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Kir Channel Molecular Physiology, Pharmacology, and Therapeutic Implications. Handb Exp Pharmacol 2021; 267:277-356. [PMID: 34345939 DOI: 10.1007/164_2021_501] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
For the past two decades several scholarly reviews have appeared on the inwardly rectifying potassium (Kir) channels. We would like to highlight two efforts in particular, which have provided comprehensive reviews of the literature up to 2010 (Hibino et al., Physiol Rev 90(1):291-366, 2010; Stanfield et al., Rev Physiol Biochem Pharmacol 145:47-179, 2002). In the past decade, great insights into the 3-D atomic resolution structures of Kir channels have begun to provide the molecular basis for their functional properties. More recently, computational studies are beginning to close the time domain gap between in silico dynamic and patch-clamp functional studies. The pharmacology of these channels has also been expanding and the dynamic structural studies provide hope that we are heading toward successful structure-based drug design for this family of K+ channels. In the present review we focus on placing the physiology and pharmacology of this K+ channel family in the context of atomic resolution structures and in providing a glimpse of the promising future of therapeutic opportunities.
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Bautista-Medina MA, Gallardo-Blanco HL, Martinez-Garza LE, Cerda-Flores RM, Lavalle-Gonzalez FJ, Villarreal-Perez JZ. Association study in Mexican patients with thyrotoxic hypokalemic periodic paralysis. Biomed Rep 2020; 13:24. [PMID: 32765863 PMCID: PMC7403830 DOI: 10.3892/br.2020.1331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/26/2020] [Indexed: 11/29/2022] Open
Abstract
Hypokalemic periodic paralysis type 1 (OMIM; HOKPP1) and type 2 (OMIM; HOKPP2) are diseases of the muscle characterized by episodes of painless muscle weakness, and is associated with low potassium blood levels. Hyperthyroidism has been associated with thyrotoxic periodic paralysis (TTPP) (OMIM; TTPP1 and TTPP2), and genetic susceptibility has been implicated. In the present study, the clinical and epidemiological characteristics of patients with TTPP are described, together with their association with genetic variants reported previously in other populations. A prospective and a retrospective search of the medical records of patients who attended the emergency department at the Hospital Universitario ‘Dr. Jose E. Gonzalez’ in Monterrey, Nuevo León, Mexico, and were diagnosed with TTPP was performed. A total of 16 gene variants in the genes MUC1, CACNA1S, KCNE3 and SCN4A, and nine ancestry informative markers (AIMs), were analysed by Multiplex TaqMan™ Open Array assay, and a genetic association study was performed. A total of 11 patients were recruited, comprising nine males and two females (age range, 19-52 years) and 64 control subjects. Only two cases (18%) had a previous diagnosis of hyperthyroidism; the rest were diagnosed subsequently with Graves' disease. Based on the analysis, two DNA variants were found to potentially confer an increased risk for TTPP: S1PR1 rs3737576 [odds ratio (OR), 4.38; 95% confidence interval (CI), 1.08-17.76] and AIM rs2330442 (OR, 4.50; 95% CI, 1.21-16.69), and one variant was suggested to be possibly associated with TTPP, namely MUC1 rs4072037 (OR, 3.08; 95% CI, 0.841-1.38). However, there were no statistically significant associations between any of the 24 DNA variants and TTPP in a population from northeast Mexico.
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Affiliation(s)
- Mario Arturo Bautista-Medina
- Endocrinology Department, University Hospital José Eleuterio González, Autonomous University of Nuevo León, Monterrey, Nuevo León 64460, Mexico
| | - Hugo Leonid Gallardo-Blanco
- Department of Genetics, University Hospital José Eleuterio González, Autonomous University of Nuevo León, Monterrey, Nuevo León 64460, Mexico
| | - Laura Elia Martinez-Garza
- Department of Genetics, University Hospital José Eleuterio González, Autonomous University of Nuevo León, Monterrey, Nuevo León 64460, Mexico
| | | | - Fernando Javier Lavalle-Gonzalez
- Endocrinology Department, University Hospital José Eleuterio González, Autonomous University of Nuevo León, Monterrey, Nuevo León 64460, Mexico
| | - Jesus Zacarias Villarreal-Perez
- Endocrinology Department, University Hospital José Eleuterio González, Autonomous University of Nuevo León, Monterrey, Nuevo León 64460, Mexico
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Deeter A, Dalman M, Haddad J, Duan ZH. Inferring gene and protein interactions using PubMed citations and consensus Bayesian networks. PLoS One 2017; 12:e0186004. [PMID: 29049295 PMCID: PMC5648141 DOI: 10.1371/journal.pone.0186004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 09/22/2017] [Indexed: 11/25/2022] Open
Abstract
The PubMed database offers an extensive set of publication data that can be useful, yet inherently complex to use without automated computational techniques. Data repositories such as the Genomic Data Commons (GDC) and the Gene Expression Omnibus (GEO) offer experimental data storage and retrieval as well as curated gene expression profiles. Genetic interaction databases, including Reactome and Ingenuity Pathway Analysis, offer pathway and experiment data analysis using data curated from these publications and data repositories. We have created a method to generate and analyze consensus networks, inferring potential gene interactions, using large numbers of Bayesian networks generated by data mining publications in the PubMed database. Through the concept of network resolution, these consensus networks can be tailored to represent possible genetic interactions. We designed a set of experiments to confirm that our method is stable across variation in both sample and topological input sizes. Using gene product interactions from the KEGG pathway database and data mining PubMed publication abstracts, we verify that regardless of the network resolution or the inferred consensus network, our method is capable of inferring meaningful gene interactions through consensus Bayesian network generation with multiple, randomized topological orderings. Our method can not only confirm the existence of currently accepted interactions, but has the potential to hypothesize new ones as well. We show our method confirms the existence of known gene interactions such as JAK-STAT-PI3K-AKT-mTOR, infers novel gene interactions such as RAS- Bcl-2 and RAS-AKT, and found significant pathway-pathway interactions between the JAK-STAT signaling and Cardiac Muscle Contraction KEGG pathways.
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Affiliation(s)
- Anthony Deeter
- Integrated Bioscience, University of Akron, Akron, Ohio, United States of America
- Department of Computer Science, University of Akron, Akron, Ohio, United States of America
- * E-mail:
| | - Mark Dalman
- College of Public Health, Department of Biostatistics, Environmental Health Sciences and Epidemiology, Kent State University, Kent, Ohio, United States of America
- College of Podiatric Medicine, Department of Preclinical Sciences, Kent State University, Kent, Ohio, United States of America
| | - Joseph Haddad
- Department of Computer Science, University of Akron, Akron, Ohio, United States of America
| | - Zhong-Hui Duan
- Integrated Bioscience, University of Akron, Akron, Ohio, United States of America
- Department of Computer Science, University of Akron, Akron, Ohio, United States of America
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Phospholemman, a major regulator of skeletal muscle Na+/K+-ATPase, is not mutated in probands with hypokalemic periodic paralysis. Exp Ther Med 2017; 14:3229-3232. [DOI: 10.3892/etm.2017.4848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 02/24/2017] [Indexed: 11/05/2022] Open
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Tang ZW, He Y, Yao Y, Qiu L, Tian HM. Size of quadriceps femoris may contribute to thyrotoxic periodic paralysis. Med Hypotheses 2015; 85:749-53. [DOI: 10.1016/j.mehy.2015.10.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 08/25/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
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Wang XY, Ren BW, Yong ZH, Xu HY, Fu QX, Yao HB. Mutation analysis of CACNA1S and SCN4A in patients with hypokalemic periodic paralysis. Mol Med Rep 2015; 12:6267-74. [PMID: 26252573 DOI: 10.3892/mmr.2015.4201] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 07/22/2015] [Indexed: 11/05/2022] Open
Abstract
Mutations in CACNA1S (calcium channel, voltage‑dependent, L type, alpha 1S subunit) and SCN4A (sodium channel, voltage‑gated, type IV, alpha subunit) are associated with hypokalemic periodic paralysis (HPP). The aim of the current study was to investigate CACNA1S and SCN4A mutations in patients with HPP. Mutations in CACNA1S and SCN4A were detected in three familial hypokalemic periodic paralysis (FHPP) pedigrees and in two thyrotoxic hypokalemic periodic paralysis (THPP) pedigrees using polymerase chain reaction, DNA sequencing and sequence alignment with GenBank data. A single base mutation from cytosine to guanine at site 1582 was identified in exon 11 of CACNA1S in one FHPP pedigree, resulting in an arginine to glycine (R528G) substitution. A single base mutation from thymine to cytosine at site 2012 was identified in exon 12 of SCN4A in one THPP pedigree, resulting in a phenylalanine to serine (F671S) substitution. No mutations in CACNA1S or SCN4A were identified in the remaining three pedigrees. The present study indicated that CACNA1S and SCN4A mutations are relatively rare in patients with HPP, and further studies are required to determine whether these mutation‑associated substitutions are representative of patients with HPP.
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Affiliation(s)
- Xiao-Ying Wang
- Department of Endocrinology, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
| | - Bing-Wen Ren
- Department of Cadres Medical Care, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
| | - Zeng-Hua Yong
- Department of Endocrinology, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
| | - Hong-Yan Xu
- Department of Endocrinology, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
| | - Qiu-Xia Fu
- Department of Endocrinology, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
| | - He-Bin Yao
- Department of Endocrinology, Chinese People's Liberation Army Navy General Hospital, Beijing 100048, P.R. China
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Abstract
Thyroid disorders are common in the general population and in hospitalized patients. Thyroid disease may present first with neurological complications or else may occur concurrently in patients suffering other neurological disorders, particularly those with an autoimmune etiology. For this reason neurologists will commonly encounter patients with thyroid disease. This chapter provides an overview of the neurological complications and associations of disorders of the thyroid gland. Particular emphasis is placed on conditions such as thyrotoxic periodic paralysis and myxedema coma in which the underlying thyroid disorder may be occult leading to a first, often emergency, presentation to a neurologist. Information about clinical features, diagnosis, pathogenesis, therapy, and prognosis is provided. Emphasis is placed on those aspects most likely to be relevant to the practicing neurologist and the interested reader is directed to references to good, recent review articles for further information.
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Affiliation(s)
- Clare A Wood-Allum
- Sheffield Institute for Translational Neuroscience, University of Sheffield and Department of Neurology, Royal Hallamshire Hospital, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience, University of Sheffield and Department of Neurology, Royal Hallamshire Hospital, Sheffield, UK.
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Boissier E, Georgin-Lavialle S, Cochereau D, Ducloux R, Ranque B, Aslangul E, Pouchot J. [Thyrotoxic periodic paralysis: a case series of four patients and literature review]. Rev Med Interne 2013; 34:565-72. [PMID: 23602559 DOI: 10.1016/j.revmed.2013.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 02/27/2013] [Accepted: 03/10/2013] [Indexed: 11/24/2022]
Abstract
PURPOSE Periodic thyrotoxic hypokalemic paralysis (TPP) is a neuromuscular complication of hyperthyroidism. It is more common in young Asian males than in Caucasian and African patients. We report four new cases and review the literature. CASE REPORTS Four consecutive patients were diagnosed with TPP. They were all men with a median age of 34.5 years at presentation. Two patients originated from the Philippines, one was African and one was Caucasian ethnic background. They all presented with a paresis or flaccid paralysis, without respiratory failure. Previous similar episodes in their past medical history, the presence of profound hypokalemia (mean serum potassium level of 2 mmol/L) and the presence of clinical and biological signs of hyperthyroidism led to the diagnosis of TPP. All four patients were diagnosed with Graves' disease. Outcome was favourable in all four patients with the symptomatic treatment of TPP and treatment of Graves' disease. CONCLUSION TPP is a severe condition, due to a dysfunction of the Na(+)-K(+) ATPase pump. Initial management relies on β-blocker treatment and careful potassium supplementation. Then, medical or surgical etiological treatment of the thyrotoxicosis is essential to prevent a recurrence. The disease is probably underdiagnosed: it must be suspected when a profound hypokaliema resolves very quickly (<12hours); hyperthyroidism should always be included in the differential diagnosis of a paresis associated with hypokalemia.
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Affiliation(s)
- E Boissier
- Service de médecine interne, hôpital européen Georges-Pompidou, université Paris Descartes, AP-HP, Sorbonne Paris Cité, 20, rue Leblanc, 75015 Paris, France
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García-Martín A, García-Castro JM, Cortés-Berdonces M, Varsavsky M, Torres Vela E. [Thyrotoxic periodic paralysis: an increasingly common complication of hyperthyroidism]. ENDOCRINOLOGIA Y NUTRICION : ORGANO DE LA SOCIEDAD ESPANOLA DE ENDOCRINOLOGIA Y NUTRICION 2012; 59:394-6. [PMID: 22226497 DOI: 10.1016/j.endonu.2011.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 09/27/2011] [Accepted: 10/04/2011] [Indexed: 10/14/2022]
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A Rare Case of Thyrotoxic Periodic Paralysis Presenting to the Medical Examiner. Am J Forensic Med Pathol 2011; 32:232-5. [DOI: 10.1097/paf.0b013e318219ca5b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pseudoparalysie périodique hypokaliémique thyréotoxique : intérêt du traitement par propranolol. Presse Med 2009; 38:1539-41. [DOI: 10.1016/j.lpm.2008.07.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 06/21/2008] [Accepted: 07/31/2008] [Indexed: 11/20/2022] Open
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Soonthornpun S, Setasuban W, Thamprasit A. Insulin resistance in subjects with a history of thyrotoxic periodic paralysis (TPP). Clin Endocrinol (Oxf) 2009; 70:794-7. [PMID: 18759868 DOI: 10.1111/j.1365-2265.2008.03395.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Hyperinsulinaemia has been suggested as an important factor for developing hypokalaemic paralysis in patients with thyrotoxic periodic paralysis (TPP). Since hyperinsulinaemia is a common feature of insulin resistance, there may be a causal relationship between insulin resistance and TPP. OBJECTIVE To compare insulin sensitivity between subjects with a history of TPP and others with a history of thyrotoxicosis without periodic paralysis. METHODS Insulin sensitivity measured by euglycaemic hyperinsulinaemic clamp and 75-g oral glucose tolerance test (OGTT) were performed nonselectively in 10 subjects with a history of TPP (TPP group) and 10 age- and sex-matched subjects with a history of simple thyrotoxicosis (control group). All participants had euthyroidism and fasting plasma glucose of < 5.55 mmol/l at the time of the study. RESULTS Body mass index and waist circumference of the TPP group were higher than that of the control group. One of 10 (10%) subjects in the TPP group and 6 of 10 (60%) in the control group had BMI of < 23 kg/m2. Areas under the curve (AUC) of plasma glucose after OGTT were comparable, while the AUC of serum insulin of the TPP group was higher than in the control group. The TPP group had lower insulin sensitivity than the control group. CONCLUSION The subjects with a history of TPP were more obese and had lower insulin sensitivity than those with a history of simple thyrotoxicosis. Insulin resistance with compensatory hyperinsulinaemia may be a key feature of the pathogenesis of TPP.
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Affiliation(s)
- Supamai Soonthornpun
- Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
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Jongjaroenprasert W, Chanprasertyotin S, Butadej S, Nakasatien S, Charatcharoenwitthaya N, Himathongkam T, Ongphiphadhanakul B. Association of genetic variants in GABRA3 gene and thyrotoxic hypokalaemic periodic paralysis in Thai population. Clin Endocrinol (Oxf) 2008; 68:646-51. [PMID: 17970773 DOI: 10.1111/j.1365-2265.2007.03083.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Genetic predisposition has been suggested to play role in the pathogenesis of thyrotoxic hypokalaemic periodic paralysis (THPP). OBJECTIVES In this study, we assessed the differences of single-nucleotide polymorphisms (SNP) allelic frequency between THPP patients and well-characterized controls in order to find the susceptibility genetic variants related to THPP using microarray-based assessments on pooled DNA. METHODS Fifty cases of THPP and 50 male hyperthyroid patients without hypokalaemia as controls were recruited. Equal amounts of individual genomic DNA were pooled from each group. Estimated allele frequencies of SNPs were derived by averaging relative allele signal score obtained by Affymetrix GeneChip(R) Mapping 10K Arrays. RESULTS Sixty-nine loci that display robust allele frequency differences between THPP and controls were identified. SNP rs750841 (A > T) in intron 3 of the gamma-aminobutyric acid (GABA) receptor alpha3 subunit (GABRA3) gene possessed the most significant difference in allele frequency (27% in THPP case and 5% in controls, P = 0.007). Actual allele frequencies obtained from genotyping in each individual were very similar to the estimated frequency from the pools (28% in THPP and 2% in controls, and P = 0.0002). Nearby DNA sequences of GABRA3 were sequenced and an additional two SNPs were found (A > C at exon 1 and G > T of rs12688128). Allele A of rs750841 and allele G of rs12688128 in intron 3 were predominantly found in THPP with significant genetic relative risk of 19 (P < 0.0002; 95%CI 2.4-151.6). CONCLUSIONS Whole-genome scanning on pooled DNA provides an accurate, useful screening tool for elucidating genetic underpinnings of THPP. SNPs at intron 3 of GABRA3 are found to be associated with THPP.
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Abstract
Toxic thyroid adenoma presenting as hypokalemic periodic paralysis is extraordinarily rare. We describe a 26-year-old Japanese man who suffered from acute and painful muscle weakness of extremity in the morning. Physical examination showed a left anterior neck mass and laboratory tests revealed hypokalemia during his paralysis, and thyrotoxicosis. Neck sonogram showed a solitary nodule in the left lobe of the thyroid. Thyroid scintigraphy revealed a hot nodule of the tumor region with suppressed uptake in the other thyroid area. The tumor was surgically removed and his paralytic attack ceased. No somatic mutation of TSH receptor was found in his thyroid adenoma and no known genetic mutations of ionic channel genes, such as calcium (CACN1S), sodium (SCN4A) and potassium (KCNE3), were found. Although thyrotoxic periodic paralysis is usually accompanied with Graves' disease, thyrotoxicosis of other conditions including Plummer's disease should be considered.
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Affiliation(s)
- Tetsuya Tagami
- Clinical Research Institute, Division of Endocrinology and Metabolism, Kyoto Medical Center, National Hospital Organization, Japan
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15
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Abstract
Thyroid hormones exert multiple effects on the neuromuscular system and the brain, with the most important being their role in stimulating the development and differentiation of the neuromuscular system and brain in foetal and neonatal life. In the presence of hyperthyroidism, muscular and neurological symptoms may be the presenting clinical features of the disease. The frequency and severity of neuromuscular complications vary considerably and are probably related to the degree of hyperthyroidism, although in some patients the neuromuscular dysfunction is caused by associated disorders rather than by hyperthyroidism per se. This update focuses on the most common neurological and muscular disorders that occur in patients with thyrotoxicosis. It is beyond the scope of this paper to discuss thyroid eye disease and cardiac complications, in themselves separate complications of specific myocytes.
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Affiliation(s)
- Annie W C Kung
- Department of Medicine, The University of Hong Kong, Hong Kong, China.
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Pompeo A, Nepa A, Maddestra M, Feliziani V, Genovesi N. Thyrotoxic hypokalemic periodic paralysis: An overlooked pathology in western countries. Eur J Intern Med 2007; 18:380-90. [PMID: 17693226 DOI: 10.1016/j.ejim.2007.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 03/12/2007] [Accepted: 03/16/2007] [Indexed: 11/26/2022]
Abstract
Thyrotoxic hypokalemic periodic paralysis (THPP) is a complication of hyperthyroidism that is mostly diagnosed in Asian populations; consequently, it can be difficult to recognize in western populations. THPP represents an endocrine emergency that can result in respiratory insufficiency, cardiac arrhythmias, and death. Its differential diagnosis from the other more common forms of hypokalemic paralysis is important to avoid inappropriate therapy. Here, we discuss the main pathogenetic hypotheses, clinical features, and therapies of this disease. We also report an example of THPP management in our primary care unit.
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Affiliation(s)
- Arsenio Pompeo
- Division of Internal Medicine, "Floraspe Renzetti" Hospital, A.S.L. 103 Lanciano-Vasto, via del Mare, 1. 66034 Lanciano (Ch), Italy
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Arimura K, Arimura Y, Ng AR, Sakoda SI, Higuchi I. Muscle membrane excitability after exercise in thyrotoxic periodic paralysis and thyrotoxicosis without periodic paralysis. Muscle Nerve 2007; 36:784-8. [PMID: 17722048 DOI: 10.1002/mus.20865] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We evaluated whether the paralytic attacks in thyrotoxic periodic paralysis (TPP) are primarily due to the abnormal excitability of the muscle membrane caused by a preexisting latent abnormality or to the effects of thyroid hormone. The prolonged exercise (PE) test was used to evaluate muscle membrane excitability in 21 patients with TPP and 11 patients with thyrotoxicosis without paralytic attacks (Tw/oPP) in the hyperthyroid state. The PE tests were compared between the hyperthyroid and euthyroid states in five of the TPP and three of the Tw/oPP patients. Compared to 20 healthy subjects, a significant increase in compound muscle action potential (CMAP) amplitudes immediately after exercise and a significant time-dependent gradual decline in CMAP amplitudes starting from 20 min after exercise were observed in the TPP patients. A significant decline in CMAP amplitudes was also observed in the Tw/oPP patients but only at 50 min after exercise. All of the TPP and Tw/oPP patients had a tendency to improve in the euthyroid state; the PE tests remained abnormal only in the TPP patients. Paralytic attacks in TPP patients are due primarily to a preexisting latent abnormal excitability of the muscle membrane, possibly genetic in origin.
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Affiliation(s)
- Kimiyoshi Arimura
- Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
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Donovan L, Parkins VM, Mahalingham A. Thyrotoxic periodic paralysis in pregnancy with impaired glucose tolerance: a case report and discussion of management issues. Thyroid 2007; 17:579-83. [PMID: 17614780 DOI: 10.1089/thy.2006.0288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Thyrotoxic periodic paralysis (TPP) is an unusual presentation of hyperthyroidism in women. The occurrence of this condition in the context of pregnancy is even more uncommon. Impaired glucose tolerance, pregnancy, and TPP impact overall management of thyrotoxicosis. There is little guidance in the literature for management under this constellation of circumstances. PATIENT AND INTERVENTION This is a case report of a previously healthy 36-year-old Filipino female presenting at 15 weeks gestation with tetraparesis, hypokalemia, and new onset Graves' disease with impaired glucose tolerance. Normal thyroid function was achieved in the mother without further episodes of TPP and a healthy, euthyroid male was delivered at 38 weeks gestation. Acute and long-term management strategies used in this case are described in detail. CONCLUSIONS A synthesis of the available literature allowed development of a practical management strategy applicable to a variety of situations involving TPP in pregnancy.
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Affiliation(s)
- Lois Donovan
- Division of Endocrinology, Department of Internal Medicine, University of Calgary and the Calgary Health Region, Calgary, Alberta, Canada.
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Elston MS, Orr-Walker BJ, Dissanayake AM, Conaglen JV. Thyrotoxic, hypokalaemic periodic paralysis: Polynesians, an ethnic group at risk. Intern Med J 2007; 37:303-7. [PMID: 17504277 DOI: 10.1111/j.1445-5994.2007.01313.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Thyrotoxic, hypokalaemic periodic paralysis (TPP) is a reversible cause of severe muscle weakness that occurs in a small minority of thyrotoxic patients. Most cases to date have been reported in Asian men. AIMS To evaluate the ethnic distribution of patients with TPP. METHODS Retrospective analysis of all patients presenting with thyrotoxicosis and hypokalaemia with paralysis to two New Zealand hospitals. RESULTS Seventy-one per cent of the 21 patients with TPP were of Polynesian ethnicity (Maori and Pacific Islander), 24% Asian and 5% European. Based on population demographics, these figures suggest a 37-fold overrepresentation for Polynesians and 159-fold for Asians compared with New Zealand Europeans. CONCLUSION Polynesian, in addition to Asian people, are two ethnic groups at particular risk of TPP, and this condition must be considered in the differential diagnosis for patients presenting to the emergency department with severe hypokalaemia and weakness.
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Affiliation(s)
- M S Elston
- Department of Endocrinology, Middlemore Hospital, Auckland, New Zealand
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Tang NLS, Chow CC, Ko GTC, Tai MHL, Kwok R, Yao XQ, Cockram CS. The alpha(1S) subunit of the L-type calcium channel is not a predisposition gene for thyrotoxic periodic paralysis. Clin Endocrinol (Oxf) 2007; 66:229-34. [PMID: 17223993 DOI: 10.1111/j.1365-2265.2006.02713.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Thyrotoxic periodic paralysis (TTP) has been associated with genetic variations in the gene encoding the alpha 1 subunit of the L-type calcium channel (CACNA1S). Mutations in CACNA1S are known to account for the majority of cases of familial hypokalaemic periodic paralysis (HOKPP). In this study we have examined 48 genetic polymorphisms in the CACNA1S gene and genotyped a tagging set of representative polymorphisms to determine the role of this gene in TPP. DESIGN AND PATIENTS A genetic association study was carried out with 98 TPP patients and 162 male thyrotoxic controls. Among 47 polymorphisms evaluated for linkage disequilibrium (LD) and the spectrum of haplotypes in the Chinese population, 31 were selected as tagging single-nucleotide polymorphisms (SNPs) for genotyping the whole sample. A new genotyping protocol was used to analyse an insertion/deletion (I/D) polymorphism. RESULTS We studied the LD among 47 polymorphisms in the CACNA1S gene, which comprised a set of high-density markers with an average of one SNP every 2 kb. Subsequently, 31 tagSNPs were genotyped for all the samples. The gene is composed of three LD blocks. With this block structure, we were confident that variations of the gene were comprehensively covered by the tagSNPs. No significant association was found between the polymorphisms and TPP. CONCLUSION We established the LD structure of this calcium channel subunit gene (CACNA1S) for the first time. However, its genetic variations are not associated with TPP in Chinese patients.
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Affiliation(s)
- Nelson L S Tang
- Department of Chemical Pathology, Faculty of Medicine, The Chinese Univerisity of Hong Kong SAR, China.
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