Ethical implications of a new application of preimplantation diagnosis.

Making use of advancements in molecular biology techniques, as well as a better understanding of the human genome, researchers have identified numerous alleles (gene variants) which are associated with certain diseases. In familial cases these problematic alleles are passed on from parent to offspring. Recently, couples have elected to undergo Preimplantation Genetic Diagnosis (PGD) in order to ensure they do not pass on such alleles to their children. In this procedure, an embryo is produced in vitro using the mother’s egg and the father’s sperm. The embryo allowed to grow over three days; its cells divide into identical copies of one another through the process of mitosis. One of these cells is extracted from the embryo by researchers, who then use molecular biology techniques to detect certain genetic abnormalities. If this one cell “passes the test,” and is free of any harmful genetic mutations, it can be inferred that the rest of the cells in the embryo are healthy as well. The developing embryo can then be implanted into the mother’s uterus, where it will hopefully develop into a fetus as though it were conceived naturally. The process of embryo selection and discard, however, raises several ethical issues (Damewood, 2001). They include the following: