CACNA1D and hypokalemic periodic paralysis: Most cases of hypokalemic periodic paralysis (HPP) are inherited, typically following an autosomal dominant pattern, with mutations identified in genes encoding several ion channels such as calcium voltage-gated channel subunit alpha 1 S (CACNA1S), sodium voltage-gated channel alpha subunit 4 (SCN4A) and potassium voltage-gated channel subfamily E regulatory subunit 3 (KCNE3) [5].