Dentatorubral-pallidoluysian atrophy: a rare cause of epilepsy, ataxia and chorea

A 34-year-old woman presented with insidious onset and gradually progressive cerebellar ataxia over 10 years, with generalised convulsions. On examination, there were myoclonic jerks, choreiform movements and cerebellar syndrome. Her family history suggested an autosomal dominant inheritance with anticipation. Genetic analysis for trinucleotide repeat disorders led to a diagnosis of dentatorubral-pallidoluysian atrophy (60 CAG repeats in the atrophin-1 gene). This rare spinocerebellar ataxia should be considered in the differential diagnosis of inherited ataxia when combined with seizures and chorea. Other features suggesting a repeat expansion disorder are variable phenotypes within the same family and possible anticipation.