Chromosome 19 houses a mutation in gene CACNA1A, LOC126862864 (calcium voltage-gated channel subunit alpha1 A| MED14-independent group 3 enhancer GRCh37_chr19:13371552-13372751). Classify its clinical impact — is it pathogenic or benign, and what disease does it lead to if any?
Pathogenic; Migraine, familial hemiplegic, 1