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Treatment-Resistant Schizophrenia, Clozapine Resistance, Genetic Associations, and Implications for Precision Psychiatry: A Scoping Review. Genes (Basel) 2023; 14:genes14030689. [PMID: 36980961 PMCID: PMC10048540 DOI: 10.3390/genes14030689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/03/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
Treatment-resistant schizophrenia (TRS) is often associated with severe burden of disease, poor quality of life and functional impairment. Clozapine is the gold standard for the treatment of TRS, although it is also known to cause significant side effects in some patients. In view of the burgeoning interest in the role of genetic factors in precision psychiatry, we conducted a scoping review to narratively summarize the current genetic factors associated with TRS, clozapine resistance and side effects to clozapine treatment. We searched PubMed from inception to December 2022 and included 104 relevant studies in this review. Extant evidence comprised associations between TRS and clozapine resistance with genetic factors related to mainly dopaminergic and serotoninergic neurotransmitter systems, specifically, TRS and rs4680, rs4818 within COMT, and rs1799978 within DRD2; clozapine resistance and DRD3 polymorphisms, CYP1A2 polymorphisms; weight gain with LEP and SNAP-25 genes; and agranulocytosis risk with HLA-related polymorphisms. Future studies, including replication in larger multi-site samples, are still needed to elucidate putative risk genes and the interactions between different genes and their correlations with relevant clinical factors such as psychopathology, psychosocial functioning, cognition and progressive changes with treatment over time in TRS and clozapine resistance.
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2
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de Bartolomeis A, Vellucci L, Barone A, Manchia M, De Luca V, Iasevoli F, Correll CU. Clozapine's multiple cellular mechanisms: What do we know after more than fifty years? A systematic review and critical assessment of translational mechanisms relevant for innovative strategies in treatment-resistant schizophrenia. Pharmacol Ther 2022; 236:108236. [PMID: 35764175 DOI: 10.1016/j.pharmthera.2022.108236] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 12/21/2022]
Abstract
Almost fifty years after its first introduction into clinical care, clozapine remains the only evidence-based pharmacological option for treatment-resistant schizophrenia (TRS), which affects approximately 30% of patients with schizophrenia. Despite the long-time experience with clozapine, the specific mechanism of action (MOA) responsible for its superior efficacy among antipsychotics is still elusive, both at the receptor and intracellular signaling level. This systematic review is aimed at critically assessing the role and specific relevance of clozapine's multimodal actions, dissecting those mechanisms that under a translational perspective could shed light on molecular targets worth to be considered for further innovative antipsychotic development. In vivo and in vitro preclinical findings, supported by innovative techniques and methods, together with pharmacogenomic and in vivo functional studies, point to multiple and possibly overlapping MOAs. To better explore this crucial issue, the specific affinity for 5-HT2R, D1R, α2c, and muscarinic receptors, the relatively low occupancy at dopamine D2R, the interaction with receptor dimers, as well as the potential confounder effects resulting in biased ligand action, and lastly, the role of the moiety responsible for lipophilic and alkaline features of clozapine are highlighted. Finally, the role of transcription and protein changes at the synaptic level, and the possibility that clozapine can directly impact synaptic architecture are addressed. Although clozapine's exact MOAs that contribute to its unique efficacy and some of its severe adverse effects have not been fully understood, relevant information can be gleaned from recent mechanistic understandings that may help design much needed additional therapeutic strategies for TRS.
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Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy.
| | - Licia Vellucci
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Mirko Manchia
- Section of Psychiatry, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy; Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Felice Iasevoli
- Section of Psychiatry, Laboratory of Translational and Molecular Psychiatry and Unit of Treatment Resistant Psychosis, Department of Neuroscience, Reproductive Science and Dentistry, University Medical School of Naples "Federico II", Naples, Italy
| | - Christoph U Correll
- The Zucker Hillside Hospital, Department of Psychiatry, Northwell Health, Glen Oaks, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Department of Psychiatry and Molecular Medicine, Hempstead, NY, USA; Charité Universitätsmedizin Berlin, Department of Child and Adolescent Psychiatry, Berlin, Germany
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3
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Duello TM, Rivedal S, Wickland C, Weller A. Race and genetics versus 'race' in genetics: A systematic review of the use of African ancestry in genetic studies. Evol Med Public Health 2021; 9:232-245. [PMID: 34815885 PMCID: PMC8604262 DOI: 10.1093/emph/eoab018] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 06/09/2021] [Indexed: 08/11/2023] Open
Abstract
Social scientists have long understood race to be a social category invented to justify slavery and evolutionary biologists know the socially constructed racial categories do not align with our biological understanding of genetic variation. The completion of the Human Genome Project in 2003 confirmed humans are 99.9% identical at the DNA level and there is no genetic basis for race. A systematic review of the PubMed medical literature published since 2003 was conducted to assess the use of African ancestry to denote study populations in genetic studies categorized as clinical trials, to examine the stated rationale for its use and to assess the use of evolutionary principles to explain human genetic diversity. We searched for papers that included the terms 'African', 'African American' or 'Black' in studies of behavior (20 papers), physiological responses, the pharmacokinetics of drugs and/or disease associations (62 papers), and as a genetic category in studies, including the examination of genotypes associated with life stress, pain, stuttering and drug clearance (126 papers). Of these, we identified 74 studies in which self-reported race alone or in combination with admixture mapping was used to define the study population. However, none of these studies provided a genetic explanation for the use of the self-identified race as a genetic category and only seven proffered evolutionary explanations of their data. The concept of continuous genetic variation was not clearly articulated in any of these papers, presumably due to the paucity of evolutionary science in the college and medical school curricula.
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Affiliation(s)
- Theresa M Duello
- Department of Obstetrics and Gynecology, School of
Medicine and Public Health, University of Wisconsin –
Madison, Madison, WI 53706, USA
| | - Shawna Rivedal
- Department of Obstetrics and Gynecology, School of
Medicine and Public Health, University of Wisconsin –
Madison, Madison, WI 53706, USA
| | - Colton Wickland
- Department of Obstetrics and Gynecology, School of
Medicine and Public Health, University of Wisconsin –
Madison, Madison, WI 53706, USA
| | - Annika Weller
- Department of Obstetrics and Gynecology, School of
Medicine and Public Health, University of Wisconsin –
Madison, Madison, WI 53706, USA
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4
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Maes MS, Lu JY, Tiwari AK, Freeman N, de Luca V, Müller DJ, Voineskos AN, Potkin SG, Lieberman JA, Meltzer HY, Remington G, Kennedy JL, Zai CC. Schizophrenia-associated gene dysbindin-1 and tardive dyskinesia. Drug Dev Res 2020; 82:678-684. [PMID: 32394511 DOI: 10.1002/ddr.21681] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 12/15/2022]
Abstract
Tardive dyskinesia (TD) is a potentially irreversible movement disorder observed following long-term antipsychotic exposure. Its cause is unknown; however, a genetic component has been supported by studies of affected families. Dysbindin-1, encoded by the dystrobrevin-binding protein 1 DTNBP1 gene, has been associated with schizophrenia and is potentially involved in dopamine neurotransmission through its regulation of dopamine release and dopamine D2 receptor recycling, making it a candidate for investigation in TD. We investigated common variants across the DTNBP1 gene in our schizophrenia/patients with schizoaffective disorder of European ancestry. We found a number of DTNBP1 three-marker haplotypes to be associated with TD occurrence and TD severity (p < 0.05). These preliminary findings, if replicated in larger independent samples, would suggest that drugs targeting dysbindin-1 may be an option in the prevention and treatment of TD.
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Affiliation(s)
- Miriam S Maes
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Justin Y Lu
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Arun K Tiwari
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Natalie Freeman
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
| | - Vincenzo de Luca
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Daniel J Müller
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Aristotle N Voineskos
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Steven G Potkin
- Department of Psychiatry and Human Behavior, Long Beach Veterans Administration Health Care System, University of California, Irvine, California, USA
| | - Jeffrey A Lieberman
- New York State Psychiatric Institute, Columbia University, New York City, New York, USA
| | - Herbert Y Meltzer
- Psychiatry and Behavioral Sciences, Pharmacology and Physiology, Chemistry of Life Processes Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Gary Remington
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - James L Kennedy
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Clement C Zai
- Tanenbaum Centre for Pharmacogenetics, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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5
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Jerome RN, Pulley JM, Sathe NA, Krishnaswami S, Dickerson AB, Worley KJ, Wilkins CH. Exploring Biologic Predictors Response Disparities to Atypical Antipsychotics among Blacks: A Quasi-Systematic Review. Ethn Dis 2020; 30:229-240. [PMID: 32269465 DOI: 10.18865/ed.30.s1.229] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Purpose Management of schizophrenia among Blacks in the United States is affected by persistent disparities. This review explored response to atypical antipsychotics among Blacks compared with other groups to assess systematic variation that may contribute to disparities. Methods We conducted a quasi-systematic review of studies reporting response to atypical antipsychotics among Blacks compared with other groups, including effects of genetic variation. Results Of 48 identified research articles, 29 assessed differences in outcomes without inclusion of genetic variation and 20 explored effects of genetic variation; of note: one article included both types of data. Analysis of the 29 papers with clinical outcomes only suggests that while data on efficacy and risk of movement disorders were heterogeneous, findings indicate increased risk of metabolic effects and neutropenia among Blacks. Of the 20 articles exploring effects of genetic variation, allelic or genotypic variations involving several genes were associated with altered efficacy or safety among Blacks but not Whites, including risk of decreased response involving variation in DRD4 and DRD1, and improved efficacy associated with variants in DRD2, COMT, and RGS4. Others showed significant improvement in treatment response only among Whites, including variation in DTNBP1, DRD4, and GNB3. Conclusions The current analysis can help tailor management among Blacks using an atypical antipsychotic. Heterogeneity in genetic variation effects and response allele frequency suggests that pharmacogenetics approaches for atypical antipsychotics will need to explicitly incorporate race and ethnicity.
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Affiliation(s)
- Rebecca N Jerome
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, TN
| | - Jill M Pulley
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, TN
| | - Nila A Sathe
- Vanderbilt Evidence-Based Practice Center, Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, TN.,Vanderbilt Department of Health Policy, Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, TN
| | - Shanthi Krishnaswami
- Vanderbilt Evidence-Based Practice Center, Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, TN
| | - Alyssa B Dickerson
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, TN
| | - Katherine J Worley
- Vanderbilt Institute for Clinical and Translational Research, Vanderbilt University Medical Center, Nashville, TN.,Vanderbilt Evidence-Based Practice Center, Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, TN
| | - Consuelo H Wilkins
- Department of Medicine, Vanderbilt University Medical Center and Department of Internal Medicine, Meharry Medical College, Nashville, TN
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6
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Radouani F, Zass L, Hamdi Y, Rocha JD, Sallam R, Abdelhak S, Ahmed S, Azzouzi M, Benamri I, Benkahla A, Bouhaouala-Zahar B, Chaouch M, Jmel H, Kefi R, Ksouri A, Kumuthini J, Masilela P, Masimirembwa C, Othman H, Panji S, Romdhane L, Samtal C, Sibira R, Ghedira K, Fadlelmola F, Kassim SK, Mulder N. A review of clinical pharmacogenetics Studies in African populations. Per Med 2020; 17:155-170. [PMID: 32125935 PMCID: PMC8093600 DOI: 10.2217/pme-2019-0110] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Effective interventions and treatments for complex diseases have been implemented globally, however, coverage in Africa has been comparatively lower due to lack of capacity, clinical applicability and knowledge on the genetic contribution to disease and treatment. Currently, there is a scarcity of genetic data on African populations, which have enormous genetic diversity. Pharmacogenomics studies have the potential to revolutionise treatment of diseases, therefore, African populations are likely to benefit from these approaches to identify likely responders, reduce adverse side effects and optimise drug dosing. This review discusses clinical pharmacogenetics studies conducted in African populations, focusing on studies that examined drug response in complex diseases relevant to healthcare. Several pharmacogenetics associations have emerged from African studies, as have gaps in knowledge.
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Affiliation(s)
- Fouzia Radouani
- Research Department, Chlamydiae & Mycoplasmas Laboratory, Institut Pasteur du Maroc, Casablanca 20360, Morocco
| | - Lyndon Zass
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, CIDRI Africa Wellcome Trust Centre, University of Cape Town, South Africa
| | - Yosr Hamdi
- Laboratory of Biomedical Genomics & Oncogenetics, Institut Pasteur de Tunis, Université Tunis El Manar, 13, Place Pasteur BP 74, 1002 Tunis, Belvédère, Tunisie
| | - Jorge da Rocha
- Sydney Brenner Institute for Molecular Bioscience, University of The Witwatersrand, Johannesburg, South Africa
| | - Reem Sallam
- Medical Biochemistry & Molecular Biology Department, Faculty of Medicine, Ain Shams University, Abbaseya, Cairo 11381, Egypt
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics & Oncogenetics, Institut Pasteur de Tunis, Université Tunis El Manar, 13, Place Pasteur BP 74, 1002 Tunis, Belvédère, Tunisie
| | - Samah Ahmed
- Centre for Bioinformatics & Systems Biology, Faculty of Science, University of Khartoum, 321 Khartoum, Sudan.,Faculty of Clinical & Industrial Pharmacy, National University, Khartoum, Sudan
| | - Maryame Azzouzi
- Research Department, Chlamydiae & Mycoplasmas Laboratory, Institut Pasteur du Maroc, Casablanca 20360, Morocco
| | - Ichrak Benamri
- Research Department, Chlamydiae & Mycoplasmas Laboratory, Institut Pasteur du Maroc, Casablanca 20360, Morocco.,Systems & Data Engineering Team, National School of Applied Sciences of Tangier, Morocco
| | - Alia Benkahla
- Laboratory of Bioinformatics, Biomathematics & Biostatistics LR 16 IPT 09, Institute Pasteur de Tunis, Tunisia
| | - Balkiss Bouhaouala-Zahar
- Laboratory of Venoms & Therapeutic Molecules, Pasteur Institute of Tunis, 13 Place Pasteur, BP74, Tunis Belvedere- University of Tunis El Manar, Tunisia
| | - Melek Chaouch
- Laboratory of Bioinformatics, Biomathematics & Biostatistics LR 16 IPT 09, Institute Pasteur de Tunis, Tunisia
| | - Haifa Jmel
- Laboratory of Biomedical Genomics & Oncogenetics, Institut Pasteur de Tunis, Université Tunis El Manar, 13, Place Pasteur BP 74, 1002 Tunis, Belvédère, Tunisie
| | - Rym Kefi
- Laboratory of Biomedical Genomics & Oncogenetics, Institut Pasteur de Tunis, Université Tunis El Manar, 13, Place Pasteur BP 74, 1002 Tunis, Belvédère, Tunisie
| | - Ayoub Ksouri
- Laboratory of Bioinformatics, Biomathematics & Biostatistics LR 16 IPT 09, Institute Pasteur de Tunis, Tunisia.,Laboratory of Venoms & Therapeutic Molecules, Pasteur Institute of Tunis, 13 Place Pasteur, BP74, Tunis Belvedere- University of Tunis El Manar, Tunisia
| | - Judit Kumuthini
- H3ABioNet, Bioinformatics Department, Centre for Proteomic & Genomic Research, Cape Town, South Africa
| | - Phumlani Masilela
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, CIDRI Africa Wellcome Trust Centre, University of Cape Town, South Africa
| | - Collen Masimirembwa
- Sydney Brenner Institute for Molecular Bioscience, University of The Witwatersrand, Johannesburg, South Africa.,DMPK Department, African Institute of Biomedical Science & Technology, Harare, Zimbabwe
| | - Houcemeddine Othman
- Sydney Brenner Institute for Molecular Bioscience, University of The Witwatersrand, Johannesburg, South Africa
| | - Sumir Panji
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, CIDRI Africa Wellcome Trust Centre, University of Cape Town, South Africa
| | - Lilia Romdhane
- Laboratory of Biomedical Genomics & Oncogenetics, Institut Pasteur de Tunis, Université Tunis El Manar, 13, Place Pasteur BP 74, 1002 Tunis, Belvédère, Tunisie.,Département des Sciences de la Vie, Faculté des Sciences de Bizerte, Université Carthage, 7021 Jarzouna, BP 21, Tunisie
| | - Chaimae Samtal
- Biotechnology Laboratory, Faculty of Sciences Dhar El Mahraz, Sidi Mohammed Ben Abdellah University, Fez 30000, Morocco.,Department of Biology, University of Mohammed Premier, Oujda, Morocco.,Department of Biology Faculty of Sciences, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
| | - Rania Sibira
- Centre for Bioinformatics & Systems Biology, Faculty of Science, University of Khartoum, 321 Khartoum, Sudan.,Department of Neurosurgery, National Center For Neurological Sciences, Khartoum, Sudan
| | - Kais Ghedira
- Laboratory of Bioinformatics, Biomathematics & Biostatistics LR 16 IPT 09, Institute Pasteur de Tunis, Tunisia
| | - Faisal Fadlelmola
- Centre for Bioinformatics & Systems Biology, Faculty of Science, University of Khartoum, 321 Khartoum, Sudan
| | - Samar Kamal Kassim
- Medical Biochemistry & Molecular Biology Department, Faculty of Medicine, Ain Shams University, Abbaseya, Cairo 11381, Egypt
| | - Nicola Mulder
- Computational Biology Division, Department of Integrative Biomedical Sciences, IDM, CIDRI Africa Wellcome Trust Centre, University of Cape Town, South Africa
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Samanaite R, Gillespie A, Sendt KV, McQueen G, MacCabe JH, Egerton A. Biological Predictors of Clozapine Response: A Systematic Review. Front Psychiatry 2018; 9:327. [PMID: 30093869 PMCID: PMC6070624 DOI: 10.3389/fpsyt.2018.00327] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/29/2018] [Indexed: 01/04/2023] Open
Abstract
Background: Clozapine is the recommended antipsychotic for treatment-resistant schizophrenia (TRS) but there is significant variability between patients in the degree to which clozapine will improve symptoms. The biological basis of this variability is unknown. Although clozapine has efficacy in TRS, it can elicit adverse effects and initiation is often delayed. Identification of predictive biomarkers of clozapine response may aid initiation of clozapine treatment, as well as understanding of its mechanism of action. In this article we systematically review prospective or genetic studies of biological predictors of response to clozapine. Methods: We searched the PubMed database until 20th January 2018 for studies investigating "clozapine" AND ("response" OR "outcome") AND "schizophrenia." Inclusion required that studies examined a biological variable in relation to symptomatic response to clozapine. For all studies except genetic-studies, inclusion required that biological variables were measured before clozapine initiation. Results: Ninety-eight studies met the eligibility criteria and were included in the review, including neuroimaging, blood-based, cerebrospinal fluid (CSF)-based, and genetic predictors. The majority (70) are genetic studies, collectively investigating 379 different gene variants, however only three genetic variants (DRD3 Ser9Gly, HTR2A His452Tyr, and C825T GNB3) have independently replicated significant findings. Of the non-genetic variables, the most consistent predictors of a good response to clozapine are higher prefrontal cortical structural integrity and activity, and a lower ratio of the dopamine and serotonin metabolites, homovanillic acid (HVA): 5-hydroxyindoleacetic acid (5-HIAA) in CSF. Conclusions: Recommendations include that future studies should ensure adequate clozapine trial length and clozapine plasma concentrations, and may include multivariate models to increase predictive accuracy.
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Affiliation(s)
- Ruta Samanaite
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Amy Gillespie
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Kyra-Verena Sendt
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Grant McQueen
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - James H. MacCabe
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Alice Egerton
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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8
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Porcelli S, Crisafulli C, Calabrò M, Serretti A, Rujescu D. Possible biomarkers modulating haloperidol efficacy and/or tolerability. Pharmacogenomics 2016; 17:507-29. [PMID: 27023437 DOI: 10.2217/pgs.16.5] [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: 11/21/2022] Open
Abstract
Haloperidol (HP) is widely used in the treatment of several forms of psychosis. Despite of its efficacy, HP use is a cause of concern for the elevated risk of adverse drug reactions. adverse drug reactions risk and HP efficacy greatly vary across subjects, indicating the involvement of several factors in HP mechanism of action. The use of biomarkers that could monitor or even predict HP treatment impact would be of extreme importance. We reviewed the elements that could potentially be used as peripheral biomarkers of HP effectiveness. Although a validated biomarker still does not exist, we underlined the several potential findings (e.g., about cytokines, HP metabolites and genotypic biomarkers) which could pave the way for future research on HP biomarkers.
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Affiliation(s)
- Stefano Porcelli
- Department of Biomedical & NeuroMotor Sciences, University of Bologna, Italy
| | - Concetta Crisafulli
- Department of Biomedical Science & Morphological & Functional Images, University of Messina, Italy
| | - Marco Calabrò
- Department of Biomedical Science & Morphological & Functional Images, University of Messina, Italy
| | - Alessandro Serretti
- Department of Biomedical & NeuroMotor Sciences, University of Bologna, Italy
| | - Dan Rujescu
- Department of Psychiatry, University of Halle, Halle, Germany
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9
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Kohlrausch FB. Pharmacogenetics in schizophrenia: a review of clozapine studies. BRAZILIAN JOURNAL OF PSYCHIATRY 2014; 35:305-17. [PMID: 24142094 DOI: 10.1590/1516-4446-2012-0970] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/19/2012] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Clozapine is quite effective to treat schizophrenia, but its use is complicated by several factors. Although many patients respond to antipsychotic therapy, about 50% of them exhibit inadequate response, and ineffective medication trials may entail weeks of unremitted illness, potential adverse drug reactions, and treatment nonadherence. This review of the literature sought to describe the main pharmacogenetic studies of clozapine and the genes that potentially influence response to treatment with this medication in schizophrenics. METHODS We searched the PubMed database for studies published in English in the last 20 years using keywords related to the topic. RESULTS AND CONCLUSIONS Our search yielded 145 studies that met the search and selection criteria. Of these, 21 review articles were excluded. The 124 studies included for analysis showed controversial results. Therefore, efforts to identify key gene mechanisms that will be useful in predicting clozapine response and side effects have not been fully successful. Further studies with new analysis approaches and larger sample sizes are still required.
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10
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Pharmacogenetic Applications and Pharmacogenomic Approaches in Schizophrenia. CURRENT GENETIC MEDICINE REPORTS 2013. [DOI: 10.1007/s40142-012-0006-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Association study of 27 annotated genes for clozapine pharmacogenetics: validation of preexisting studies and identification of a new candidate gene, ABCB1, for treatment response. J Clin Psychopharmacol 2012; 32:441-8. [PMID: 22722500 DOI: 10.1097/jcp.0b013e31825ac35c] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Pharmacogenetic studies on clozapine (CLZ) have provided meaningful insights but have shown redundancies owing to wide interindividual variability and insufficient replication. The present study was designed to validate hitherto suggested candidate genes on CLZ pharmacokinetics and pharmacodynamics and explore new markers through an integrative study. METHODS Based on a literature review, a total of 127 variations in 27 candidate genes were selected and analyzed. Ninety-six schizophrenic patients of Korean ethnicity with constant CLZ dosing were recruited, and information on body weight and smoking habits was gathered, as well as plasma drug levels and treatment responses. RESULTS Among the pharmacokinetic-related single nucleotide polymorphisms, rs2069521 and rs2069522 in CYP1A2 for CLZ/(dose/weight) and norclozapine/(dose/weight) and rs1135840 in CYP2D6 for norclozapine/CLZ showed borderline associations that were insignificant after correction for multiple testing. Regarding treatment response, significant associations were exhibited in rs7787082 and rs10248420 of ABCB1 (P = 0.0005 and P = 0.0013, respectively) even after correction, and the rs7787082 G and rs10248420 A alleles in ABCB1 were more frequently observed in nonresponders. We also observed a trend in the associations of rs13064530 in HRH1 and rs4938013 in DRD2/ANKK1 with treatment response. CONCLUSIONS We could not convincingly replicate most of the previous studies, a result that is possibly due to modest association between the suggested genes. Rather, we found a new candidate gene, ABCB1, for treatment response, which may provide a hypothesis on the relationship between the blood-brain distribution of CLZ and its clinical efficacy.
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12
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Vyas NS, Shamsi SA, Malhotra AK, Aitchison KJ, Kumari V. Can genetics inform the management of cognitive deficits in schizophrenia? J Psychopharmacol 2012; 26:334-48. [PMID: 22328662 DOI: 10.1177/0269881111434623] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
There is no doubt that schizophrenia has a significant genetic component and a number of candidate genes have been identified for this debilitating disorder. Of note, several of these are implicated in cognition. Cognitive deficits constitute core symptoms of schizophrenia, and while current antipsychotic treatment strategies aim to help psychosis-related symptomatology, the cognitive symptom domain is largely inadequately treated. A number of other pharmacological approaches (e.g. using drugs that target specific neurotransmitter systems) have also been attempted for the amelioration of cognitive deficits in this population; however, these too have had limited success so far. Psychological interventions appear promising, though there has been speculation regarding whether or not these produce long-term functional improvements. Pharmacogenetic studies of the cognitive effects of currently available antipsychotics, although in relatively early stages, suggest that the treatment of cognitive deficits in schizophrenia may be advanced by focusing on genetic variants associated with specific cognitive dysfunctions in the general population and using this to match the most relevant pharmacological and/or psychological interventions with the genetic and cognitive profiles of the target population. Such a strategy would encourage bottom-up advances in drug development and provide a platform for individualised treatment of cognitive deficits in schizophrenia.
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Affiliation(s)
- Nora S Vyas
- King's College London, Institute of Psychiatry, MRC SGDP Centre, London, UK.
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13
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Reynolds GP. The pharmacogenetics of symptom response to antipsychotic drugs. Psychiatry Investig 2012; 9:1-7. [PMID: 22396678 PMCID: PMC3285735 DOI: 10.4306/pi.2012.9.1.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 12/12/2011] [Accepted: 12/12/2011] [Indexed: 12/16/2022] Open
Abstract
Antipsychotic drugs are limited in their efficacy by the relatively poor response of negative and cognitive symptoms of schizophrenia as well as by the substantial variability in response between patients. Pharmacogenetic studies have sought to identify the genetic factors that underlie the individual variability in response to treatment, with a past emphasis on dopamine and serotonin receptors as candidate genes. Few studies have separated effects on positive and negative symptoms, despite the established differences in response to drug treatment between these syndromes. Where this has been done most findings are consistent with the conclusion that dopamine receptor polymorphisms relate to positive symptom response, while negative symptom improvement is influenced by polymorphisms of genes involved in 5-HT neurotransmission. A wide range of polymorphisms in other candidate genes have been investigated, with some positive findings in those genes associated with glutamatergic transmission and/or risk factors for schizophrenia. However, there remains a lack of good replicated findings; furthermore there is little evidence to support drug-specific genetic associations with treatment response. While most past studies focused on single candidate genes, technology now permits genome-wide association studies with response to antipsychotics. Although not without major limitations, these "hypothesis-free" approaches are beginning to identify further important risk factors for treatment response. Again there is little consistency between various studies, although some of the polymorphisms identified are in genes involved in neurodevelopment, which is increasingly being recognized as important in the pathophysiology of schizophrenia.
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Affiliation(s)
- Gavin P Reynolds
- Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield S1 1WB U.K.
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14
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Abstract
There is substantial interindividual variability in the effects of treatment with antipsychotic drugs not only in the emergence of adverse effects but also in symptom response. It is becoming increasingly clear that much of this variability is due to genetic factors; pharmacogenetics is the study of those factors, with the eventual goal of identifying genetic predictors of treatment effects. There have been many reported associations of single nucleotide polymorphisms (SNPs) in candidate genes with the consequences of antipsychotic drug treatment. Thus variations in dopaminergic and serotoninergic genes may influence positive and negative symptom outcome, respectively. Among the adverse effects, tardive dyskinesia and weight gain have been the most studied, with some consistent associations of functional SNPs in genes relating to pharmacological mechanisms. Technological advance has permitted large-scale genome-wide association studies (GWAS), but as yet there are few reports that replicate prior findings with candidate genes. Nevertheless, GWAS may identify associations which provide new clues relating to underlying mechanisms.
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Affiliation(s)
- Gavin P Reynolds
- Biomedical Research Centre, Sheffield Hallam University, Sheffield, UK.
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15
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Abstract
This review presents the findings of pharmacogenetic studies exploring the influence of gene variants on antipsychotic treatment response, in terms of both symptom improvement and adverse effects, in patients with schizophrenia. Despite numerous studies in the field, replicating findings across different cohorts that include subjects of different ethnic groups has been challenging. It is clear that non-genetic factors have an important contribution to antipsychotic treatment response. Differing clinical, demographic and environmental characteristics of the cohorts studied have added substantial complexity to the interpretation of the positive and negative findings of many studies. Pharmacogenomic genome-wide investigations are beginning to yield interesting data although they have failed to replicate the most robust findings of candidate gene studies, and are limited by the sample size, especially given the need for studying homogeneous cohorts. Most of the studies conducted on cohorts treated with single antipsychotics have investigated clozapine, olanzapine or risperidone response. These studies have provided some of the most replicated associations with treatment efficacy. Serotonergic system gene variants are significantly associated with the efficacy of clozapine and risperidone, but may have less influence on the efficacy of olanzapine. Dopamine D3 receptor polymorphisms have been more strongly associated with the efficacy of clozapine and olanzapine, and D2 genetic variants with the efficacy of risperidone. Serotonin influences the control of feeding behaviour and has been hypothesized to have a role in the development of antipsychotic-induced weight gain. Numerous studies have linked the serotonin receptor 2C (5-HT2C) -759-C/T polymorphism with weight gain. The leptin gene variant, -2548-G/A, has also been associated with weight gain in several studies. Pharmacogenetic studies support the role of cytochrome P450 enzymes and dopamine receptor variants in the development of antipsychotic-induced movement disorders, with a contribution of serotonergic receptors and other gene variants implicated in the mechanism of action of antipsychotics. Clozapine-induced agranulocytosis has been associated with polymorphisms in the major histocompatibility complex gene (HLA).
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Affiliation(s)
- Maria J Arranz
- Department of Psychological Medicine, Institute of Psychiatry, Kings College London, London, UK.
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16
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Abstract
Schizophrenia (SCZ) is among the most disabling of mental disorders. Several neurobiological hypotheses have been postulated as responsible for SCZ pathogenesis: polygenic/multifactorial genomic defects, intrauterine and perinatal environment-genome interactions, neurodevelopmental defects, dopaminergic, cholinergic, serotonergic, gamma-aminobutiric acid (GABAergic), neuropeptidergic and glutamatergic/N-Methyl-D-Aspartate (NMDA) dysfunctions, seasonal infection, neuroimmune dysfunction, and epigenetic dysregulation. SCZ has a heritability estimated at 60-90%. Genetic studies in SCZ have revealed the presence of chromosome anomalies, copy number variants, multiple single-nucleotide polymorphisms of susceptibility distributed across the human genome, aberrant single nucleotide polymorphisms (SNPs) in microRNA genes, mitochondrial DNA mutations, and epigenetic phenomena. Pharmacogenetic studies of psychotropic drug response have focused on determining the relationship between variation in specific candidate genes and the positive and adverse effects of drug treatment. Approximately, 18% of neuroleptics are major substrates of CYP1A2 enzymes, 40% of CYP2D6, and 23% of CYP3A4; 24% of antidepressants are major substrates of CYP1A2 enzymes, 5% of CYP2B6, 38% of CYP2C19, 85% of CYP2D6, and 38% of CYP3A4; 7% of benzodiazepines are major substrates of CYP2C19 enzymes, 20% of CYP2D6, and 95% of CYP3A4. About 10-20% of Western populations are defective in genes of the CYP superfamily. Only 26% of Southern Europeans are pure extensive metabolizers for the trigenic cluster integrated by the CYP2D6+CYP2C19+CYP2C9 genes. The pharmacogenomic response of SCZ patients to conventional psychotropic drugs also depends on genetic variants associated with SCZ-related genes. Consequently, the incorporation of pharmacogenomic procedures both to drugs in development and drugs on the market would help to optimize therapeutics in SCZ and other central nervous system (CNS) disorders.
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Affiliation(s)
- Ramón Cacabelos
- EuroEspes Biomedical Research Center, 15165-Bergondo, Coruña, Spain.
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17
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Abstract
Central nervous system disorders are the third greatest health problem in developed countries, and schizophrenia represents some of the most disabling ailments in young individuals. There is an abuse and/or misuse of antipsychotics, and recent advances in pharmacogenomics pose new challenges for the clinical management of this complex disorder. Schizophrenia is a multi-factorial/polygenic complex disorder in which hundreds of different genes are potentially involved, leading to the phenotypic expression of the disease in conjunction with epigenetic and environmental phenomena. Consequently, structural and functional genomic changes induce proteomic and metabolomic defects associated with the disease phenotype. Disease-related genomic profiles and genetic variants in genes involved in drug metabolism are responsible for drug efficacy and safety. About 20% of Caucasians are defective in CYP2D6 enzymes, which participate in the metabolism of 25-30% of central nervous system drugs. Approximately 40% of antipsychotics are substrates of CYP2D6 enzymes, 23% are substrates of CYP3A4, and 18% are substrates of CYP1A2. In order to achieve a mature discipline of pharmacogenomics of schizophrenia it would be effective to accelerate: (i) the education of physicians and the public in the use of genomic screening in daily clinical practice; (ii) the standardization of genetic testing for major categories of drugs; (iii) the validation of pharmacogenomic procedures according to drug category and pathology; (iv) the regulation of ethical, social, and economic issues; and (v) the incorporation of pharmacogenomic procedures of drugs in development and drugs on the market in order to optimize therapeutics.
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Affiliation(s)
- Ramón Cacabelos
- EuroEspes Biomedical Research Center, Institute for CNS Disorders and Genomic Medicine, Bergondo, Coruña, Spain
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18
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Abstract
Existing psychotropic medications for the treatment of mental illnesses, including antidepressants, mood stabilizers, and antipsychotics, are clinically suboptimal. They are effective in only a subset of patients or produce partial responses, and they are often associated with debilitating side effects that discourage adherence. There is growing enthusiasm in the promise of pharmacogenetics to personalize the use of these treatments to maximize their efficacy and tolerability; however, there is still a long way to go before this promise becomes a reality. This article reviews the progress that has been made in research toward understanding how genetic factors influence psychotropic drug responses and the challenges that lie ahead in translating the research findings into clinical practices that yield tangible benefits for patients with mental illnesses.
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Affiliation(s)
- Peter P Zandi
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Hampton House, Room 857, 624 North Broadway, Baltimore, MD 21205, USA.
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Suzuki T, Uchida H, Watanabe K, Kashima H. Factors associated with response to clozapine in schizophrenia: a review. PSYCHOPHARMACOLOGY BULLETIN 2011; 44:32-60. [PMID: 22506438 PMCID: PMC5044555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Clozapine has been serving as the gold standard medication for patients with treatment-resistant schizophrenia who failed to respond to other antipsychotics. However, factors affecting response to this medication have not been comprehensively reviewed recently. METHODS In order to find factors associated with response to clozapine in schizophrenia, a literature search was conducted using PubMed through January 2011 with keywords of clozapine, response, and schizophrenia. Cross-referencing of relevant articles was also performed. Factors were arbitrarily classified into the following: demographic/clinical, oral dosage/pharmacokinetic, biochemical, (electro)physiological, genetic, imaging, and combinations. RESULTS A synthesis from 280 articles indicated that demographic and clinical variables such as high baseline symptoms and low premorbid functioning have not been particularly useful in predicting response to clozapine. Pharmacokinetic evidence points to a threshold clozapine level of 350 ng/ml but in a context of significant inter- as well as intra-individual variability. Pharmacokinetic perspectives appear to have more implication in special situations including poor response, suspected toxicity and nonadherence. A number of laboratory-based studies have reported on many potential candidates for response prediction to clozapine, however, reproducibility, specificity, robustness of the findings, as well as clinical feasibility and cost-effectiveness all pose a significant practical challenge, in relation with the fact that pathophysiological bases of treatment resistance in schizophrenia largely remain to be elucidated. CONCLUSIONS No unequivocal factors to clozapine response were found despite a relatively rich body of the literature, which calls for more works on this important topic. Clozapine level of 350 ng/ml appears to be useful in case of nonresponse.
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Affiliation(s)
- Takefumi Suzuki
- Keio University, School of Medicine, Department of Neuropsychiatry, 35, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
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Future Trends in the Pharmacogenomics of Brain Disorders and Dementia: Influence of APOE and CYP2D6 Variants. Pharmaceuticals (Basel) 2010. [PMCID: PMC4034082 DOI: 10.3390/ph3103040] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
About 80% of functional genes in the human genome are expressed in the brain and over 1,200 different genes have been associated with the pathogenesis of CNS disorders and dementia. Pharmacogenetic studies of psychotropic drug response have focused on determining the relationship between variations in specific candidate genes and the positive and adverse effects of drug treatment. Approximately, 18% of neuroleptics are substrates of CYP1A2 enzymes, 40% of CYP2D6, and 23% of CYP3A4; 24% of antidepressants are substrates of CYP1A2 enzymes, 5% of CYP2B6, 38% of CYP2C19, 85% of CYP2D6, and 38% of CYP3A4; 7% of benzodiazepines are substrates of CYP2C19 enzymes, 20% of CYP2D6, and 95% of CYP3A4. 10-20% of Western populations are defective in genes of the CYP superfamily; and the pharmacogenomic response of psychotropic drugs also depends on genetic variants associated with dementia. Prospective studies with anti-dementia drugs or with multifactorial strategies have revealed that the therapeutic response to conventional drugs in Alzheimer’s disease is genotype-specific. The disease-modifying effects (cognitive performance, biomarker modification) of therapeutic intervention are APOE-dependent, with APOE-4 carriers acting as the worst responders (APOE-3/3 > APOE-3/4 > APOE-4/4). APOE-CYP2D6 interactions also influence the therapeutic outcome in patients with dementia.
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21
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Li MD, Yoon D, Lee JY, Han BG, Niu T, Payne TJ, Ma JZ, Park T. Associations of variants in CHRNA5/A3/B4 gene cluster with smoking behaviors in a Korean population. PLoS One 2010; 5:e12183. [PMID: 20808433 PMCID: PMC2922326 DOI: 10.1371/journal.pone.0012183] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 07/21/2010] [Indexed: 11/18/2022] Open
Abstract
Multiple genome-wide and targeted association studies reveal a significant association of variants in the CHRNA5-CHRNA3-CHRNB4 (CHRNA5/A3/B4) gene cluster on chromosome 15 with nicotine dependence. The subjects examined in most of these studies had a European origin. However, considering the distinct linkage disequilibrium patterns in European and other ethnic populations, it would be of tremendous interest to determine whether such associations could be replicated in populations of other ethnicities, such as Asians. In this study, we performed comprehensive association and interaction analyses for 32 single-nucleotide polymorphisms (SNPs) in CHRNA5/A3/B4 with smoking initiation (SI), smoking quantity (SQ), and smoking cessation (SC) in a Korean sample (N = 8,842). We found nominally significant associations of 7 SNPs with at least one smoking-related phenotype in the total sample (SI: P = 0.015 approximately 0.023; SQ: P = 0.008 approximately 0.028; SC: P = 0.018 approximately 0.047) and the male sample (SI: P = 0.001 approximately 0.023; SQ: P = 0.001 approximately 0.046; SC: P = 0.01). A spectrum of haplotypes formed by three consecutive SNPs located between rs16969948 in CHRNA5 and rs6495316 in the intergenic region downstream from the 5' end of CHRNB4 was associated with these three smoking-related phenotypes in both the total and the male sample. Notably, associations of these variants and haplotypes with SC appear to be much weaker than those with SI and SQ. In addition, we performed an interaction analysis of SNPs within the cluster using the generalized multifactor dimensionality reduction method and found a significant interaction of SNPs rs7163730 in LOC123688, rs6495308 in CHRNA3, and rs7166158, rs8043123, and rs11072793 in the intergenic region downstream from the 5' end of CHRNB4 to be influencing SI in the male sample. Considering that fewer than 5% of the female participants were smokers, we did not perform any analysis on female subjects specifically. Together, our detected associations of variants in the CHRNA5/A3/B4 cluster with SI, SQ, and SC in the Korean smoker samples provide strong evidence for the contribution of this cluster to the etiology of SI, ND, and SC in this Asian population.
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Affiliation(s)
- Ming D. Li
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Dankyu Yoon
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, Korea
| | - Jong-Young Lee
- Center for Genome Science, National Institute of Health, Seoul, Korea
| | - Bok-Ghee Han
- Center for Genome Science, National Institute of Health, Seoul, Korea
| | - Tianhua Niu
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Thomas J. Payne
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, Mississippi, United States of America
| | - Jennie Z. Ma
- Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Taesung Park
- Department of Statistics, College of Natural Science, Seoul National University, Seoul, Korea
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22
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Sun YH, Shen Y, Xu Q. DTNBP1 gene is associated with some symptom factors of schizophrenia in Chinese Han nationality. ACTA ACUST UNITED AC 2010; 25:85-9. [PMID: 20598229 DOI: 10.1016/s1001-9294(10)60027-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE To study the association of DTNBP1 gene with some symptom factors of schizophrenia. METHODS A total of 285 unrelated schizophrenic individuals were recruited from December 2004 to January 2009 for genetic analysis, and their symptom factors were assessed based on the Positive and Negative Syndrome Scale (PANSS). The quantitative trait test was performed by the UNPHASED program (version 3.0.12) to investigate the association between scored positive and negative symptoms and the single nucleotide polymorphisms (SNPs) in DTNBP1 gene. RESULTS The quantitative trait test showed allelic association of rs909706 with the excitement symptom of schizophrenia (P<0.05, adjusted by 10,000 permutations), while the genotype C/G of rs2619539 with a negative symptom, lack of spontaneity and flow of conversation (P<0.05, adjusted by 10,000 permutations). CONCLUSION DTNBP1 variations are possibly associated with some symptoms of schizophrenia, which could partly explain the relationship between the susceptibility gene DTNBP1 and that disease.
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Affiliation(s)
- Yu-hui Sun
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China
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23
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Abstract
Existing psychotropic medications for the treatment of mental illnesses, including antidepressants, mood stabilizers, and antipsychotics, are clinically suboptimal. They are effective in only a subset of patients or produce partial responses, and they are often associated with debilitating side effects that discourage adherence. There is growing enthusiasm in the promise of pharmacogenetics to personalize the use of these treatments to maximize their efficacy and tolerability; however, there is still a long way to go before this promise becomes a reality. This article reviews the progress that has been made in research toward understanding how genetic factors influence psychotropic drug responses and the challenges that lie ahead in translating the research findings into clinical practices that yield tangible benefits for patients with mental illnesses.
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Affiliation(s)
- Peter P Zandi
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Hampton House, Baltimore, MD 21205, USA.
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