Sandbox WWC6: Difference between revisions

* [https://en.wikipedia.org/wiki/Nav1.9 NaV1.9]: found in dorsal root ganglia. <ref name = "sod"/>

Hyperkalemic period paralysis is caused by the mutations T704M, S906T, A1156T, M1360V, A1448C and/or M1592V. <ref name = "Hyper">http://neuromuscular.wustl.edu/mother/activity.html#hrpp</ref> These mutations cause periodic or permanent weakness. <ref name = "Hyper"/> Physiologically, this is a gain of function mutation. During rest after exercise, or after eating foods rich in K⁺, the extracellular K⁺ increases, which mildly depolarizes the membrane.<ref name = "Hyper"/> This causes abnormal Na⁺ channels to open, and they are unable to inactivate. <ref name = "Hyper"/> This sustained depolarization of the membrane causes even more abnormal Na⁺ channels to open and ultimately this leads to loss of excitability and weakness. <ref name = "Hyper"/> This symptom usually appears within the first decade of life and can be aggravated by exercise, cold, potassium loading, fasting or pregnancy. <ref name = "Hyper"/> Attacks are usually brief and do not need treatment. <ref name = "Hyper"/>