Gene Therapy and Fetal Medicine

Abstract

In the genetic clinic, once the couple have come to understand that their child’s problems arise as a result of a particular change in the DNA sequence of a fully characterised gene, they sometimes ask whether it would be possible to correct the DNA mutation by genetic engineering. They may have seen articles in the press that refer to the recent successes in making mouse models of cystic fibrosis (CF) (see Wilson and Collins, 1992) and conclude, quite reasonably, that if the normal mouse equivalent of the human cystic fibrosis transmembrane conductance regulator (CFTR) gene can be deliberately changed to a mutant gene causing the mouse to have CF, then a naturally occurring CF mutation in a human could be changed back to normal. In terms of genetic engineering alone, their conclusion would be right. Combine the fact that generating CF mouse models involves genetic manipulation of the early embryo, with paragraph 1.1 of the Report of the Committee of Enquiry into Human Fertilisation and Embryology (Warnock, 1984) — ‘It is now possible to observe the very earliest stages of human development and with these discoveries came the hope of remedying defects at this very early stage’, and the couple can be forgiven for thinking that gene therapy for CF is likely to involve the human embryo. In this conclusion, they would be wrong.