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von Mücke-Heim IA, Deussing JM. The P2X7 receptor in mood disorders: Emerging target in immunopsychiatry, from bench to bedside. Neuropharmacology 2023; 224:109366. [PMID: 36470368 DOI: 10.1016/j.neuropharm.2022.109366] [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: 08/31/2022] [Revised: 11/09/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022]
Abstract
Psychiatric disorders are among the most burdensome disorders worldwide. Though therapies have evolved over the last decades, treatment resistance still affects many patients. Recently, neuroimmune systems have been identified as important factors of mood disorder biology. The underlying dysregulation in neuroimmune cross-talk is driven by genetic risk factors and accumulating adverse environmental influences like chronic psychosocial stress. These result in a cluster of proinflammatory cytokines and quantitative and functional changes of immune cell populations (e.g., microglia, monocytes, T cells), varying by disease entity and state. Among the emerging immune targets, purinergic signalling revolving around the membranous and ATP specific P2X7 receptor (P2X7R) has gained wider attention and clinical studies making use of antagonistic drugs are on-going. Still, no clinically meaningful applications have been identified so far. A major problem is the often overly simplified approach taken to translate findings from bench to bedside. Therefore, the present review focuses on purinergic signalling via P2X7R in the context of recent advances in immunopsychiatric mood disorder research. Our aim is to provide an overview of the current P2X7R-related findings, from bench to bedside. First, we summarize the characteristics of purinergic signalling and P2X7R, followed by a depiction of genetic and clinical data connecting P2X7R to mood disorders. We close with our perspective on current developments and discuss changes necessary to translate the evident potential of P2X7R signalling modulation into meaningful clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.
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Affiliation(s)
| | - Jan M Deussing
- Max Planck Institute for Psychiatry, Molecular Neurogenetics, Munich, Germany.
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Yang Q, Li Y, Li B, Gong Y. A novel multi-class classification model for schizophrenia, bipolar disorder and healthy controls using comprehensive transcriptomic data. Comput Biol Med 2022; 148:105956. [PMID: 35981456 DOI: 10.1016/j.compbiomed.2022.105956] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/30/2022] [Accepted: 08/06/2022] [Indexed: 01/01/2023]
Abstract
Two common psychiatric disorders, schizophrenia (SCZ) and bipolar disorder (BP), confer lifelong disability and collectively affect 2% of the world population. Because the diagnosis of psychiatry is based only on symptoms, developing more effective methods for the diagnosis of psychiatric disorders is a major international public health priority. Furthermore, SCZ and BP overlap considerably in terms of symptoms and risk genes. Therefore, the clarity of the underlying etiology and pathology remains lacking for these two disorders. Although many studies have been conducted, a classification model with higher accuracy and consistency was found to still be necessary for accurate diagnoses of SCZ and BP. In this study, a comprehensive dataset was combined from five independent transcriptomic studies. This dataset comprised 120 patients with SCZ, 101 patients with BP, and 149 healthy subjects. The partial least squares discriminant analysis (PLS-DA) method was applied to identify the gene signature among multiple groups, and 341 differentially expressed genes (DEGs) were identified. Then, the disease relevance of these DEGs was systematically performed, including (α) the great disease relevance of the identified signature, (β) the hub genes of the protein-protein interaction network playing a key role in psychiatric disorders, and (γ) gene ontology terms and enriched pathways playing a key role in psychiatric disorders. Finally, a popular multi-class classifier, support vector machine (SVM), was applied to construct a novel multi-class classification model using the identified signature for SCZ and BP. Using the independent test sets, the classification capacity of this multi-class model was assessed, which showed this model had a strong classification ability.
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Affiliation(s)
- Qingxia Yang
- Department of Bioinformatics, Smart Health Big Data Analysis and Location Services Engineering Lab of Jiangsu Province, School of Geographic and Biologic Information, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
| | - Yi Li
- Institute of Genomic Medicine, Wenzhou Medical University, Wenzhou, China
| | - Bo Li
- College of Life Sciences, Chongqing Normal University, Chongqing, Chongqing, 401331, China
| | - Yaguo Gong
- School of Pharmacy, Macau University of Science and Technology, Macau, China.
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Urbina-Treviño L, von Mücke-Heim IA, Deussing JM. P2X7 Receptor-Related Genetic Mouse Models – Tools for Translational Research in Psychiatry. Front Neural Circuits 2022; 16:876304. [PMID: 35422688 PMCID: PMC9001905 DOI: 10.3389/fncir.2022.876304] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/07/2022] [Indexed: 11/20/2022] Open
Abstract
Depression is a common psychiatric disorder and the leading cause of disability worldwide. Although treatments are available, only about 60% of treated patients experience a significant improvement in disease symptoms. Numerous clinical and rodent studies have identified the purinergic P2X7 receptor (P2X7R) as one of the genetic factors potentially contributing to the disease risk. In this respect, genetically engineered mouse models targeting the P2X7R have become increasingly important in studying designated immunological features and subtypes of depression in vivo. This review provides an overview of the P2X7R -related mouse lines currently available for translational psychiatric research and discusses their strengths, weaknesses, and potentials.
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Affiliation(s)
- Lidia Urbina-Treviño
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig Maximilian University of Munich, Munich, Germany
| | - Iven-Alex von Mücke-Heim
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- International Max Planck Research School for Translational Psychiatry, Munich, Germany
| | - Jan M. Deussing
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- *Correspondence: Jan M. Deussing,
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Gonçalves MCB, Andrejew R, Gubert C. The Purinergic System as a Target for the Development of Treatments for Bipolar Disorder. CNS Drugs 2022; 36:787-801. [PMID: 35829960 PMCID: PMC9345801 DOI: 10.1007/s40263-022-00934-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/15/2022] [Indexed: 11/27/2022]
Abstract
The neurobiological and neurochemical mechanisms underlying the pathophysiology of bipolar disorder are complex and not yet fully understood. From circadian disruption to neuroinflammation, many pathways and signaling molecules are important contributors to bipolar disorder development, some specific to a disease subtype or a cycling episode. Pharmacological agents for bipolar disorder have shown only partial efficacy, including mood stabilizers and antipsychotics. The purinergic hypothesis for bipolar disorder emerges in this scenario as a promising target for further research and drug development, given its role in neurotransmission and neuroinflammation that results in behavioral and mood regulation. Here, we review the basic concepts of purinergic signaling in the central nervous system and its contribution to bipolar disorder pathophysiology. Allopurinol and novel P2X7 receptor antagonists are promising candidates for treating bipolar disorder. We further explore currently available pharmacotherapies and the emerging new purinergic targets for drug development in bipolar disorder.
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Affiliation(s)
| | - Roberta Andrejew
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Carolina Gubert
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, 30 Royal Parade, Parkville, VIC, 3032, Australia.
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Szopa A, Socała K, Serefko A, Doboszewska U, Wróbel A, Poleszak E, Wlaź P. Purinergic transmission in depressive disorders. Pharmacol Ther 2021; 224:107821. [PMID: 33607148 DOI: 10.1016/j.pharmthera.2021.107821] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Purinergic signaling involves the actions of purine nucleotides and nucleosides (such as adenosine) at P1 (adenosine), P2X, and P2Y receptors. Here, we present recent data contributing to a comprehensive overview of the association between purinergic signaling and depression. We start with background information on adenosine production and metabolism, followed by a detailed characterization of P1 and P2 receptors, with an emphasis on their expression and function in the brain as well as on their ligands. We provide data suggestive of altered metabolism of adenosine in depressed patients, which might be regarded as a disease biomarker. We then turn to considerable amount of preclinical/behavioral data obtained with the aid of the forced swim test, tail suspension test, learned helplessness model, or unpredictable chronic mild stress model and genetic activation/inactivation of P1 or P2 receptors as well as nonselective or selective ligands of P1 or P2 receptors. We also aimed to discuss the reason underlying discrepancies observed in such studies.
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Affiliation(s)
- Aleksandra Szopa
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland.
| | - Katarzyna Socała
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland
| | - Anna Serefko
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland
| | - Urszula Doboszewska
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland
| | - Andrzej Wróbel
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, PL 20-090 Lublin, Poland
| | - Ewa Poleszak
- Department of Applied and Social Pharmacy, Laboratory of Preclinical Testing, Medical University of Lublin, Chodźki 1, PL 20-093 Lublin, Poland.
| | - Piotr Wlaź
- Department of Animal Physiology and Pharmacology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Akademicka 19, PL 20-033 Lublin, Poland.
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Vereczkei A, Abdul-Rahman O, Halmai Z, Nagy G, Szekely A, Somogyi A, Faludi G, Nemoda Z. Association of purinergic receptor P2RX7 gene polymorphisms with depression symptoms. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:207-216. [PMID: 30664971 DOI: 10.1016/j.pnpbp.2019.01.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/08/2019] [Accepted: 01/13/2019] [Indexed: 12/23/2022]
Abstract
INTRODUCTION The activation of the ATP-gated P2RX7 (purinergic receptor P2X, ligand-gated ion channel, 7) produces microglial activation, a process which has been demonstrated in depression, bipolar disorder, and schizophrenia. Emerging data over the last years highlighted the importance of P2X7 cation channel as a potential drug target for these central nervous system disorders. The Gln460Arg (rs2230912) polymorphism of the P2RX7 gene has been widely studied in mood disorders, however the results are still controversial. Therefore, we aimed to investigate the C-terminal region of this gene in major depressive and bipolar disorders (MDD and BD) by studying possibly functional, non-synonymous polymorphisms within a 7 kb long region around the Gln460Arg, including Ala348Thr (rs1718119), Thr357Ser (rs2230911), and Glu496Ala (rs3751143) variants. Since Gln460Arg is located at the 3' end of the P2RX7 gene, we included additional, potentially functional single nucleotide polymorphisms (SNPs) from the 3' untranslated region (UTR), which can be in linkage with Gln460Arg. Based on in silico search, we chose two SNPs in putative microRNA target sites which are located in consecutive positions: rs1653625 and rs1718106. METHODS P2RX7 SNPs from the C-terminal region were selected based on previous functional assays, 3' UTR variants were chosen using PolymiRTS and Patrocles databases. The genotyping of the non-synonymous SNPs was carried out by pre-designed TaqMan® kits, while the 3' UTR variants were analyzed by PCR-RFLP method. Case-control analyses were carried out between 315 inpatients with acute major depressive episode (195 MDD, 120 BD) and 406 healthy control subjects. The two subscales of the Hospital Anxiety and Depression Scale (HADS) self-report questionnaire were used for quantitative analyses, including an additional, "at-risk" population of 218 patients with diabetes mellitus. The in vitro reporter gene assays were carried out on HEK and SK-N-FI cells transiently transfected with pMIR vector constructs containing the P2RX7 3' UTR downstream of the luciferase gene. RESULTS Haplotype analysis indicated a relatively high linkage between the analyzed P2RX7 SNPs. Our case-control study did not yield any association between P2RX7 gene variants and depression. However, dimensional analyses showed significant associations of the HADS depression severity scores with Gln460Arg (rs2230912) and Ala348Thr (rs1718119) in the depressed and diabetic patient groups. In the in vitro experiments, the P2RX7 3' UTR constructs with the lowest predicted binding efficiency to their miRNAs showed the highest expression of the gene. The combination of the depression-associated P2RX7 C-terminal and 3' UTR SNPs contributed to the highest depression severity score in the haplotype analysis. CONCLUSION Based on our findings, we propose that a P2RX7 haplotype combination of the Gln460Arg and neighboring SNPs contribute to the observed genetic association with depressive symptoms.
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Affiliation(s)
- Andrea Vereczkei
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Omar Abdul-Rahman
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Zsuzsa Halmai
- Department of Psychiatry, Kútvölgyi Clinical Centre, Semmelweis University, Budapest, Hungary; Bhaktivedanta College, Budapest, Hungary
| | - Geza Nagy
- 2nd Department of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Anna Szekely
- Institute of Psychology, Eötvös Loránd University, Budapest, Hungary
| | - Aniko Somogyi
- 2nd Department of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Gabor Faludi
- Department of Psychiatry, Kútvölgyi Clinical Centre, Semmelweis University, Budapest, Hungary
| | - Zsofia Nemoda
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary.
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P2X7 Receptor Signaling in Stress and Depression. Int J Mol Sci 2019; 20:ijms20112778. [PMID: 31174279 PMCID: PMC6600521 DOI: 10.3390/ijms20112778] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 12/31/2022] Open
Abstract
Stress exposure is considered to be the main environmental cause associated with the development of depression. Due to the limitations of currently available antidepressants, a search for new pharmacological targets for treatment of depression is required. Recent studies suggest that adenosine triphosphate (ATP)-mediated signaling through the P2X7 receptor (P2X7R) might play a prominent role in regulating depression-related pathology, such as synaptic plasticity, neuronal degeneration, as well as changes in cognitive and behavioral functions. P2X7R is an ATP-gated cation channel localized in different cell types in the central nervous system (CNS), playing a crucial role in neuron-glia signaling. P2X7R may modulate the release of several neurotransmitters, including monoamines, nitric oxide (NO) and glutamate. Moreover, P2X7R stimulation in microglia modulates the innate immune response by activating the NLR family pyrin domain containing 3 (NLRP3) inflammasome, consistent with the neuroimmune hypothesis of MDD. Importantly, blockade of P2X7R leads to antidepressant-like effects in different animal models, which corroborates the findings that the gene encoding for the P2X7R is located in a susceptibility locus of relevance to depression in humans. This review will discuss recent findings linked to the P2X7R involvement in stress and MDD neuropathophysiology, with special emphasis on neurochemical, neuroimmune, and neuroplastic mechanisms.
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Winham SJ, Bobo WV, Liu J, Coombes B, Backlund L, Frye MA, Biernacka JM, Schalling M, Lavebratt C. Sex-specific effects of gain-of-function P2RX7 variation on bipolar disorder. J Affect Disord 2019; 245:597-601. [PMID: 30445384 DOI: 10.1016/j.jad.2018.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/14/2018] [Accepted: 11/02/2018] [Indexed: 10/27/2022]
Abstract
BACKGROUND Patients with bipolar disorder demonstrate sex differences in clinical presentation, particularly in the sub-phenotypes related to periodicity of mood episodes, such as rapid cycling. Additionally, recent studies have linked P2RX7 gene variants with the risk of rapid cycling in clinical cohorts of patients with bipolar disorder, as well as other mood disorders. However, little is known about potential sex differences in the relationship between variants in P2RX7 and bipolar disorder. METHODS We investigated sex-specific genetic associations between variants of P2RX7 (rs1621388 and rs2230912) in 756 patients with bipolar disorder and 787 control patients matched on age, sex, and ancestry. We examined sex-specific genetic associations with bipolar disorder by comparing cases and controls, as well as rapid cycling of mood episodes in cases. Findings were replicated in an independent dataset. RESULTS P2RX7 variants implying an increased pore activity were more common in bipolar disorder, in females but not in males. Neither P2RX7 variants associated with rapid cycling among bipolar patients. LIMITATIONS Low sample size limited power for tests of SNP by sex interaction, and data about the onset of rapid cycling and the timing of medication use were not available. CONCLUSION The effects of P2RX7 variants on bipolar disorder may be sex-specific, with increased P2X7 activity potentially elevating risk for bipolar disorder in females. Future research to examine the effect of P2RX7 on bipolar disorder should consider sex-specific effects.
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Affiliation(s)
- Stacey J Winham
- Department of Health Sciences Research, Mayo Clinic, 200 First Street SW, 55905 Rochester, MN, USA.
| | - William V Bobo
- Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, FL, USA
| | - Jiajia Liu
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden; Sixth Hospital/Institute of Mental Health, Peking University, China
| | - Brandon Coombes
- Department of Health Sciences Research, Mayo Clinic, 200 First Street SW, 55905 Rochester, MN, USA
| | - Lena Backlund
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Mark A Frye
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | - Joanna M Biernacka
- Department of Health Sciences Research, Mayo Clinic, 200 First Street SW, 55905 Rochester, MN, USA; Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | - Martin Schalling
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Catharina Lavebratt
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden; Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
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Deussing JM, Arzt E. P2X7 Receptor: A Potential Therapeutic Target for Depression? Trends Mol Med 2018; 24:736-747. [PMID: 30093269 DOI: 10.1016/j.molmed.2018.07.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 02/07/2023]
Abstract
Depression is a prime contributor to global disease burden with 300 million affected patients worldwide. The persistent lack of progress with regards to pharmacotherapy stands in stark contrast to the pandemic magnitude of the disease. Alterations of inflammatory pathways in depressed patients, including altered circulating pro-inflammatory cytokines, have been put forward as a potential pathophysiological mechanism. The P2X7 receptor (P2X7R) plays an important role regulating the release of interleukin-1β and other cytokines. Comprehensive investigation of the P2X7R Gln460Arg missense mutation (rs2230912), which has been associated with major depression and bipolar disorder, has substantially contributed to validate P2X7R as a potential genetic risk factor. We propose that P2X7R is a putative target with good prospects for therapeutic intervention in depressive disorders.
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Affiliation(s)
- Jan M Deussing
- Molecular Neurogenetics, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany.
| | - Eduardo Arzt
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET-Partner Institute of the Max Planck Society; and University of Buenos Aires, Argentina, Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
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Czamara D, Müller-Myhsok B, Lucae S. The P2RX7 polymorphism rs2230912 is associated with depression: A meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry 2018; 82:272-277. [PMID: 29122639 DOI: 10.1016/j.pnpbp.2017.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 12/01/2022]
Abstract
Various studies have investigated whether single nucleotide polymorphisms (SNPs) in the gene purinergic receptor P2X7 (P2RX7), and rs2230912 specifically, were associated with mood disorders. While some studies found positive evidence, a large number of studies reported no significant associations. In a previously published meta-analysis, Feng et al. did not find a significant association and only moderate odds ratios (ORs) in case-control studies. They reported significant findings only for family-based studies. We revisited this finding and conducted a meta-analysis including 8,652 cases and 11,153 controls, adding unpublished results from the Munich Antidepressant Response Signature (MARS) study. We found a significant association between rs2230912 and combined mood disorders (major depressive disorder (MDD) or bipolar disorder (BD)) for the allelic, dominant and heterozygous-disadvantage model, all withstanding the threshold of correction for multiple testing. Stratifying by disorder revealed significant findings for the MDD-subgroup (OR of 1.12 for the allelic model), while the BD-subgroup presented with a lower effect size (OR of 1.05) and no significance. P2RX7 encodes a purinergic receptor which is expressed in the brain and also localized in immune cells. Animal studies and functional studies will be necessary to enlighten its involvement in the etiology of mood disorders and its applicability for pharmacological purposes.
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Affiliation(s)
- D Czamara
- Max Planck Institute of Psychiatry, Munich, Germany.
| | - B Müller-Myhsok
- Max Planck Institute of Psychiatry, Munich, Germany; Munich Cluster of Systems Biology, SyNergy, Germany; Institute of Translational Medicine, University of Liverpool, United Kingdom
| | - S Lucae
- Max Planck Institute of Psychiatry, Munich, Germany
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Talih F, Gebara NY, Andary FS, Mondello S, Kobeissy F, Ferri R. Delayed sleep phase syndrome and bipolar disorder: Pathogenesis and available common biomarkers. Sleep Med Rev 2018. [PMID: 29534856 DOI: 10.1016/j.smrv.2018.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Circadian rhythm disturbances are common in bipolar affective disorder (BD). Delayed sleep-wake phase syndrome (DSWPD) is the most prevalent circadian rhythm sleep-wake disorder (CRSWDs) and is frequently observed in BD. It is unclear whether DSWPD in BD is an independent process or is a consequence of BD. In this hypothetical review, we discuss the overlap between BD and DSWPD and potential common biomarkers for DSWPD and BD. The review will include a discussion of the genetics of DSWPD and BD. Biomarkers elucidating the pathophysiological processes occurring in these two disorders may offer insight into the etiology and prognosis of both conditions.
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Affiliation(s)
- Farid Talih
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon; Department of Psychiatry, American University of Beirut Medical Center, Beirut, Lebanon.
| | - Nour Y Gebara
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
| | - Farah S Andary
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Stefania Mondello
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy; Sleep Research Centre, Oasi Research Institute IRCCS, Troina, Italy
| | - Firas Kobeissy
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Raffaele Ferri
- Sleep Research Centre, Oasi Research Institute IRCCS, Troina, Italy
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Van Rheenen TE, Rossell SL. Genetic and neurocognitive foundations of emotion abnormalities in bipolar disorder. Cogn Neuropsychiatry 2013; 18:168-207. [PMID: 23088582 DOI: 10.1080/13546805.2012.690938] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Bipolar Disorder (BD) is a serious mood disorder, the aetiology of which is still unclear. The disorder is characterised by extreme mood variability in which patients fluctuate between markedly euphoric, irritable, and elevated states to periods of severe depression. The current research literature shows that BD patients demonstrate compromised neurocognitive ability in addition to these mood symptoms. Viable candidate genes implicated in neurocognitive and socioemotional processes may explain the development of these core emotion abnormalities. Additionally, links between faulty neurocognition and impaired socioemotional ability complement genetic explanations of BD pathogenesis. This review examines associations between cognition indexing prefrontal neural regions and socioemotional impairments including emotion processing and regulation. A review of the effect of COMT and TPH2 on these functions is also explored. METHODS Major computer databases including PsycINFO, Google Scholar, and Medline were consulted in order to conduct a comprehensive review of the genetic and cognitive literature in BD. RESULTS This review determines that COMT and TPH2 genetic variants contribute susceptibility to abnormal prefrontal neurocognitive function which oversees the processing and regulation of emotion. This provides for greater understanding of some of the emotional and cognitive symptoms in BD. CONCLUSIONS Current findings in this direction show promise, although the literature is still in its infancy and further empirical research is required to investigate these links explicitly.
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Affiliation(s)
- Tamsyn E Van Rheenen
- Brain and Psychological Sciences Research Centre, Faculty of Life and Social Sciences, Swinburne University, and Cognitive Neuropsychology Laboratory, Monash Alfred Psychiatry Research Center, The Alfred Hospital, Melbourne, Australia.
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P2RX7: expression responds to sleep deprivation and associates with rapid cycling in bipolar disorder type 1. PLoS One 2012; 7:e43057. [PMID: 22952630 PMCID: PMC3429455 DOI: 10.1371/journal.pone.0043057] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 07/16/2012] [Indexed: 12/30/2022] Open
Abstract
Context Rapid cycling is a severe form of bipolar disorder with an increased rate of episodes that is particularly treatment-responsive to chronotherapy and stable sleep-wake cycles. We hypothesized that the P2RX7 gene would be affected by sleep deprivation and be implicated in rapid cycling. Objectives To assess whether P2RX7 expression is affected by total sleep deprivation and if variation in P2RX7 is associated with rapid cycling in bipolar patients. Design Gene expression analysis in peripheral blood mononuclear cells (PBMCs) from healthy volunteers and case-case and case-control SNP/haplotype association analyses in patients. Participants Healthy volunteers at the sleep research center, University of California, Irvine Medical Center (UCIMC), USA (n = 8) and Swedish outpatients recruited from specialized psychiatric clinics for bipolar disorder, diagnosed with bipolar disorder type 1 (n = 569; rapid cycling: n = 121) and anonymous blood donor controls (n = 1,044). Results P2RX7 RNA levels were significantly increased during sleep deprivation in PBMCs from healthy volunteers (p = 2.3*10−9). The P2RX7 rs2230912 _A allele was more common (OR = 2.2, p = 0.002) and the ACGTTT haplotype in P2RX7 (rs1718119 to rs1621388) containing the protective rs2230912_G allele (OR = 0.45–0.49, p = 0.003–0.005) was less common, among rapid cycling cases compared to non-rapid cycling bipolar patients and blood donor controls. Conclusions Sleep deprivation increased P2RX7 expression in healthy persons and the putatively low-activity P2RX7 rs2230912 allele A variant was associated with rapid cycling in bipolar disorder. This supports earlier findings of P2RX7 associations to affective disorder and is in agreement with that particularly rapid cycling patients have a more vulnerable diurnal system.
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Abstract
Bipolar disorder is a serious disorder of mood that is associated with considerable psychosocial and economic morbidity. Even though it is more common than previously thought, it has until relatively recently been somewhat neglected in terms of research when compared to disorders such as schizophrenia and major depression. Recent advances in the fields of nosology, epidemiology, and molecular genetics in particular have begun to unravel some of the complexity of this disorder and the next few years are likely to witness substantial changes to the ways in which the broad spectrum of bipolar disorders is diagnosed and managed.
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Affiliation(s)
- Daniel J Smith
- Department of Psychological Medicine, Cardiff University, Cardiff, UK
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15
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Abstract
Whole-genome linkage and association studies of bipolar disorder are beginning to provide some compelling evidence for the involvement of several chromosomal regions and susceptibility genes in the pathogenesis of bipolar disorder. Developments in genotyping technology and efforts to combine data from different studies have helped in identifying chromosomes 6q16-q25, 13q, and 16p12 as probable susceptibility loci for bipolar disorder and confirmed CACNA1C and ANK3 as susceptibility genes for bipolar disorder. However, a lack of replication is still apparent in the literature. New studies focusing on copy number variants as well as new analytical approaches utilizing pathway analysis offer a new direction in the study of the genetics of bipolar disorder.
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Affiliation(s)
- Shaza Alsabban
- MRC Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, Box PO82, De Crespigny Park, Denmark Hill, London, England SE5 8AF, UK.
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16
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Backlund L, Nikamo P, Hukic DS, Ek IR, Träskman-Bendz L, Landén M, Edman G, Schalling M, Frisén L, Osby U. Cognitive manic symptoms associated with the P2RX7 gene in bipolar disorder. Bipolar Disord 2011; 13:500-8. [PMID: 22017219 DOI: 10.1111/j.1399-5618.2011.00952.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Several genetic loci have been suggested to be associated with bipolar disorder but results have been inconsistent. Studying associations between bipolar symptoms and candidate genes may better expose this relationship. Here we investigate the association between bipolar key symptoms and the P2RX7 gene. METHODS Key symptoms of mania were rated in two sets of medicated bipolar disorder patients (n=171 and n=475) at two specialized outpatient clinics for affective disorders and three regular psychiatric outpatient units in Sweden. The relationships between all manic symptoms according to DSM-IV were entered in a principal component analysis. We used a case-case model to reduce the genetic heterogeneity and tested associations between four factors related to manic symptoms and their association to four single nucleotide polymorphisms in the P2RX7 gene. RESULTS The combination of the cognitive symptoms, distractibility, talkativeness, and thought disorder was significantly associated with rs1718119 in the P2RX7 gene in Set 1 [odds ratio (OR) = 1.78; p=0.011]. The association was re-tested in the second set (OR = 1.42; p=0.009). In the total sample, the association was even stronger (OR = 1.49; p<0.001). None of the other factors was associated with the P2RX7 gene. Within the first factor, the distractibility symptom accounted for a significant portion of the association to rs1718119 (p=0.016). CONCLUSION There is an association between specific symptoms of bipolar disorder and the P2RX7 gene. This finding may open up new approaches to elucidating the neurobiology behind bipolar symptoms.
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Affiliation(s)
- Lena Backlund
- Department of Clinical Neuroscience Neurogenetics Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
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17
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Abstract
OBJECTIVE Linkage and association studies of bipolar affective disorder (BAD) point out chromosome 12q24 as a region of interest. METHODS To investigate this region further, we conducted an association study of 22 DNA markers within a 1.14 Mb region in a Danish sample of 166 patients with BAD and 311 control individuals. Two-hundred and four Danish patients with schizophrenia were also included in the study. RESULTS We observed highly significant allelic and genotypic association between BAD and two highly correlated markers. The risk allele of both markers considered separately conferred an odds ratio of 2 to an individual carrying one risk allele and an odds ratio of 4 for individuals carrying both risk alleles assuming an additive genetic model. These findings were supported by the haplotype analysis. In addition, we obtained a replication of four markers associated with BAD in an earlier UK study. The most significantly associated marker was also analyzed in a Scottish case-control sample and was earlier associated with BAD in the UK cohort. The association of that particular marker was strongly associated with BAD in a meta-analysis of the Danish, Scottish and UK sample (P=0.0003). The chromosome region confined by our most distant markers is gene-poor and harbours only a few predicted genes. This study implicates the Slynar locus. We confirmed one annotated Slynar transcript and identified a novel transcript in human brain cDNA. CONCLUSION This study confirms 12q24.3 as a region of functional importance in the pathogenesis of BAD and highlights the importance of focused genotyping.
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Lopez de Lara C, Jaitovich-Groisman I, Cruceanu C, Mamdani F, Lebel V, Yerko V, Beck A, Young LT, Rouleau G, Grof P, Alda M, Turecki G. Implication of synapse-related genes in bipolar disorder by linkage and gene expression analyses. Int J Neuropsychopharmacol 2010; 13:1397-410. [PMID: 20667171 PMCID: PMC3525668 DOI: 10.1017/s1461145710000714] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Several chromosomal regions have been linked to bipolar disorder (BD). However, the search for specific genes has been hampered by inconsistent findings, partly due to genetic and phenotypic heterogeneity. We focused on lithium-responsive bipolar patients, a subgroup thought to be more homogeneous and conducted a multistage study including an initial linkage study followed up by fine mapping and gene expression. Our sample consisted of 36 families (275 genotyped individuals, 132 affected) recruited through probands who were responders to long-term lithium treatment. We conducted a genome-wide scan with 811 microsatellite markers followed by fine mapping. Gene expression studies of candidate regions were conducted on six post-mortem prefrontal brain regions of 20 individuals (8 BD and 12 controls). We identified regions 3p25, 3p14 and 14q11 as showing the highest genome-wide linkage signal (LOD 2.53, 2.04 and 3.19, respectively). Fine mapping provided further support for 3p25, while only modest support was found in the other two regions. We identified a group of synaptic, mitochondrial and apoptotic genes with altered expression patterns in BD. Analysis of an independent microarray dataset supported the implication of synapse-related and mitochondrial genes in BD. In conclusion, using two complementary strategies, we found evidence of linkage to lithium-responsive BD on 3p25, 3p14 and 14q11 as well as significantly dysregulated genes on these regions suggesting altered synaptic and mitochondrial function in BD. Further studies are warranted to demonstrate the functional role of these genes in BD.
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Joo EJ, Greenwood TA, Schork N, McKinney RA, Sadovnick AD, Remick RA, Keck PE, McElroy SL, Kelsoe JR. Suggestive evidence for linkage of ADHD features in bipolar disorder to chromosome 10p14. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:260-8. [PMID: 19603423 DOI: 10.1002/ajmg.b.31005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Higher rates of bipolar disorder amongst the first-degree relatives of probands with ADHD, and increased rates of ADHD in the relatives of bipolar probands have been reported in many studies. This suggests some commonality in the genetic basis for bipolar disorder and ADHD. We hypothesized that ADHD symptoms in bipolar disorder may access a quantitative subphenotype that is genetically less complex and therefore advantageous for mapping studies. The Wender Utah Rating Scale (WURS) was used to quantify ADHD features in 57 bipolar families collected for linkage studies. The factor structure of the WURS was first examined, and heritability was estimated. Linkage analysis was then conducted using the WURS total score and factor scores as quantitative traits. Three factors were identified: impulsivity and defiant behavior, mood instability and anxiety, and inattention. The total WURS and factor scores were each significantly heritable (0.34 <h(2r) < 0.49) in bipolar families. The inattention factor obtained maximum evidence of linkage on chromosome 10p14 (LOD = 3.35, 25 cM). A LOD score of 2.06 for the total WURS score was found on chromosome 12q24 region. Childhood ADHD features in patients with bipolar disorder are heritable and may represent a genetically distinct dimension of illness. 10p14, in particular may contain a locus for inattention in bipolar disorder. Quantitative dimensional phenotypes such as this may be useful for both mapping of genes and understanding the role of genes in bipolar disorder.
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Affiliation(s)
- Eun-Jeong Joo
- Department of Psychiatry, University of California, San Diego, La Jolla, California, USA
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20
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Schosser A, Cohen-Woods S, Gaysina D, Chow PC, Martucci L, Farmer A, Korszun A, Gunashinghe C, Gray J, Jones L, Craddock N, Owen MJ, Craig IW, McGuffin P. NRG1 gene in recurrent major depression: no association in a large-scale case-control association study. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:141-7. [PMID: 19367584 DOI: 10.1002/ajmg.b.30965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The Neuregulin 1 (NRG1) gene was initially implicated in schizophrenia (SZ) and has recently been associated with bipolar disorder (BPD) in two studies. An association with major depressive disorder (MDD) has not yet been investigated but is warranted in view of the genetic overlap between MDD and BPD. We have performed a large-scale case-control study investigating the association between NRG1 polymorphisms and MDD, genotyping a selection of 14 single nucleotide polymorphisms (SNPs) spanning the NRG1 gene in a sample of 1,398 patients of White European ancestry with a diagnosis of MDD and 1,304 ethnically matched controls from three clinical sites in the UK. We found no single marker or haplotype associations that withstood correction for multiple testing. Our findings do not provide evidence that NRG1 plays a role in MDD or that this gene explains part of the genetic overlap with BPD.
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Affiliation(s)
- A Schosser
- MRC SGDP Centre, Institute of Psychiatry, King's College London, London, UK.
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21
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Green EK, Grozeva D, Raybould R, Elvidge G, Macgregor S, Craig I, Farmer A, McGuffin P, Forty L, Jones L, Jones I, O'Donovan MC, Owen MJ, Kirov G, Craddock N. P2RX7: A bipolar and unipolar disorder candidate susceptibility gene? Am J Med Genet B Neuropsychiatr Genet 2009; 150B:1063-9. [PMID: 19160446 DOI: 10.1002/ajmg.b.30931] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The chromosomal region 12q24 has been previously implicated by linkage studies of both bipolar disorder and unipolar mood disorder and we have reported two pedigrees segregating both bipolar disorder and Darier's disease that show linkage across this region. The gene P2RX7 is located in this chromosomal region and has been recently reported as a susceptibility gene for bipolar disorder and unipolar depression. The non-synonymous SNP rs2230912 (resulting in amino-acid polymorphism Q460R) showed the strongest association and has been postulated to be pathogenically relevant. We have investigated this gene in a large UK case-control sample (bipolar I disorder N = 687, unipolar recurrent major depression N = 1,036, controls N = 1,204). Neither rs2230912 nor any of 8 other SNPs genotyped across P2RX7 was found to be associated with mood disorder in general, nor specifically with bipolar or unipolar disorder. Further, sequencing of our two chromosome 12-linked bipolar-Darier families showed no evidence of rare variants at P2RX7 that could explain the linkage. Our data do not provide support for rs2230912 or the other polymorphisms studied within the P2RX7 locus, being involved in susceptibility to mood disorders.
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Affiliation(s)
- Elaine K Green
- Department of Psychological Medicine, Wales College of Medicine, Cardiff University, Heath Park, UK.
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22
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Yosifova A, Mushiroda T, Stoianov D, Vazharova R, Dimova I, Karachanak S, Zaharieva I, Milanova V, Madjirova N, Gerdjikov I, Tolev T, Velkova S, Kirov G, Owen MJ, O'Donovan MC, Toncheva D, Nakamura Y. Case-control association study of 65 candidate genes revealed a possible association of a SNP of HTR5A to be a factor susceptible to bipolar disease in Bulgarian population. J Affect Disord 2009; 117:87-97. [PMID: 19328558 DOI: 10.1016/j.jad.2008.12.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/24/2008] [Accepted: 12/24/2008] [Indexed: 11/15/2022]
Abstract
BACKGROUND Bipolar affective disorder (BAD) is a psychiatric illness characterized by episodes of mania and depression. Although the etiology is not clear, epidemiological studies suggest it is a result of an interaction of genetic and environmental factors. Despite of enormous efforts and abundant studies conducted, none has yet been identified definitively a gene susceptible to bipolar disorder. METHODS Ninety-four Bulgarian patients diagnosed with bipolar disorder and 184 Bulgarian healthy individuals, were used for genotyping of 191 single nucleotide polymorphisms (SNPs) by TaqMan and/or Invader assays. Seventeen SNPs that revealed P value less than 0.05 in the first screening were genotyped using an additional independent set of samples, consisting of 78 BAD cases and 372 controls. RESULTS After applying the Bonferonni correction on genotyping results of 172 cases and 556 controls, only one SNP, rs1800883, in the HTR5A gene revealed a significant level of P value (P=0.000097; odds ratio=1.80 (95%CI, 1.27-2.54); corrected P=0.017). CONCLUSIONS Our findings suggest that HTR5A gene could play an important role in the pathogenesis of bipolar disorder in our population. However these findings should be viewed with caution and replication studies in other populations are necessary in support of these findings.
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Affiliation(s)
- Adelina Yosifova
- Laboratory for International Alliance, RIKEN Center for Genomic Medicine, Tsurumi-ku, Yokohama, Japan
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23
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Abstract
Since the 1950s, lithium salts have been the main line of treatment for bipolar disorder (BD), both as a prophylactic and as an episodic treatment agent. Like many psychiatric conditions, BD is genetically and phenotypically heterogeneous, but evidence suggests that individuals who respond well to lithium treatment have more homogeneous clinical and molecular profiles. Response to lithium seems to cluster in families and can be used as a predictor for recurrence of BD symptoms. While molecular studies have provided important information about possible genes involved in BD predisposition or in lithium response, neither the mechanism of action of this drug nor the genetic profile of bipolar disorder is, as yet, completely understood.
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Affiliation(s)
- Cristiana Cruceanu
- McGill Group for Suicide Studies, Douglas Hospital, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Gustavo Turecki
- McGill Group for Suicide Studies, Douglas Hospital, McGill University, Montreal, Quebec H4H 1R3, Canada
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24
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Christiansen L, Tan Q, Kruse T, McGue M, Christensen K. Candidate region linkage analysis in twins discordant or concordant for depression symptomatology. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:581-4. [PMID: 18698577 PMCID: PMC3622891 DOI: 10.1002/ajmg.b.30841] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Genetic risk factors contribute considerably to both clinical affective disorders and subsyndromal mood level. There is moreover evidence to suggest that the genetic basis of bipolar disorder and unipolar depression overlap to some extent, and several linkage analyses have suggested evidence for a common susceptibility locus in affective disorders on chromosome 12q24. In this study we investigated the chromosome 12 candidate region for linkage to the mean level of depression symptomatology, over a 10-year follow-up, using a highly informative sample of concordant and discordant twin pairs selected from 4,731 participants of the Longitudinal Study of Ageing Danish Twins. Our results showed suggestive evidence of linkage to this region with a peak LOD score of 1.91 for marker D12S1634 located at 148 cM, and thus indicates that the previously identified disease locus at 12q24 is also a general vulnerability locus affecting the normal range of mood.
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Affiliation(s)
- L. Christiansen
- Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark,Department of Biochemistry, Pharmacology and Genetics, Odense University Hospital, Odense, Denmark,Correspondence to: Dr. L. Christiansen, Department of Biochemistry, Pharmacology and Genetics, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
| | - Q. Tan
- Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark,Department of Biochemistry, Pharmacology and Genetics, Odense University Hospital, Odense, Denmark
| | - T.A. Kruse
- Department of Biochemistry, Pharmacology and Genetics, Odense University Hospital, Odense, Denmark
| | - M. McGue
- Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark,Department of Psychology, University of Minnesota, Minneapolis, Minnesota
| | - K. Christensen
- Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark
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25
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McQuillin A, Bass NJ, Choudhury K, Puri V, Kosmin M, Lawrence J, Curtis D, Gurling HMD. Case-control studies show that a non-conservative amino-acid change from a glutamine to arginine in the P2RX7 purinergic receptor protein is associated with both bipolar- and unipolar-affective disorders. Mol Psychiatry 2009; 14:614-20. [PMID: 18268501 DOI: 10.1038/mp.2008.6] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three linkage studies of bipolar disorder have implicated chromosome 12q24.3 with lod scores of over 3.0 and several other linkage studies have found lods between 2 and 3. Fine mapping within the original chromosomal linkage regions has identified several loci that show association with bipolar disorder. One of these is the P2RX7 gene encoding a central nervous system-expressed purinergic receptor. A non-synonymous single nucleotide polymorphism, rs2230912 (P2RX7-E13A, G allele) and a microsatellite marker NBG6 were both previously found to be associated with bipolar disorder (P=0.00071 and 0.008, respectively). rs2230912 has also been found to show association with unipolar depression. The effect of the polymorphism is non-conservative and results in a glutamine to arginine change (Gln460Arg), which is likely to affect P2RX7 dimerization and protein-protein interactions. We have confirmed the allelic associations between bipolar disorder and the markers rs2230912 (P2RX7-E13A, G allele, P=0.043) and NBG6 (P=0.010) in a London-based sample of 604 bipolar cases and 560 controls. When we combined these data with the published case-control studies of P2RX7 and mood disorder (3586 individuals) the association between rs2230912 (Gln460Arg) and affective disorders became more robust (P=0.002). The increase in Gln460Arg was confined to heterozygotes rather than homozygotes suggesting a dominant effect (odds ratio 1.302, CI=1.129-1.503). Although further research is needed to prove that the Gln460Arg change has an aetiological role, it is so far the most convincing mutation to have been found with a role for increasing susceptibility to bipolar and genetically related unipolar disorders.
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Affiliation(s)
- A McQuillin
- Molecular Psychiatry Laboratory, Department of Mental Health Sciences, Windeyer Institute of Medical Sciences, Royal Free and University College Medical School, University College London, London, UK
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26
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Basso AM, Bratcher NA, Harris RR, Jarvis MF, Decker MW, Rueter LE. Behavioral profile of P2X7 receptor knockout mice in animal models of depression and anxiety: Relevance for neuropsychiatric disorders. Behav Brain Res 2009; 198:83-90. [DOI: 10.1016/j.bbr.2008.10.018] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 09/22/2008] [Accepted: 10/14/2008] [Indexed: 11/24/2022]
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Wang Y, Zhang J, Li X, Ji J, Yang F, Wan C, Feng G, Wan P, He L, He G. SCN8A as a novel candidate gene associated with bipolar disorder in the Han Chinese population. Prog Neuropsychopharmacol Biol Psychiatry 2008; 32:1902-4. [PMID: 18812204 DOI: 10.1016/j.pnpbp.2008.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 08/18/2008] [Accepted: 09/04/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Bipolar disorder (BPD) is a common, severe and recurrent psychiatric disorder. It has been suggested that BPD patients have a higher risk of suicide than patients with any other psychiatric illnesses. A recent study found that suicide attempt was associated with the SCN8A gene, which has been mapped close to one of the BPD susceptibility loci. Thus, SCN8A is likely to be a candidate gene for BPD. METHODS In this study, three SNPs (rs1601012, rs303810, rs60637) were analyzed in 506 bipolar patients and 507 controls of Han origin. RESULTS We found that two individual SNPs showed statistically significant differences between cases and controls in both allele and genotype distribution, but only rs303810 was still significant in allele distribution (p=0.0164) after correction. No obvious linkage disequilibrium or haplotypes were observed among these SNPs. CONCLUSION Our results indicate that SCN8A may be a potential susceptibility gene for bipolar disorder in the Han Chinese population.
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Affiliation(s)
- Yang Wang
- Bio-X Center, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
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28
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Abstract
Bipolar disorder, especially the most severe type (type I), has a strong genetic component. Family studies suggest that a small number of genes of modest effect are involved in this disorder. Family-based studies have identified a number of chromosomal regions linked to bipolar disorder, and progress is currently being made in identifying positional candidate genes within those regions, À number of candidate genes have also shown evidence of association with bipolar disorder, and genome-wide association studies are now under way, using dense genetic maps. Replication studies in larger or combined datasets are needed to definitively assign a role for specific genes in this disorder. This review covers our current knowledge of the genetics of bipolar disorder, and provides a commentary on current approaches used to identify the genes involved in this complex behavioral disorder.
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Affiliation(s)
- Michael A Escamilla
- University of Texas Health Science Center at San Antonio, South Texas Medical Genetics Research Center, 1214 Schunior St, Edinburg, TX 78539, USA.
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Genome-wide parametric linkage analyses of 644 bipolar pedigrees suggest susceptibility loci at chromosomes 16 and 20. Psychiatr Genet 2008; 18:191-8. [PMID: 18628681 DOI: 10.1097/ypg.0b013e3283050aa5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Our aim is to map chromosomal regions that harbor loci that increase susceptibility to bipolar disorder. METHODS We analyzed 644 bipolar families ascertained by the National Institute of Mental Health Human Genetics Initiative for bipolar disorder. The families have been genotyped with microsatellite loci spaced every approximately 10 cM or less across the genome. Earlier analyses of these pedigrees have been limited to nonparametric (model-free) methods and thus, information from unaffected subjects with genotypes was not considered. In this study, we used parametric analyses assuming dominant and recessive transmission and specifying a maximum penetrance of 70%, so that information from unaffecteds could be weighed in the linkage analyses. As in previous linkage analyses of these pedigrees, we analyzed three diagnostic categories: model 1 included only bipolar I and schizoaffective, bipolar cases (1565 patients of whom approximately 4% were schizoaffective, bipolar); model 2 included all individuals in model 1 plus bipolar II patients (1764 total individuals); and model 3 included all individuals in model 2 with the addition of patients with recurrent major depressive disorder (2046 total persons). RESULTS Assuming dominant inheritance the highest genome-wide pair-wise logarithm of the odds (LOD) score was 3.2 with D16S749 using model 2 patients. Multipoint analyses of this region yielded a maximum LOD score of 4.91. Under recessive transmission a number of chromosome 20 markers were positive and multipoint analyses of the area gave a maximum LOD of 3.0 with model 2 cases. CONCLUSION The chromosome 16p and 20 regions have been implicated by some studies and the data reported herein provide additional suggestive evidence of bipolar susceptibility genes in these regions.
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Harvey M, Belleau P, Barden N. Gene interactions in depression: pathways out of darkness. Trends Genet 2007; 23:547-56. [DOI: 10.1016/j.tig.2007.08.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 08/21/2007] [Accepted: 08/21/2007] [Indexed: 11/16/2022]
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31
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Cassidy F, Zhao C, Badger J, Claffey E, Dobrin S, Roche S, McKeon P. Genome-wide scan of bipolar disorder and investigation of population stratification effects on linkage: support for susceptibility loci at 4q21, 7q36, 9p21, 12q24, 14q24, and 16p13. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:791-801. [PMID: 17455214 DOI: 10.1002/ajmg.b.30524] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bipolar disorder (BPD) is a complex genetic disorder with cycling symptoms of depression and mania. Despite the extreme complexity of this psychiatric disorder, attempts to localize genes which confer vulnerability to the disorder have had some success. Chromosomal regions including 4p16, 12q24, 18p11, 18q22, and 21q21 have been repeatedly linked to BPD in different populations. Here we present the results of a whole genome scan for linkage to BPD in an Irish population. Our most significant result was at 14q24 which yielded a non-parametric LOD (NPL) score of 3.27 at the D14S588 marker with a nominal P-value of 0.0006 under a narrow (bipolar type I only) model of affection. We previously reported linkage to 14q22-24 in a subset of the families tested in this analysis. We also obtained suggestive evidence for linkage at 4q21, 9p21, 12q24, and 16p13, chromosomal regions that have all been previously linked to BPD. Additionally, we report on a novel approach to linkage analysis, STRUCTURE-Guided Linkage Analysis (SGLA), which is designed to reduce genetic heterogeneity and increase the power to detect linkage. Application of this technique resulted in more highly significant evidence for linkage of BPD to three regions including 16p13, a locus that has been repeatedly linked to numerous psychiatric disorders.
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MESH Headings
- Bipolar Disorder/genetics
- Chromosomes, Human, Pair 12/genetics
- Chromosomes, Human, Pair 14/genetics
- Chromosomes, Human, Pair 16/genetics
- Chromosomes, Human, Pair 4/genetics
- Chromosomes, Human, Pair 7/genetics
- Chromosomes, Human, Pair 9/genetics
- Female
- Genetic Linkage
- Genetic Predisposition to Disease
- Genomics
- Humans
- Ireland
- Male
- Siblings
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Affiliation(s)
- F Cassidy
- Smurfit Institute of Genetics, Trinity College, Dublin 2, Ireland
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32
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Erhardt A, Lucae S, Unschuld PG, Ising M, Kern N, Salyakina D, Lieb R, Uhr M, Binder EB, Keck ME, Müller-Myhsok B, Holsboer F. Association of polymorphisms in P2RX7 and CaMKKb with anxiety disorders. J Affect Disord 2007; 101:159-68. [PMID: 17197037 DOI: 10.1016/j.jad.2006.11.016] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 11/17/2006] [Accepted: 11/17/2006] [Indexed: 11/23/2022]
Abstract
BACKGROUND There is considerable evidence that genetic factors play an important role in the pathophysiology of affective disorders including bipolar disorder, major depressive disorder and anxiety disorders. Long-term follow up studies as well as drug treatment studies suggest that these clinical conditions share a number of pathophysiological commonalities including genetic variables. One possible candidate region is located on chromosome 12q24.31, originated from previous linkage and association studies with bipolar disorder and unipolar depression. This region contains two candidate genes for purinergic ligand-gated ion channels, P2RX7 and P2RX4, and one gene coding for calmodulin-dependent protein kinase kinase b (CaMKKb). METHODS In the present study, we investigated the genetic associations between 15 SNPs in the candidate genes P2RX7, P2RX4 and CaMKKb on chromosome 12q24.31 in 179 patients with anxiety disorders and syndromal panic attacks versus 462 healthy controls. RESULTS One nominal case-control association could be detected for a SNP in the 5'UTR region of P2RX4, which did not remain significant after correction for multiple testing. We found, however, a prominent association between severity of panic- and agoraphobia symptoms and an exonic SNP (rs3817190) in the CaMKKb gene and a trend for association with an exonic SNP in P2RX7 (rs1718119) with severity scores in the panic- and agoraphobia scale. CONCLUSION The locus 12q24.31 seems to be an important genetic region for anxiety, bipolar and unipolar disorders, suggesting a genetic overlap in the group of affective disorders. The specific contribution of the herein reported gene polymorphisms to the clinical condition is still unclear and warrants further analysis.
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Affiliation(s)
- Angelika Erhardt
- Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, D-80804 München, Germany.
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Liu X, Stancliffe D, Lee S, Mathur S, Gershenfeld HK. Genetic dissection of the tail suspension test: a mouse model of stress vulnerability and antidepressant response. Biol Psychiatry 2007; 62:81-91. [PMID: 17125744 DOI: 10.1016/j.biopsych.2006.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 08/17/2006] [Accepted: 08/19/2006] [Indexed: 12/20/2022]
Abstract
BACKGROUND The tail suspension test (TST) is a mouse screening test for antidepressants. METHODS An F2 intercross was derived from NMRI and 129S6 inbred strains (n = 747). Mice underwent standardized TST with 2 sessions: (1) baseline and (2) imipramine (30 mg/kg, intraperitoneally) TST. RESULTS A whole genome scan of this intercross mapped significant basal TST quantitative trait loci (QTL) on chromosomes (chr) 5 (peak 61 cM, Lod 5.7), 12 (peak 43 cM, Lod 5.2), and 18 (peak 51 cM, Lod 3.0). A suggestive QTL on chr 4 (peak 62 cM; Lod 3.1) overlapped regions containing previously mapped QTLs. For TST imipramine response, QTL were mapped on chr 1, 4, and 5. The chromosome 5 locus affected basal TST, antidepressant immobility response, and tail suspension-induced hyperthermia (TSIH) behaviors. An outbred NMRI F2 population provided further evidence for a chr 5 QTL. This chr 5 region harbors a cluster of gamma aminobutyric acid (GABA)-A receptor subunits and the human syntenic region includes chr 4p, 1p11, 12q24, and 22q11.24. A significant TSIH QTL (Tsih1) mapped on chr 4 near the Leptin receptor (Lepr). CONCLUSIONS These QTL provide potential regions of interest for human genetic studies in stress-diathesis models of psychiatric illness and antidepressant responsiveness.
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MESH Headings
- Animals
- Antidepressive Agents/pharmacology
- Antidepressive Agents/therapeutic use
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Chromosome Mapping
- Chromosomes, Mammalian/genetics
- Crosses, Genetic
- Disease Models, Animal
- Fever/genetics
- Genetic Predisposition to Disease/genetics
- Hindlimb Suspension/physiology
- Imipramine/pharmacology
- Imipramine/therapeutic use
- Immobilization/physiology
- Immobilization/psychology
- Immunohistochemistry
- Injections, Intraperitoneal
- Lod Score
- Mice
- Mice, Inbred Strains
- Quantitative Trait Loci/genetics
- Receptors, Cell Surface/genetics
- Receptors, GABA-A/drug effects
- Receptors, GABA-A/genetics
- Receptors, Leptin
- Stress, Psychological/drug therapy
- Stress, Psychological/etiology
- Stress, Psychological/genetics
- Terminology as Topic
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Affiliation(s)
- Xiaoqing Liu
- Department of Psychiatry, University of Texas Health Science Center at Houston, Houston, Texas, USA
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Savitz J, van der Merwe L, Solms M, Ramesar R. A linkage and family-based association analysis of a potential neurocognitive endophenotype of bipolar disorder. Neuromolecular Med 2007; 9:101-16. [PMID: 17627031 DOI: 10.1007/bf02685885] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 07/07/2006] [Accepted: 07/26/2006] [Indexed: 12/15/2022]
Abstract
The identification of the genetic variants underpinning bipolar disorder (BPD) has been impeded by a complex pattern of inheritance characterized by genetic and phenotypic heterogeneity, genetic epistasis, and gene-environment interactions. In this paper two strategies were used to ameliorate these confounding factors. A unique South African sample including 190 individuals of the relatively, reproductively isolated Afrikaner population was assessed with a battery of neuropsychological tests in an attempt to identify a BPD-associated quantitative trait or endophenotype. BPD individuals performed significantly worse than their unaffected relatives on visual and verbal memory tasks, a finding congruent with the literature. Afocused linkage and family-based association study was carried out using this memory-related endophenotype. In the largest 77-strong Afrikaner pedigree significant evidence for linkage was detected on chromosome 22q11, a region previously implicated in BPD. The quantitative transmission disequilibrium tests-based association analysis suggested that functional variants of the DRD4 and MAO-A genes modulate memory-related cognition. We speculate that polymorphisms at these loci may predispose to a subtype of BPD characterized by memory-related deficits.
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Affiliation(s)
- Jonathan Savitz
- Division of Human Genetics, Institute for Infectious Disease and Molecular Medicine, University of Cape Town, South Africa.
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Harvey M, Gagné B, Labbé M, Barden N. Polymorphisms in the neuronal isoform of tryptophan hydroxylase 2 are associated with bipolar disorder in French Canadian pedigrees. Psychiatr Genet 2007; 17:17-22. [PMID: 17167340 DOI: 10.1097/ypg.0b013e3280111877] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Tryptophan hydroxylase is the rate-limiting enzyme in the serotonin biosynthetic pathway and plays an important role in the regulation of serotonin levels. Recently, a brain-specific isoform, tryptophan hydroxylase 2 or n-tryptophan hydroxylase, has been discovered. Some studies reported genetic and functional associations between this isoform and bipolar disorder and/or major depressive disorder. The aim of this study was to investigate further association of genetic variants in French Canadian samples with bipolar disorders. METHODS Genetic variants in the tryptophan hydroxylase 2 gene were genotyped in a case-control sample consisting of 225 affected individuals (191 bipolar I and 34 bipolar II) and 221 controls and in a collection of extended pedigrees and trios from the same population 357 nuclear families (201 bipolar I, 64 bipolar II, 79 recurrent major depressive disorder). RESULTS We determined linkage disequilibrium structure in our isolated population and analyzed six tagged single nucleotide polymorphisms in the case-control sample. Whereas no single, single nucleotide polymorphism gave any significant result, a three single nucleotide polymorphism haplotype gave a global P=0.01. Family-based association showed significant association (P=0.004) of one polymorphism (rs4290270) with the major allele overtransmitted to affected offspring. CONCLUSIONS Case-control and family-based association studies further support the presence of a susceptibility locus for bipolar disorder in tryptophan hydroxylase 2 by showing statistically significant associations with both, single nucleotide polymorphism alone and haplotype of single nucleotide polymorphism markers.
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Affiliation(s)
- Mario Harvey
- Department of Neuroscience, CHUL Research Centre and Laval University, Sainte-Foy, Quebec, Canada
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36
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Savitz J, Cupido CL, Ramesar RK. Preliminary evidence for linkage to chromosome 1q31-32, 10q23.3, and 16p13.3 in a South African cohort with bipolar disorder. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:383-7. [PMID: 17171663 DOI: 10.1002/ajmg.b.30461] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although the genetic variants predisposing to the development of bipolar disorder (BPD) have yet to be conclusively identified, replicated reports of linkage to particular chromosomal regions have been encouraging. Here we carried out a non-parametric linkage analysis of nine of these candidate loci in a unique South African sample of 47 BPD pedigrees (N = 350). Three polymorphic markers per region of interest (3 x 9) were typed in a Caucasian cohort of Afrikaner and British origin. Statistically significant evidence for linkage was obtained at 1q31-32, 10q23.3, and 16p13.3 with maximum NPL scores of 2.52, 2.01, and 1.84, respectively. Our results add to the growing evidence that these chromosomal regions harbor genetic variants that play a role in the development of bipolar spectrum illness. Negative results were obtained for the remaining six candidate loci, possibly due to limited statistical power.
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Affiliation(s)
- Jonathan Savitz
- Division of Human Genetics, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
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37
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Abstract
The major findings regarding the genetics of stress response and stress-related disorders are: (i) variations in genes involved in the sympathetic system or in the hypothalamic-pituitary-adrenocortical axis are associated with altered stress responses; (ii) genes related to the renin-angiotensin-aldosterone system or inflammation/immune response show associations with cardiovascular disorders; (iii) genes involved in monoaminergic neurotransmitter systems are associated with bipolar disorder and unipolar depression. The vast majority of these association studies followed a conventional hypothesis-driven approach, restricting the gene selection to established candidates. This very conservative approach retarded our understanding of the complex interplay between genetic factors, stress response, and stress-related disorders. Chip-based whole-genome technologies will open up access to new unbiased and statistically efficient approaches that will help to identify new candidate genes, which should be thoroughly validated in clinical and preclinical confirmatory studies. This, together with the use of new text- and information-mining tools, will bring us closer to integrating all the findings into sophisticated models delineating the pathways from genes to stress response and stress-related disorders.
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Affiliation(s)
- Marcus Ising
- Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, D-80804 Munich, Germany.
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38
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Abstract
In this review, all papers relevant to the molecular genetics of bipolar disorder published from 2004 to the present (mid 2006) are reviewed, and major results on depression are summarized. Several candidate genes for schizophrenia may also be associated with bipolar disorder: G72, DISC1, NRG1, RGS4, NCAM1, DAO, GRM3, GRM4, GRIN2B, MLC1, SYNGR1, and SLC12A6. Of these, association with G72 may be most robust. However, G72 haplotypes and polymorphisms associated with bipolar disorder are not consistent with each other. The positional candidate approach showed an association between bipolar disorder and TRPM2 (21q22.3), GPR50 (Xq28), Citron (12q24), CHMP1.5 (18p11.2), GCHI (14q22-24), MLC1 (22q13), GABRA5 (15q11-q13), BCR (22q11), CUX2, FLJ32356 (12q23-q24), and NAPG (18p11). Studies that focused on mood disorder comorbid with somatic symptoms, suggested roles for the mitochondrial DNA (mtDNA) 3644 mutation and the POLG mutation. From gene expression analysis, PDLIM5, somatostatin, and the mtDNA 3243 mutation were found to be related to bipolar disorder. Whereas most previous positive findings were not supported by subsequent studies, DRD1 and IMPA2 have been implicated in follow-up studies. Several candidate genes in the circadian rhythm pathway, BmaL1, TIMELESS, and PERIOD3, are reported to be associated with bipolar disorder. Linkage studies show many new linkage loci. In depression, the previously reported positive finding of a gene-environmental interaction between HTTLPR (insertion/deletion polymorphism in the promoter of a serotonin transporter) and stress was not replicated. Although the role of the TPH2 mutation in depression had drawn attention previously, this has not been replicated either. Pharmacogenetic studies show a relationship between antidepressant response and HTR2A or FKBP5. New technologies for comprehensive genomic analysis have already been applied. HTTLPR and BDNF promoter polymorphisms are now found to be more complex than previously thought, and previous papers on these polymorphisms should be treated with caution. Finally, this report addresses some possible causes for the lack of replication in this field.
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Affiliation(s)
- Tadafumi Kato
- Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute, Wako, Saitama, Japan.
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Venken T, Del-Favero J. Chasing genes for mood disorders and schizophrenia in genetically isolated populations. Hum Mutat 2007; 28:1156-70. [PMID: 17659644 DOI: 10.1002/humu.20582] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Major affective disorders and schizophrenia are among the most common brain diseases worldwide and their predisposition is influenced by a complex interaction of genetic and environmental factors. So far, traditional linkage mapping studies for these complex disorders have not achieved the same success as the positional cloning of genes for Mendelian diseases. The struggle to identify susceptibility genes for complex disorders has stimulated the development of alternative approaches, including studies in genetically isolated populations. Since isolated populations are likely to have both a reduced number of genetic vulnerability factors and environmental background and are therefore considered to be more homogeneous compared to outbred populations, the use of isolated populations in genetic studies is expected to improve the chance of finding susceptibility loci and genes. Here we review the role of isolated populations, based on linkage and association studies, in the identification of susceptibility genes for bipolar disorder and schizophrenia.
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Affiliation(s)
- Tine Venken
- Applied Molecular Genomics Group, Department of Molecular Genetics, VIB, Antwerpen, Belgium
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40
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Dikeos DG, Papadimitriou GN, Souery D, Del-Favero J, Massat I, Blackwood D, Cichon S, Daskalopoulou E, Ivezic S, Kaneva R, Karadima G, Lorenzi C, Milanova V, Muir W, Nöthen M, Oruc L, Rietschel M, Serretti A, Van Broeckhoven C, Soldatos CR, Stefanis CN, Mendlewicz J. Lack of genetic association between the phospholipase A2 gene and bipolar mood disorder in a European multicentre case-control study. Psychiatr Genet 2006; 16:169-71. [PMID: 16829784 DOI: 10.1097/01.ypg.0000218615.19892.86] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The possible association between phospholipase A2 gene and bipolar mood disorder was examined in 557 bipolar patients and 725 controls (all personally interviewed), recruited from seven countries (Belgium, Bulgaria, Croatia, Germany, Greece, Italy, and UK). The frequencies of the eight alleles that were identified did not differ between patients and control individuals in the whole population, while the power to detect an association based on our sample was relatively high. Some differences were noted among the various ethnic groups, but no significant trends existed, suggesting that population stratification by country may not be responsible for a type II error. On the basis of these results, mutations of the phospholipase A2 gene, at least in the region close to the polymorphism examined between exons 1 and 2, are not involved in the pathogenesis of bipolar mood disorder.
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Affiliation(s)
- Dimitris G Dikeos
- Department of Psychiatry, Athens University Medical School and University Mental Health Research Institute, Greece, and Department of Psychiatry, University Clinics of Brussels, Erasme Hospital, Free University of Brussels, Belgium.
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41
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Hamdani N, Gorwood P. Les hypothèses étiopathogéniques des troubles bipolaires. Encephale 2006; 32 Pt 2:S519-25. [PMID: 17099567 DOI: 10.1016/s0013-7006(06)76197-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- N Hamdani
- AP-HP, CHU Louis-Mourier, service de psychiatrie du Professeur Adès, 178, rue des Renouillers, 92701 Colombes cedex
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42
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Abstract
Major depressive disorder (MDD) is common and moderately heritable. Recurrence and early age at onset characterize cases with the greatest familial risk. Major depressive disorder and the neuroticism personality trait have overlapping genetic susceptibilities. Most genetic studies of MDD have considered a small set of functional polymorphisms relevant to monoaminergic neurotransmission. Meta-analyses suggest small positive associations between the polymorphism in the serotonin transporter promoter region (5-HTTLPR) and bipolar disorder, suicidal behavior, and depression-related personality traits but not yet to MDD itself. This polymorphism might also influence traits related to stress vulnerability. Newer hypotheses of depression neurobiology suggest closer study of genes related to neurotoxic and neuroprotective (neurotrophic) processes and to overactivation of the hypothalamic-pituitary axis, with mixed evidence regarding association of MDD with polymorphisms in one such gene (brain-derived neurotrophic factor [BDNF]). Several genome-wide linkage studies of MDD and related traits have been reported or are near completion. There is some evidence for convergence of linkage findings across studies, but more data are needed to permit meta-analysis. Future directions will include more intensive, systematic study of linkage candidate regions and of the whole genome for genetic association; gene expression array studies; and larger-scale studies of gene-environment interactions and of depression-related endophenotypes.
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Affiliation(s)
- Douglas F Levinson
- Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-3309, USA.
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Detera-Wadleigh SD, McMahon FJ. G72/G30 in schizophrenia and bipolar disorder: review and meta-analysis. Biol Psychiatry 2006; 60:106-14. [PMID: 16581030 DOI: 10.1016/j.biopsych.2006.01.019] [Citation(s) in RCA: 214] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Revised: 01/19/2006] [Accepted: 01/28/2006] [Indexed: 01/31/2023]
Abstract
Association of the G72/G30 locus with schizophrenia and bipolar disorder has now been reported in several studies. The G72/G30 locus may be one of several that account for the evidence of linkage that spans a broad region of chromosome 13q. However, the story of G72/G30 is complex. Our meta-analysis of published association studies shows highly significant evidence of association between nucleotide variations in the G72/G30 region and schizophrenia, along with compelling evidence of association with bipolar disorder. But the associated alleles and haplotypes are not identical across studies, and some strongly associated variants are located approximately 50 kb telomeric of G72. Interestingly, G72 and G30 are transcribed in opposite directions; hence, their transcripts could cross-regulate translation. A functional native protein and functional motifs for G72 or G30 remain to be demonstrated. The interaction of G72 with d-amino acid oxidase, itself of interest as a modulator of N-methyl-d-aspartate receptors through regulation of d-serine levels, has been reported in one study and could be a key functional link that deserves further investigation. The association findings in the G72/G30 region, among the most compelling in psychiatry, may expose an important molecular pathway involved in susceptibility to schizophrenia and bipolar disorder.
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Affiliation(s)
- Sevilla D Detera-Wadleigh
- National Institute of Mental Health Intramural Research Program, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland 20892-3719, USA.
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44
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Abstract
The enormous public health importance of mood disorders, when considered alongside their substantial heritabilities, has stimulated much work, predominantly in bipolar disorder but increasingly in unipolar depression, aimed at identifying susceptibility genes using both positional and functional molecular genetic approaches. Several regions of interest have emerged in linkage studies and, recently, evidence implicating specific genes has been reported; the best supported include BDNF and DAOA but further replications are required and phenotypic relationships and biological mechanisms need investigation. The complexity of psychiatric phenotypes is demonstrated by (a) the evidence accumulating for an overlap in genetic susceptibility across the traditional classification systems that divide disorders into schizophrenia and mood disorders, and (b) evidence suggestive of gene-environment interactions.
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Affiliation(s)
- Nick Craddock
- Department of Psychological Medicine, The Henry Wellcome Building for Biomedical Research in Wales, Wales School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
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45
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Lucae S, Salyakina D, Barden N, Harvey M, Gagné B, Labbé M, Binder EB, Uhr M, Paez-Pereda M, Sillaber I, Ising M, Brückl T, Lieb R, Holsboer F, Müller-Myhsok B. P2RX7, a gene coding for a purinergic ligand-gated ion channel, is associated with major depressive disorder. Hum Mol Genet 2006; 15:2438-45. [PMID: 16822851 DOI: 10.1093/hmg/ddl166] [Citation(s) in RCA: 193] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The P2RX7 gene is located within a region on chromosome 12q24.31 that has been identified as a susceptibility locus for affective disorders by linkage and association studies. P2RX7 is a purinergic ATP-binding calcium channel expressed in neurons as well as in microglial cells in various brain regions. We investigated 29 single nucleotide polymorphisms (SNPs) within the P2RX7 gene and adjacent genes in a sample of 1000 German Caucasian patients suffering from recurrent major depressive disorder (MDD). These were contrasted with diagnosed healthy Caucasian controls from the same population (n=1029). A non-synonymous coding SNP in the P2RX7 gene (rs2230912), previously found to be associated with bipolar disorder, was significantly associated (P=0.0019) with MDD. This polymorphism results in an amino acid exchange in the C-terminal cytosolic domain of the P2RX7 channel protein, suggesting that the observed P2RX7 polymorphism might play a causal role in the development of depression.
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Affiliation(s)
- Susanne Lucae
- The Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804 Munich, Germany
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Barden N, Harvey M, Gagné B, Shink E, Tremblay M, Raymond C, Labbé M, Villeneuve A, Rochette D, Bordeleau L, Stadler H, Holsboer F, Müller-Myhsok B. Analysis of single nucleotide polymorphisms in genes in the chromosome 12Q24.31 region points to P2RX7 as a susceptibility gene to bipolar affective disorder. Am J Med Genet B Neuropsychiatr Genet 2006; 141B:374-82. [PMID: 16673375 DOI: 10.1002/ajmg.b.30303] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Previous results from our genetic analyses using pedigrees from a French Canadian population suggested that the interval delimited by markers on chromosome 12, D12S86 and D12S378, was the most probable genomic region to contain a susceptibility gene for affective disorders. Association studies with microsatellite markers using a case/control sample from the same population (n = 427) revealed significant allelic associations between the bipolar phenotype and marker NBG6. Since this marker is located in intron 9 of the P2RX7 gene, we analyzed the surrounding genomic region for the presence of polymorphisms in regulatory, coding and intron/exon junction sequences. Twenty four (24) SNPs were genotyped in a case/control sample and 12 SNPs in all pedigrees used for linkage analysis. Allelic, genotypic or family-based association studies suggest the presence of two susceptibility loci, the P2RX7 and CaMKK2 genes. The strongest association was observed in bipolar families at the non-synonymous SNP P2RX7-E13A (rs2230912, P-value = 0.000708), which results from an over-transmission of the mutant G-allele to affected offspring. This Gln460Arg polymorphism occurs at an amino acid that is conserved between humans and rodents and is located in the C-terminal domain of the P2X7 receptor, known to be essential for normal P2RX7 function.
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Affiliation(s)
- Nicholas Barden
- Neuroscience, CHUL Research Centre and Université Laval, Quebec, Canada.
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47
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Reif A, Herterich S, Strobel A, Ehlis AC, Saur D, Jacob CP, Wienker T, Töpner T, Fritzen S, Walter U, Schmitt A, Fallgatter AJ, Lesch KP. A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function. Mol Psychiatry 2006; 11:286-300. [PMID: 16389274 DOI: 10.1038/sj.mp.4001779] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nitric oxide (NO) is a gaseous neurotransmitter thought to play important roles in several behavioral domains. On a neurobiological level, NO acts as the second messenger of the N-methyl-D-aspartate receptor and interacts with both the dopaminergic as well as the serotonergic system. Thus, NO is a promising candidate molecule in the pathogenesis of endogenous psychoses and a potential target in their treatment. Furthermore, the chromosomal locus of the gene for the NO-producing enzyme NOS-I, 12q24.2, represents a major linkage hot spot for schizophrenic and bipolar disorder. To investigate whether the gene encoding NOS-I (NOS1) conveys to the genetic risk for those diseases, five NOS1 polymorphisms as well as a NOS1 mini-haplotype, consisting of two functional polymorphisms located in the transcriptional control region of NOS1, were examined in 195 chronic schizophrenic, 72 bipolar-I patients and 286 controls. Single-marker association analysis showed that the exon 1c promoter polymorphism was linked to schizophrenia (SCZ), whereas synonymous coding region polymorphisms were not associated with disease. Long promoter alleles of the repeat polymorphism were associated with less severe psychopathology. Analysis of the mini-haplotype also revealed a significant association with SCZ. Mutational screening did not detect novel exonic polymorphisms in patients, suggesting that regulatory rather than coding variants convey the genetic risk on psychosis. Finally, promoter polymorphisms impacted on prefrontal functioning as assessed by neuropsychological testing and electrophysiological parameters elicited by a Go-Nogo paradigm in 48 patients (continuous performance test). Collectively these findings suggest that regulatory polymorphisms of NOS1 contribute to the genetic risk for SCZ, and modulate prefrontal brain functioning.
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Affiliation(s)
- A Reif
- Department of Psychiatry and Psychotherapy (Section for Clinical and Molecular Psychobiology and Laboratory for Psychophysiology and Functional Imaging), Julius-Maximilians-University Würzburg, Würzburg, Germany.
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48
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Boomsma DI, Cacioppo JT, Slagboom PE, Posthuma D. Genetic Linkage and Association Analysis for Loneliness in Dutch Twin and Sibling Pairs Points to a Region on Chromosome 12q23–24. Behav Genet 2005; 36:137-46. [PMID: 16378171 DOI: 10.1007/s10519-005-9005-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Accepted: 08/03/2005] [Indexed: 02/05/2023]
Abstract
We obtained evidence from a large study in Dutch twins (N=8,387) and siblings (N=2,295) that variation in loneliness has a genetic component. The heritability estimate for loneliness, which was assessed as an ordinal trait, was 40% and did not differ between males and females. There were 682 sibling pairs with genotypic (around 400 microsatellite markers) data. We combined phenotypic and genotypic data to carry out a genome scan to localize QTLs for loneliness. One region on chromosome 12q23.3-24.3, showed near suggestive linkage. Genetic association tests within this region revealed significant association (p-value 0.009) with one of the alleles of marker D12S79 and with one of the alleles of neighbouring marker D12S395 (p-value 0.043). We review evidence for linkage in this region for psychiatric disorders and discuss our findings within this context.
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Affiliation(s)
- Dorret I Boomsma
- Department of Biological Psychology, Vrije Universiteit, Amsterdam, The Netherlands.
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Abstract
What began as a search for a specific gene for bipolar disorder has now become a search for multiple susceptibility genes as it has be-come clear that the genetic basis of bipolar disorder probably involves multiple genes interacting with each other and with environmental components in as-yet mysterious ways. This article reviews the most recent findings and the emerging picture in the genetics of bipolar disorder.
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Affiliation(s)
- Jennifer L Payne
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, 600 North Wolfe Street, Meyer 3-181, Baltimore, MD 21287, USA.
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Shink E, Harvey M, Tremblay M, Gagné B, Belleau P, Raymond C, Labbé M, Dubé MP, Lafrenière RG, Barden N. Analysis of microsatellite markers and single nucleotide polymorphisms in candidate genes for susceptibility to bipolar affective disorder in the chromosome 12Q24.31 region. Am J Med Genet B Neuropsychiatr Genet 2005; 135B:50-8. [PMID: 15768393 DOI: 10.1002/ajmg.b.30165] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previous results from our genetic analyses using pedigrees from a French Canadian population suggested that the interval delimited by markers D12S86 and D12S378 on chromosome 12 was the most probable genomic region to contain a susceptibility gene for affective disorders. Here we present a more detailed genetic analysis of a 7.7 Mb genomic region located on 12q24.31. This region was saturated with 20 microsatellite markers to refine the candidate region and linkage analysis performed in 41 families from the Saguenay-Lac-St-Jean (SLSJ) region of Quebec. The results of two point parametric analysis using MFLINK supported the presence of a susceptibility locus on chromosome 12q24.31. Association studies with microsatellite markers using a case/control sample from the same population (n = 401) and analyzed with CLUMP revealed significant allelic associations between the bipolar phenotype and markers NBG6 (P = 0.008) and NBG12 (P < 10(-3)). According to these results, we investigated candidate genes in the NBG12 area. We analyzed 32 genes for the presence of polymorphisms in coding sequences and intron/exon junctions and genotyped 22 non-synonymous SNPs in the SLSJ case/control sample. Two uncommon polymorphisms (minor allele frequency < or = 0.03) found in KIAA1595 and FLJ22471 genes, gave P-values below 0.05 with the T1 statistic. Moreover, using haplotype analysis, a nearly significant haplotypic association was observed at the HM74 gene. These results do not give strong support for a role in the susceptibility to bipolar disorder of any of these genes analyzed. However, the significance of rare polymorphisms should be explored by further analyses.
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Affiliation(s)
- Eric Shink
- Neuroscience, CHUL Research Center and Laval University, CHUQ Pavillon CHUL, Ste-Foy, Québec, Canada
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