Screening and the new genetics; a public health perspective on the ethical debate.

Advances in the diagnostic applications of molecular genetics have made possible the identification of recessive carrier states in the population. The debate surrounding screening for cystic fibrosis therefore has a public health significance which transcends that specific disorder. The two most frequently cited objectives of screening for a recessive carrier state are to reduce the prevalence of the disorder and to inform the reproductive choices of individuals and couples at risk. The later aim represents a paradigm shift in the philosophy of screening in that no preventive principle is involved. Instead, information is regarded as worth while in itself, regardless of outcome. The authors argue that the benefits arising from the information generated in the course of genetic carrier screening cannot be presumed merely by asserting a "right to know' ethical imperative, and draw attention to the danger that a combination of technical capability, professional zeal and consumer demand will override currently accepted screening principles. In this event, future efforts to subject screening programmes to rational evaluation could be undermined.