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Periodic hyperkalemic paralysis

Chunxiang Fan, Ninghui Mao, Frank Lehmann-Horn, Jan Bürmann, Karin Jurkat-Rott
Hyperkalemic periodic paralysis (HyperPP) is a dominantly inherited muscle disease caused by mutations in SCN4A gene encoding skeletal muscle voltage gated Nav 1.4 channels. We identified a novel Nav 1.4 mutation I692M in 14 families out of the 104 genetically identified HyperPP families in the Neuromuscular Centre Ulm and is therefore as frequent as I693T (13 families out of 14 HyperPP families) in Germany. Surprisingly, in 13 families, a known polymorphism S906T was also present. It was on the affected allele in at least 10 families compatible with a possible founder effect in central Europe...
October 6, 2016: Clinical Genetics
Valeria A Sansone, James Burge, Michael P McDermott, Patty C Smith, Barbara Herr, Rabi Tawil, Shree Pandya, John Kissel, Emma Ciafaloni, Perry Shieh, Jeffrey W Ralph, Antony Amato, Steve C Cannon, Jaya Trivedi, Richard Barohn, Brian Crum, Hiroshi Mitsumoto, Alan Pestronk, Giovanni Meola, Robin Conwit, Michael G Hanna, Robert C Griggs
OBJECTIVE: To determine the short-term and long-term effects of dichlorphenamide (DCP) on attack frequency and quality of life in hyperkalemic (HYP) and hypokalemic (HOP) periodic paralysis. METHODS: Two multicenter randomized, double-blind, placebo-controlled trials lasted 9 weeks (Class I evidence), followed by a 1-year extension phase in which all participants received DCP. Forty-four HOP and 21 HYP participants participated. The primary outcome variable was the average number of attacks per week over the final 8 weeks of the double-blind phase...
April 12, 2016: Neurology
Shiemaa Khogali, Brooke Lucas, Tarek Ammar, Danica Dejong, Michael Barbalinardo, Lawrence J Hayward, Jean-Marc Renaud
The mechanisms responsible for the onset and progressive worsening of episodic muscle stiffness and weakness in hyperkalemic periodic paralysis (HyperKPP) are not fully understood. Using a knock-in HyperKPP mouse model harboring the M1592V NaV1.4 channel mutant, we interrogated changes in physiological defects during the first year, including tetrodotoxin-sensitive Na(+) influx, hindlimb electromyographic (EMG) activity and immobility, muscle weakness induced by elevated [K(+)]e, myofiber-type composition, and myofiber damage...
December 2015: Physiological Reports
Tarek Ammar, Wei Lin, Amanda Higgins, Lawrence J Hayward, Jean-Marc Renaud
The diaphragm muscle of hyperkalemic periodic paralysis (HyperKPP) patients and of the M1592V HyperKPP mouse model rarely suffers from the myotonic and paralytic symptoms that occur in limb muscles. Enigmatically, HyperKPP diaphragm expresses the mutant NaV1.4 channel and, more importantly, has an abnormally high Na(+) influx similar to that in extensor digitorum longus (EDL) and soleus, two hindlimb muscles suffering from the robust HyperKPP abnormalities. The objective was to uncover the physiological mechanisms that render HyperKPP diaphragm asymptomatic...
December 2015: Journal of General Physiology
Ami Mankodi, Christopher Grunseich, Martin Skov, Lisa Cook, Georg Aue, Enkhtsetseg Purev, Dara Bakar, Tanya Lehky, Karin Jurkat-Rott, Thomas H Pedersen, Richard W Childs
We report a patient with paramyotonia congenita/hyperkalemic periodic paralysis due to Nav1.4 I693T mutation who had worsening of myotonia and muscle weakness in the setting of hypomagnesemia and hypocalcemia with marked recovery after magnesium administration. Computer simulations of the effects of the I693T mutation were introduced in the muscle fiber model by both hyperpolarizing shifts in the Nav1.4 channel activation and a faster recovery from slow channel inactivation. A further shift in the Nav1.4 channel activation in the hyperpolarizing direction as expected with low divalent cations resulted in myotonia that progressed to membrane inexcitability...
November 2015: Neuromuscular Disorders: NMD
Young Han Lee, Hyung Soo Lee, Hyo Eun Lee, Seok Hahn, Tai Seung Nam, Ha Young Shin, Young Chul Choi, Seung Min Kim
BACKGROUND AND PURPOSE: Hyperkalemic periodic paralysis (hyperKPP) is a muscle sodium-ion channelopathy characterized by recurrent paralytic attacks. A proportion of affected individuals develop fixed or chronic progressive weakness that results in significant disability. However, little is known about the pathology of hyperKPP-induced fixed weakness, including the pattern of muscle involvement. The aim of this study was to characterize the patterns of muscle involvement in hyperKPP by whole-body magnetic resonance imaging (MRI)...
October 2015: Journal of Clinical Neurology
Xiao-li Liu, Xiao-jun Huang, Xing-hua Luan, Hai-yan Zhou, Tian Wang, Jing-yi Wang, Sheng-di Chen, Hui-dong Tang, Li Cao
SCN4A encodes the Nav1.4 channel and mutations in SCN4A lead to different ionic channelopathies. In this study, one sporadic individual of periodic paralysis, one paramyotonia family and 200 normal healthy controls are enrolled. Genomic DNA was extracted from peripheral blood leukocytes, followed by polymerase chain reaction and DNA sequencing of candidate genes, including SCN4A and CACNA1S. As a result, heterozygous mutations c.2024G>A (R675Q) and c.1333G>A (V445M) of gene SCN4A were identified in the hypokalemic periodic paralysis patient and the paramyotonia congenita family respectively...
2015: Channels
Y H Choi, M C T Penedo, P Daftari, I C Velez, K Hinrichs
Preimplantation genetic diagnosis has great potential in the horse, but information on evaluation of equine embryo biopsy samples is limited. Blastocysts were biopsied using a Piezo drill and methods for whole-genome amplification (WGA) investigated. Results for 33 genetic loci were then compared between biopsy samples from in vitro-produced (IVP) and in vivo-recovered (VIV) blastocysts. Under the experimental conditions described, WGA using the Qiagen Repli-g Midi kit was more accurate than that using the Illustra Genomiphi V2 kit (98...
March 17, 2015: Reproduction, Fertility, and Development
W David Arnold, Daniel H Feldman, Sandra Ramirez, Liuyuan He, Darine Kassar, Adam Quick, Tara L Klassen, Marian Lara, Joanna Nguyen, John T Kissel, Christoph Lossin, Ricardo A Maselli
OBJECTIVE: To describe the unique phenotype and genetic findings in a 57-year-old female with a rare form of congenital myasthenic syndrome (CMS) associated with longstanding muscle fatigability, and to investigate the underlying pathophysiology. METHODS: We used whole-cell voltage clamping to compare the biophysical parameters of wild-type and Arg1457His-mutant Nav 1.4. RESULTS: Clinical and neurophysiological evaluation revealed features consistent with CMS...
May 2015: Annals of Neurology
Rahul R Singh, S Veronica Tan, Michael G Hanna, Stephanie A Robb, Antonia Clarke, Heinz Jungbluth
Laryngospasm is a rare but potentially life-threatening occurrence in infants and usually has infective, allergic, metabolic, or anatomic causes. Underlying genetic conditions are rarely considered. Mutations in SCN4A encoding the voltage-gated sodium channel NaV1.4 have been implicated in a wide spectrum of neuromuscular disorders with variable onset, ranging from a rare form of congenital myasthenic syndrome to both hypokalemic and hyperkalemic forms of periodic paralysis and paramyotonia congenita. Here we report on 3 unrelated patients without family history presenting with recurrent, life-threatening episodes of laryngospasm from the first months of life...
November 2014: Pediatrics
Kensuke Shiga, Ikuko Mizuta, Yu-ichi Noto, Masanori Nakagawa, Ryogen Sasaki, Masanaga Yamawaki
A 73-year-old man with recurrent periodic paralytic episodes lasting for two weeks each admitted to our hospital because of the leg weakness and the elevated value of serum creatine kinase. On admission, weakness in the proximal legs and mild eye lid myotonia were noted. Needle electromyography revealed abundant myotonic discharges. The prolonged exercise test showed a continuous reduction of compound muscle action potentials in the abductor digiti minimi muscle. Direct sequencing of SCN4A in the proband showed a G-to-A alteration at position 4774 that results in a change of 1592(nd) methionine to valine (M1592V)...
2014: Rinshō Shinkeigaku, Clinical Neurology
Brooke Lucas, Tarek Ammar, Shiemaa Khogali, Danica DeJong, Michael Barbalinardo, Cameron Nishi, Lawrence J Hayward, Jean-Marc Renaud
Hyperkalemic periodic paralysis (HyperKPP) is characterized by myotonic discharges that occur between episodic attacks of paralysis. Individuals with HyperKPP rarely suffer respiratory distress even though diaphragm muscle expresses the same defective Na(+) channel isoform (NaV1.4) that causes symptoms in limb muscles. We tested the hypothesis that the extent of the HyperKPP phenotype (low force generation and shift toward oxidative type I and IIA fibers) in muscle is a function of 1) the NaV1.4 channel content and 2) the Na(+) influx through the defective channels [i...
June 1, 2014: Physiological Genomics
June-Bum Kim
Channelopathies are a heterogeneous group of disorders resulting from the dysfunction of ion channels located in the membranes of all cells and many cellular organelles. These include diseases of the nervous system (e.g., generalized epilepsy with febrile seizures plus, familial hemiplegic migraine, episodic ataxia, and hyperkalemic and hypokalemic periodic paralysis), the cardiovascular system (e.g., long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia), the respiratory system (e...
January 2014: Korean Journal of Pediatrics
J D Areta-Higuera, M Algaba-Montes, A Á Oviedo-García
Periodic paralysis is a rare disorder that causes episodes of severe muscle weakness that can be confused with other diseases, including epilepsy or myasthenia gravis. Hyperkalemic and hypokalemic paralysis are included within these diseases, the latter being divided into periodic paralysis (familial, thyrotoxic or sporadic) and non-periodic paralysis. In this regard, we present a case of familial hypokalemic periodic paralysis in an eighteen year-old female who was diagnosed with epilepsy in childhood, as well as a subclinical hypothyroidism (for which she received replacement therapy) months ago...
May 2014: Semergen
Mohammad Reza Salehiomran, Somayeh Naserkhaki, Mahmoud Hajiahmadi
BACKGROUND: Diseases that cause acute flaccid paralysis (AFP) often progress rapidly, thus may cause life threatening complications, therefore, their diagnosis and cure are important. This study was carried out to investigate the causes of acute generalized weakness in children referred to Amirkola Children's Hospital, in Babol, Iran. METHODS: In this case series, the epidemiological causes of the disease and clinical features of 15 cases with acute generalized weakness from April 2005 to September 2010 were evaluated...
2012: Caspian Journal of Internal Medicine
Rashid Saleem, Gururaj Setty, Arif Khan, Duncan Farrell, Nahin Hussain
Skeletal muscle sodium channelopathies (SMSCs) including hyperkalemic periodic paralysis (HyperPP), paramyotonia congenita (PC), and sodium channel myotonia are caused by sodium channel gene (SCN4A) mutations, with altered sarcolemal excitability, and can present as episodes of skeletal muscle weakness, paralysis, and myotonia. We report a teenage boy, who presented with features of HyperPP, PC, myotonia congenita, and sodium channel myotonia. His electromyography (EMG) revealed myopathic changes, myotonia, and Fournier EMG pattern I, and posed a diagnostic challenge...
May 2013: Journal of Pediatric Neurosciences
G Charles, C Zheng, F Lehmann-Horn, K Jurkat-Rott, J Levitt
This exploratory study aims to create an evidence-based comprehensive characterization of hyperkalemic periodic paralysis (hyperPP). HyperPP is a rare genetic disorder that causes episodes of flaccid paralysis. Disease descriptions in the literature are based upon isolated clinical encounters and case reports. We describe the experience of a large cohort of genetically diagnosed individuals with hyperPP. We surveyed genetically characterized individuals age 18 and over to assess disease comorbidities, diagnostic testing, management, and quality of life issues relevant to hyperPP...
October 2013: Journal of Neurology
Weon-Jin Ko, Kwang-Yeol Kim, So-Mi Kim, Seung-Jae Hong, Sang-Hoon Lee, Ran Song, Hyung-In Yang, Yeon-Ah Lee
Type 1 myotonic dystrophy (DM1) is an autosomal-dominant inherited disorder with a multisystem involvement, caused by an abnormal expansion of the CTG sequence of the dystrophic myotonia protein kinase (DMPK) gene. DM1 is a variable multisystem disorder with muscular and nonmuscular abnormalities. Increasingly, endocrine abnormalities, such as gonadal, pancreatic, and adrenal dysfunction are being reported. But, Electrolytes imbalance is a very rare condition in patients with DM1 yet. Herein we present a 42-yr-old Korean male of DM1 with abnormally elevated serum sodium and potassium...
July 2013: Journal of Korean Medical Science
Cui-jie Wei, Dong Wang, Shuo Wang, Hui Jiao, Dao-jun Hong, Li-hua Pu, Hui Xiong
OBJECTIVE: Periodic paralysis (PP) is one type of skeletal muscle channelopathies characterized by episodic attacks of weakness. It is usually classified into hyperkalemic periodic paralysis (HyperPP), hypokalemic periodic paralysis (HypoPP) and normokalemic periodic paralysis (NormoPP) based on the blood potassium levels. HypoPP is the most common type of these three and NormoPP is the rarest one. The aim of this study was to explore the clinical and genetic features of a Chinese family with normokalemic periodic paralysis (NormoKPP)...
January 2013: Zhonghua Er Ke za Zhi. Chinese Journal of Pediatrics
Alejandro Horga, Dipa L Raja Rayan, Emma Matthews, Richa Sud, Doreen Fialho, Siobhan C M Durran, James A Burge, Simona Portaro, Mary B Davis, Andrea Haworth, Michael G Hanna
OBJECTIVES: To obtain minimum point prevalence rates for the skeletal muscle channelopathies and to evaluate the frequency distribution of mutations associated with these disorders. METHODS: Analysis of demographic, clinical, electrophysiologic, and genetic data of all patients assessed at our national specialist channelopathy service. Only patients living in the United Kingdom with a genetically defined diagnosis of nondystrophic myotonia or periodic paralysis were eligible for the study...
April 16, 2013: Neurology
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