Chorea-acanthocytosis presenting as motor neuron disease.

INTRODUCTION: Chorea-acanthocytosis (ChAc) is a rare autosomal recessive disease characterized by involuntary movements, seizures, cognitive changes, myopathy, and axonal neuropathy.

METHODS: We report a patient who presented with gait impairment and dysarthria. Clinical and neurophysiological assessment disclosed upper and lower motor neuron signs suggestive of motor neuron disease (MND).

RESULTS: Later observation of involuntary movements prompted further investigation. Acanthocytes were identified, and the patient's chorein level was low. Genetic studies identified a novel double heterozygous mutation of the chorein gene involving an exon-stop mutation associated with another mutation that can affect the normal splicing of the RNA.

CONCLUSIONS: We speculate that this genetic mutation could cause the atypical presentation. ChAc should be included in the differential diagnosis of atypical MND.