Doctors on the frontier of in vitro fertilization now offer to test embryos for predisposition to treatable cancers and other ailments using the same technique that detects some serious childhood maladies. As scientists learn more about the code that builds human life, critics warn of an age when the wealthy will be able to buy a healthier brood.
Already, it is possible to test embryos for an inherited form of deafness or a mild skin condition, or for a predisposition to arthritis or obesity. Some clinics test for gender. As scientists learn more about the genetic basis for inherited traits, and as people learn more about their genetic makeup, the embryo screening menu and its array of ethical dilemmas are only expected to grow.
?From a technology perspective we can test anything,? said Mark Hughes, director of the Genesis Genetics Institute in Detroit, who is performing P.G.D. this month for two couples who want to avoid passing on a susceptibility to breast cancer. ?The issue becomes what is considered serious enough to warrant such testing and who decides that.?
The process is also difficult and expensive. P.G.D., which requires in vitro fertilization, can cost tens of thousands of dollars. While insurance companies often pay for the more traditional uses of the procedure, they have not done so for cancer-risk genes, fertility experts say. The barrier to affordability, some critics fear, could make preimplantation diagnosis for cancer risk the first significant step toward a genetic class divide in which the wealthy will become more genetically pure than the poor.