ATP1A3 and early-onset autosomal dominant Alzheimer disease: On the other hand, p.Arg656Cys is predicted to be highly deleterious, may contribute to other anatomical distributions of dystonia, and, like ATP1A3, could be involved in the etiopathogenesis of other neurological disorders such as Parkinson disease, Alzheimer disease, and brain tumors (Kawalia et al., 2017; Korosec, Glavac, Volavsek, & Ravnik‐Glavac, 2009; Matak et al., 2016).