Ion Channel - Diseases of Ion Channels

Diseases of Ion Channels

There are a number of chemicals and genetic disorders which disrupt normal functioning of ion channels and have disastrous consequences for the organism. Genetic disorders of ion channels and their modifiers are known as Channelopathies. See Category:Channelopathy for a full list.

Chemicals

• Tetrodotoxin (TTX), used by puffer fish and some types of newts for defense. It blocks sodium channels.
• Saxitoxin, is produced by a dinoflagellate also known as "red tide". It blocks voltage dependent sodium channels.
• Conotoxin, is used by cone snails to hunt prey.
• Lidocaine and Novocaine belong to a class of local anesthetics which block sodium ion channels.
• Dendrotoxin is produced by mamba snakes, and blocks potassium channels.
• Iberiotoxin is produced by the Buthus tamulus (Eastern Indian scorpion) and blocks potassium channels.
• Heteropodatoxin is produced by Heteropoda venatoria (brown huntsman spider or laya) and blocks potassium channels.

Genetic

• Shaker gene mutations cause a defect in the voltage gated ion channels, slowing down the repolarization of the cell.
• Equine hyperkalaemic periodic paralysis as well as Human hyperkalaemic periodic paralysis (HyperPP) are caused by a defect in voltage dependent sodium channels.
• Paramyotonia congenita (PC) and potassium aggravated myotonias (PAM)
• Generalized epilepsy with febrile seizures plus (GEFS+)
• Episodic Ataxia (EA), characterized by sporadic bouts of severe discoordination with or without myokymia, and can be provoked by stress, startle, or heavy exertion such as exercise.
• Familial hemiplegic migraine (FHM)
• Spinocerebellar ataxia type 13
• Long QT syndrome is a ventricular arrhythmia syndrome caused by mutations in one or more of presently ten different genes, most of which are potassium channels and all of which affect cardiac repolarization.
• Brugada syndrome is another ventricular arrhythmia caused by voltage-gated sodium channel gene mutations.
• Cystic fibrosis is caused by mutations in the CFTR gene, which is a chloride channel.
• Mucolipidosis type IV is caused by mutations in the gene encoding the TRPML1 channel