ITPR1 and cerebellar ataxia: Genetic diagnoses were more diverse in non-repeat expansion SCA, with pathogenic variants involving 17 genes, the most frequent being ATX-CACNA1A (3 families, 14.3%) and ATP1A3-related ataxia, ATX-ITPR1, ATX/HSP-KCNA2, and ATX-PRKCG (2 families, 9.5% each) (Fig. 2).