Recombinant DNA technology has made possible the identification of a DNA marker for Huntington's disease (HD). In spite of limitations to a presymptomatic test based on this work, and a variety of ethical and policy concerns associated with presymptomatic testing in general, it is likely that such a testing program can and will soon be developed. Its impact needs to be carefully considered by the health care community and policymakers. A presymptomatic test for HD is sought by those at risk and should be made available with proper safeguards to protect confidentiality. Given its potential impact, testing should be offered in a setting that provides diverse and continuing support. Research institutions with a variety of counseling programs, health care professionals, HD lay organizations, and society at large can work together to develop programs that provide the support necessary for responsible, autonomous decision making.