Acanthocytosis and neurological impairment--a review.

Acanthocytes have a distinct morphology and are not normally found in peripheral blood. They occur in association with at least three neurological syndromes. In abetalipoproteinaemia, a progressive spinocerebellar ataxia and retinopathy occurs secondary to malabsorption of vitamin E. Cases with chorea are often familial, with orofacial dyskinesia and an axonal neuropathy causing areflexia and muscle wasting. Areflexia and a subclinical myopathy also occur in the McLeod syndrome, in which there is abnormal expression of Kell blood group antigens. The exact mechanism of acanthocytosis in each disorder remains uncertain: passive changes in membrane lipids, surface receptor/ligand interactions, and a primary membrane defect are among the possibilities.