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Zhao X, Song L, Yang A, Zhang Z, Zhang J, Yang YT, Zhao XM. Prioritizing genes associated with brain disorders by leveraging enhancer-promoter interactions in diverse neural cells and tissues. Genome Med 2023; 15:56. [PMID: 37488639 PMCID: PMC10364416 DOI: 10.1186/s13073-023-01210-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/10/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Prioritizing genes that underlie complex brain disorders poses a considerable challenge. Despite previous studies have found that they shared symptoms and heterogeneity, it remained difficult to systematically identify the risk genes associated with them. METHODS By using the CAGE (Cap Analysis of Gene Expression) read alignment files for 439 human cell and tissue types (including primary cells, tissues and cell lines) from FANTOM5 project, we predicted enhancer-promoter interactions (EPIs) of 439 cell and tissue types in human, and examined their reliability. Then we evaluated the genetic heritability of 17 diverse brain disorders and behavioral-cognitive phenotypes in each neural cell type, brain region, and developmental stage. Furthermore, we prioritized genes associated with brain disorders and phenotypes by leveraging the EPIs in each neural cell and tissue type, and analyzed their pleiotropy and functionality for different categories of disorders and phenotypes. Finally, we characterized the spatiotemporal expression dynamics of these associated genes in cells and tissues. RESULTS We found that identified EPIs showed activity specificity and network aggregation in cell and tissue types, and enriched TF binding in neural cells played key roles in synaptic plasticity and nerve cell development, i.e., EGR1 and SOX family. We also discovered that most neurological disorders exhibit heritability enrichment in neural stem cells and astrocytes, while psychiatric disorders and behavioral-cognitive phenotypes exhibit enrichment in neurons. Furthermore, our identified genes recapitulated well-known risk genes, which exhibited widespread pleiotropy between psychiatric disorders and behavioral-cognitive phenotypes (i.e., FOXP2), and indicated expression specificity in neural cell types, brain regions, and developmental stages associated with disorders and phenotypes. Importantly, we showed the potential associations of brain disorders with brain regions and developmental stages that have not been well studied. CONCLUSIONS Overall, our study characterized the gene-enhancer regulatory networks and genetic mechanisms in the human neural cells and tissues, and illustrated the value of reanalysis of publicly available genomic datasets.
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Affiliation(s)
- Xingzhong Zhao
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China
| | - Liting Song
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China
| | - Anyi Yang
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China
| | - Zichao Zhang
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China
| | - Jinglong Zhang
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China
| | - Yucheng T Yang
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China.
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China.
| | - Xing-Ming Zhao
- Institute of Science and Technology for Brain-Inspired Intelligence, and Department of Neurology of Zhongshan Hospital, Fudan University, 220 Handan Road, Shanghai, 200433, China.
- MOE Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200433, China.
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
- Internatioal Human Phenome Institutes (Shanghai), Shanghai, 200433, China.
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Han H, Yu Y, Shi J, Yao Y, Li W, Kong N, Wu Y, Wang C, Wang S, Meng X, Kou C. Associations of histone deacetylase-2 and histone deacetylase-3 genes with schizophrenia in a Chinese population. Asia Pac Psychiatry 2013; 5:11-6. [PMID: 23857786 DOI: 10.1111/j.1758-5872.2012.00205.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 04/03/2012] [Indexed: 12/14/2022]
Abstract
INTRODUCTION To explore the association between histone deacetylase-2 (HDAC2) and histone deacetylase-3 (HDAC3) gene polymorphisms and schizophrenia. METHODS A total of 208 family trios consisting of fathers, mothers and affected offspring with schizophrenia were recruited as our subjects. Four tag SNPs on HDAC2 (rs10499080, rs6568819, rs2499618 and rs13204445) and two tag SNPs on HDAC3 (rs11741808, rs2530223) genes were selected. The Mass ARRAY Assay Design software (Sequenom) was used to design amplification and allele specific extension primers. The Hardy-Weinberg equilibrium (HWE) for genotypic distributions was tested using the chi-square goodness-of-fit test. Allelic association for a single tag SNP was analyzed by using family-based association tests including the haplotype-based haplotype relative risk (HHRR) test and the transmission disequilibrium test (TDT). RESULTS The genotypic distributions of HDAC2 SNPs rs6568819, rs2499618 and rs13204445 and HDAC3 SNPs rs11741808 and rs2530223 were all in Hardy-Weinberg equilibrium (P > 0.05). HHRR analysis revealed no associations between the SNPs and schizophrenia (P > 0.05). In addition, the TDT did not show any significant associations between HDAC2 and HDAC3 SNPs and schizophrenia (P > 0.05). DISCUSSION HDAC2 and HDAC3 might not be associated with schizophrenia in the Chinese population.
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Affiliation(s)
- Hongzhi Han
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, China
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Ni J, Lu W, Wu Z, Chen J, Yi Z, Zhang C. T102C polymorphism of serotonin 2A type receptor gene confers susceptibility to (early onset) schizophrenia in Han Chinese: an association study and meta-analysis. Asia Pac Psychiatry 2013; 5:24-30. [PMID: 23857788 DOI: 10.1111/appy.12027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 11/25/2012] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Several lines of evidence have indicated that serotonin 2A receptor (HTR2A) may be involved in the pathophysiology of schizophrenia. One functional polymorphism in HTR2A (T102C) has been widely investigated; however, the results have been inconsistent. The purpose of this study was to evaluate the association between HTR2A T02C polymorphism and schizophrenia in a Chinese Han population. METHODS We performed a case-control study, using an early onset sample, which may be an attractive subgroup for genetic studies. In addition, we performed a meta-analysis of the combined sample groups in Han Chinese. RESULTS Our study, based on 385 schizophrenic patients and 399 controls, found a significant genotype-wise association of T102C and schizophrenia (P = 0.02). After applying stratified analyses, the dominant model for T allele produced significant association (OR = 1.60, 95%CI = 1.11-2.30, P = 0.01). In the meta-analysis including all of the published population-based association studies in Han Chinese and the present association study, the pooled genotype-wise result in a dominant model was statistically significant with a summary OR of 1.25 (95%CI = 1.04-1.50, P = 0.02). DISCUSSION Our results suggest that the HTR2A T102C polymorphism may confer susceptibility to schizophrenia in Han Chinese.
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Affiliation(s)
- Jianliang Ni
- The First Geriatric Department, Tongde Hospital of Zhejiang Province, Hangzhou, China
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Costain G, Bassett AS. Clinical applications of schizophrenia genetics: genetic diagnosis, risk, and counseling in the molecular era. APPLICATION OF CLINICAL GENETICS 2012; 5:1-18. [PMID: 23144566 PMCID: PMC3492098 DOI: 10.2147/tacg.s21953] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Schizophrenia is a complex neuropsychiatric disease with documented clinical and genetic heterogeneity, and evidence for neurodevelopmental origins. Driven by new genetic technologies and advances in molecular medicine, there has recently been concrete progress in understanding some of the specific genetic causes of this serious psychiatric illness. In particular, several large rare structural variants have been convincingly associated with schizophrenia, in targeted studies over two decades with respect to 22q11.2 microdeletions, and more recently in large-scale, genome-wide case-control studies. These advances promise to help many families afflicted with this disease. In this review, we critically appraise recent developments in the field of schizophrenia genetics through the lens of immediate clinical applicability. Much work remains in translating the recent surge of genetic research discoveries into the clinic. The epidemiology and basic genetic parameters (such as penetrance and expression) of most genomic disorders associated with schizophrenia are not yet well characterized. To date, 22q11.2 deletion syndrome is the only established genetic subtype of schizophrenia of proven clinical relevance. We use this well-established association as a model to chart the pathway for translating emerging genetic discoveries into clinical practice. We also propose new directions for research involving general genetic risk prediction and counseling in schizophrenia.
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Affiliation(s)
- Gregory Costain
- Clinical Genetics Research Program, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada ; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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Babin SL, Hood AJ, Wassef AA, Williams NG, Patel SS, Sereno AB. Effects of haloperidol on cognition in schizophrenia patients depend on baseline performance: a saccadic eye movement study. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:1753-64. [PMID: 21689713 PMCID: PMC3169101 DOI: 10.1016/j.pnpbp.2011.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/03/2011] [Accepted: 06/03/2011] [Indexed: 11/16/2022]
Abstract
Schizophrenic patients are heterogeneous with respect to voluntary eye movement performance, with some showing impairment (e.g., high antisaccade error rates) and others having intact performance. To investigate how this heterogeneity may correlate with different cognitive outcomes after treatment, we used a prosaccade and antisaccade task to investigate the effects of haloperidol in schizophrenic subjects at three time points: baseline (before medication), 3-5 days post-medication, and 12-14 days post-medication. We also investigated changes on the Stroop Task and the Positive and Negative Syndrome Scale (PANSS) in these same subjects. Results were compared to matched controls. When considered as a single patient group, haloperidol had no effects across sessions on reflexive and voluntary saccadic eye movements of schizophrenic patients. In contrast, the performance of the Control group improved slightly but significantly across sessions on the voluntary eye movement task. When each subject was considered separately, interestingly, for schizophrenic patients change in voluntary eye movement performance across sessions depended on the baseline performance in a non-monotonic manner. That is, there was maximal worsening of voluntary eye movement performance at an intermediate level of baseline performance and the worsening decreased on either side of this intermediate baseline level. When patients were divided into categorical subgroups (nonimpaired and impaired), consistent with the non-monotonic relationship, haloperidol worsened voluntary eye movement performance in the nonimpaired patients and improved performance in the impaired patients. These results were only partially reflected in the Stroop Test. Both patient subgroups showed clinically significant improvement over time as measured by the PANSS. These findings suggest that haloperidol has different effects on cognitive performance in impaired and nonimpaired schizophrenic patients that are not evident in clinical ratings based on the PANSS. Given that good cognitive function is important for long-term prognosis and that there is heterogeneity in schizophrenia, these findings are critical for optimal evaluation and treatment of schizophrenic patients.
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Lin PI, Shuldiner AR. Rethinking the genetic basis for comorbidity of schizophrenia and type 2 diabetes. Schizophr Res 2010; 123:234-43. [PMID: 20832248 DOI: 10.1016/j.schres.2010.08.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 07/29/2010] [Accepted: 08/12/2010] [Indexed: 11/16/2022]
Abstract
The co-occurrence of schizophrenia (SCZ) and type 2 diabetes mellitus (T2D) has been well documented. This review article focuses on the hypothesis that the co-occurrence of SCZ and T2D may be, at least in part, driven by shared genetic factors. Previous genetic studies of T2D and SCZ evidence have disclosed a number of overlapped risk loci. However, the putative common genetic factors for SCZ and T2D remain inconclusive due to inconsistent findings. A systemic review of methods of identifying genetic loci contributing to the comorbidity link between SCZ and T2D is hence needed. In the current review article, we have discussed several different approaches to localizing the shared susceptibility genes for these two diseases. To begin with, one could start with probing the gene involved in both glucose and dopamine metabolisms. Additionally, hypothesis-free genome-wide association studies (GWAS) may provide more clues to the common genetic basis for these two diseases. Genetic similarities inferred from GWAS may shed some light on the genetic mechanism underlying the comorbidity link between SCZ and T2D. Meanwhile, endophenotypes (e.g., adiponectin level in T2D and working memory in SCZ) may serve as alternative phenotypes that are more directly influenced by genes than target diseases. Hence, endophenotypes of these diseases may be more tractable to identification. To summarize, novel approaches are needed to dissect the complex genetic basis of the comorbidity of SCZ and T2D.
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Affiliation(s)
- P I Lin
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States.
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Alkelai A, Kohn Y, Olender T, Sarner-Kanyas K, Rigbi A, Hamdan A, Ben-Asher E, Lancet D, Lerer B. Evidence for an interaction of schizophrenia susceptibility loci on chromosome 6q23.3 and 10q24.33-q26.13 in Arab Israeli families. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:914-25. [PMID: 19152384 DOI: 10.1002/ajmg.b.30918] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A genome scan for schizophrenia related loci in Arab Israeli families by Lerer et al. [Lerer et al. (2003); Mol Psychiatry 8:488-498] detected significant evidence for linkage at chromosome 6q23. Subsequent fine mapping [Levi et al. (2005); Eur J Hum Genet 13:763-771], association [Amann-Zalcenstein et al. (2006); Eur J Hum Genet 14:1111-1119] and replication studies [Ingason et al. (2007); Eur J Hum Genet 15:988-991] identified AHI1 as a putative susceptibility gene. The same genome scan revealed suggestive evidence for a schizophrenia susceptibility locus in the 10q23-26 region. Genes at these two loci may act independently in the pathogenesis of the disease in our homogeneous sample of Arab Israeli families or may interact with each other and with other factors in a common biological pathway. The purpose of our current study was to test the hypothesis of genetic interaction between these two loci and to identify the type of interaction between them. The initial stage of our study focused on the 10q23-q26 region which has not been explored further in our sample. The second stage of the study included a test for possible genetic interaction between the 6q23.3 locus and the refined 10q24.33-q26.13 locus. A final candidate region of 19.9 Mb between markers D10S222 (105.3 Mb) and D10S587 (125.2 Mb) was found on chromosome 10 by non-parametric and parametric linkage analyses. These linkage findings are consistent with previous reports in the same chromosomal region. Two-locus multipoint linkage analysis under three complex disease inheritance models (heterogeneity, multiplicative, and additive models) yielded a best maximum LOD score of 7.45 under the multiplicative model suggesting overlapping function of the 6q23.3 and 10q24.33-q26.13 loci.
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Affiliation(s)
- A Alkelai
- Biological Psychiatry Laboratory, Department of Psychiatry, Hadassah-Hebrew University Medical Center, Ein Karem, Jerusalem, Israel
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Turetsky BI, Greenwood TA, Olincy A, Radant AD, Braff DL, Cadenhead KS, Dobie DJ, Freedman R, Green MF, Gur RE, Gur RC, Light GA, Mintz J, Nuechterlein KH, Schork NJ, Seidman LJ, Siever LJ, Silverman JM, Stone WS, Swerdlow NR, Tsuang DW, Tsuang MT, Calkins ME. Abnormal auditory N100 amplitude: a heritable endophenotype in first-degree relatives of schizophrenia probands. Biol Psychiatry 2008; 64:1051-9. [PMID: 18701089 PMCID: PMC2653714 DOI: 10.1016/j.biopsych.2008.06.018] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 06/05/2008] [Accepted: 06/30/2008] [Indexed: 01/31/2023]
Abstract
BACKGROUND N100 evoked potential amplitude and gating abnormalities have been widely observed in schizophrenia patients. However, previous studies have been inconclusive as to whether similar deficits are present in unaffected family members. The Consortium on the Genetics of Schizophrenia (COGS) is a multisite National Institute of Mental Health (NIMH) initiative examining neurocognitive and neurophysiological measures as endophenotypes for genetic studies of schizophrenia. We report initial results from the COGS dataset of auditory N100 amplitude and gating as candidate endophenotypes. METHODS Evoked potential data were acquired from 142 schizophrenia probands, 373 unaffected first-degree relatives, and 221 community comparison subjects (CCS), using an auditory paired-click stimulation paradigm. Amplitude of the N100 response to each click and the click 2/click 1 ratio were dependent variables. Heritability was estimated based on kinships using Solar v.2.1.2. Group differences were examined after subjects were categorized as either "broad" or "narrow," based on the presence (broad) or absence (narrow) of nonpsychotic psychiatric comorbidity. RESULTS Heritability estimates were .40 and .29 for click1 and click2 amplitudes and .22 for the ratio. Broad and narrow patients both had impaired click 1 amplitudes. Broad relatives, but not narrow relatives, exhibited similar impairments. There were no group differences for either click 2 amplitude or the gating ratio. CONCLUSIONS N100 amplitude is a heritable measure that is abnormal in patients and a subset of relatives for whom psychiatric comorbidity may be a genetically associated phenotype. Auditory N100 gating, although heritable, is less viable as a schizophrenia endophenotype.
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Affiliation(s)
- Bruce I. Turetsky
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tiffany A. Greenwood
- Department of Psychiatry, University of California San Diego, San Diego, California, USA
| | - Ann Olincy
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, Colorado, USA
| | - Allen D. Radant
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, and VA Puget Sound Health Care System, Seattle, Washington, USA
| | - David L. Braff
- Department of Psychiatry, University of California San Diego, San Diego, California, USA
| | - Kristin S. Cadenhead
- Department of Psychiatry, University of California San Diego, San Diego, California, USA
| | - Dorcas J. Dobie
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, and VA Puget Sound Health Care System, Seattle, Washington, USA
| | - Robert Freedman
- Department of Psychiatry, University of Colorado Health Sciences Center, Denver, Colorado, USA
| | - Michael F. Green
- Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA.,VA Greater Los Angeles Healthcare System
| | - Raquel E. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ruben C. Gur
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gregory A. Light
- Department of Psychiatry, University of California San Diego, San Diego, California, USA
| | - James Mintz
- Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Keith H. Nuechterlein
- Department of Psychiatry and Biobehavioral Sciences, Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA
| | - Nicholas J. Schork
- Scripps Genomic Medicine, La Jolla, CA, USA,Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Larry J. Seidman
- Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, Massachusetts, and Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, Massachusetts, USA
| | - Larry J. Siever
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, New York, USA.,James J. Peters VA Medical Center and VISN3 MIRECC
| | - Jeremy M. Silverman
- Department of Psychiatry, The Mount Sinai School of Medicine, New York, New York, USA
| | - William S. Stone
- Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, Massachusetts, and Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, Massachusetts, USA
| | - Neal R. Swerdlow
- Department of Psychiatry, University of California San Diego, San Diego, California, USA
| | - Debby W. Tsuang
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, and VA Puget Sound Health Care System, Seattle, Washington, USA
| | - Ming T. Tsuang
- Department of Psychiatry, University of California San Diego, San Diego, California, USA.,Massachusetts Mental Health Center Public Psychiatry Division of the Beth Israel Deaconess Medical Center, Harvard Medical School Department of Psychiatry, Boston, Massachusetts, and Harvard Institute of Psychiatric Epidemiology and Genetics, Boston, Massachusetts, USA
| | - Monica E. Calkins
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Calkins ME, Iacono WG, Ones DS. Eye movement dysfunction in first-degree relatives of patients with schizophrenia: a meta-analytic evaluation of candidate endophenotypes. Brain Cogn 2008; 68:436-61. [PMID: 18930572 DOI: 10.1016/j.bandc.2008.09.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2008] [Indexed: 10/21/2022]
Abstract
Several forms of eye movement dysfunction (EMD) are regarded as promising candidate endophenotypes of schizophrenia. Discrepancies in individual study results have led to inconsistent conclusions regarding particular aspects of EMD in relatives of schizophrenia patients. To quantitatively evaluate and compare the candidacy of smooth pursuit, saccade and fixation deficits in first-degree biological relatives, we conducted a set of meta-analytic investigations. Among 18 measures of EMD, memory-guided saccade accuracy and error rate, global smooth pursuit dysfunction, intrusive saccades during fixation, antisaccade error rate and smooth pursuit closed-loop gain emerged as best differentiating relatives from controls (standardized mean differences ranged from .46 to .66), with no significant differences among these measures. Anticipatory saccades, but no other smooth pursuit component measures were also increased in relatives. Visually-guided reflexive saccades were largely normal. Moderator analyses examining design characteristics revealed few variables affecting the magnitude of the meta-analytically observed effects. Moderate effect sizes of relatives v. controls in selective aspects of EMD supports their endophenotype potential. Future work should focus on facilitating endophenotype utility through attention to heterogeneity of EMD performance, relationships among forms of EMD, and application in molecular genetics studies.
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Affiliation(s)
- Monica E Calkins
- Department of Psychiatry, University of Pennsylvania School of Medicine, Neuropsychiatry Section, Schizophrenia Research Center and Brain Behavior Laboratory, Philadelphia, PA 19104, USA.
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Lin PI, Mitchell BD. Approaches for unraveling the joint genetic determinants of schizophrenia and bipolar disorder. Schizophr Bull 2008; 34:791-7. [PMID: 18502736 PMCID: PMC2632441 DOI: 10.1093/schbul/sbn050] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Since Emil Kraepelin proposed in 1919 that dementia praecox (schizophrenia) be differentiated from manic depression (bipolar disorder), the concept of nosological dichotomy has greatly influenced the diagnosis, treatment, and research of pathogenesis of these 2 disorders. However, this concept has recently been challenged by increasing evidence showing biological overlap between schizophrenia and bipolar disorder. This article reviews some of the previous evidence for phenomenological and molecular overlaps between these 2 disorders. We then discuss approaches for examining shared etiological mechanisms with a concentration on genetic factors. We have put a particular emphasis on incorporating the concept of endophenotypes in research of shared genetic liability for these 2 disorders.
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Affiliation(s)
- Ping-I Lin
- Division of Endocrinology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Braxton D. Mitchell
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Catonsville, MD
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Szatmari P, Maziade M, Zwaigenbaum L, Mérette C, Roy MA, Joober R, Palmour R. Informative phenotypes for genetic studies of psychiatric disorders. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:581-8. [PMID: 17219386 DOI: 10.1002/ajmg.b.30426] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite its initial promise, there has been both progress and some set backs in genetic studies of the major psychiatric disorders of childhood and adulthood. Finding true susceptibility genes may be delayed because the most genetically informative phenotypes are not being used on a regular basis in linkage analysis and association studies. It is highly likely that using alternative phenotypes instead of DSM diagnostic categories will lead more rapid success in the search for these susceptibility genes. The objective of this paper is to describe the different types of informative phenotypes that can be employed in psychiatric genetic studies, to clarify their uses, to identify several methodologic issues the design and conduct of linkage and association studies that use alternative phenotypes and finally to suggest possible solutions to those difficulties. This is a conceptual review with a focus on methodological issues that may arise in psychiatric genetics and examples are taken from the literature on autism, schizophrenia, bipolar disorder, and alcoholism.
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Affiliation(s)
- Peter Szatmari
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada.
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Bertola V, Cordeiro Q, Zung S, Miracca EC, Vallada H. Association analysis between the C516T polymorphism in the 5-HT2A receptor gene and schizophrenia. ARQUIVOS DE NEURO-PSIQUIATRIA 2007; 65:11-4. [PMID: 17420819 DOI: 10.1590/s0004-282x2007000100004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Accepted: 11/14/2006] [Indexed: 11/22/2022]
Abstract
Data from epidemiological studies have demonstrated that genetics is an important risk factor for schizophrenia. Disturbances of serotonergic brain pathways have been implicated in the pathophysiology of schizophrenia. Some studies have suggested that the efficacy of atypical antipsychotics on schizophrenia treatment may be related to the serotonin 2A receptor (5-HT2A), and that serotonergic drugs may induce psychotic symptoms. Thus, the aim of this study was to investigate the association between the C516T polymorphism and schizophrenia in a Brazilian population composed by 246 patients and 315 healthy matched controls in a case-control approach. No statistically differences were observed in allelic (chi2=1.77, 1d.f., p=0.18) or genotypic (chi2=1.69, 2d.f., p=0.42) distributions between cases and controls. The results suggest that the C516T polymorphism of the 5-HT2A receptor gene is not related to the susceptibility for schizophrenia in our Brazilian sample.
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Affiliation(s)
- Vivian Bertola
- Department and Institute of Psychiatry, Medical School, University of São Paulo, São Paulo, SP, Brazil
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Radant AD, Dobie DJ, Calkins ME, Olincy A, Braff DL, Cadenhead KS, Freedman R, Green MF, Greenwood TA, Gur RE, Light GA, Meichle SP, Mintz J, Nuechterlein KH, Schork NJ, Seidman LJ, Siever LJ, Silverman JM, Stone WS, Swerdlow NR, Tsuang MT, Turetsky BI, Tsuang DW. Successful multi-site measurement of antisaccade performance deficits in schizophrenia. Schizophr Res 2007; 89:320-9. [PMID: 17023145 DOI: 10.1016/j.schres.2006.08.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 08/08/2006] [Accepted: 08/11/2006] [Indexed: 10/24/2022]
Abstract
The antisaccade task is a promising schizophrenia endophenotype; it is stable over time and reflects neurophysiological deficits present in both schizophrenia subjects and their first-degree relatives. Meaningful genetic research requires large sample sizes that are best ascertained using multi-site study designs. To establish the criterion validity of the antisaccade task in a multi-site design, the Consortium on the Genetics of Schizophrenia (COGS) examined whether seven sites could detect previously reported antisaccade deficits in schizophrenia subjects. Investigators presented 3 blocks of 20 antisaccade stimuli to 143 schizophrenia subjects and 195 comparison subjects. Frequent collaborator communication, standardized training, and ongoing quality assurance optimized testing uniformity. Data were discarded from only 1.2% of subjects due to poor quality, reflecting the high fidelity of data collection and scoring methods. All sites detected a significant difference in the proportion of correct antisaccades between schizophrenia and comparison subjects (p<.02 at all sites); group differences in gain and latency were less robust. Regression analyses to adjust for the effects of group, site, age, gender, smoking, and parental education on the proportion of correct antisaccades revealed a significant effect of group, site, and age but no effect of gender, smoking, or parental education, and no group-by-site interactions. Intraclass correlations between proportion of correct antisaccades across the blocks of stimuli ranged from 0.87 to 0.93, demonstrating good within-session reliability at sites. These results confirm previous findings of antisaccade deficits in schizophrenia subjects and support the use of the antisaccade task as a potential schizophrenia endophenotype in multi-site genetic studies.
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Affiliation(s)
- Allen D Radant
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States.
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14
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Serretti A, Artioli P. Ethical problems in pharmacogenetic studies of psychiatric disorders. THE PHARMACOGENOMICS JOURNAL 2006; 6:289-95. [PMID: 16550208 DOI: 10.1038/sj.tpj.6500388] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- A Serretti
- Institute of Psychiatry, University of Bologna, Bologna, Italy.
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15
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Pae CU, Artioli P, Serretti A, Kim TS, Kim JJ, Lee CU, Lee SJ, Lee C, Paik IH. No evidence for interaction between 5-HT2A receptor and serotonin transporter genes in schizophrenia. Neurosci Res 2005; 52:195-9. [PMID: 15893580 DOI: 10.1016/j.neures.2005.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Revised: 03/10/2005] [Accepted: 03/11/2005] [Indexed: 11/18/2022]
Abstract
This study was to aim at investigating the potential interaction for the serotonin receptor gene (5-HTR) 2A and serotonin transporter gene (5-HTTLPR) polymorphisms in the development of schizophrenia, as well as the interaction of the two polymorphisms in relation with symptomatology, family history, age of onset and antipsychotic response. Genomic DNA analysis with polymerase chain reaction (PCR) was used for the genotyping. One hundred and eleven (111) patients with schizophrenia and 172 normal controls participated in the study. We did not find any association between the individual polymorphism and schizophrenia. The significant interaction effect between 5-HTTLPR and 5-HTR2A polymorphisms on the development of schizophrenia as well as on the antipsychotics response, family history, symptomatology and age at onset, was not found. However, subject with 5-HTR2A*TT genotype were found to have lower age of onset, compared to their counterparts (p=0.01). These results suggest that the interaction between 5-HTTLPR and 5-HTR2A polymorphisms may not contribute to susceptibility to schizophrenia as well as some clinical factors such as antipsychotic response, at least in the Korean population.
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Affiliation(s)
- Chi-Un Pae
- Department of Psychiatry, Kangnam St. Mary's Hospital, The Catholic University of Korea, College of Medicine, 505 Banpo-Dong, Seocho-Gu, Seoul 137-701, South Korea
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16
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Tang Y, Lu A, Ran R, Aronow BJ, Schorry EK, Hopkin RJ, Gilbert DL, Glauser TA, Hershey AD, Richtand NW, Privitera M, Dalvi A, Sahay A, Szaflarski JP, Ficker DM, Ratner N, Sharp FR. Human blood genomics: distinct profiles for gender, age and neurofibromatosis type 1. ACTA ACUST UNITED AC 2005; 132:155-67. [PMID: 15582155 DOI: 10.1016/j.molbrainres.2003.10.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2003] [Indexed: 10/26/2022]
Abstract
Application of gene expression profiling to human diseases will be limited by availability of tissue samples. It was postulated that germline genetic defects affect blood cells to produce unique expression patterns. This hypothesis was addressed by using a test neurological disease-neurofibromatosis type 1 (NF1), an autosomal dominant genetic disease caused by mutations of the NF1 gene at chromosome 17q11.2. Oligonucleotide arrays were used to survey the blood gene expression pattern of 12 NF1 patients compared to 96 controls. A group of genes related to tissue remodeling, bone development and tumor suppression were down-regulated in NF1 blood samples. In addition, there were blood genomic patterns for gender and age: Y chromosome genes showing higher expression in males, indicating a gene-dosage effect; and genes related to lymphocyte functions showing higher expression in children. The results suggest that genetic mutations can be manifested at the transcriptional level in peripheral blood cells and blood gene expression profiling may be useful for studying phenotypic differences of human genetic diseases and possibly providing diagnostic and prognostic markers.
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Affiliation(s)
- Yang Tang
- Department of Neurology, University of Cincinnati, Vontz Center, Room 2327, 3125 Eden Avenue, Cincinnati, OH 45267-0536, USA
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17
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Serretti A, Smeraldi E. Neural network analysis in pharmacogenetics of mood disorders. BMC MEDICAL GENETICS 2004; 5:27. [PMID: 15588300 PMCID: PMC539307 DOI: 10.1186/1471-2350-5-27] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Accepted: 12/09/2004] [Indexed: 01/17/2023]
Abstract
Background The increasing number of available genotypes for genetic studies in humans requires more advanced techniques of analysis. We previously reported significant univariate associations between gene polymorphisms and antidepressant response in mood disorders. However the combined analysis of multiple gene polymorphisms and clinical variables requires the use of non linear methods. Methods In the present study we tested a neural network strategy for a combined analysis of two gene polymorphisms. A Multi Layer Perceptron model showed the best performance and was therefore selected over the other networks. One hundred and twenty one depressed inpatients treated with fluvoxamine in the context of previously reported pharmacogenetic studies were included. The polymorphism in the transcriptional control region upstream of the 5HTT coding sequence (SERTPR) and in the Tryptophan Hydroxylase (TPH) gene were analysed simultaneously. Results A multi layer perceptron network composed by 1 hidden layer with 7 nodes was chosen. 77.5 % of responders and 51.2% of non responders were correctly classified (ROC area = 0.731 – empirical p value = 0.0082). Finally, we performed a comparison with traditional techniques. A discriminant function analysis correctly classified 34.1 % of responders and 68.1 % of non responders (F = 8.16 p = 0.0005). Conclusions Overall, our findings suggest that neural networks may be a valid technique for the analysis of gene polymorphisms in pharmacogenetic studies. The complex interactions modelled through NN may be eventually applied at the clinical level for the individualized therapy.
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Affiliation(s)
- Alessandro Serretti
- Istituto Scientifico Universitario Ospedale San Raffaele, Department of Neuropsychiatric Sciences, Milano, Italy
- Università Vita-Salute San Raffaele, School of Medicine, Milano, Italy
| | - Enrico Smeraldi
- Istituto Scientifico Universitario Ospedale San Raffaele, Department of Neuropsychiatric Sciences, Milano, Italy
- Università Vita-Salute San Raffaele, School of Medicine, Milano, Italy
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18
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Wang H, Ng K, Hayes D, Gao X, Forster G, Blaha C, Yeomans J. Decreased amphetamine-induced locomotion and improved latent inhibition in mice mutant for the M5 muscarinic receptor gene found in the human 15q schizophrenia region. Neuropsychopharmacology 2004; 29:2126-39. [PMID: 15213703 DOI: 10.1038/sj.npp.1300502] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
M5 muscarinic receptors are coexpressed with D2 dopamine receptors in the ventral tegmentum and striatum, and are important for reward in rodents. Previously, we reported that disruption of the M5 receptor gene in mice reduced dopamine release in the nucleus accumbens. In this study, we established a polymerase chain reaction (PCR) genotyping method for M5 mutant mice, and, using RT-PCR, found that M5 mRNA expression was highest in the ventral tegmentum, striatum, and thalamus in wild-type mice. In the M5 mutant mice, D2 mRNA expression was increased in several brain structures, including the striatum. Genome mapping studies showed the M5 gene is localized to chromosome 2E4 in mice, and to 15q13 in humans in the region that has been linked to schizophrenia. Amphetamine-induced locomotion, but not baseline locomotion or motor functions, decreased in M5 mutant mice, consistent with lower accumbal dopamine release. Previous reports found latent inhibition improvement in rats following nucleus accumbens lesions, or blockade of dopamine D2 receptors with neuroleptic drugs. Here, latent inhibition was significantly increased in M5 mutant mice as compared with controls, consistent with reduced dopamine function in the nucleus accumbens. In summary, our results showed that M5 gene disruption in mice decreased amphetamine-induced locomotion and increased latent inhibition, suggesting that increased M5 mesolimbic function may be relevant to schizophrenia.
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MESH Headings
- Acoustic Stimulation/methods
- Amphetamine/pharmacology
- Animals
- Behavior, Animal
- Blotting, Southern/methods
- Brain/anatomy & histology
- Brain/metabolism
- Central Nervous System Stimulants/pharmacology
- Chromosome Mapping/methods
- Chromosomes, Human, Pair 15
- Dose-Response Relationship, Drug
- Genotype
- Humans
- Inhibition, Psychological
- Locomotion/drug effects
- Mice
- Mice, Mutant Strains
- Pain Measurement/drug effects
- Psychomotor Performance/drug effects
- RNA, Messenger/biosynthesis
- Receptor, Muscarinic M5/genetics
- Receptor, Muscarinic M5/metabolism
- Receptor, Muscarinic M5/physiology
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/immunology
- Reflex, Startle/drug effects
- Reflex, Startle/radiation effects
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Time Factors
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Affiliation(s)
- Haoran Wang
- Department of Psychology, University of Toronto, Toronto, Canada
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19
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Abstract
We are rapidly approaching the postgenomic era in which we will know all of the 3 billion DNA bases in the human genome sequence and all of the variations in the genome sequence that are ultimately responsible for genetic influence on behavior. These ongoing advances and new techniques will make it easier to identify genes associated with psychopathology. Progress in identifying such genes has been slower than some experts expected, probably because many genes are involved for each phenotype, which means the effect of any one gene is small. Nonetheless, replicated linkages and associations are being found, for example, for dementia, reading disability, and hyperactivity. The future of genetic research lies in finding out how genes work (functional genomics). It is important for the future of psychology that pathways between genes and behavior be examined at the top-down psychological level of analysis (behavioral genomics), as well as at the bottom-up molecular biological level of cells or the neuroscience level of the brain. DNA will revolutionize psychological research and treatment during the coming decades.
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Affiliation(s)
- Robert Plomin
- Social, Genetic and Developmental Psychiatry Research Centre, Institute of Psychiatry, King's College London, DeCrespigny Park, London SE5 8AF, UK.
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21
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Iwayama-Shigeno Y, Yamada K, Toyota T, Shimizu H, Hattori E, Yoshitsugu K, Fujisawa T, Yoshida Y, Kobayashi T, Toru M, Kurumaji A, Detera-Wadleigh S, Yoshikawa T. Distribution of haplotypes derived from three common variants of the NR4A2 gene in Japanese patients with schizophrenia. Am J Med Genet B Neuropsychiatr Genet 2003; 118B:20-4. [PMID: 12627459 DOI: 10.1002/ajmg.b.10053] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Dysregulation in dopaminergic neurotransmission might play a role in the pathogenesis of schizophrenia, and therefore genetic components of the dopamine (DA) pathway may confer risk. The NR4A2 (Nurr1) gene is essential for the development and maintenance of mesencephalic DA-synthesizing neurons. Moreover, Nurr1 forms a heterodimer with the retinoid X receptor and disturbances in the retinoid-signaling cascade may be involved in susceptibility to schizophrenia. To investigate the potential genetic contribution of NR4A2, we performed a case-control association study using three common variants in the gene [-2922(C)2-3, IVS6 + 17 approximately +18insG, EX8 + 657(CA)9-10] that were in strong linkage disequilibrium with each other. We did not detect a significant allelic or genotypic association. Haplotypes derived from all three polymorphisms generated similar results. These data do not support the notion that the NR4A2 gene plays a major role in risk for schizophrenia among Japanese individuals.
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Affiliation(s)
- Yoshimi Iwayama-Shigeno
- Laboratory for Molecular Psychiatry, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-city, Saitama 351-0198, Japan
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22
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23
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Palmer CGS, Turunen JA, Sinsheimer JS, Minassian S, Paunio T, Lönnqvist J, Peltonen L, Woodward JA. RHD maternal-fetal genotype incompatibility increases schizophrenia susceptibility. Am J Hum Genet 2002; 71:1312-9. [PMID: 12439825 PMCID: PMC378569 DOI: 10.1086/344659] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2002] [Accepted: 09/06/2002] [Indexed: 12/19/2022] Open
Abstract
Fetal events and obstetric complications are associated with schizophrenia. Here we report the results of a family-based candidate-gene study that assesses the role of maternal-fetal genotype incompatibility at the RHD locus in schizophrenia. We adapted the case-parent-trio log-linear modeling approach to test for RHD maternal-fetal genotype incompatibility and to distinguish this effect from a high-risk allele at or near the RHD locus and from a direct maternal effect alone. Eighty-eight patient-parent trios, 72 patient-mother pairs, and 21 patient-father pairs were genotyped at the RHD locus. Of the 181 patients, 62% were male and 81% were second born or later. Only three patients were born after prophylaxis against maternal isoimmunization had become common practice. There was significant evidence for an RHD maternal-fetal genotype incompatibility, and the incompatibility parameter was estimated at 2.6. There was no evidence to support linkage/association with schizophrenia at or near the RHD locus nor any evidence to support the role of maternal genotype effect alone. Our results replicate previous findings that implicate the RHD locus in schizophrenia, and the candidate-gene design of this study allows the elimination of alternative explanations for the role of this locus in disease. Thus, the present study provides increasing evidence that the RHD locus increases schizophrenia risk through a maternal-fetal genotype incompatibility mechanism that increases risk of an adverse prenatal environment (e.g., Rh incompatibility) rather than through linkage/association with the disorder, linkage disequilibrium with an unknown nearby susceptibility locus, or a direct maternal effect alone. This is the first candidate-gene study to explicitly test for and provide evidence of a maternal-fetal genotype incompatibility mechanism in schizophrenia.
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Affiliation(s)
- Christina G S Palmer
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, 90095, USA.
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Novak G, Kim D, Seeman P, Tallerico T. Schizophrenia and Nogo: elevated mRNA in cortex, and high prevalence of a homozygous CAA insert. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2002; 107:183-9. [PMID: 12425946 DOI: 10.1016/s0169-328x(02)00492-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Schizophrenia is a major psychiatric disorder which is hypothesized to result from abnormal neurodevelopment or neural changes in adulthood and possibly associated with altered gene expression. To search for genes overexpressed in schizophrenia, cDNA library subtractive hybridization experiments between post-mortem human frontal cerebral cortices from schizophrenia individuals and neurological controls were carried out. One of the genes over-expressed in schizophrenia was identified as Nogo (also known as reticulon 4, RTN4, NI 250, or RTN-X), a myelin-associated protein which inhibits the outgrowth of neurites and nerve terminals. The elevated expression of Nogo mRNA in schizophrenia was confirmed by quantitative reverse transcription-polymerase chain reaction studies: 16.5 pg Nogo cDNA/microg total RNA in schizophrenia, and 10.2 pg Nogo cDNA/microg total RNA in controls (n=7; P=0.01, t-test for n<30). To identify possible polymorphisms in this gene, the Nogo nucleotide sequence was determined in a series of schizophrenia and control samples. The Nogo mRNA was found to contain a CAA insert polymorphism in the 3'-untranslated region. The prevalence of individuals homozygous for this CAA insert was significantly higher in schizophrenia compared to controls in genomic DNA samples extracted from post-mortem brain and blood samples: 17/81 or 21% in schizophrenia and 2/61 or 3% in controls (P=0.0022, chi(2)- and Fisher's exact-tests). Because the 3'-untranslated regions of eukaryotic genes are known to regulate gene expression, the increased frequency of the Nogo CAA insert in schizophrenia may contribute to abnormal regulation of Nogo gene expression, and may indicate a role for Nogo in disturbed neurodevelopment in schizophrenia.
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Affiliation(s)
- G Novak
- Department of Pharmacology, Medical Sciences Building, University of Toronto, Room 4344, Medical Science Building, 8 Taddle Creek Road, Ontario, M5S 1A8, Toronto, Canada
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25
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Maheshwari M, Christian SL, Liu C, Badner JA, Detera-Wadleigh S, Gershon ES, Gibbs RA. Mutation screening of two candidate genes from 13q32 in families affected with Bipolar disorder: human peptide transporter (SLC15A1) and human glypican5 (GPC5). BMC Genomics 2002; 3:30. [PMID: 12392603 PMCID: PMC140024 DOI: 10.1186/1471-2164-3-30] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2002] [Accepted: 10/22/2002] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Multiple candidate regions as sites for Schizophrenia and Bipolar susceptibility genes have been reported, suggesting heterogeneity of susceptibility genes or oligogenic inheritance. Linkage analysis has suggested chromosome 13q32 as one of the regions with evidence of linkage to Schizophrenia and, separately, to Bipolar disorder (BP). SLC15A1 and GPC5 are two of the candidate genes within an approximately 10-cM region of linkage on chromosome 13q32. In order to identify a possible role for these candidates as susceptibility genes, we performed mutation screening on the coding regions of these two genes in 7 families (n-20) affected with Bipolar disorder showing linkage to 13q32. RESULTS Genomic organization revealed 23 exons in SLC15A1 and 8 exons in GPC5 gene respectively. Sequencing of the exons did not reveal mutations in the GPC5 gene in the 7 families affected with BP. Two polymorphic variants were discovered in the SLC15A1 gene. One was T to C substitution in the third position of codon encoding alanine at 1403 position of mRNA in exon 17, and the other was A to G substitution in the untranslated region at position 2242 of mRNA in exon 23. CONCLUSIONS Mutation analysis of 2 candidate genes for Bipolar disorder on chromosome 13q32 did not identify any potentially causative mutations within the coding regions or splice junctions of the SLC15A1 or GPC5 genes in 7 families showing linkage to 13q32. Further studies of the regulatory regions are needed to completely exclude these genes as causative for Bipolar disorder.
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Affiliation(s)
- Manjula Maheshwari
- Department of Molecular & Human Genetics, Human Genome Sequencing Center, One Baylor Plaza, N1519 Houston, TX 77030, USA
| | - SL Christian
- Department of Psychiatry, University of Chicago, Chicago, IL 60637, USA
| | - C Liu
- Department of Psychiatry, University of Chicago, Chicago, IL 60637, USA
| | - JA Badner
- Department of Psychiatry, University of Chicago, Chicago, IL 60637, USA
| | - S Detera-Wadleigh
- National Institute of Mental Health Intramural Research Program, National Institutes of Health, Bethesda, MD 20892-4094, USA
| | - ES Gershon
- Department of Psychiatry, University of Chicago, Chicago, IL 60637, USA
| | - Richard A Gibbs
- Department of Molecular & Human Genetics, Human Genome Sequencing Center, One Baylor Plaza, N1519 Houston, TX 77030, USA
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