OBJECTIVE: To explore the genetic basis for a child featuring congenital insensitivity to pain (CIP). METHODS: Targeted capture and next generation sequencing (NGS) was carried out for the proband. Suspected pathogenic variants were confirmed by Sanger sequencing of the proband and his parents. RESULTS: The proband was found to harbor compound heterozygous variants of SCN9A gene, namely c.1598delA (p.N533Ifs*31) and c.295_296delCGinsAT (p.R99I), which were respectively inherited from his father and mother. Both variants were predicted to be pathogenic, and neither was reported previously. CONCLUSION The compound heterozygous variants of the SCN9A gene probably underlay the CIP in this child. Above finding has enabled genetic counseling for this family.
Channelopathies ; Child ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; NAV1.7 Voltage-Gated Sodium Channel/genetics* ; Pain Insensitivity, Congenital/genetics*

Hereditary cardiac disease accounts for a large proportion of sudden cardiac death (SCD) in young adults. Hereditary cardiac disease can be divided into hereditary structural heart disease and channelopathies. Hereditary structural heart disease mainly includes hereditary cardiomyopathy, which results in arhythmia, heart failure and SCD. The autopsy and histopathological examinations of SCD caused by channelopathies lack characteristic morphological manifestations. Therefore, how to determine the cause of death in the process of examination has become one of the urgent problems to be solved in forensic identification. Based on the review of recent domestic and foreign research results on channelopathies and hereditary cardiomyopathy, this paper systematically reviews the pathogenesis and molecular genetics of channelopathies and hereditary cardiomyopathy, and discusses the application of postmortem genetic testing in forensic identification, to provide reference for forensic pathology research and identification of SCD.
Autopsy/methods* ; Channelopathies/genetics* ; Death, Sudden, Cardiac/pathology* ; Genetic Testing ; Heart Diseases/genetics* ; Humans ; Young Adult

To analyze the clinical manifestations and gene mutations in children with congenital insensitivity to pain with anhidrosis (CIPA), and review related literature. An infant diagnosed with congenital insensitivity to pain with anhidrosis was reported. The main clinical manifestations of the infant were painless, no sweat, and repeated fever. Peripheral blood of the infant and his parents was collected, and candidate variants were confirmed by Sanger sequencing. The results of molecular genetic analysis showed that there were compound heterozygous mutations (c.36G>A, c.851-33T>A) of neurotrophic tyrosine kinase receptor type 1 (NTRK1) in the infant. c.36G>A and c.851-33T>A were inherited from his father and mother, respectively. c.851-33T>A is a previously reported mutation, c.36G>A is an unreported mutation, which can lead to the tryptophan changing into a stop codon. According to the American College of Medical Genetics and Genomics (ACMG) variant interpretation guidelines, the mutation is interpreted as pathogenic, and the biological hazard is potentially harmful. Congenital insensitivity to pain with anhidrosis is a rare inherited disorder. Genetic molecular genetic analysis is helpful to diagnose and discover new gene mutations.
Channelopathies ; Humans ; Infant ; Mutation ; Pain Insensitivity, Congenital ; Receptor, trkA

OBJECTIVE: To explore the clinical features of a Chinese pedigree affected with skeletal muscle sodium channelopathies due to variation of SCN4A gene. METHODS: Potential variation of the 24 exons of the SCN4A gene was screened using PCR and Sanger sequencing. RESULTS: Four family members were affected with the disease in an autosomal dominant inheritance pattern. Three patients had normekalemic periodic paralysis, while 1 showed paramyotonia congenita. Genetic analysis detected a missense variation c.2078T>C (p.Ile693Thr) in exon 13 of the SCN4A gene in the proband and other 3 affected relatives. CONCLUSION Normokalemic periodic paralysis and paramyotonia congenita can occur in different family members with skeletal muscle sodium channelopathies due to c.2078T>C(p.Ile693Thr) variation of SCN4A gene.
Channelopathies ; genetics ; Humans ; Muscle, Skeletal ; physiopathology ; Mutation ; NAV1.4 Voltage-Gated Sodium Channel ; genetics ; Pedigree

The recommendations outlined constitute the first clinical practice guidelines of the Korean Heart Rhythm Society regarding catheter ablation of ventricular arrhythmias (VA). This is a guideline PART 2, which includes VA in the structurally normal heart, inherited primary arrhythmia syndromes, VA related to congenital heart disease, as well as VA and sudden cardiac death observed in specific populations. In the structurally normal heart, treatment is guided by the occurrence of symptoms or the frequency of arrhythmias that cause ventricular dysfunction over time. Catheter ablation can be recommended in patients in whom anti-arrhythmic medications are ineffective. The sites of origin of arrhythmic activity are known to be the outflow tract, fascicles, papillary muscle, or the annulus. Specific cardiac channelopathies include congenital long QT and Brugada syndrome. This guideline discusses the diagnostic criteria, risk stratification, and treatment of these syndromes. We have included recommendations for adult congenital heart disease. Moreover, we have discussed the management of VA occurring in specific populations such as in patients with psychiatric and neurological disorders, pregnant patients, those with obstructive sleep apnea or drug-related pro-arrhythmias, athletes, and elderly patients.
Adult ; Aged ; Arrhythmias, Cardiac ; Athletes ; Brugada Syndrome ; Catheter Ablation ; Catheters ; Channelopathies ; Death, Sudden, Cardiac ; Heart ; Heart Defects, Congenital ; Humans ; Nervous System Diseases ; Papillary Muscles ; Sleep Apnea, Obstructive ; Ventricular Dysfunction

Voltage-gated sodium (Na) channels are essential for the rapid upstroke of action potentials and the propagation of electrical signals in nerves and muscles. Defects of Na channels are associated with a variety of channelopathies. More than 1000 disease-related mutations have been identified in Na channels, with Na1.1 and Na1.5 each harboring more than 400 mutations. Na channels represent major targets for a wide array of neurotoxins and drugs. Atomic structures of Na channels are required to understand their function and disease mechanisms. The recently determined atomic structure of the rabbit voltage-gated calcium (Ca) channel Ca1.1 provides a template for homology-based structural modeling of the evolutionarily related Na channels. In this Resource article, we summarized all the reported disease-related mutations in human Na channels, generated a homologous model of human Na1.7, and structurally mapped disease-associated mutations. Before the determination of structures of human Na channels, the analysis presented here serves as the base framework for mechanistic investigation of Na channelopathies and for potential structure-based drug discovery.
Animals ; Calcium Channels, L-Type ; chemistry ; genetics ; metabolism ; Channelopathies ; genetics ; metabolism ; Humans ; Mutation ; NAV1.1 Voltage-Gated Sodium Channel ; chemistry ; genetics ; metabolism ; NAV1.5 Voltage-Gated Sodium Channel ; chemistry ; genetics ; metabolism ; NAV1.7 Voltage-Gated Sodium Channel ; chemistry ; genetics ; metabolism ; Protein Domains ; Rabbits ; Structure-Activity Relationship

Inner ear is composed of cochlea, vestibule, and endolymphatic sac which are enclosed by thin layer of epithelial cells. The enclosed space is filled with fluid named as endolymph where the [K⁺] is high and [Na⁺] is low. This unique ion composition is very important in maintaining normal hearing and balance function by providing K⁺ ions into sensory hair cells, which finally depolarize hair cells to facilitate the transport of sound and acceleration stimulation to central nervous system. The ion composition of inner ear is maintained by various ion transport through ion channels, transporters, and exchangers in the inner ear sensory and extra-sensory epithelium. The disruption of normal endolymphatic ion composition by the deterioration of the function of those ion channels can cause dysfunction of sensory epithelium, which consequently results in hearing and balance disorders. One of the possible pathology from the disruption of inner ear ion homeostasis is endolymphatic hydrops which is a phenomenon of excessive fluid accumulation of inner ear. The dysfunction of ion channels in inner ear epithelium can be an etiology of Ménière's disease since endolymphatic hydrops is a main pathological finding of the disease. In this review, we discussed about the possible pathological mechanism of Ménière's disease as a perspective of channelopathy as well as the role of various ion channels in the regulation of inner ear fluid volume based on the findings revealed by electrophysiological studies.
Acceleration ; Central Nervous System ; Channelopathies ; Cochlea ; Ear, Inner ; Electrophysiology ; Endolymph ; Endolymphatic Hydrops ; Endolymphatic Sac ; Epithelial Cells ; Epithelium ; Hair ; Hearing ; Homeostasis ; Ion Channels ; Ion Transport ; Ions ; Meniere Disease ; Pathology

Due to the negative autopsy and without cardiac structural abnormalities, unexpected sudden cardiac death （USCD） is always a tough issue for forensic pathological expertise. USCD may be associated with parts of fatal arrhythmic diseases. These arrhythmic diseases may be caused by disorders of cardiac ion channels or channel-related proteins. Caveolin can combine with multiple myocardial ion channel proteins through its scaffolding regions and plays an important role in maintaining the depolarization and repolarization of cardiac action potential. When the structure and function of caveolin are affected by gene mutations or abnormal protein expression, the functions of the regulated ion channels are correspondingly impaired, which leads to the occurrence of multiple channelopathies, arrhythmia or even sudden cardiac death. It is important to study the effects of caveolin on the functions of ion channels for exploring the mechanisms of malignant arrhythmia and sudden cardiac death.
Arrhythmias, Cardiac/physiopathology* ; Autopsy ; Caveolins/metabolism* ; Channelopathies/genetics* ; Death, Sudden, Cardiac/pathology* ; Forensic Pathology ; Humans ; Ion Channels/metabolism* ; Mutation ; Myocardium

Long QT syndrome (LQTS) is a rare cardiac channelopathy associated with syncope and sudden death due to torsades de pointes and ventricular fibrillation. Syncope and sudden death are frequently associated with physical and emotional stress. Management of patients with LQTS consists of life-style modification, β-blockers, left cardiac sympathetic denervation (LCSD), and implantable cardioverter-defibrillator (ICD) implantation. Prohibition of competitive exercise and avoidance of QT-prolonging drugs are important issues in life-style modification. Although β-blockers are the primary treatment modality for patients with LQTS, these drugs are not completely effective in some patients. Lifelong ICD implantation in young and active patients is associated with significant complications. LCSD is a relatively simple and highly effective surgical procedure. However, LCSD is rarely used.
Channelopathies ; Death, Sudden ; Defibrillators, Implantable ; Humans ; Long QT Syndrome* ; Stress, Psychological ; Sympathectomy ; Syncope ; Torsades de Pointes ; Ventricular Fibrillation

Potassium channels and transporters maintain potassium homeostasis and play significant roles in several different biological actions via potassium ion regulation. In previous decades, the key revelations that potassium channels and transporters are involved in the production of gastric acid and the regulation of secretion in the stomach have been recognized. Drugs used to treat peptic ulceration are often potassium transporter inhibitors. It has also been reported that potassium channels are involved in ulcerative colitis. Direct toxicity to the intestines from nonsteroidal anti-inflammatory drugs has been associated with altered potassium channel activities. Several reports have indicated that the long-term use of the antianginal drug Nicorandil, an adenosine triphosphate-sensitive potassium channel opener, increases the chances of ulceration and perforation from the oral to anal regions throughout the gastrointestinal (GI) tract. Several of these drug features provide further insights into the role of potassium channels in the occurrence of ulceration in the GI tract. The purpose of this review is to investigate whether potassium channelopathies are involved in the mechanisms responsible for ulceration that occurs throughout the GI tract.
Adenosine ; Channelopathies* ; Colitis, Ulcerative ; Gastric Acid ; Gastrointestinal Tract ; Homeostasis ; Intestines ; Nicorandil ; Peptic Ulcer ; Potassium Channels ; Potassium* ; Stomach ; Ulcer*