Britain permits controversial genetic test.
The HFEA regulates reproductive technologies by granting or denying licenses for their use. The July ruling makes PGD licensable in cases where tissue typing is the sole purpose of testing. Previously, tissue-typing PGD was permissible only when performed in conjunction with a disease prevention test--when combined with a test for Fanconi Anemia, for trample. Although the HFEA's about-face has triggered significant criticism, it represents a triumph for British bioethics regulation.
Critics of the HFEA's new policy have focused on the supposed instrumentalization of the embryo selected to be a tissue match. For instance, the director of Human Genetics Alert, a bioethics watchdog group, told The Guardian, "It is wrong to create a child simply as a means to an end, however good that end might be, because to do so turns a child into an object." But the claim is unconvincing. Although the desire to save a child through the creation of a tissue donor may be a powerful motivation for parents seeking tissue-typing PGD, there is no evidence to suggest that this is their sole motivation. Indeed, couples pursuing tissue-typing PGD have stated quite clearly that they will love and care for their newborn as much as for their other children. The couples' own claims aside, parents willing to go to such extraordinary lengths to save their child seem likely to be the sort of parents who would care deeply for each of their children in their own right.
In arriving at its new policy, the HFEA re-examined the risks associated with IVF and embryo biopsy--interventions that are required for PGD--and concluded that these risks are acceptable regardless of whether PDG tissue typing is done in conjunction with disease testing or in isolation from it. Previously, in sharp contrast, the HFEA had decided that the potential harms of IVF and embryo biopsy were acceptable only when balanced against the potential benefits of identifying and avoiding an inherited generic disease (as with tissue-typing PGD used in conjunction with disease testing.)
Some research indicates that IVF may increase the risk of major birth defects. However, these findings do not evaluate the risks of IVF for infertility patients as distinct from the risks of IVF for PGD patients. Infertility can occur in conjunction with other genetic abnormalities. For instance, imprinting errors--a component of IVF-linked risks--correlate with certain sperm defects. (1) Consequently; some of the birth defects observed in IVF babies are likely due to the genetic health of gametes rather than the safety of IVF.
Nor is there evidence to suggest that embryo biopsy is harmful to embryos. In fact, animal trials and human embryo experience, as well as the natural occurrence of twinning, signify the safety of embryo biopsy. Moreover, a study of PGD outcomes published in August concluded that the risk of birth defects is no greater for PGD babies than for those conceived naturally, indicating that neither IVF nor embryo biopsy pose serious threats to embryos. (2)
Given the available data, the HFEA's new policy on tissue-typing PGD is undeniably more fair and ethical. It is right and good that tissue-typing PGD should be available with or without disease testing.
(1.) C.J. Marques et al., "Genomic Imprinting in Disruptive Spermatogenesis," The Lancet 363 (2004): 1700-702,
(2.) Y. Verlinsky et al., "Over a Decade of Experience with Preimplantation Genetic Diagnosis: A Multicenter Report," Fertility and Sterility 82 (2004): 292-94.
Natalie Ram is a research associate in the Bioethics Department at Dalhousie University. Her research is supported in part by a CIHR grant. "Towards Single Embryo Transfer in the Human." Thanks are owed to Francoise Baylis for helpful comments on an earlier draft.