There is always a problem when new medical technologies lead to clinical services for which we have no or little evidence of their impact. The desirable approach is to carry out clinical trials to determine their effectiveness and safety. Predictive genetic testing is a technological development with possible psychological and social effects that have been much discussed. Because predictive testing can be offered to children, as well as to adults, the discussion has been wide-ranging, encompassing issues such as competence to give informed consent, the rights of the child and autonomy.

The complexity of these issues does not mean that policies should be formulated without the backing of relevant research. Indeed, it could be argued that such testing should only be offered as part of a research protocol determining its effects and the circumstances under which it is most effective and least harmful.

There are three general approaches to the clinical introduction of genetic developments that can be identified in past practice. One is to herald caution, and keep the debate within professional circles. The second is to consult widely, seeking the opinions of potential users of new services and the general public. The third is to promote rapidly the research that will address the questions of psychological and social impact. In Chapter 7, Clarke and Flinter emphasise the first approach; I shall discuss the second two approaches.

The current view of clinical geneticists is summarised by Clarke and Flinter as follows: