Attitudes of Those at Risk for Huntington's Disease toward Presymptomatic Provocative Testing

To the Editor: Klawans et al.¹ originally reported on the potential use of levodopa loading to predict the presence of the gene for Huntington's disease in at-risk subjects, and an eight-year follow-up study² demonstrated a prognostic capability for this test. Fahn³ pointed out several problems with provocative testing with levodopa, including the psychological consequences of inducing transient chorea symptoms in subjects, which might result in suicide. He suggested that the ideal test would be one in which the subject would be unaware of the results. Bates,⁴ however, maintained that the results of presymptomatic tests should not be withheld from.