ABSTRACT
This chapter explores the range and limitations of predictive genetic tests and attempts to show how the information can be used in conjunction with other genetic and clinical data to make the assessment of risk as accurate as possible. It discusses the approach to take when counselling individuals who are at risk of developing a genetic condition and who wish to discuss the possibility of predictive genetic testing. One of the major tasks in genetic counselling is to take patients through genetic testing with appropriate information, discussion and preparation beforehand, appropriate support afterwards. In the setting of predictive genetic testing for non-medical reasons, as with prenatal genetic diagnosis, genetic counselling element of the integrated counselling-plus-testing package is guided by the principle of non-directiveness. Once a safe and effective intervention has become available that prevents progression of disease, this situation will change: testing for Huntington’s disease will, in this respect, become much more like testing for familial adenomatous polyposis coli.
