ATP1A2 and migraine disorder: Likewise, familial hemiplegic subtypes of migraine – a common primary headache disorder that presents with moderate to severe unilateral pain attacks with several typical variants with or without aura – are associated with specific disease-associated mutations in the voltage-gated calcium channel CACNA1A (FHM1), the sodium/potassium-transporting ATPase subunit ATP1A2 (FHM2), and the voltage-gated sodium channel SCN1A (FHM3) genes [83].