Since the identification of a CAG repeat expansion in the TATA-box binding protein (TBP) gene in a patient with ataxia in 1999 and then verification of this expansion in patients with SCA17 in 2001, several SCA17 rodent models, including both knock-in and transgenic models in mice and rats, have been established to explore the phenotypic features and pathogenesis of SCA17.
The SCA17 clinical phenotype includes characteristics associated with cerebellar and cortical atrophy such as ataxia, dementia, epilepsy, chorea and parkinsonian features.
We conclude that, however rare, SCA17 must be considered as a cause of Huntington's disease-like phenotypes and ataxia syndromes, also in isolated cases.
Our results show that (1) a significant number of isolated cases of ataxia are due to TNR expansions; (2) expanded DRPLA alleles in Portuguese families may have evolved from an ancestral haplotype; and (3) small (CAG)(n) expansions at the TBP gene may cause SCA17.
To investigate whether the expansion of CAG repeats of the TATA-binding protein (TBP) gene is involved in the pathogenesis of neurodegenerative diseases, we have screened 118 patients with various forms of neurological disease and identified a sporadic-onset patient with unique neurologic symptoms consisting of ataxia and intellectual deterioration associated with de novo expansion of the CAG repeat of the TBP gene.