CACNA1A and Global developmental delay: While FHM1 and EA2 are relatively narrowly-defined classes of disorders, a subset of patients harboring missense mutations in CaV2.1 present with migraine and/or ataxia as well as one or more of the following symptoms: congenital ataxia, congenital encephalopathies, epilepsy, developmental delay, stroke, injury-induced coma and/or respiratory failure38–51.