Spinocerebellar ataxia type 3 (Orphanet_98757) (SCA3), also known as Machado-Joseph disease, is the most common subtype of type 1 autosomal dominant cerebellar ataxia (ADCA type 1; see this term), a neurodegenerative disorder, and is characterized by ataxia, external progressive ophthalmoplegia, and other neurological manifestations. Also known as: Autosomal dominant striatonigral degeneration, Azorean disease of the nervous system, MJD, Machado disease, Machado-Joseph disease, Nigro-spino-dentatal degeneration with nuclear ophthalmoplegia, SCA3.