Preimplantation Research Paper

213

CONTROVERSY

Extending preimplantation genetic diagnosis: medical and non-medical uses
J A Robertson
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J Med Ethics 2003;29:213–216

New uses of preimplantation genetic diagnosis (PGD) to screen embryos prior to transfer raise ethical, legal, and policy issues that deserve close attention. Extensions for medical purposes, such as to identify susceptibility genes, late onset disease, and human leukocyte antigen
(HLA) matching, are usually ethically acceptable.
Whether embryo screening for gender, perfect pitch, or other non-medical characteristics are also acceptable depends upon the parental needs
About 1000 cycles have involved single gene mutational analysis.1 Mutational analysis requires additional skills beyond karyotyping for aneuploidies, including the ability to conduct the mutliplex polymerase chain reaction (PCR) of the gene of interest and related markers. Several new indications for PGD single gene mutational analysis have recently been reported.
New uses include PGD to detect mutations for susceptibility to cancer and for late onset disorders such as Alzheimer’s disease.2 3 In addition, parents with children needing hematopoietic stem cell transplants have used PGD to ensure that their next child is free of disease and a good tissue match for an existing child.4 Some persons are also requesting PGD for gender selection for both first and later born children, and others have speculated that selection of embryos for a variety of non-medical traits is likely in the future.
PGD is ethically controversial because it involves the screening and likely destruction of embryos, and the selection of offspring on the basis of expected traits. While persons
As long as competent caregivers will be available for the child, the likely death or disability of a parent does not justify condemning or stopping this use, anymore than that reproduction by men going off to war should be discouraged.
A third new medical indication—HLA matching to an existing child—enables a couple to have their next child serve as a matched hematopoietic stem cell donor for an existing sick child. It may also ensure that the new child does not also suffer from that same disease. The availability of PGD, however, should not hinge on that fact, as the Human Fertilisation and Embryology Authority, in the UK, now requires.9 A couple that would coitally conceive a child to be a tissue donor should be free to use PGD to make sure that that child will be a suitable match, regardless of whether that child is also at risk for genetic disease. Parents who choose PGD for this purpose are likely to value the new child for its own sake, and not only for the stem cells that it will make available. They do not use the new child as a “mere means” simply because they have selected HLA matched embryos for transfer.10 11

NON-MEDICAL USES OF