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Sturchio A, Duker AP, Muñoz-Sanjuan I, Espay AJ. Subtyping monogenic disorders: Huntington disease. HANDBOOK OF CLINICAL NEUROLOGY 2023; 193:171-184. [PMID: 36803810 DOI: 10.1016/b978-0-323-85555-6.00003-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Huntington disease is a highly disabling neurodegenerative disease characterized by psychiatric, cognitive, and motor deficits. The causal genetic mutation in huntingtin (Htt, also known as IT15), located on chromosome 4p16.3, leads to an expansion of a triplet coding for polyglutamine. The expansion is invariably associated with the disease when >39 repeats. Htt encodes for the protein huntingtin (HTT), which carries out many essential biological functions in the cell, in particular in the nervous system. The precise mechanism of toxicity is not known. Based on a one-gene-one-disease framework, the prevailing hypothesis ascribes toxicity to the universal aggregation of HTT. However, the aggregation process into mutant huntingtin (mHTT) is associated with a reduction of the levels of wild-type HTT. A loss of wild-type HTT may plausibly be pathogenic, contributing to the disease onset and progressive neurodegeneration. Moreover, many other biological pathways are altered in Huntington disease, such as in the autophagic system, mitochondria, and essential proteins beyond HTT, potentially explaining biological and clinical differences among affected individuals. As one gene does not mean one disease, future efforts at identifying specific Huntington subtypes are important to design biologically tailored therapeutic approaches that correct the corresponding biological pathways-rather than continuing to exclusively target the common denominator of HTT aggregation for elimination.
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Affiliation(s)
- Andrea Sturchio
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States; Department of Clinical Neuroscience, Neuro Svenningsson, Karolinska Institutet, Stockholm, Sweden.
| | - Andrew P Duker
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States
| | | | - Alberto J Espay
- James J. and Joan A. Gardner Family Center for Parkinson's disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH, United States.
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Lin H, Yang Y, Hou C, Huang Y, Zhou L, Zheng J, Lv G, Mao R, Chen S, Xu P, Zhou Y, Wang P, Zhou D. Validation of the functions and prognostic values of synapse-associated proteins in lower-grade glioma. Biosci Rep 2021; 41:BSR20210391. [PMID: 33969375 PMCID: PMC8164110 DOI: 10.1042/bsr20210391] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 02/05/2023] Open
Abstract
Synapse and synapse-associated proteins (SAPs) play critical roles in various neurodegeneration diseases and brain tumors. However, in lower-grade gliomas (LGG), SAPs have not been explored systematically. Herein, we are going to explore SAPs expression profile and its clinicopathological significance in LGG which can offer new insights to glioma therapy. In the present study, we integrate a list of SAPs that covered 231 proteins with synaptogenesis activity and post synapse formation. The LGG RNA-seq data were downloaded from GEO, TCGA and CGGA database. The prognosis associated SAPs in key modules of PPI (protein-protein interaction networks) was regarded as hub SAPs. Western blot, quantitative reverse transcription PCR (qRT-PCR) and immunochemistry results from HPA database were used to verify the expression of hub SAPs. There were 68 up-regulated SAPs and 44 down-regulated SAPs in LGG tissue compared with normal brain tissue. Data from function enrichment analysis revealed functions of differentially expressed SAPs in synapse organization and glutamatergic receptor pathway in LGGs. Survival analysis revealed that four SAPs, GRIK2, GABRD, GRID2 and ARC were correlate with the prognosis of LGG patients. Interestingly, we found that GABRD were up-regulated in LGG patients with seizures, indicating that SAPs may link to the pathogenesis of seizures in glioma patients. The four-SAPs signature was revealed as an independent prognostic factor in gliomas. Our study presented a novel strategy to assess the prognostic risks of LGGs, based on the expression of SAPs.
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Affiliation(s)
- Han Lin
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Yong Yang
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Chongxian Hou
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yuqing Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Liting Zhou
- International Department, Affiliated High School of South China Normal University, Guangzhou, China
| | - Jiantao Zheng
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Guangzhao Lv
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Rui Mao
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Shanwei Chen
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Peihong Xu
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Yujun Zhou
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Southern Medical University, Guangzhou, China
| | - Peng Wang
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Dong Zhou
- Department of Neurosurgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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Chen Z, Sequeiros J, Tang B, Jiang H. Genetic modifiers of age-at-onset in polyglutamine diseases. Ageing Res Rev 2018; 48:99-108. [PMID: 30355507 DOI: 10.1016/j.arr.2018.10.004] [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] [Received: 02/25/2018] [Revised: 08/03/2018] [Accepted: 10/17/2018] [Indexed: 11/25/2022]
Abstract
Polyglutamine (polyQ) diseases are a group of clinically and genetically heterogeneous neurodegenerative diseases. Expansion size correlates with age-at-onset (AO) and severity, and shows a critical threshold for each polyQ disease. Although an expanded CAG tract is sufficient to trigger disease, not all variation in AO is explained by (CAG)n length, which suggests the contribution of other modifying factors. Methods used to identify genetic modifiers in polyQ diseases have progressed from candidate genes to unbiased genome-wide searches. Inconsistency of results from candidate-genes studies are partly explained by sample size, study design and variable population frequency of "polymorphisms"; a genome-wide search may help elucidating more precise disease mechanisms underlying specific interaction networks. We review known genetic modifiers for polyQ diseases, and discuss developing strategies to find modulation, from common variants to networks disclosing small cumulative effects of key genes and modifying pathways. This may lead to a better understanding of genotype-phenotype correlation and the proposal of new potential targets for therapeutical interventions.
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Hu S, Hu H, Mak S, Cui G, Lee M, Shan L, Wang Y, Lin H, Zhang Z, Han Y. A Novel Tetramethylpyrazine Derivative Prophylactically Protects against Glutamate-Induced Excitotoxicity in Primary Neurons through the Blockage of N-Methyl-D-aspartate Receptor. Front Pharmacol 2018; 9:73. [PMID: 29483871 PMCID: PMC5816056 DOI: 10.3389/fphar.2018.00073] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/22/2018] [Indexed: 12/18/2022] Open
Abstract
The over-activation of NMDA receptor via the excessive glutamate is believed to one of the most causal factors associated with Alzheimer’s disease (AD), a progressive neurodegenerative brain disorder. Molecules that could protect against glutamate-induced neurotoxicity may hold therapeutic values for treating AD. Herein, the neuroprotective mechanisms of dimeric DT-010, a novel derivative of naturally occurring danshensu and tetramethylpyrazine, were investigated using primary rat cerebellar granule neurons (CGNs) and hippocampal neurons. It was found that DT-010 (3–30 μM) markedly prevented excitotoxicity of CGNs caused by glutamate, as evidenced by the promotion of neuronal viability as well as the reversal of abnormal morphological changes. While its parent molecules did not show any protective effects even when their concentration reached 50 μM. Additionally, DT-010 almost fully blocked intracellular accumulation of reactive oxygen species caused by glutamate and exogenous oxidative stimulus. Moreover, Western blot results demonstrated that DT-010 remarkably attenuated the inhibition of pro-survival PI3K/Akt/GSK3β pathway caused by glutamate. Ca2+ imaging with Fluo-4 fluorescence analysis further revealed that DT-010 greatly declined glutamate-induced increase in intracellular Ca2+. Most importantly, with the use of whole-cell patch clamp electrophysiology, DT-010 directly inhibited NMDA-activated whole-cell currents in primary hippocampal neurons. Molecular docking simulation analysis further revealed a possible binding mode that inhibited NMDA receptor at the ion channel, showing that DT-010 favorably binds to Asn602 of NMDA receptor via arene hydrogen bond. These results suggest that DT-010 could be served as a novel NMDA receptor antagonist and protect against glutamate-induced excitotoxicity from blocking the upstream NMDA receptors to the subsequent Ca2+ influx and to the downstream GSK3β cascade.
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Affiliation(s)
- Shengquan Hu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China.,Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China
| | - Huihui Hu
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Shinghung Mak
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China.,Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
| | - Guozhen Cui
- Department of Bioengineering, Zunyi Medical University, Zhuhai, China
| | - Mingyuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Taipa, Macau
| | - Luchen Shan
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Yuqiang Wang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Huangquan Lin
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Zaijun Zhang
- Institute of New Drug Research and Guangzhou Key Laboratory of Innovative Chemical Drug Research in Cardio-cerebrovascular Diseases, Jinan University College of Pharmacy, Guangzhou, China
| | - Yifan Han
- Department of Applied Biology and Chemical Technology, Institute of Modern Chinese Medicine, The Hong Kong Polytechnic University, Hong Kong, China.,Shenzhen Research Institute, The Hong Kong Polytechnic University, Shenzhen, China
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Arning L. The search for modifier genes in Huntington disease – Multifactorial aspects of a monogenic disorder. Mol Cell Probes 2016; 30:404-409. [DOI: 10.1016/j.mcp.2016.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/29/2016] [Accepted: 06/29/2016] [Indexed: 11/24/2022]
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Exploring Genetic Factors Involved in Huntington Disease Age of Onset: E2F2 as a New Potential Modifier Gene. PLoS One 2015; 10:e0131573. [PMID: 26148071 PMCID: PMC4493078 DOI: 10.1371/journal.pone.0131573] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/03/2015] [Indexed: 01/09/2023] Open
Abstract
Age of onset (AO) of Huntington disease (HD) is mainly determined by the length of the CAG repeat expansion (CAGexp) in exon 1 of the HTT gene. Additional genetic variation has been suggested to contribute to AO, although the mechanism by which it could affect AO is presently unknown. The aim of this study is to explore the contribution of candidate genetic factors to HD AO in order to gain insight into the pathogenic mechanisms underlying this disorder. For that purpose, two AO definitions were used: the earliest age with unequivocal signs of HD (earliest AO or eAO), and the first motor symptoms age (motor AO or mAO). Multiple linear regression analyses were performed between genetic variation within 20 candidate genes and eAO or mAO, using DNA and clinical information of 253 HD patients from REGISTRY project. Gene expression analyses were carried out by RT-qPCR with an independent sample of 35 HD patients from Basque Country Hospitals. We found suggestive association signals between HD eAO and/or mAO and genetic variation within the E2F2, ATF7IP, GRIN2A, GRIN2B, LINC01559, HIP1 and GRIK2 genes. Among them, the most significant was the association between eAO and rs2742976, mapping to the promoter region of E2F2 transcription factor. Furthermore, rs2742976 T allele patient carriers exhibited significantly lower lymphocyte E2F2 gene expression, suggesting a possible implication of E2F2-dependent transcriptional activity in HD pathogenesis. Thus, E2F2 emerges as a new potential HD AO modifier factor.
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Gusella JF, MacDonald ME, Lee JM. Genetic modifiers of Huntington's disease. Mov Disord 2014; 29:1359-65. [DOI: 10.1002/mds.26001] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 07/22/2014] [Indexed: 11/06/2022] Open
Affiliation(s)
- James F. Gusella
- Molecular Neurogenetics Unit, Department of Neurology and Center for Human Genetic Research; Massachusetts General Hospital; Boston Massachusetts USA
| | - Marcy E. MacDonald
- Molecular Neurogenetics Unit, Department of Neurology and Center for Human Genetic Research; Massachusetts General Hospital; Boston Massachusetts USA
| | - Jong-Min Lee
- Molecular Neurogenetics Unit, Department of Neurology and Center for Human Genetic Research; Massachusetts General Hospital; Boston Massachusetts USA
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Lee JH, Lee JM, Ramos EM, Gillis T, Mysore JS, Kishikawa S, Hadzi T, Hendricks AE, Hayden MR, Morrison PJ, Nance M, Ross CA, Margolis RL, Squitieri F, Gellera C, Gomez-Tortosa E, Ayuso C, Suchowersky O, Trent RJ, McCusker E, Novelletto A, Frontali M, Jones R, Ashizawa T, Frank S, Saint-Hilaire MH, Hersch SM, Rosas HD, Lucente D, Harrison MB, Zanko A, Abramson RK, Marder K, Sequeiros J, Landwehrmeyer GB, Shoulson I, Myers RH, MacDonald ME, Gusella JF. TAA repeat variation in the GRIK2 gene does not influence age at onset in Huntington's disease. Biochem Biophys Res Commun 2012; 424:404-8. [PMID: 22771793 PMCID: PMC3752397 DOI: 10.1016/j.bbrc.2012.06.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 06/25/2012] [Indexed: 11/29/2022]
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expanded CAG trinucleotide repeat whose length is the major determinant of age at onset but remaining variation appears to be due in part to the effect of genetic modifiers. GRIK2, which encodes GluR6, a mediator of excitatory neurotransmission in the brain, has been suggested in several studies to be a modifier gene based upon a 3' untranslated region TAA trinucleotide repeat polymorphism. Prior to investing in detailed studies of the functional impact of this polymorphism, we sought to confirm its effect on age at onset in a much larger dataset than in previous investigations. We genotyped the HD CAG repeat and the GRIK2 TAA repeat in DNA samples from 2,911 Huntington's disease subjects with known age at onset, and tested for a potential modifier effect of GRIK2 using a variety of statistical approaches. Unlike previous reports, we detected no evidence of an influence of the GRIK2 TAA repeat polymorphism on age at motor onset. Similarly, the GRIK2 polymorphism did not show significant modifier effect on psychiatric and cognitive age at onset in HD. Comprehensive analytical methods applied to a much larger sample than in previous studies do not support a role for GRIK2 as a genetic modifier of age at onset of clinical symptoms in Huntington's disease.
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Affiliation(s)
- Ji-Hyun Lee
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA 02114, USA.
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Tsai YC, Metzger S, Riess O, Soehn AS, Nguyen HP. Genetic analysis of polymorphisms in the kalirin gene for association with age-at-onset in European Huntington disease patients. BMC MEDICAL GENETICS 2012; 13:48. [PMID: 22720673 PMCID: PMC3433364 DOI: 10.1186/1471-2350-13-48] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 06/21/2012] [Indexed: 01/01/2023]
Abstract
Background Huntington disease (HD) is caused by an expanded CAG repeat in the HD gene. Although the length of the CAG repeat strongly correlates with the age-at-onset (AAO), AAO in HD individuals may differ dramatically in spite of similar expanded CAG repeat lengths. Additional genetic or environmental factors are thought to influence the disease onset. Several modifier genes have been discovered so far but they do not fully explain the variability of AAO in HD. To potentially identify a novel genetic modifier, we analyzed single nucleotide polymorphisms (SNPs) in the kalirin (KALRN) gene. Kalirin is a protein crucially involved in spine plasticity and its interaction with huntingtin-associated protein-1 (HAP-1) and a potential protein dysfunction might contribute to spine pathogenesis in HD. Methods The selected SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and association of SNPs with AAO was investigated with the framework of linear models in an analysis of variance and covariance. Results Eleven SNPs in the kalirin gene were examined in an association study in European HD patients. The ten coding SNPs under investigation were monomorphic, whereas SNP rs10934657 in the promoter region showed a minor allele frequency >1%. An analysis of covariance together with the influence of the expanded HD allele was applied in 680 HD patients. SNP rs10934657 did not affect the AAO of the examined HD population. Conclusions The results did not reveal an association between the analyzed kalirin polymorphisms and the AAO in HD. However, it does not exclude other SNPs of the kalirin gene as susceptible genetic modifiers.
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Affiliation(s)
- Yu-Chun Tsai
- Department of Medical Genetics, University of Tuebingen, Calwerstr 7, Tuebingen, 72076, Germany
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Characterization of a large group of individuals with huntington disease and their relatives enrolled in the COHORT study. PLoS One 2012; 7:e29522. [PMID: 22359536 PMCID: PMC3281013 DOI: 10.1371/journal.pone.0029522] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 11/29/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Careful characterization of the phenotype and genotype of Huntington disease (HD) can foster better understanding of the condition. METHODS We conducted a cohort study in the United States, Canada, and Australia of members of families affected by HD. We collected demographic and clinical data, conducted the Unified Huntington's Disease Rating Scale and Mini-Mental State Examination, and determined Huntingtin trinucleotide CAG repeat length. We report primarily on cross-sectional baseline data from this recently completed prospective, longitudinal, observational study. RESULTS As of December 31, 2009, 2,318 individuals enrolled; of these, 1,985 (85.6%) were classified into six analysis groups. Three groups had expanded CAG alleles (36 repeats or more): individuals with clinically diagnosed HD [n = 930], and clinically unaffected first-degree relatives who had previously pursued [n = 248] or not pursued [n = 112] predictive DNA testing. Three groups lacked expanded alleles: first-degree relatives who had previously pursued [n = 41] or not pursued [n = 224] genetic testing, and spouses and caregivers [n = 430]. Baseline mean performance differed across groups in all motor, behavioral, cognitive, and functional measures (p<0.001). Clinically unaffected individuals with expanded alleles weighed less (76.0 vs. 79.6 kg; p = 0.01) and had lower cognitive scores (28.5 vs. 29.1 on the Mini Mental State Examination; p = 0.008) than individuals without expanded alleles. The frequency of "high normal" repeat lengths (27 to 35) was 2.5% and repeat lengths associated with reduced penetrance (36 to 39) was 2.7%. CONCLUSION Baseline analysis of COHORT study participants revealed differences that emerge prior to clinical diagnosis. Longitudinal investigation of this cohort will further characterize the natural history of HD and genetic and biological modifiers. TRIAL REGISTRATION Clinicaltrials.gov NCT00313495.
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Abstract
Huntington’s disease (HD) is caused by the expansion of a CAG repeat within exon 1 of the huntingtin (HTT) gene. Although the variation in age at onset is partly explained by the lengths of the expanded repeat, the unexplained variation is heritable, emphasizing the role of the so-called genetic background on disease expression. Identification of modifier genes can confirm intracellular pathways already suspected to be involved in pathophysiological processes related to HD pathogenesis, but it may also point to completely new pathways and processes that have not yet been considered. Most importantly, confirmed modifier genes provide new targets for the development of therapies. Up to now, a wide range of susceptible HD modifier genes related to different biochemical pathways has been examined. On the basis of the published literature in this field, this review provides an overview of HD modifiers and integrates them into selected pathophysiology aspects.
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Affiliation(s)
| | - Jörg T Epplen
- Department of Human Genetics, Ruhr-University Bochum, Universitätsstr., 150, 44801 Bochum, Germany
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Smith AK, Fang H, Whistler T, Unger ER, Rajeevan MS. Convergent genomic studies identify association of GRIK2 and NPAS2 with chronic fatigue syndrome. Neuropsychobiology 2011; 64:183-94. [PMID: 21912186 PMCID: PMC3701888 DOI: 10.1159/000326692] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Accepted: 02/21/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND There is no consistent evidence of specific gene(s) or molecular pathways that contribute to the pathogenesis, therapeutic intervention or diagnosis of chronic fatigue syndrome (CFS). While multiple studies support a role for genetic variation in CFS, genome-wide efforts to identify associated loci remain unexplored. We employed a novel convergent functional genomics approach that incorporates the findings from single-nucleotide polymorphism (SNP) and mRNA expression studies to identify associations between CFS and novel candidate genes for further investigation. METHODS We evaluated 116,204 SNPs in 40 CFS and 40 nonfatigued control subjects along with mRNA expression of 20,160 genes in a subset of these subjects (35 CFS subjects and 27 controls) derived from a population-based study. RESULTS Sixty-five SNPs were nominally associated with CFS (p<0.001), and 165 genes were differentially expressed (≥4-fold; p≤0.05) in peripheral blood mononuclear cells of CFS subjects. Two genes, glutamate receptor, ionotropic, kinase 2 (GRIK2) and neuronal PAS domain protein 2 (NPAS2), were identified by both SNP and gene expression analyses. Subjects with the G allele of rs2247215 (GRIK2) were more likely to have CFS (p=0.0005), and CFS subjects showed decreased GRIK2 expression (10-fold; p=0.015). Subjects with the T allele of rs356653 (NPAS2) were more likely to have CFS (p=0.0007), and NPAS2 expression was increased (10-fold; p=0.027) in those with CFS. CONCLUSION Using an integrated genomic strategy, this study suggests a possible role for genes involved in glutamatergic neurotransmission and circadian rhythm in CFS and supports further study of novel candidate genes in independent populations of CFS subjects.
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Affiliation(s)
- Alicia K. Smith
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Ga., USA
| | - Hong Fang
- Z-Tech Corporation, an ICF International Company at NCTR/Food and Drug Administration, Jefferson, Ark., USA
| | - Toni Whistler
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Ga., USA
| | - Elizabeth R. Unger
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Ga., USA
| | - Mangalathu S. Rajeevan
- Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, Atlanta, Ga., USA
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