CACNA1S gene mutations are responsible for 60% of its with HYPOkalemic periodic paralysis 

HYPOkalemic periodic paralysis episodes can be triggered by large carbohydrate meals, salt, insulin, steroids and rest after exercise. 

SCN4A mutations are the most common mutation with HYPERkalemic periodic paralysis. SCN4A mutations are also responsible for ~ 20% of hypokalemic periodic cases.