From Slate:

British regulators approved an application to reject embryos for the probability of early Alzheimer’s. Circumstances: 1) The age of onset in the husband’s mother was 49. 2) The disease runs only in the husband’s mother’s family. 3) To make sure he doesn’t produce a child with the disease, the clinic “will screen embryos to ensure only the chromosome from [his father's] side is passed on.” 4) The husband refuses to be tested to find out whether he carries the gene in the first place. Consequently, the approved weeding process poses “a one in four risk that a healthy embryo will be discarded.” Clinic’s arguments: 1) Nature discards healthy embryos, too. 2) This kind of screening is so hard that people will do it only for “life-threatening diseases.” 3) Early Alzheimer’s might leave the kid “only half a live worth living.” Rebuttals: 1) So now we’re snuffing embryos that would live normally to 49. 2) And we’re snuffing embryos that might never get the disease. 3) You’re promising us an imminent Alzheimer’s cure from stem cells—but you’re tossing embryos on the theory that they’re doomed to Alzheimer’s 50 years from now? (Related columns: The slippery slope of embryo screening.) Question: In this situation, would you use the same test? Debate it here.