Congenital Myopathy 22a, Classic, also known as cmyp22a, is related to myopathy and normokalemic periodic paralysis. An important gene associated with Congenital Myopathy 22a, Classic is SCN4A (Sodium Voltage-Gated Channel Alpha Subunit 4). Affiliated tissues include skeletal muscle and eye, and related phenotypes are ptosis and hypotonia