Preimplantation genetic diagnosis for susceptibility conditions: a new frontier or a logical extension?

A susceptibility or "lower penetrance" condition is a condition to which a person may be predisposed by virtue of a particular gene mutation they carry within their genetic code. Genetic testing for susceptibility to late-onset conditions, an increasingly available phenomenon, has recently been associated with preimplantation genetic diagnosis (PGD). Performing PGD for conditions that occur later in life and that may be preventable or, if not, may be treatable, or that may never even develop, is highly contentious. It constitutes a significant departure from traditional PGD, going beyond testing for serious heritable disorders that are apparent at birth or in very early childhood or late-onset diseases that are certain to manifest themselves. It is likely that, as technology advances, there will be a growing demand for PGD to detect these types of conditions. This article considers the issues raised by susceptibility testing. It questions whether embryonic testing for late-onset susceptibility conditions is more appropriately a matter for regulatory restraint or reproductive liberty.