[Chorea-acanthocytosis: report of a new family].

Chorea-acanthocytosis is a rare cause of chorea. The genetic origin of the disease was proven with the isolation of the gene on chromosome 9q21. We report the case of two sisters who had two different expressions of this disease. The first sister developed secondary epilepsy associated with abnormal movement of the face. The second presented abnormal movements of the face and apathy. Both improved with serotoninergic treatment. Diagnosis was suggested on the basis of clinical findings and confirmed by identification of acanthocyes and integrity of the Kell blood antigen. Search for acanthocytes should be performed in all patients with chorea. Chorea associated with acanthocytosis has a better prognosis than chorea arising from other causes. Other neurological manifestations or complications may be present or mot; long-term follow-up in a specialized center iq needed for prevention.