We have studied a mutation c.6200C>A (p.A2067D) in the ATM gene that is unique to the Mennonite populations of Canada, Mexico, Central America, Northern Germany, and Netherlands, and is usually associated with dystonia, not ataxia, in young patients (Sandoval et al. 1999; Yanofsky et al. 2009; Saunders-Pullman et al. 2012). The gene discussed is ATM; the disease is cerebellar ataxia.