Abstract
Huntington's disease (HD) is a dominantly inherited neurological disorder characterized by chorea, psychiatric symptoms, and cognitive decline but typically lacks muscular atrophy and weakness. We herein report a case of genetically confirmed HD showing progressive systemic weakness with findings of upper and lower motor neuron involvement due to amyotrophic lateral sclerosis (ALS). The current patient and the previously reported cases with complications of HD and ALS indicate that cytosine-adenine-guanine (CAG) repeat expansion in the huntingtin gene might have a pathogenic role in causing the two neurological disorders.