CACNA1A encodes the alpha1A subunit of voltage-gated P/Q-type calcium channels (Cav2.1), which are critical for calcium-dependent neuronal processes including neurotransmitter release and synaptic transmission 1. These high-voltage activated channels are specifically blocked by omega-agatoxin-IVA but insensitive to dihydropyridines, distinguishing them from other calcium channel subtypes. Pathogenic CACNA1A variants cause multiple neurological disorders with overlapping phenotypes, including familial hemiplegic migraine type 1 (FHM1), episodic ataxia type 2 (EA2), and spinocerebellar ataxia type 6 (SCA6) 123. Recent studies reveal an expanded phenotypic spectrum encompassing developmental delay/intellectual disability (96% of cases), epilepsy (55%), autism spectrum disorder (23%), and paroxysmal movement disorders 4. Gain-of-function variants typically cause more severe phenotypes with intractable seizures and recurrent status epilepticus, while loss-of-function variants often present with refractory absence seizures 5. The molecular mechanisms involve disrupted calcium signaling affecting neuronal development, migration, and synapse formation 6. Treatment approaches include antiepileptics (lamotrigine, valproate, topiramate), calcium channel blockers (flunarizine, verapamil), and acetazolamide, though many patients develop refractory symptoms 53.