Kcnma1H444Q/H444Q and Kcnma1‒/‒ mice had reduced latencies to fall from the hanging wire under basal conditions, but only Kcnma1‒/‒ mice are profoundly impaired on the rotarod and running wheels due to ataxia (Figure 6—figure supplements 1 and 2). Here, KCNMA1 is linked to cerebellar ataxia.