In European natives, pathogenic mutations should be searched in genes producing SCA1 (ATXN1), SCA2 (ATXN2), SCA3 (ATXN3), SCA6 (CACNA1A), SCA7 (ATXN7), SCA 12 (PPP2R2B), fragile X tremor ataxia syndrome (FMR1), SCA17 (TBP), CANVAS syndrome (RFC1), and Friedreich ataxia (FXN) [53﻿]. The gene discussed is CACNA1A; the disease is Down syndrome.