Stem cell and gene therapies may involve either permanent or temporary insertion of stem cells or genetic material. Both stem cell therapies and gene therapies can have reproductive effects in the sense that the genetic changes introduced are transmitted in the germline or the stem cells can give rise to germ cells. Some stem cell or gene therapies may therefore actualise the continuing treatment-enhancement debate; that is, whether there is an ethical difference between treating disease and enhancing normal function and whether such a difference makes some or all enhancement morally problematic. Many stem cell and gene therapies will have to be given in the fetal period or during early childhood to be effective or to have their full effect. This raises the issue of proxy consent for very young children. A final set of issues arises in relation to resource allocation within the healthcare system.

This chapter discusses the consensus views obtained from the 57th Study Group on various aspects of reproductive genetics. It emphasizes that fetal karyotyping should remain the gold standard test following invasive prenatal diagnosis until appropriately tested and evaluated higher-resolution whole-genome analytical methods can be introduced. Preimplantation genetic diagnosis (PGD) for saviour siblings should be permitted or denied based on the permissibility or impermissibility of live-organ donation by children. Focused basic research is needed to understand the normal genetic and epigenetic events that occur during primordial germ cell specification from embryonic stem (ES) cells and in the differentiation of primordial germ cells. Improvements in vector design and safety will be needed before safe targeted delivery to the fetus can be achieved; studies into long-term safety in large animal models (non-human primates) should be supported. Research is needed into the long-term outcomes of novel therapeutic interventions.