RT Journal A1 Quarrell OJ, Bloch MM, Hayden MR T1 INsurance and the presymptomatic diagnosis of delayed-onset disease JF JAMA JO JAMA YR 1989 FD November 3 VO 262 IS 17 SP 2384 OP 2385 DO 10.1001/jama.1989.03430170044017 UL http://dx.doi.org/10.1001/jama.1989.03430170044017 AB To the Editor. —  We read, with interest, the article by Brandt et al1 in which they described the preliminary results of their predictive testing program for Huntington's disease. We agree that presymptomatic diagnosis of a neurodegenerative disorder, for which no effective treatment is available, raises a number of ethical and social issues. However, we are concerned that the statement "individuals may well be advised to be cautious about disclosing either their participation in testing or test results" may be interpreted by insurance companies as encouraging individuals to withhold information. In addition, the authors are worried about insurance companies discriminating against individuals based on the results of genetic tests.Any discussion of life insurance in relation to predictive tests must take account of reality, and whether we like it or not, insurance companies believe in discrimination. They assign individuals to a group; the members of that group have approximately