Early-onset SCA17 with 43 TBP repeats: expanding the phenotype?

Abstract

The SCA17 clinical phenotype includes characteristics associated with cerebellar and cortical atrophy such as ataxia, dementia, epilepsy, chorea and parkinsonian features. Here we describe the case of a 38-year-old male presenting with ataxia, cognitive impairment and seizures, who was found to carry 43 repeats on one allele of the TATA-binding protein (TBP) gene. Therefore, genetic analysis of TBP gene triplets was performed on the patient's entire family, identifying three asymptomatic carriers of the same allele. A neuroradiological phenotype appeared to segregate with this allele, suggesting that it may play at least a contributory role in the determination of SCA17.