Chorea-acanthocytosis (CHAC. MIM 200150) is an autosomal recessive neurodeg
enerative disorder characterized by the gradual onset of hyperkinetic movem
ents and abnormal erythrocyte morphology(1,2) (acanthocytosis). Neurologica
l findings closely resemble those observed in Huntington disease(3-8). We i
dentified a gene in the CHAC critical region(9) and found 16 different muta
tions in individuals with chorea-acanthocytosis. CHAC encodes an evolutiona
rily conserved protein that is probably involved in protein sorting.