiology. It also defines "isolated" and "combined" tremor syndromes depending on whether tremor is the sole clinical manifestation or is associated with other neurological or systemic signs. This syndromic approach provides a guide to investigate the underlying etiology of tremors, either genetic or acquired. Several genetic defects have been proven to cause tremor disorders, including autosomal dominant and recessive, X-linked, and mitochondrial diseases, as well as chromosomal abnormalities. Furthermore, some tremor syndromes are recognized in individuals with a positive family history, but their genetic confirmation is pending. Although most genetic tremor disorders show a combined clinical picture, there are some distinctive conditions in which tremor may precede the appearance of other neurological signs by years or remain the prominent manifestation throughout the disease course, previously leading to misdiagnosis as essential tremor (ET). Advances in the knowledge of genetically determined tremors may have been hampered by the inclusion of heterogeneous entities in previous studies on ET. The recent classification of tremors therefore aims to provide more consistent clinical data for deconstructing the genetic basis of tremor syndromes in the next-generation and long-read sequencing era. This review outlines the wide spectrum of tremor disorders with defined or presumed genetic etiology, both isolated and combined, unraveling diagnostic clues of these conditions and focusing mainly on ET-like phenotypes. Furthermore, we suggest a phenotype-to-genotype algorithm to support clinicians in identifying tremor syndromes and guiding genetic investigations.
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Affiliation(s)
- Francesca Magrinelli
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Anna Latorre
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom.
| | - Bettina Balint
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom; Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany.
| | - Melissa Mackenzie
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom.
| | - Eoin Mulroy
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom.
| | - Maria Stamelou
- Department of Neurology, Attikon University Hospital, Athens, Greece.
| | - Michele Tinazzi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.
| | - Kailash P Bhatia
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, United Kingdom.
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Abstract
Highlights In the current review, we thoroughly reviewed 74 identified articles regarding genes and genetic loci that confer susceptibility to ET. Over 50 genes/genetic loci have been examined for possible association with ET, but consistent results failed to be reported raising the need for collaborative multiethnic studies. Background: Essential tremor (ET) is a common movement disorder, which is mainly characterized by bilateral tremor (postural and/or kinetic) in the upper limbs, with other parts of the body possibly involved. While the pathophysiology of ET is still unclear, there is accumulating evidence indicating that genetic variability may be heavily involved in ET pathogenesis. This review focuses on the role of genetic risk factors in ET susceptibility. Methods: The PubMed database was searched for articles written in English, for studies with humans with ET, controls without ET, and genetic variants. The terms “essential tremor” and “polymorphism” (as free words) were used during search. We also performed meta-analyses for the most examined genetic variants. Results: Seventy four articles concerning LINGO1, LINGO2, LINGO4, SLC1A2, STK32B, PPARGC1A, CTNNA3, DRD3, ALAD, VDR, HMOX1, HMOX2, LRRK1,LRRK2, GBA, SNCA, MAPT, FUS, CYPsIL17A, IL1B, NOS1, ADH1B, TREM2, RIT2, HNMT, MTHFR, PPP2R2B, GSTP1, PON1, GABA receptors and GABA transporter, HS1BP3, ADH2, hSKCa3 and CACNL1A4 genes, and ETM genetic loci were included in the current review. Results from meta-analyses revealed a marginal association for the STK32B rs10937625 and a marginal trend for association (in sensitivity analysis) for the LINGO1 rs9652490, with ET. Discussion: Quite a few variants have been examined for their possible association with ET. LINGO1 rs9652490 and STK32B rs10937625 appear to influence, to some extent, ET susceptibility. However, the conflicting results and the lack of replication for many candidate genes raise the need for collaborative multiethnic studies.
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Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JA. An Update on the Neurochemistry of Essential Tremor. Curr Med Chem 2020; 27:1690-1710. [DOI: 10.2174/0929867325666181112094330] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 09/03/2018] [Accepted: 11/05/2018] [Indexed: 12/21/2022]
Abstract
Background:
The pathophysiology and neurochemical mechanisms of essential
tremor (ET) are not fully understood, because only a few post-mortem studies have been reported,
and there is a lack of good experimental model for this disease.
Objective:
The main aim of this review is to update data regarding the neurochemical features
of ET. Alterations of certain catecholamine systems, the dopaminergic, serotonergic,
GABAergic, noradrenergic, and adrenergic systems have been described, and are the object of
this revision.
Methods:
For this purpose, we performed a literature review on alterations of the neurotransmitter
or neuromodulator systems (catecholamines, gammaaminobutyric acid or GABA,
excitatory amino acids, adenosine, T-type calcium channels) in ET patients (both post-mortem
or in vivo) or in experimental models resembling ET.
Results and Conclusion:
The most consistent data regarding neurochemistry of ET are related
with the GABAergic and glutamatergic systems, with a lesser contribution of adenosine
and dopaminergic and adrenergic systems, while there is not enough evidence of a definite
role of other neurotransmitter systems in ET. The improvement of harmaline-induced tremor
in rodent models achieved with T-type calcium channel antagonists, cannabinoid 1 receptor,
sphingosine-1-phosphate receptor agonists, and gap-junction blockers, suggests a potential
role of these structures in the pathogenesis of ET.
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Affiliation(s)
| | | | - Elena García-Martín
- University Institute of Molecular Pathology Biomarkers, UNEx. ARADyAL Instituto de Salud Carlos III, Caceres, Spain
| | - José A.G. Agúndez
- University Institute of Molecular Pathology Biomarkers, UNEx. ARADyAL Instituto de Salud Carlos III, Caceres, Spain
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Primrose syndrome: a phenotypic comparison of patients with a ZBTB20 missense variant versus a 3q13.31 microdeletion including ZBTB20. Eur J Hum Genet 2020; 28:1044-1055. [PMID: 32071410 DOI: 10.1038/s41431-020-0582-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 11/14/2019] [Accepted: 12/03/2019] [Indexed: 12/23/2022] Open
Abstract
Primrose syndrome is characterized by variable intellectual deficiency, behavior disorders, facial features with macrocephaly, and a progressive phenotype with hearing loss and ectopic calcifications, distal muscle wasting, and contractures. In 2014, ZBTB20 variants were identified as responsible for this syndrome. Indeed, ZBTB20 plays an important role in cognition, memory, learning processes, and has a transcription repressive effect on numerous genes. A more severe phenotype was discussed in patients with missense single nucleotide variants than in those with large deletions. Here, we report on the clinical and molecular results of 14 patients: 6 carrying ZBTB20 missense SNVs, 1 carrying an early truncating indel, and 7 carrying 3q13.31 deletions, recruited through the AnDDI-Rares network. We compared their phenotypes and reviewed the data of the literature, in order to establish more powerful phenotype-genotype correlations. All 57 patients presented mild-to-severe ID and/or a psychomotor delay. Facial features were similar with macrocephaly, prominent forehead, downslanting palpebral fissures, ptosis, and large ears. Hearing loss was far more frequent in patients with missense SNVs (p = 0.002), ectopic calcification, progressive muscular wasting, and contractures were observed only in patients with missense SNVs (p nonsignificant). Corpus callosum dysgenesis (p = 0.00004), hypothyroidism (p = 0.047), and diabetes were also more frequent in this group. However, the median age was 9.4 years in patients with deletions and truncating variant compared with 15.1 years in those with missense SNVs. Longer follow-up will be necessary to determine whether the phenotype of patients with deletions is also progressive.
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Abstract
Essential tremor (ET) is a neurological movement disorder characterised by bilateral limb kinetic/postural tremor, with or without tremor in other body parts including head, voice and lower limbs. Since no causative genes for ET have been identified, it is likely that the disorder occurs as a result of complex genetic factors interacting with various cellular and environmental factors that can result in abnormal function of circuitry involving the cerebello-thalamo-cortical pathway. Genetic analyses have uncovered at least 14 loci and 11 genes that are related to ET, as well as various risk or protective genetic factors. Limitations in ET genetic analyses include inconsistent disease definition, small sample size, varied ethnic backgrounds and many other factors that may contribute to paucity of relevant genetic data in ET. Genetic analyses, coupled with functional and animal studies, have led to better insights into possible pathogenic mechanisms underlying ET. These genetic studies may guide the future development of genetic testing and counselling, and specific, pathogenesis-targeted, therapeutic strategies.
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Abstract
Essential tremor (ET) is one of the most common neurologic disorders, and genetic factors are thought to contribute significantly to disease etiology. There has been a relative lack of progress in understanding the genetic etiology of ET. This could reflect a number of factors, including the presence of substantial phenotypic and genotypic heterogeneity. Thus, a meticulous approach to phenotyping is important for genetic research. A lack of standardized phenotyping across studies and patient centers likely has contributed to the relative lack of success of genomewide association studies in ET. To dissect the genetic architecture of ET, whole-genome sequencing will likely be of value. This will allow specific hypotheses about the mode of inheritance and genetic architecture to be tested. A number of approaches still remain unexplored in ET genetics, including the contribution of copy number variants, uncommon moderate-effect alleles, rare variant large-effect alleles (including Mendelian and complex/polygenic modes of inheritance), de novo and gonadal mosaicism, epigenetic changes, and noncoding variation.
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Affiliation(s)
- Lorraine N Clark
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, and Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Elan D Louis
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York; and Departments of Neurology and of Chronic Disease Epidemiology and Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, New Haven, CT, United States.
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Hervé B, Fauvert D, Dard R, Roume J, Cognard S, Goidin D, Lozach F, Molina-Gomes D, Vialard F. The emerging microduplication 3q13.31: Expanding the genotype-phenotype correlations of the reciprocal microdeletion 3q13.31 syndrome. Eur J Med Genet 2016; 59:463-9. [DOI: 10.1016/j.ejmg.2016.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/18/2016] [Accepted: 08/23/2016] [Indexed: 01/26/2023]
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Jiménez-Jiménez FJ, García-Martín E, Alonso-Navarro H, Lorenzo-Betancor O, Ortega-Cubero S, Pastor P, Calleja M, Agúndez JAG. A family study of DRD3 rs6280, SLC1A2 rs3794087 and MAPT rs1052553 variants in essential tremor. Neurol Res 2016; 38:880-7. [PMID: 27456607 DOI: 10.1080/01616412.2016.1210355] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND/OBJECTIVE Despite many data suggesting a role of genetic factors in the risk for essential tremor (ET), the responsible genes have not been identified. We analyzed in ET Spanish families three single nucleotide polymorphisms (SNPs): DRD3 rs6280, SLC1A2 rs3794087, and MAPT rs1052553) previously related to an increased risk for developing the disease. METHODS We recruited 45 subjects with ET and 13 subjects without tremor belonging to 11 families who were evaluated because of familial tremor. Diagnosis of probable or definite ET was done according to TRIG criteria. Genotyping of the 3 SNPs was done using TaqMan-based qPCR assays. Data were compared with those of healthy controls of our laboratory. Family-based association testing for disease traits was performed as well. RESULTS rs6280 and rs3794087 genotype and allelic frequencies did not differ significantly between subjects with ET and healthy controls. However, rs1052553AA genotype and the allele rs1052553A allele were significantly more frequent among ET patients. rs1052553A allele was non-significantly overrepresented in ET patients compared with controls when considering only the more severely affected member of each ET family. Family-based association test for disease traits showed lack of association between ET and the three SNPs studied. CONCLUSIONS Our results showed a lack of association between rs6280 and rs3794087 with the risk for ET, though a marginal increased risk for ET was observed among the rs1052553A allele carriers, which was not confirmed with a family-based association study.
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Affiliation(s)
- Félix Javier Jiménez-Jiménez
- a Section of Neurology , Hospital Universitario del Sureste , Arganda del Rey , Spain.,b Department of Medicine-Neurology , Hospital "Príncipe de Asturias", Universidad de Alcalá , Alcalá de Henares , Spain
| | | | - Hortensia Alonso-Navarro
- a Section of Neurology , Hospital Universitario del Sureste , Arganda del Rey , Spain.,b Department of Medicine-Neurology , Hospital "Príncipe de Asturias", Universidad de Alcalá , Alcalá de Henares , Spain
| | - Oswaldo Lorenzo-Betancor
- d Neurogenetics Laboratory, Division of Neurosciences , Center for Applied Medical Research, Universidad de Navarra , Pamplona , Spain.,e Department of Neurology , Complejo Asistencial Universitario de Palencia , Palencia , Spain
| | - Sara Ortega-Cubero
- d Neurogenetics Laboratory, Division of Neurosciences , Center for Applied Medical Research, Universidad de Navarra , Pamplona , Spain.,e Department of Neurology , Complejo Asistencial Universitario de Palencia , Palencia , Spain.,f CIBERNED,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas , Instituto de Salud Carlos III , Madrid , Spain
| | - Pau Pastor
- d Neurogenetics Laboratory, Division of Neurosciences , Center for Applied Medical Research, Universidad de Navarra , Pamplona , Spain.,f CIBERNED,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas , Instituto de Salud Carlos III , Madrid , Spain.,g Movement Disorders Unit, Deparment of of Neurology , Hospital Mutua de Terrassa , Terrassa , Spain
| | - Marisol Calleja
- a Section of Neurology , Hospital Universitario del Sureste , Arganda del Rey , Spain
| | - José A G Agúndez
- c Department of Pharmacology , Universidad de Extremadura , Cáceres , Spain
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Liu X, Hernandez N, Kisselev S, Floratos A, Sawle A, Ionita-Laza I, Ottman R, Louis ED, Clark LN. Identification of candidate genes for familial early-onset essential tremor. Eur J Hum Genet 2016; 24:1009-15. [PMID: 26508575 PMCID: PMC5070884 DOI: 10.1038/ejhg.2015.228] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 12/17/2022] Open
Abstract
Essential tremor (ET) is one of the most common causes of tremor in humans. Despite its high heritability and prevalence, few susceptibility genes for ET have been identified. To identify ET genes, whole-exome sequencing was performed in 37 early-onset ET families with an autosomal-dominant inheritance pattern. We identified candidate genes for follow-up functional studies in five ET families. In two independent families, we identified variants predicted to affect function in the nitric oxide (NO) synthase 3 gene (NOS3) that cosegregated with disease. NOS3 is highly expressed in the central nervous system (including cerebellum), neurons and endothelial cells, and is one of three enzymes that converts l-arginine to the neurotransmitter NO. In one family, a heterozygous variant, c.46G>A (p.(Gly16Ser)), in NOS3, was identified in three affected ET cases and was absent in an unaffected family member; and in a second family, a heterozygous variant, c.164C>T (p.(Pro55Leu)), was identified in three affected ET cases (dizygotic twins and their mother). Both variants result in amino-acid substitutions of highly conserved amino-acid residues that are predicted to be deleterious and damaging by in silico analysis. In three independent families, variants predicted to affect function were also identified in other genes, including KCNS2 (KV9.2), HAPLN4 (BRAL2) and USP46. These genes are highly expressed in the cerebellum and Purkinje cells, and influence function of the gamma-amino butyric acid (GABA)-ergic system. This is in concordance with recent evidence that the pathophysiological process in ET involves cerebellar dysfunction and possibly cerebellar degeneration with a reduction in Purkinje cells, and a decrease in GABA-ergic tone.
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Affiliation(s)
- Xinmin Liu
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Nora Hernandez
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA
| | - Sergey Kisselev
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Aris Floratos
- Department of Biomedical Informatics, Columbia University, New York, NY, USA
- Center for Computational Biology and Bioinformatics, Columbia University, New York, NY, USA
| | - Ashley Sawle
- Department of Biomedical Informatics, Columbia University, New York, NY, USA
- Center for Computational Biology and Bioinformatics, Columbia University, New York, NY, USA
| | - Iuliana Ionita-Laza
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Ruth Ottman
- G.H Sergievsky Center, Columbia University, New York, NY, USA
- Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
- Division of Epidemiology, New York State Psychiatric Institute, New York, NY, USA
| | - Elan D Louis
- Department of Neurology, Yale School of Medicine, Yale University, New Haven, CT, USA
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA
| | - Lorraine N Clark
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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Clark LN, Louis ED. Challenges in essential tremor genetics. Rev Neurol (Paris) 2015; 171:466-74. [PMID: 26003805 PMCID: PMC4863985 DOI: 10.1016/j.neurol.2015.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 01/28/2015] [Accepted: 02/02/2015] [Indexed: 12/17/2022]
Abstract
The field of essential tremor (ET) genetics remains extremely challenging. The relative lack of progress in understanding the genetic etiology of ET, however, does not reflect the lack of a genetic contribution, but rather, the presence of substantial phenotypic and genotypic heterogeneity. A meticulous approach to phenotyping is important for genetic research in ET. The only tool for phenotyping is the clinical history and examination. There is currently no ET-specific serum or imaging biomarker or defining neuropathological feature (e.g., a protein aggregate specific to ET) that can be used for phenotyping, and there is considerable clinical overlap with other disorders such as Parkinson's disease (PD) and dystonia. These issues greatly complicate phenotyping; thus, in some studies, as many as 30-50% of cases labeled as "ET" have later been found to carry other diagnoses (e.g., dystonia, PD) rather than ET. A cursory approach to phenotyping (e.g., merely defining ET as an "action tremor") is likely a major issue in some family studies of ET, and this as well as lack of standardized phenotyping across studies and patient centers is likely to be a major contributor to the relative lack of success of genome wide association studies (GWAS). To dissect the genetic architecture of ET, whole genome sequencing (WGS) in carefully characterized and well-phenotyped discovery and replication datasets of large case-control and familial cohorts will likely be of value. This will allow specific hypotheses about the mode of inheritance and genetic architecture to be tested. There are a number of approaches that still remain unexplored in ET genetics, including the contribution of copy number variants (CNVs), 'uncommon' moderate effect alleles, 'rare' variant large effect alleles (including Mendelian and complex/polygenic modes of inheritance), de novo and gonadal mosaicism, epigenetic changes and non-coding variation. Using these approaches is likely to yield new ET genes.
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Affiliation(s)
- L N Clark
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, 650 West 168th Street, New York, NY, 10032, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - E D Louis
- Department of Neurology, Yale School of Medicine, Yale University, 800 Howard Ave # 2, New Haven, CT 06519, USA.
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Ohno Y, Shimizu S, Tatara A, Imaoku T, Ishii T, Sasa M, Serikawa T, Kuramoto T. Hcn1 is a tremorgenic genetic component in a rat model of essential tremor. PLoS One 2015; 10:e0123529. [PMID: 25970616 PMCID: PMC4430019 DOI: 10.1371/journal.pone.0123529] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/18/2015] [Indexed: 01/12/2023] Open
Abstract
Genetic factors are thought to play a major role in the etiology of essential tremor (ET); however, few genetic changes that induce ET have been identified to date. In the present study, to find genes responsible for the development of ET, we employed a rat model system consisting of a tremulous mutant strain, TRM/Kyo (TRM), and its substrain TRMR/Kyo (TRMR). The TRM rat is homozygous for the tremor (tm) mutation and shows spontaneous tremors resembling human ET. The TRMR rat also carries a homozygous tm mutation but shows no tremor, leading us to hypothesize that TRM rats carry one or more genes implicated in the development of ET in addition to the tm mutation. We used a positional cloning approach and found a missense mutation (c. 1061 C>T, p. A354V) in the hyperpolarization-activated cyclic nucleotide-gated 1 channel (Hcn1) gene. The A354V HCN1 failed to conduct hyperpolarization-activated currents in vitro, implicating it as a loss-of-function mutation. Blocking HCN1 channels with ZD7288 in vivo evoked kinetic tremors in nontremulous TRMR rats. We also found neuronal activation of the inferior olive (IO) in both ZD7288-treated TRMR and non-treated TRM rats and a reduced incidence of tremor in the IO-lesioned TRM rats, suggesting a critical role of the IO in tremorgenesis. A rat strain carrying the A354V mutation alone on a genetic background identical to that of the TRM rats showed no tremor. Together, these data indicate that body tremors emerge when the two mutant loci, tm and Hcn1A354V, are combined in a rat model of ET. In this model, HCN1 channels play an important role in the tremorgenesis of ET. We propose that oligogenic, most probably digenic, inheritance is responsible for the genetic heterogeneity of ET.
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Affiliation(s)
- Yukihiro Ohno
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569–1094, Japan
| | - Saki Shimizu
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569–1094, Japan
| | - Ayaka Tatara
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569–1094, Japan
| | - Takuji Imaoku
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569–1094, Japan
| | - Takahiro Ishii
- Department of Physiology and Neurobiology, Graduate School of Medicine, Kyoto University, Kyoto, 606–8501, Japan
| | | | - Tadao Serikawa
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki, 569–1094, Japan
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606–8501, Japan
| | - Takashi Kuramoto
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, 606–8501, Japan
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Van Gerpen JA, Ross OA. Essential Tremor. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00036-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Schmouth JF, Dion PA, Rouleau GA. Genetics of essential tremor: From phenotype to genes, insights from both human and mouse studies. Prog Neurobiol 2014; 119-120:1-19. [DOI: 10.1016/j.pneurobio.2014.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/16/2014] [Accepted: 05/02/2014] [Indexed: 11/30/2022]
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Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Lorenzo-Betancor O, Pastor P, Agúndez JAG. Update on genetics of essential tremor. Acta Neurol Scand 2013; 128:359-71. [PMID: 23682623 DOI: 10.1111/ane.12148] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2013] [Indexed: 12/25/2022]
Abstract
Despite the research, few advances in the etiopathogenesis on essential tremor (ET) have been made to date. The high frequency of positive family history of ET and the observed high concordance rates in monozygotic compared with dizygotic twins support a major role of genetic factors in the development of ET. In addition, a possible role of environmental factors has been suggested in the etiology of ET (at least in non-familial forms). Although several gene variants in the LINGO1 gene may increase the risk of ET, to date no causative mutated genes have been identified. In this review, we summarize the studies performed on families with tremor, twin studies, linkage studies, case-control association studies, and exome sequencing in familial ET.
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Affiliation(s)
- F. J. Jiménez-Jiménez
- Section of Neurology; Hospital Universitario del Sureste; Arganda del Rey Madrid Spain
| | - H. Alonso-Navarro
- Section of Neurology; Hospital Universitario del Sureste; Arganda del Rey Madrid Spain
| | - E. García-Martín
- Department of Biochemistry and Molecular Biology; University of Extremadura; Cáceres Spain
- AMGenomics; Edificio Tajo, Avda. de la Universidad s/n; Cáceres Spain
| | - O. Lorenzo-Betancor
- Neurogenetics Laboratory; Division of Neurosciences; Center for Applied Medical Research (CIMA); University of Navarra; Pamplona Spain
- Department of Neurology; Clínica Universidad de Navarra; University of Navarra School of Medicine; Pamplona Spain
| | - P. Pastor
- Neurogenetics Laboratory; Division of Neurosciences; Center for Applied Medical Research (CIMA); University of Navarra; Pamplona Spain
- Department of Neurology; Clínica Universidad de Navarra; University of Navarra School of Medicine; Pamplona Spain
- CIBERNED; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas; Instituto de Salud Carlos III; Madrid Spain
| | - J. A. G. Agúndez
- AMGenomics; Edificio Tajo, Avda. de la Universidad s/n; Cáceres Spain
- Department of Pharmacology; University of Extremadura; Cáceres Spain
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Katoh M. Functional proteomics, human genetics and cancer biology of GIPC family members. Exp Mol Med 2013; 45:e26. [PMID: 23743496 PMCID: PMC3701287 DOI: 10.1038/emm.2013.49] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Accepted: 04/04/2013] [Indexed: 12/24/2022] Open
Abstract
GIPC1, GIPC2 and GIPC3 consist of GIPC homology 1 (GH1) domain, PDZ domain and GH2 domain. The regions around the GH1 and GH2 domains of GIPC1 are involved in dimerization and interaction with myosin VI (MYO6), respectively. The PDZ domain of GIPC1 is involved in interactions with transmembrane proteins [IGF1R, NTRK1, ADRB1, DRD2, TGFβR3 (transforming growth factorβ receptor type III), SDC4, SEMA4C, LRP1, NRP1, GLUT1, integrin α5 and VANGL2], cytosolic signaling regulators (APPL1 and RGS19) and viral proteins (HBc and HPV-18 E6). GIPC1 is an adaptor protein with dimerizing ability that loads PDZ ligands as cargoes for MYO6-dependent endosomal trafficking. GIPC1 is required for cell-surface expression of IGF1R and TGFβR3. GIPC1 is also required for integrin recycling during cell migration, angiogenesis and cytokinesis. On early endosomes, GIPC1 assembles receptor tyrosine kinases (RTKs) and APPL1 for activation of PI3K-AKT signaling, and G protein-coupled receptors (GPCRs) and RGS19 for attenuation of inhibitory Gα signaling. GIPC1 upregulation in breast, ovarian and pancreatic cancers promotes tumor proliferation and invasion, whereas GIPC1 downregulation in cervical cancer with human papillomavirus type 18 infection leads to resistance to cytostatic transforming growth factorβ signaling. GIPC2 is downregulated in acute lymphocytic leukemia owing to epigenetic silencing, while Gipc2 is upregulated in estrogen-induced mammary tumors. Somatic mutations of GIPC2 occur in malignant melanoma, and colorectal and ovarian cancers. Germ-line mutations of the GIPC3 or MYO6 gene cause nonsyndromic hearing loss. As GIPC proteins are involved in trafficking, signaling and recycling of RTKs, GPCRs, integrins and other transmembrane proteins, dysregulation of GIPCs results in human pathologies, such as cancer and hereditary deafness.
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Affiliation(s)
- Masaru Katoh
- Division of Integrative Omics and Bioinformatics, National Cancer Centre, Tokyo, Japan.
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Pino-Ángeles A, Reyes-Palomares A, Melgarejo E, Sánchez-Jiménez F. Histamine: an undercover agent in multiple rare diseases? J Cell Mol Med 2013; 16:1947-60. [PMID: 22435405 PMCID: PMC3822965 DOI: 10.1111/j.1582-4934.2012.01566.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Histamine is a biogenic amine performing pleiotropic effects in humans, involving tasks within the immune and neuroendocrine systems, neurotransmission, gastric secretion, cell life and death, and development. It is the product of the histidine decarboxylase activity, and its effects are mainly mediated through four different G-protein coupled receptors. Thus, histamine-related effects are the results of highly interconnected and tissue-specific signalling networks. Consequently, alterations in histamine-related factors could be an important part in the cause of multiple rare/orphan diseases. Bearing this hypothesis in mind, more than 25 rare diseases related to histamine physiopathology have been identified using a computationally assisted text mining approach. These newly integrated data will provide insight to elucidate the molecular causes of these rare diseases. The data can also help in devising new intervention strategies for personalized medicine for multiple rare diseases.
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Abstract
PURPOSE OF REVIEW This review summarizes some key findings of the past few years on the genetics of the two common movement disorders Parkinson's disease and essential tremor. RECENT FINDINGS Within the last two years, genome-wide association (GWA) analyses have revealed a number of novel low-risk susceptibility variants for Parkinson's disease, among them HLA-DRB5, BST1, ACMSD, STK39, MCCC1/LAMP3, SYT11, and CCDC62/HIP1R) and have confirmed LINGO1 as risk factor for essential tremor. The identification of copy number variations in the Parkin gene in healthy control individuals suggests no major role of these variations in late onset Parkinson's disease. Drosophila studies on Parkin and Pink1 have uncovered a role in the mitochondrial quality control pathway in the pathogenesis of the disease. LRRK2 has been found to interact with the microRNAs processing protein Argonaut, thereby affecting protein translation. Notably, despite the high familial risk for essential tremor no high-risk gene has been found to date. The possibility of a nonmendelian transmission in some cases is discussed. SUMMARY GWA studies and positional cloning approaches have led to the identification of a number of risk genes for Parkinson's disease, which give novel insights into pathogenic pathways of the disease. In contrast, our knowledge of the genetics of essential tremor is scarce. Except for LINGO1, no other risk gene has so far been identified. New technologies such as next generation high throughput sequencing might help to identify more risk genes.
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Current perspectives on the selective regulation of dopamine D2 and D3 receptors. Arch Pharm Res 2010; 33:1521-38. [DOI: 10.1007/s12272-010-1005-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 01/07/2023]
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García-Martín E, Martínez C, Alonso-Navarro H, Benito-León J, Puertas I, Rubio L, López-Alburquerque T, Agúndez JAG, Jiménez-Jiménez FJ. Dopamine receptor D3 (DRD3) genotype and allelic variants and risk for essential tremor. Mov Disord 2010; 24:1910-5. [PMID: 19645064 DOI: 10.1002/mds.22518] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
To investigate the possible association between dopamine receptor D3 genotype (DRD3) and allelic variants and the risk for developing essential tremor (ET). Leukocytary DNA from 201 patients with ET and 282 healthy controls was studied for the genotype DRD3 and the occurrence of DRD3 allelic variants by using allele-specific PCR amplification and MslI-RFLP's analyses. A meta-analysis of previous studies was performed. The frequencies of the DRD3Ser/Gly genotype and of the allelic variant DRDGly were significantly higher in patients with ET than in controls (P < 0.017 and <0.005, respectively), These findings were especially relevant in women (OR = 1.73, 95% CI: 1.15-2.59, P = 0.008), and in patients with earlier onset of the disease with (P = 0.014). The frequencies of the DRD3Ser/Gly and DRD3Gly/Gly genotypes and of the allelic variant DRD3Gly in patients were significantly higher in patients with voice tremor, but not with head, tongue, or chin tremor, than in controls. The meta-analysis indicated association of variant genotypes with ET risk (OR = 1.18, 95% CI 1.01-1.38). These results suggest that DRD3 genotype and the variant DRD3Gly allelic variant is associated with the risk for and age at onset of ET, and with the risk for voice tremor, in Caucasian Spanish people.
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Affiliation(s)
- Elena García-Martín
- Department of Biochemistry and Molecular Biology, School of Biological Sciences, University of Extremadura, Badajoz, Spain
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Dopamine receptor D3 gene and essential tremor in large series of German, Danish and French patients. Eur J Hum Genet 2008; 17:766-73. [PMID: 19092771 DOI: 10.1038/ejhg.2008.243] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The genetic causes of essential tremor (ET) seem to be heterogeneous. Recently, ET has been found associated with a functional variant (Ser9Gly) of the dopamine D(3) receptor (DRD3), located in the ETM1 locus on chromosome 3q13.3 described for the first time in 1997. We examined this variant in three different populations from Germany, Denmark and France. We undertook an association study of the Ser9Gly variant in 202 cases with a familial history from unrelated families with ET, 97 cases with isolated non-familial ET and 528 healthy controls. In addition, linkage and segregation analyses were carried out in 22 ET families. The distribution of genotypes and allele frequencies showed no significant differences in the whole sample and in a subanalysis of familial and sporadic cases. Age at onset of tremor, tremor duration and tremor severity did not show an association with the genotype. In addition, the DRD3 variant was not found linked to the disease in a subset of informative ET families. We did not find a significant association of the DRD3 variant with ET nor linkage to the DRD3 receptor in German, Danish and French ET patients and families, suggesting that it is unlikely to be a causal factor for ET.
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Shaikh AG, Miura K, Optican LM, Ramat S, Tripp RM, Zee DS. Hypothetical membrane mechanisms in essential tremor. J Transl Med 2008; 6:68. [PMID: 18990221 PMCID: PMC2613385 DOI: 10.1186/1479-5876-6-68] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 11/06/2008] [Indexed: 11/20/2022] Open
Abstract
Background Essential tremor (ET) is the most common movement disorder and its pathophysiology is unknown. We hypothesize that increased membrane excitability in motor circuits has a key role in the pathogenesis of ET. Specifically, we propose that neural circuits controlling ballistic movements are inherently unstable due to their underlying reciprocal innervation. Such instability is enhanced by increased neural membrane excitability and the circuit begins to oscillate. These oscillations manifest as tremor. Methods Postural limb tremor was recorded in 22 ET patients and then the phenotype was simulated with a conductance-based neuromimetic model of ballistic movements. The model neuron was Hodgkin-Huxley type with added hyperpolarization activated cation current (Ih), low threshold calcium current (IT), and GABA and glycine mediated chloride currents. The neurons also featured the neurophysiological property of rebound excitation after release from sustained inhibition (post-inhibitory rebound). The model featured a reciprocally innervated circuit of neurons that project to agonist and antagonist muscle pairs. Results Neural excitability was modulated by changing Ih and/or IT. Increasing Ih and/or IT further depolarized the membrane and thus increased excitability. The characteristics of the tremor from all ET patients were simulated when Ih was increased to ~10× the range of physiological values. In contrast, increasing other membrane conductances, while keeping Ih at a physiological value, did not simulate the tremor. Increases in Ih and IT determined the frequency and amplitude of the simulated oscillations. Conclusion These simulations support the hypothesis that increased membrane excitability in potentially unstable, reciprocally innervated circuits can produce oscillations that resemble ET. Neural excitability could be increased in a number of ways. In this study membrane excitability was increased by up-regulating Ih and IT. This approach suggests new experimental and clinical ways to understand and treat common tremor disorders.
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Affiliation(s)
- Aasef G Shaikh
- Department of Neurology, The Johns Hopkins University, Baltimore, MD, USA.
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Vitale C, Gulli R, Ciotti P, Scaglione C, Bellone E, Avanzino L, Lantieri F, Abbruzzese G, Martinelli P, Barone P, Mandich P. DRD3 Ser9Gly variant is not associated with essential tremor in a series of Italian patients. Eur J Neurol 2008; 15:985-7. [DOI: 10.1111/j.1468-1331.2008.02164.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Inashkina I, Radovica I, Smeltere L, Vitols E, Jankevics E. Case-control study of patients with essential tremor in Latvia. Eur J Neurol 2008; 15:988-90. [DOI: 10.1111/j.1468-1331.2008.02225.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
PURPOSE OF REVIEW This review focuses on recent findings on the aetiological, clinical, pathological and genetic heterogeneity of essential tremor and new therapeutic approaches. RECENT FINDINGS Although essential tremor is one of the most common movement disorders, understanding of the causes and mechanisms of the disease is still very limited. Studies on the clinical presentation of essential tremor have expanded the clinical dimension, now including nontremor manifestations such as cerebellar signs, neuropsychological characteristics, distinct personality traits and behavioural symptoms. Results of neuropathologic and imaging studies are conflicting, with hints of neurodegeneration or a nondegenerative disturbance of functional circuits or receptors. Genetic heterogeneity of essential tremor has been demonstrated by linkage to three different chromosomal loci so far, and several negative genetic studies. New animal models are reinforcing previous hypotheses about gamma-aminobutyrate (GABA)-ergic mechanisms in essential tremor. New therapeutic agents for essential tremor have been tested and demonstrated to be partly effective. SUMMARY The traditional view of essential tremor as a single disease entity has been replaced with the concept that this disorder is a complex and heterogeneous disease. Heterogeneity of the condition, and lack of diagnostic criteria and objective diagnostic tests add to this problem. Many conflicting results may be due to differences in patient selection.
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Affiliation(s)
- Delia Lorenz
- Department of Neurology, Universitätsklinikum Schleswig-Holstein, Campus Kiel Christian-Albrechts-Universität, Kiel, Germany
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Shahed J, Jankovic J. Exploring the relationship between essential tremor and Parkinson's disease. Parkinsonism Relat Disord 2007; 13:67-76. [PMID: 16887374 DOI: 10.1016/j.parkreldis.2006.05.033] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 05/16/2006] [Accepted: 05/23/2006] [Indexed: 10/24/2022]
Abstract
Although essential tremor (ET) and Parkinson's disease (PD) are considered distinct disorders, there is overlap in some clinical features. In some PD patients, a long-standing postural tremor in the hands may precede the onset of parkinsonian features by several years or decades. Furthermore, large families with both ET and PD phenotypes have been described and autopsy studies have demonstrated Lewy body pathology in brains of ET patients. Functional neuroimaging suggests that some ET patients have dopaminergic deficit. We examine here the evidence for and against an association between ET and PD, and critically review data supporting the notion that a subset of ET patients is predisposed to developing PD.
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Affiliation(s)
- Joohi Shahed
- Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Department of Neurology, 6550 Fannin, Suite 1801, Houston, TX, USA.
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Jeanneteau F, Funalot B, Jankovic J, Deng H, Lagarde JP, Lucotte G, Sokoloff P. A functional variant of the dopamine D3 receptor is associated with risk and age-at-onset of essential tremor. Proc Natl Acad Sci U S A 2006; 103:10753-8. [PMID: 16809426 PMCID: PMC1502303 DOI: 10.1073/pnas.0508189103] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Familial essential tremor (ET), the most common inherited movement disorder, is generally transmitted as an autosomal dominant trait. A genome-wide scan for ET revealed one major locus on chromosome 3q13. Here, we report that the Ser9Gly variant in the dopamine D(3) receptor gene (DRD3), localized on 3q13.3, is associated and cosegregates with familial ET in 23 out of 30 French families. Sequencing revealed no other nonsynonymous variants in the DRD3-coding sequence and in the first 871 bp of the 5' flanking region. Moreover, Gly-9 homozygous patients presented with more severe and/or earlier onset forms of the disease than heterozygotes. A replication study comparing 276 patients with ET and 184 normal controls confirmed the association of the Gly-9 variant with risk and age-at-onset of ET. In human embryonic kidney (HEK) 293-transfected cells, the Gly-9 variant did not differ from the Ser-9 variant with respect to glycosylation and to anterograde and retrograde trafficking, but dopamine had an affinity that was four to five times higher. With the Gly-9 variant, the dopamine-mediated cAMP response was increased, and the mitogen-associated protein kinase (MAPK) signal was prolonged, as compared with the Ser-9 variant. The gain-of-function produced by the Gly-9 variant may explain why drugs active against tremor in Parkinson's disease (PD) are usually not effective in the treatment of ET and suggests that DRD3 partial agonists or antagonists should be considered as novel therapeutic options for patients with ET.
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Affiliation(s)
- Freddy Jeanneteau
- *Institut National de la Santé et de la Recherche Médicale, Unité de Neurobiologie et Pharmacologie Moléculaire, U573, Centre Paul Broca, 75014 Paris, France
| | - Benoît Funalot
- *Institut National de la Santé et de la Recherche Médicale, Unité de Neurobiologie et Pharmacologie Moléculaire, U573, Centre Paul Broca, 75014 Paris, France
- Service de Neurologie, Centre Hospitalier Ste-Anne, 75014 Paris, France
| | - Joseph Jankovic
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030
| | - Hao Deng
- Department of Neurology, Baylor College of Medicine, Houston, TX 77030
| | - Jean-Pierre Lagarde
- Laboratoire de Génétique Moléculaire, Hôpital de la Pitié-Salpétrière, 75013 Paris, France; and
| | - Gérard Lucotte
- Centre de Neurogénétique Moléculaire, 75005 Paris, France
| | - Pierre Sokoloff
- *Institut National de la Santé et de la Recherche Médicale, Unité de Neurobiologie et Pharmacologie Moléculaire, U573, Centre Paul Broca, 75014 Paris, France
- To whom correspondence should be addressed. E-mail:
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