To test or not to test: an ethical conflict with presymptomatic testing of individuals at 25% risk for Huntington's disorder.

The first presymptomatic test for Huntington's disease was developed in the 1980s. With the detection of the gene causing the disorder in 1993, it became possible to do direct mutation tests with almost 100% sensitivity and specificity. The author discusses some of the ethical issues that arise when an adult child at 25% risk for the disease wishes to have the test, but the parent(s) at 50% risk refuses to have one. If the child tests positive, the genetic status of the parent will also be disclosed. No matter what course of action is chosen in this situation, the ethically legitimate interests of either child or parent might be violated. The author examines different alternatives and suggests a solution that might be acceptable to all parties.