State-of-the-art for DNA technology in newborn screening

Just as metabolites, hormones and proteins are measured in newborn screenin g tests, DNA has become an analyte that is important in the screens for cer tain disorders. DNA confirmatory testing on the original dried blood specim en reduces the age at diagnostic confirmation and antibiotic prophylaxis in itiation for neonates with sickle cell disease. Molecular genetic analysis of the initial specimens from newborns with elevated immunoreactive trypsin ogen (IRT) for cystic fibrosis (CF) screening permits reduction of the IRT threshold value, improving specificity without comproInising sensitivity. B ecause of this cost reduction, CF neonatal screening programs routinely inc orpotate DNA confirmatory testing into their initial CF screening algorithm . DNA analysis is also a valuable adjunct in screening programs for congeni tal adrenal hyperplasia (CAH), improving sensitivity and specificity. Incor poration of DNA into newborn screening programs will continue to be stimula ted by development of robust, high throughput technologies for evaluation o f this analyte. New paradigms for neonatal screening are evolving, includin g hearing screening in the newborn nursery. DNA testing, such as for mutati ons in the connexin 26 gene, may have a role in the evaluation of those scr eened positive. Newborn screening dried blood specimens are DNA databases. Therefore, there are significant ethical, legal and social issues that must be considered in the storage and utilization of neonatal screening specime ns.