Myokymia (fine twitching or intermittent cramps and stiffness) is a persistent interictal feature, which is very suggestive of KCNA1 but is recognized in other EAs including EA3 (no known causative gene, linked to cytogenic region Chr1q42) and PxMD-UBR4 (previously called EA8). The gene discussed is KCNA1; the disease is Myokymia.