Channelopathy

Channelopathies are diseases caused by disturbed function of ion channel subunits or the proteins that regulate them. These diseases may be either congenital (often resulting from a mutation or mutations in the encoding genes) or acquired (often resulting from autoimmune attack on an ion channel).
There are many distinct dysfunctions known to be caused by ion channel mutations. The genes for the construction of ion channels are highly conserved amongst mammals and one condition, hyperkalemic periodic paralysis, was first identified in the descendants of Impressive, a registered Quarter Horse.
The channelopathies of human skeletal muscle include hyper- and hypokalemic (high and low potassium blood concentrations) periodic paralysis, myotonia congenita and paramyotonia congenita.
Channelopathies affecting synaptic function are a type of synaptopathy.
Types.
The types in the following table are commonly accepted. Channelopathies currently under research, like Kir4.1 potassium channel in multiple sclerosis, are not included. 
External links.
VIDEO Channel Surfing in Pediatrics by Carl E. Stafstrom, M.D., at the UW-Madison Health Sciences Learning Center.