CACNA1A and Global developmental delay: CACNA1A mutations cause several dominantly inherited or sporadic neurologic disorders with a wide spectrum of neurological symptoms (Spacey, 2015): hemiplegic migraine with aura (including severe forms with cerebral edema and coma), cerebellar signs (including episodic, permanent, early or late onset progressive ataxia, cerebellar atrophy, nystagmus, vertigo, dysarthria), seizures, and developmental delay.