EA2 has been linked to mutations in the CACNA1A gene, encoding a calcium channel complex that is abundant in the central nervous system and the cerebellum.10,26 EA2 was considered as a differential diagnosis for the family described in this study due to similarities in phenotype, such as the mode of inheritance, the episodic nature of nystagmus, and the resemblance of accompanying symptoms. This evidence concerns the gene CACNA1A and pathologic nystagmus.