Haw River syndrome

an autosomal dominant neurodegenerative disorder characterized by ataxia, chorea, seizures, and dementia, with onset usually between ages 15 to 30 years, and death within 15 to 25 years. It is a triplet repeat disorder caused by expansion of the CAG triplet repeat in the DPRLA gene encoding the atrophin-1 protein, as occurs in dentatorubral-pallidoluysian atrophy (q.v.), although there are some differences in clinical expression and pathology, including lack of myoclonic seizures, and extensive demyelinization of the subcortical white matter, basal ganglia calcifications, and neuroaxonal dystrophy.