SCN1A and familial or sporadic hemiplegic migraine: Mutations in the three ion channels genes, CACNA1A (calcium voltage-gated channel subunit alpha 1 A), ATP1A2 (ATPase Na+/K+ transporting subunit alpha 2), and SCN1A (sodium voltage-gated channel alpha subunit 1) were identified as specifically causal for hemiplegic migraines, a rare variant of MA, and genome-wide association studies have identified 38 loci associated with increased risk of migraines [60].