Spinocerebellar Ataxia Type 17 (SCA17) is the most recently discovered member of the polyQ disease family, resulting from CAG/CAA expansion in the gene that encodes the TATA box-binding protein (TBP), an essential player in the basal transcriptional machinery of all eukaryotes (Koide et al. 1999; Nakamura et al. 2001). The gene discussed is TBP; the disease is spinocerebellar ataxia type 17.