Who should be offered genetic screening?

General The conditions dealt with here are those where detection of women or couples at risk of having children with burdensome disorders with little or no curative treatment, is feasible. One objective of screening is avoidance of birth of affected individuals by identifying those at risk, prospectively. As important is the reassurance which can follow negative tests. Voluntary participation of well-informed clients is a vital prerequisite. Screening may increase couples' options, one of which may include prenatal tests and termination of affected pregnancies. All screening programmes have their enthusiastic supporters and opponents. Some of the arguments are so philosophical and paternalistic as to be incapable of resolution. Others rightly attract careful appraisal, such as knock-on effects on clinical and laboratory services and those which follow on false-positive and negative screening results. It is important to devote a great deal of thought to the groups who should be made aware of screening or testing. The guiding principle ofwhom to choose is that the offer is seen as useful by the individual or family. Sometimes individuals themselves have made enquiries about tests, or mentioned the existence ofone ofthe diseases in the family. Any doctor who does not respond by offering to organize tests when a family story ofany of these severely disabling conditions is forthcoming , is neglecting the patient. A practical aspect is whether tests can be offered before or only in pregnancy. Pregnancy screening To screen for Down's syndrome or neural tube defect in the fetus there must be a pregnancy in existence. The current commercial atmosphere in the National Health Service means that certain organizers of such tests are beginning to market their products rather aggressively. This includes the advertising campaign of writing to district managers and purchasers and by producing glossy literature for use by professionals and prospective patient clients. In this respect I refer specifically to biochemical screening tests for Down's syndrome, the so-called Triple or 'Triple +' Test. There was no similar campaign when a fetoprotein (AFP) screening was originally introduced for neural tube defect detection and certainly no glossy literature was produced. Whatever the motives, however, the existence of client/patient orientated literature for all screening programmes is important and its preparation deserves great care. In introducing triple screening for Down's syn-drome/neural tube defect, adequate attention to the knock-on effects on counselling, ultrasound, obstetric and cytogenetic services has not been paid. Centres which offer such tests …