International perspectives on newborn screening.

The development of electrospray tandem mass spectrometry (MS-MS) has greatly increased the number of diseases that can be detected by newborn blood-spot screening. Different countries are introducing the technology at different rates and for different disease panels. Current policies in the United Kingdom, Germany and the United States are taken as examples. In the United Kingdom, many laboratories are using MS-MS for routine screening for phenylketonuria but, except for those participating in a two-year pilot study of screening for medium-chain acyl-CoA dehydrogenase deficiency, are forbidden use MS-MS to screen for other disorders. In Germany there has been considerable experience of MS-MS screening for a wide range of diseases, but recently the Federal Ministry for Health and Social Security prescribed a much more restricted disease panel, with the instruction that any other diagnostic results are to be suppressed and not reported. By contrast, a recent report from the American College of Medical Genetics, still being debated, recommends screening procedures that will detect an extremely broad range of disorders, including some that are very rare or of unproven clinical significance. The lack of even broad concordance at the level of national policy is extremely disturbing. Though all discussion is nominally founded on the ten principles laid down by Wilson and Jungner in 1968, there seems no generally accepted way of using these principles, or derived criteria, as objective decision tools. Alternative, less categorical, approaches are needed: the disorders concerned are not homogeneous entities and there may be advantages to screening other than reducing morbidity or mortality.