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Khan R, Chaturvedi P, Sahu P, Ludhiadch A, Singh P, Singh G, Munshi A. Role of Potassium Ion Channels in Epilepsy: Focus on Current Therapeutic Strategies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:67-87. [PMID: 36578258 DOI: 10.2174/1871527322666221227112621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Epilepsy is one of the prevalent neurological disorders characterized by disrupted synchronization between inhibitory and excitatory neurons. Disturbed membrane potential due to abnormal regulation of neurotransmitters and ion transport across the neural cell membrane significantly contributes to the pathophysiology of epilepsy. Potassium ion channels (KCN) regulate the resting membrane potential and are involved in neuronal excitability. Genetic alterations in the potassium ion channels (KCN) have been reported to result in the enhancement of the release of neurotransmitters, the excitability of neurons, and abnormal rapid firing rate, which lead to epileptic phenotypes, making these ion channels a potential therapeutic target for epilepsy. The aim of this study is to explore the variations reported in different classes of potassium ion channels (KCN) in epilepsy patients, their functional evaluation, and therapeutic strategies to treat epilepsy targeting KCN. METHODOLOGY A review of all the relevant literature was carried out to compile this article. RESULTS A large number of variations have been reported in different genes encoding various classes of KCN. These genetic alterations in KCN have been shown to be responsible for disrupted firing properties of neurons. Antiepileptic drugs (AEDs) are the main therapeutic strategy to treat epilepsy. Some patients do not respond favorably to the AEDs treatment, resulting in pharmacoresistant epilepsy. CONCLUSION Further to address the challenges faced in treating epilepsy, recent approaches like optogenetics, chemogenetics, and genome editing, such as clustered regularly interspaced short palindromic repeats (CRISPR), are emerging as target-specific therapeutic strategies.
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Affiliation(s)
- Rahul Khan
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Pragya Chaturvedi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Prachi Sahu
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Abhilash Ludhiadch
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, 151001 India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
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Kang SW, Kim SK, Han YR, Hong D, Chon J, Chung JH, Hong SJ, Park MS, Ban JY. Promoter Polymorphism (-308G/A) of Tumor Necrosis Factor-Alpha ( TNF-α) Gene and Asthma Risk: An Updated Meta-Analysis. Genet Test Mol Biomarkers 2019; 23:363-372. [PMID: 31161819 DOI: 10.1089/gtmb.2018.0238] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background and Aims: The relationship between the promoter polymorphism (-308G/A) of the tumor necrosis factor-alpha (TNF-α) gene and the susceptibility to asthma has been tested in several studies. However, the results have been inconsistent. Therefore, we performed an updated meta-analysis to evaluate the relationship between this promoter polymorphism of the TNF-α gene and the risk of asthma. Methods: Fifty case-control studies were included in this meta-analysis which provided 17,937 controls and 9961 asthma patients. The pooled p-value, odds ratio (OR), and 95% confidence interval (95% CI) were used to investigate the strength of the association of this polymorphism of the TNF-α gene with the risk of asthma. The meta-analysis was carried out by Comprehensive Meta-Analysis software. Results: The results of our meta-analysis revealed that the TNF-α polymorphism (-308, G/A) was strongly associated with the risk of asthma (p < 0.05 in the allelic, dominant, and recessive models, respectively). In further analyses, based on age group and ethnicity, we observed this association for all subpopulations examined (p < 0.05 in allelic, dominant, and recessive models, respectively). Conclusion: This large-scale meta-analysis supports a strong association between the TNF-α gene promoter polymorphism (-308G/A) and the development to asthma in both children and adults.
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Affiliation(s)
- Sang Wook Kang
- 1 Department of Dental Pharmacology, School of Dentistry, Dankook University, Cheonan, Republic of Korea
| | - Su Kang Kim
- 2 Department of Biomedical Laboratory Science, Catholic Kwandong University, Gangneung, Republic of Korea
| | - Young Rok Han
- 3 Department of Physical Medicine and Rehabilitation, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - DongWhan Hong
- 3 Department of Physical Medicine and Rehabilitation, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Jinmann Chon
- 3 Department of Physical Medicine and Rehabilitation, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Joo-Ho Chung
- 4 Kohwang Medical Research Institute, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Seoung-Jin Hong
- 5 Department of Prosthodontics, Kyung Hee University Dental Hospital, Seoul, Republic of Korea
| | - Min-Su Park
- 6 Department of Surgery, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Ju Yeon Ban
- 1 Department of Dental Pharmacology, School of Dentistry, Dankook University, Cheonan, Republic of Korea
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Bocksteins E. Kv5, Kv6, Kv8, and Kv9 subunits: No simple silent bystanders. J Gen Physiol 2016; 147:105-25. [PMID: 26755771 PMCID: PMC4727947 DOI: 10.1085/jgp.201511507] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/11/2015] [Indexed: 12/19/2022] Open
Abstract
Members of the electrically silent voltage-gated K(+) (Kv) subfamilies (Kv5, Kv6, Kv8, and Kv9, collectively identified as electrically silent voltage-gated K(+) channel [KvS] subunits) do not form functional homotetrameric channels but assemble with Kv2 subunits into heterotetrameric Kv2/KvS channels with unique biophysical properties. Unlike the ubiquitously expressed Kv2 subunits, KvS subunits show a more restricted expression. This raises the possibility that Kv2/KvS heterotetramers have tissue-specific functions, making them potential targets for the development of novel therapeutic strategies. Here, I provide an overview of the expression of KvS subunits in different tissues and discuss their proposed role in various physiological and pathophysiological processes. This overview demonstrates the importance of KvS subunits and Kv2/KvS heterotetramers in vivo and the importance of considering KvS subunits and Kv2/KvS heterotetramers in the development of novel treatments.
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Affiliation(s)
- Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology, and Pharmacology, Department for Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium
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Reardon BJ, Hansen JG, Crystal RG, Houston DK, Kritchevsky SB, Harris T, Lohman K, Liu Y, O'Connor GT, Wilk JB, Mezey J, Gao C, Cassano PA. Vitamin D-responsive SGPP2 variants associated with lung cell expression and lung function. BMC MEDICAL GENETICS 2013; 14:122. [PMID: 24274704 PMCID: PMC3907038 DOI: 10.1186/1471-2350-14-122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 11/08/2013] [Indexed: 12/05/2022]
Abstract
Background Vitamin D is associated with lung health in epidemiologic studies, but mechanisms mediating observed associations are poorly understood. This study explores mechanisms for an effect of vitamin D in lung through an in vivo gene expression study, an expression quantitative trait loci (eQTL) analysis in lung tissue, and a population-based cohort study of sequence variants. Methods Microarray analysis investigated the association of gene expression in small airway epithelial cells with serum 25(OH)D in adult non-smokers. Sequence variants in candidate genes identified by the microarray were investigated in a lung tissue eQTL database, and also in relation to cross-sectional pulmonary function in the Health, Aging, and Body Composition (Health ABC) study, stratified by race, with replication in the Framingham Heart Study (FHS). Results 13 candidate genes had significant differences in expression by serum 25(OH)D (nominal p < 0.05), and a genome-wide significant eQTL association was detected for SGPP2. In Health ABC, SGPP2 SNPs were associated with FEV1 in both European- and African-Americans, and the gene-level association was replicated in European-American FHS participants. SNPs in 5 additional candidate genes (DAPK1, FSTL1, KAL1, KCNS3, and RSAD2) were associated with FEV1 in Health ABC participants. Conclusions SGPP2, a sphingosine-1-phosphate phosphatase, is a novel vitamin D-responsive gene associated with lung function. The identified associations will need to be followed up in further studies.
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Affiliation(s)
- Brian J Reardon
- Division of Nutritional Sciences, Cornell University, 209 Savage Hall, Ithaca, NY 14853, USA.
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Linta L, Stockmann M, Lin Q, Lechel A, Proepper C, Boeckers TM, Kleger A, Liebau S. Microarray-Based Comparisons of Ion Channel Expression Patterns: Human Keratinocytes to Reprogrammed hiPSCs to Differentiated Neuronal and Cardiac Progeny. Stem Cells Int 2013; 2013:784629. [PMID: 23690787 PMCID: PMC3649712 DOI: 10.1155/2013/784629] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 03/06/2013] [Indexed: 11/17/2022] Open
Abstract
Ion channels are involved in a large variety of cellular processes including stem cell differentiation. Numerous families of ion channels are present in the organism which can be distinguished by means of, for example, ion selectivity, gating mechanism, composition, or cell biological function. To characterize the distinct expression of this group of ion channels we have compared the mRNA expression levels of ion channel genes between human keratinocyte-derived induced pluripotent stem cells (hiPSCs) and their somatic cell source, keratinocytes from plucked human hair. This comparison revealed that 26% of the analyzed probes showed an upregulation of ion channels in hiPSCs while just 6% were downregulated. Additionally, iPSCs express a much higher number of ion channels compared to keratinocytes. Further, to narrow down specificity of ion channel expression in iPS cells we compared their expression patterns with differentiated progeny, namely, neurons and cardiomyocytes derived from iPS cells. To conclude, hiPSCs exhibit a very considerable and diverse ion channel expression pattern. Their detailed analysis could give an insight into their contribution to many cellular processes and even disease mechanisms.
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Affiliation(s)
- Leonhard Linta
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Marianne Stockmann
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Qiong Lin
- Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelstrasse 30, 52074 Aachen, Germany
| | - André Lechel
- Department of Internal Medicine I, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Christian Proepper
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Tobias M. Boeckers
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Alexander Kleger
- Department of Internal Medicine I, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Stefan Liebau
- Institute for Anatomy Cell Biology, Ulm University, Albert-Einstein Allee 11, 89081 Ulm, Germany
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Yim PD, Gallos G, Perez-Zoghbi JF, Trice J, Zhang Y, Siviski M, Sonett J, Emala CW. Chloride channel blockers promote relaxation of TEA-induced contraction in airway smooth muscle. J Smooth Muscle Res 2013; 49:112-24. [PMID: 24662476 PMCID: PMC4131261 DOI: 10.1540/jsmr.49.112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 12/19/2013] [Indexed: 01/21/2023] Open
Abstract
Enhanced airway smooth muscle (ASM) contraction is an important component in the pathophysiology of asthma. We have shown that ligand gated chloride channels modulate ASM contractile tone during the maintenance phase of an induced contraction, however the role of chloride flux in depolarization-induced contraction remains incompletely understood. To better understand the role of chloride flux under these conditions, muscle force (human ASM, guinea pig ASM), peripheral small airway luminal area (rat ASM) and airway smooth muscle plasma membrane electrical potentials (human cultured ASM) were measured. We found ex vivo guinea pig airway rings, human ASM strips and small peripheral airways in rat lungs slices relaxed in response to niflumic acid following depolarization-induced contraction induced by K(+) channel blockade with tetraethylammonium chloride (TEA). In isolated human airway smooth muscle cells TEA induce depolarization as measured by a fluorescent indicator or whole cell patch clamp and this depolarization was reversed by niflumic acid. These findings demonstrate that ASM depolarization induced contraction is dependent on chloride channel activity. Targeting of chloride channels may be a novel approach to relax hypercontractile airway smooth muscle in bronchoconstrictive disorders.
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Affiliation(s)
- Peter D Yim
- Departments of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York, NY USA
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Valverde MA, Cantero-Recasens G, Garcia-Elias A, Jung C, Carreras-Sureda A, Vicente R. Ion channels in asthma. J Biol Chem 2011; 286:32877-82. [PMID: 21799020 DOI: 10.1074/jbc.r110.215491] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ion channels are specialized transmembrane proteins that permit the passive flow of ions following their electrochemical gradients. In the airways, ion channels participate in the production of epithelium-based hydroelectrolytic secretions and in the control of intracellular Ca(2+) levels that will ultimately activate almost all lung cells, either resident or circulating. Thus, ion channels have been the center of many studies aiming to understand asthma pathophysiological mechanisms or to identify therapeutic targets for better control of the disease. In this minireview, we focus on molecular, genetic, and animal model studies associating ion channels with asthma.
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Affiliation(s)
- Miguel A Valverde
- Laboratory of Molecular Physiology and Channelopathies, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, 08003 Barcelona, Spain.
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Kaminuma O, Suko M, Mori A. Genetic factors in the treatment of bronchial asthma. Expert Rev Clin Immunol 2010; 2:727-35. [PMID: 20477628 DOI: 10.1586/1744666x.2.5.727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Owing to the recent vast progress in analytical tools and procedures to elucidate the relationship between genes and diseases, many candidate genes leading to the development of bronchial asthma have been reported. However, the quantitative phenotypes of asthma, such as decrease in forced expiratory volume in the first second, serum hyper-IgE, bronchial hyperresponsiveness and blood hyper-eosinophilia, do not represent this disease completely. On the other hand, eosinophilic inflammation of the bronchial mucosa represents accurately the feature of bronchial asthma, although accurate quantification of its status is difficult. While the production of interleukin (IL)-5 in peripheral CD4(+) T cells probably correlates with eosinophilic inflammation of the airway, the effectiveness of anti-IL-5 antibody for the treatment of bronchial asthma is controversial. Since intervention with asthma-causing gene products may not be sufficient for the treatment of this disease, identification of therapy-responsive genes should become more important in the near future.
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Affiliation(s)
- Osamu Kaminuma
- The Tokyo Metropolitan Institute of Medical Science, Department of Allergy and Immunology, 3-18-22, Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.
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Morales JL, Krzeminski J, Amin S, Perdew GH. Characterization of the antiallergic drugs 3-[2-(2-phenylethyl) benzoimidazole-4-yl]-3-hydroxypropanoic acid and ethyl 3-hydroxy-3-[2-(2-phenylethyl)benzoimidazol-4-yl]propanoate as full aryl hydrocarbon receptor agonists. Chem Res Toxicol 2008; 21:472-82. [PMID: 18179178 DOI: 10.1021/tx700350v] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates most of the toxic effects of numerous chlorinated (e.g., TCDD) and nonchlorinated polycyclic aromatic compounds (e.g., benzo[ a]pyrene). Studies in AhR null mice suggested that this receptor may also play a role in the modulation of immune responses. Recently, two drugs, namely, M50354 and M50367 (ethyl ester derivative of M50354), were described as AhR ligands with high efficacy toward reducing atopic allergic symptoms in an AhR-dependent manner by skewing T helper cell differentiation toward a T H1 phenotype [Negishi et al. (2005) J. Immunol. 175 (11), 7348-7356]. Surprisingly, these drugs were shown to have minimal activity toward inducing classical dioxin responsive element-driven AhR-mediated CYP1A1 transcription. We synthesized and reevaluated the ability of these drugs to regulate AhR activity. In contrast to previously published data, both M50354 and M50367 were found to be potent inducers of several AhR target genes, namely, CYP1A1, CYP1B1, and UGT1A2. M50367 was a more effective agonist than M50354, perhaps accounting for its higher bioavailability in vivo. However, M50354 was capable of displacing an AhR-specific radioligand more effectively than M50367. This is consistent with M50354 being the active metabolite of M50367. In conclusion, two selective inhibitors of TH2 differentiation are full AhR agonists.
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Affiliation(s)
- José Luis Morales
- Graduate Program in Biochemistry, Microbiology, and Molecular Biology, Department of Pharmacology, College of Medicine, The Pennsylvania State University, University Park, PA 16802, USA
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Zheng G, Song K, Elston RC. Adaptive two-stage analysis of genetic association in case-control designs. Hum Hered 2007; 63:175-86. [PMID: 17310127 DOI: 10.1159/000099830] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 11/29/2006] [Indexed: 01/03/2023] Open
Abstract
We study a two-stage analysis of genetic association for case-control studies. In the first stage, we compare Hardy-Weinberg disequilibrium coefficients between cases and controls and, in the second stage, we apply the Cochran- Armitage trend test. The two analyses are statistically independent when Hardy-Weinberg equilibrium holds in the population, so all the samples are used in both stages. The significance level in the first stage is adaptively determined based on its conditional power. Given the level in the first stage, the level for the second stage analysis is determined with the overall Type I error being asymptotically controlled. For finite sample sizes, a parametric bootstrap method is used to control the overall Type I error rate. This two-stage analysis is often more powerful than the Cochran-Armitage trend test alone for a large association study. The new approach is applied to SNPs from a real study.
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Affiliation(s)
- Gang Zheng
- Office of Biostatistics Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA.
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Chen JM, Férec C, Cooper DN. A systematic analysis of disease-associated variants in the 3' regulatory regions of human protein-coding genes I: general principles and overview. Hum Genet 2006; 120:1-21. [PMID: 16645853 DOI: 10.1007/s00439-006-0180-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 03/26/2006] [Indexed: 10/24/2022]
Abstract
The 3' regulatory regions (3' RRs) of human genes play an important role in regulating mRNA 3' end formation, stability/degradation, nuclear export, subcellular localization and translation and are consequently rich in regulatory elements. Although 3' RRs contain only approximately 0.2% of known disease-associated mutations, this is likely to represent a rather conservative estimate of their actual prevalence. In an attempt to catalogue 3' RR-mediated disease and also to gain a greater understanding of the functional role of regulatory elements within 3' RRs, we have performed a systematic analysis of disease-associated 3' RR variants; 121 3' RR variants in 94 human genes were collated. These included 17 mutations in the upstream core polyadenylation signal sequence (UCPAS), 81 in the upstream sequence (USS) between the translational termination codon and the UCPAS, 6 in the left arm of the 'spacer' sequence (LAS) between the UCPAS and the pre-mRNA cleavage site (CS), 3 in the right arm of the 'spacer' sequence (RAS) or downstream core polyadenylation signal sequence (DCPAS) and 7 in the downstream sequence (DSS) of the 3'-flanking region, with 7 further mutations being treated as isolated examples. All the UCPAS mutations and the rather unusual cases of the DMPK, SCA8, FCMD and GLA mutations exert a significant effect on the mRNA phenotype and are usually associated with monogenic disease. By contrast, most of the remaining variants are polymorphisms that exert a comparatively minor influence on mRNA expression, but which may nevertheless predispose to or otherwise modify complex clinical phenotypes. Considerable efforts have been made to validate/elucidate the mechanisms through which the 3' untranslated region (3' UTR) variants affect gene expression. It is hoped that the integrative approach employed here in the study of naturally occurring variants of actual or potential pathological significance will serve to complement ongoing efforts to identify all functional regulatory elements in the human genome.
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