The "Hot Topic Keynotes: Channelopathies" session of the 26th International Neurotoxicology Conference brought together toxicologists studying interactions of environmental toxicants with ion channels, to review the state of the science of channelopathies and to discuss the potential for interactions between environmental exposures and channelopathies. This session presented an overview of chem...

1. Epi4K Consortium; Epilepsy Phenome/Genome Project; Allen AS et al. De novo mutations in epileptic encephalopathies. Nature 2013: 501 (7466): 217–221. 2. OrhanG, BockM, Schepers D et al. Dominant-negative effects of KCNQ2 mutations are associated with epileptic encephalopathy. AnnNeurol 2014: 75 (3): 382–394. 3. Pena SD, Coimbra RL. Ataxia and myoclonic epilepsy due to a heterozygous new muta...

A forward genetic screen of mice treated with the mutagen ENU identified a mutant mouse with chronic motor incoordination. This mutant, named Pingu (Pgu), carries a missense mutation, an I402T substitution in the S6 segment of the voltage-gated potassium channel Kcna2. The gene Kcna2 encodes the voltage-gated potassium channel α-subunit Kv1.2, which is abundantly expressed in the large axon ter...

SOD1 is a cause of the fatal, paralytic disorder ALS. Although mechanisms underlying mutant SOD1 neurotoxicity remain uncertain, this protein associates with mitochondria. In this issue of Neuron, Israelson et al. show that mutant SOD1 binds and inhibits the mitochondrial channel VDAC1. This finding sheds light onto possible molecular links between mutant SOD1, mitochondrial dysfunction, and sp...

Neuromyotonia is a heterogeneous group of genetic and autoimmune channelopathies resulting in hyperexcitability of peripheral nerves. We report an unusual case of neuromyotonia, which to our knowledge has not been previously described. The patient developed intermittent attacks of severe painful muscle stiffness accompanied by sweating, myokymia and raised serum creatine kinase. Genetic analysi...

In myotonic dystrophy (dystrophia myotonica [DM]), an increase in the excitability of skeletal muscle leads to repetitive action potentials, stiffness, and delayed relaxation. This constellation of features, collectively known as myotonia, is associated with abnormal alternative splicing of the muscle-specific chloride channel (ClC-1) and reduced conductance of chloride ions in the sarcolemma. ...

Hypokalemic periodic paralysis is a rare but serious disorder that is typically caused by a channelopathy. Thyrotoxicosis, heavy exercise, high carbohydrate meal and some drugs can trigger channelopathy in genetically predisposed individuals. A 33-year-old male patient presented to the emergency department with weakness in the lower extremities. He stated that he had done heavy physical activit...