Orphanet rare-disease nomenclature entry Orphanet_94148 (Autosomal dominant cerebellar ataxia type 3) is autosomal dominant cerebellar ataxia (ACDA; see this term) type 3 is a group of neurodegenerative disorders characterized by mostly pure cerebellar syndromes with occasional non-cerebellar signs (e.g. pyramidal signs, peripheral neuropathy, writer's cramp) and includes spinocerebellar ataxia (SCA) type 5 (SCA5), SCA6, SCA11, SCA26, SCA30, and SCA31 (see these terms). Also known as: ADCA3, ADCAIII, Autosomal dominant cerebellar ataxia type III, Pure cerebellar syndrome - mild pyramidal signs.