Cellular hypersensitivity to brain antigen in children of a family with hereditary ataxia.

Sensitisation to brain antigen was demonstrated in eight of 24 clinically normal first generation children in a family with hereditary ataxia. This ratio is consistent with that expected in a dominantly inherited condition. It suggests that immunological reactivity may precede the clinical expression of disease, with important implications for presymptomatic diagnosis and for pathogenesis of degenerative disease.