• Should people be required to be tested for genetic defects? Until recently, children of patients with Huntington’s disease had to wait until they developed symptoms themselves— usually in midlife—to know whether they had inherited the disease. A genetic test is now available that can detect carriers of the defective gene, those who will eventually develop the disease should they live long enough. Eventually, perhaps, genetic engineering may provide a means of modifying the defective gene or its effects. Because researchers have not yet developed ways to cure or control Huntington’s disease, some potential carriers prefer not to know whether they have inherited the gene. A famous example is Arlo Guthrie, a folksinger like his father, Woody Guthrie, who is best remembered for the classic song, “This Land Is Your Land, This Land Is My Land,” and who died from the disease in 1967. Arlo preferred not to know whether he carried the gene and never underwent genetic testing. Fortunately, he escaped his father’s fate.

If you were in Arlo’s position, would you want to know if you had inherited Huntington’s? Or would you prefer keeping yourself in the dark and living your life as best you could?

What about AD? Would you want to know if you have AD or are carrying genes that put you at heightened risk? New brainscanning technology makes it possible to diagnose the disease, but the effects of learning that you have Alzheimer’s can be emotionally devastating. Without any effective treatment or means of slowing it down, is it worth knowing? People with positive brain scans for Alzheimer’s also stand the risk of being denied long-term care insurance

(Kolata, 2012). However, proponents of testing argue that providing information can help remove uncertainty, help people prepare as best they can, and identify candidates for experimental treatment programs that may lead to advances in treatment or prevention.

When asked, most people in a recent study said they would prefer not knowing whether AD is imprinted in their genes (Miller, 2012).