KCNA1 and Hypomagnesemia: EA1 mutant L328V (which is associated with tetany and hypomagnesemia) is located in the intracellular end of Kv1.1 S5 (Fig. 5a) and results in complete current loss in a dominant negative manner, i.e., Kv1.1-L328V and Kv1.1/Kv1.1-L328V channels are each nonfunctional45.